阅读说明：本技术 软组织植入物袋 (Soft tissue implant bag ) 是由 保罗·布伦南 蒂莫西·格雷姆·摩尔 于 2018-12-21 设计创作，主要内容包括：提供了一种可减少包膜挛缩的发生的软组织植入物袋。该袋由可生物降解的生物相容的聚氨酯泡沫制成。聚氨酯含有可生物降解的多元醇,并且泡沫具有配置用于细胞浸润的孔径。该软组织植入物袋可用于例如隆乳和乳房重建。(Provided is a soft tissue implant bag which can reduce occurrence of capsular contracture. The bag is made of a biodegradable, biocompatible polyurethane foam. The polyurethane contains a biodegradable polyol, and the foam has a pore size configured for cellular infiltration. The soft tissue implant bag can be used, for example, for breast augmentation and breast reconstruction.)

1. A soft tissue implant bag comprising an inner surface, an outer surface, and an opening sized to receive an implant;

wherein at least an outer surface of the bag comprises a polyurethane foam comprising a pore structure configured for cellular infiltration.

2. The soft tissue implant bag of claim 1, wherein the inner surface of the bag comprises polyurethane foam.

3. The soft tissue implant bag of claim 1 or 2, wherein the bag consists essentially of polyurethane foam.

4. The soft tissue implant bag of any one of claims 1 to 3, wherein the foam is biodegradable.

5. The soft tissue implant bag of any one of claims 1 to 4, wherein the foam is thermoset.

6. The soft tissue implant bag of any one of claims 1 to 5, wherein the foam has a thickness of about 0.1mm to about 10mm, or about 0.2mm to about 5mm, or about 0.3mm to about 3mm, or about 0.3mm to about 2 mm.

7. The soft tissue implant bag of any one of claims 1 to 6, wherein the polyurethane foam has an average pore size of greater than 50 μm, or greater than 75 μm, or greater than 100 μm, or greater than 200 μm, or greater than 300 μm, or greater than 400 μm.

8. The soft tissue implant bag of any one of claims 1 to 7, wherein the foam has an average pore size of 100 to 300 μm.

9. The soft tissue implant bag of any one of claims 1 to 8, wherein the polyurethane foam degrades under astm f1635 conditions such that the quality of the foam is reduced by 10% to 90% within a period of 1 year, or within 11 months, or within 10 months, or within 9 months, or within 8 months, or within 7 months, or within 6 months, or within 5 months, or within 4 months, or within 3 months, or within 2 months, or within 1 month.

10. The soft tissue implant bag of any one of claims 1 to 9, wherein the implant is substantially free of aromatic functional groups.

11. The soft tissue implant pocket of any one of claims 1 to 10, wherein the foam of the soft tissue implant pocket independently shrinks less than 20%, or less than 15%, or less than 10%, or less than 5% in any single surface region after 20 days under in vivo conditions, or 60 days under in vivo conditions, or 90 days under in vivo conditions, or 120 days under in vivo conditions, or 200 days under in vivo conditions, or 1 year under in vivo conditions, or 2 years under in vivo conditions.

12. The soft tissue implant bag of any one of claims 1 to 11, wherein the foam of the soft tissue implant bag independently shrinks less than 20%, or less than 15%, or less than 10%, or less than 5% in any single surface area after 10 days under in vivo conditions.

13. The soft tissue implant bag of any one of claims 1 to 12, wherein the polyurethane foam is derived from one or more biodegradable polyols and one or more isocyanates.

14. The soft tissue implant bag of any one of claims 1 to 12, wherein the polyurethane foam is derived from a mixture of one or more biodegradable polyols and one or more non-biodegradable polyols and one or more isocyanates.

15. The soft tissue implant bag of claim 13 or 14, wherein the biodegradable polyol is a polyester polyol.

16. The soft tissue implant bag of any one of claims 13 to 15, wherein the foam is derived from one or more biodegradable polyols having a molecular weight of less than or equal to about 2000 daltons, or less than or equal to about 1500 daltons, or less than or equal to about 1300 daltons.

17. The soft tissue implant bag of any one of claims 13 to 16, wherein the biodegradable polyol has a molecular weight of from about 200 to about 2,000 daltons, or from about 200 to about 1,500 daltons, or from about 200 to about 1300 daltons, or from about 600 to about 1500 daltons, or from about 900 to about 1300 daltons.

18. The soft tissue implant bag of any one of claims 13-16, wherein the biodegradable polyol has a molecular weight of less than or equal to about 10,000 daltons, or less than or equal to about 8,000 daltons, or less than or equal to about 6,000 daltons, or less than or equal to about 4,000 daltons, or less than or equal to about 2,000 daltons, or less than or equal to about 1,500 daltons, or less than or equal to about 1,000 daltons, or less than or equal to about 800 daltons, or less than or equal to about 600 daltons, or less than or equal to about 500 daltons, or less than or equal to about 400 daltons, or less than or equal to about 350 daltons, or less than or equal to about 300 daltons.

19. The soft tissue implant bag of any one of claims 13 to 16, wherein the biodegradable polyol has a molecular weight of less than 500 daltons, or less than 400 daltons, or less than 350 daltons, or less than 300 daltons.

20. The soft tissue implant bag of any one of claims 13 to 19, wherein the biodegradable polyol is derived from one or more polyol initiators and one or more hydroxy acids, diacids, or cyclic esters and combinations thereof.

21. The soft tissue implant bag of any one of claims 13 to 20, wherein the biodegradable polyol is derived from one or more polyol initiators and at least one hydroxy acid.

22. The soft tissue implant bag of any one of claims 13 to 20, wherein the biodegradable polyol is derived from one or more polyol initiators and at least one diacid.

23. The soft tissue implant bag of any one of claims 13 to 20, wherein the biodegradable polyol is derived from one or more polyol initiators and at least one cyclic ester.

24. The soft tissue implant bag of any one of claims 13 to 20, wherein the biodegradable polyol is derived from one or more polyol initiators, at least one hydroxy acid and at least one diacid.

25. The soft tissue implant bag of any one of claims 13 to 20, wherein the biodegradable polyol is derived from one or more polyol initiators, at least one hydroxy acid and at least one cyclic ester.

26. The soft tissue implant bag of any one of claims 13 to 20, wherein the biodegradable polyol is derived from one or more polyol initiators, at least one diacid, and at least one cyclic ester.

27. The soft tissue implant bag of any one of claims 13 to 20, wherein the biodegradable polyol is derived from one or more polyol initiators, at least one hydroxy acid, at least one diacid, and at least one cyclic ester.

28. The soft tissue implant bag of any one of claims 20 to 27, wherein the one or more polyol initiators are pentaerythritol, trimethylolpropane, glycerol, 1, 4-butanediol, ethylene glycol, sorbitol, glucose, sucrose, 1, 2-propanediol, 1, 3-propanediol, pentanediol, inositol, hexamethylene glycol, heptanediol, octanediol, nonanediol, decanediol, dodecanediol, 2-ethyl-1, 3-hexanediol (EHD), 2, 4-trimethylpentane-1, 3-diol (TMPD), 1, 4-cyclohexanedimethanol, diethylene glycol, dipropylene glycol, and combinations thereof.

29. The soft tissue implant bag of claim 20, wherein the hydroxy acid is selected from the group consisting of l-lactic acid, d, l-lactic acid, mandelic acid, phenyllactic acid, hydroxybutyric acid, hydroxyvaleric acid, glycolic acid, and combinations thereof.

30. The soft tissue implant bag of claim 20, wherein the cyclic ester is selected from the group consisting of-caprolactone, glycolide, lactide, mandelate, and p-dioxanone, and combinations thereof.

31. The soft tissue implant bag of claim 20, wherein the diacid is selected from the group consisting of oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, and hexadecanedioic acid, and combinations thereof.

32. The soft tissue implant bag of any one of claims 13 to 31, wherein the biodegradable polyol is prepared by a ring opening polymerization and/or condensation reaction.

33. The soft tissue implant bag of any one of claims 13 to 32, wherein the foam is further derived from one or more non-biodegradable polyols, such as polyether polyols.

34. The soft tissue implant bag of claim 33, wherein the polyether polyol is selected from one or more of ethoxylated glycerin, propoxylated glycerin, ethoxylated glycerin-co-propoxylated glycerin, ethoxylated glycerin-propoxylated glycerin block copolymer, ethoxylated pentaerythritol, propoxylated pentaerythritol, and propoxylated trimethylolpropane.

35. The soft tissue implant bag of claim 33 or 34, wherein the one or more non-biodegradable polyols have a molecular weight of less than or equal to about 2000 daltons, or less than or equal to about 1500 daltons, or less than or equal to about 1300 daltons.

36. The soft tissue implant bag of any one of claims 33 to 35, wherein the non-biodegradable polyol has a molecular weight of about 200 to about 2,000 daltons, or about 200 to about 1,500 daltons, or about 200 to about 1300 daltons, or about 600 to about 1500 daltons, or about 900 to about 1300 daltons.

37. The soft tissue implant bag of any one of claims 33-35, wherein the non-biodegradable polyol has a molecular weight of less than or equal to about 10,000 daltons, or less than or equal to about 8,000 daltons, or less than or equal to about 6,000 daltons, or less than or equal to about 4,000 daltons, or less than or equal to about 2,000 daltons, or less than or equal to about 1,500 daltons, or less than or equal to about 1,000 daltons, or less than or equal to about 800 daltons, or less than or equal to about 600 daltons, or less than or equal to about 500 daltons, or less than or equal to about 400 daltons, or less than or equal to about 350 daltons, or less than or equal to about 300 daltons.

38. The soft tissue implant bag of any one of claims 33 to 35, wherein the non-biodegradable polyol has a molecular weight of less than 500 daltons, or less than 400 daltons, or less than 350 daltons, or less than 300 daltons.

39. The soft tissue implant pocket of any one of claims 1 to 38, wherein the pocket further comprises a polyurethane substrate located on and sized to cover an interior surface of the pocket.

40. The soft tissue implant pocket of any one of claims 2 to 38, wherein the pocket further comprises a polyurethane substrate between the inner foam surface and the outer foam surface of the pocket.

41. The soft tissue implant bag of claim 39 or 40, wherein the polyurethane substrate is thermoplastic.

42. The soft tissue implant bag of claim 39 or 40, wherein the polyurethane substrate is biodegradable.

43. The soft tissue implant bag of any one of claims 39 to 42, wherein the polyurethane substrate comprises oriented polyurethane.

44. The soft tissue implant bag of claim 43, wherein the polyurethane substrate comprises biaxially oriented polyurethane.

45. The soft tissue implant bag of claim 43 or 44, wherein the oriented polyurethane is annealed.

46. The soft tissue implant bag of any one of claims 39 to 45, wherein the substrate has a thickness of about 20 μm to about 1000 μm, or about 50 μm to about 500 μm, or about 50 μm to about 400 μm.

47. A soft tissue implant, comprising:

a soft tissue implant pocket, the pocket comprising an inner surface and an outer surface; and

an implant sealed in the pouch;

wherein at least an outer surface of the bag comprises a polyurethane foam comprising a pore structure configured for cellular infiltration.

48. A soft tissue implant comprising the soft tissue implant pocket of any one of claims 1-46 and an implant sealed within the pocket.

49. A method of making a soft tissue implant bag comprising the steps of:

(a) placing the first polyurethane foam sheet on the second polyurethane foam sheet such that edges of the sheets are substantially aligned; and

(b) heat sealing the aligned edges, leaving an opening sized for introduction of an implant;

wherein the foam sheet comprises the polyurethane foam of any one of claims 1 to 38.

50. A method of making a soft tissue implant bag comprising the steps of:

(a) folding the polyurethane foam sheet so that edges of the sheet are substantially aligned; and

(b) heat sealing the aligned edges, leaving an opening sized for introduction of an implant;

wherein the foam sheet comprises the polyurethane foam of any one of claims 1 to 38.

51. A method of making a soft tissue implant bag comprising the steps of:

(a) folding the foam/substrate laminate such that edges of the laminate are substantially aligned; and

(b) heat sealing the aligned edges, leaving an opening sized for introduction of an implant;

wherein the foam/substrate laminate comprises the polyurethane foam of any of claims 1-38 and the substrate of any of claims 40-46.

52. In another aspect of the present disclosure, there is provided a method of making a soft tissue implant pocket comprising the steps of:

(a) placing the first polyurethane foam/substrate laminate on the second polyurethane foam/substrate laminate such that edges of the laminates are substantially aligned; and

(b) heat sealing the aligned edges, leaving an opening sized for introduction of an implant;

wherein the foam/substrate laminate comprises the polyurethane foam of any of claims 1-38 and the substrate of any of claims 40-46.

53. In another aspect of the present disclosure, there is provided a method of making a soft tissue implant pocket comprising the steps of:

(a) folding the foam/substrate/foam laminate such that edges of the laminate are substantially aligned; and

(b) heat sealing the aligned edges, leaving an opening sized for introduction of an implant;

wherein the foam/substrate/foam laminate comprises the polyurethane foam of any one of claims 1 to 38 and the substrate of any one of claims 40 to 46.

54. In another aspect of the present disclosure, there is provided a method of making a soft tissue implant pocket comprising the steps of:

(a) placing the first foam/substrate/foam laminate on the second foam/substrate/foam laminate such that edges of the laminate are substantially aligned; and

(b) heat sealing the aligned edges, leaving an opening sized for introduction of an implant;

wherein the foam/substrate/foam laminate comprises the polyurethane foam of any one of claims 1 to 38 and the substrate of any one of claims 40 to 46.

55. Use of the soft tissue implant bag of any one of claims 1 to 46 to reduce or eliminate capsular contracture.

56. A method of reducing or eliminating capsular contracture, comprising placing an implant in the soft tissue implant pocket of any one of claims 1-46, sealing the pocket, and implanting the pocket in a subject.

57. Use of the implant of claim 47 or 48 in breast augmentation.

58. A soft tissue implant bag comprising an inner surface, an outer surface, and an opening sized to receive an implant;

wherein the inner and outer surfaces of the bag comprise a biodegradable polyurethane foam comprising a pore structure configured for cellular infiltration;

wherein the foam has an average pore size of 100 to 300 microns.

59. The soft tissue implant bag of claim 58, wherein a polyurethane substrate is disposed between the inner and outer surfaces of the bag.

Technical Field

The present disclosure relates to a soft tissue implant pocket that reduces the incidence of capsular contracture and also reduces implant movement. The bag comprises a biodegradable, biocompatible polyurethane foam and can be used, for example, for breast augmentation and breast reconstruction.

Background

Soft tissue implants are widely used for cosmetic, aesthetic and reconstructive purposes. In some cases, one potential adverse event caused by the introduction of soft tissue implants is capsular contracture. Shortly after implant implantation, the natural inflammatory response of the human body begins to deposit collagen around the implant in the form of a fibrous capsule.

The problems of capsular formation and contracture occur in connection with many implant types, such as pacemakers, dural substitutes, implantable cardiac defibrillators, and breast and other aesthetic implants.

Capsular contracture in the breast augmentation occurs when the internal scar tissue forms a tight or contracting capsule around the breast implant and causes it to contract until the deformation hardens. As a result, the breast may feel painful and hard, and the envelope may affect the appearance or shape of the breast. This may occur for both silicone implants and saline implants.

Capsular contracture of breast implants is the most common indicator of further surgery. Clinically significant capsular contracture rates between 15% and 45% have been reported (index of capsule containment in silicone cosmetic evaluation mapping homogeneity: A meta-analysis, Y. El-Sheik et al, CanJ plant Surg Vol 16, No 4,211).

Implants with smooth surfaces are most susceptible to capsule formation and contracture, and surface texturing has been used to reduce contracture. In some cases, particularly where the surface morphology of the implant is not uniform in texture, collagen formation may be uneven, resulting in physical discomfort and unsightly bumps, "seams," or uneven external surface formation.

In this regard, Polyurethane textured coatings have been used in an attempt to reduce capsule formation and contracture (Polyurethane-coated Breast Implants revised: A30-Yeast Follow-Up, N.Castel et al, ArchPlast Surg 2015,42, 186.).

However, in 1992, the U.S. Food and Drug Administration (FDA) declared a suspension in the use of silicone breast implants because they may be associated with breast cancer. Furthermore, polyurethanes derived from aromatic isocyanates have been demonstrated to degrade in vitro into potentially carcinogenic by-products.

There is therefore a need in the art for means to reduce or even eliminate capsule formation and contracture using biocompatible products. The present disclosure addresses these needs.

The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as, an acknowledgment or admission or any form of suggestion that the prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of technology to which this specification relates.

Disclosure of Invention

In a first aspect, the present disclosure provides a soft tissue implant bag comprising an inner surface, an outer surface, and an opening sized to receive an implant; wherein at least an outer surface of the bag comprises a polyurethane foam comprising a pore structure configured for cellular infiltration.

In a second aspect, the present disclosure provides a soft tissue implant comprising: a soft tissue implant pocket comprising an inner surface and an outer surface; an implant sealed in the pouch; wherein at least an outer surface of the bag comprises a polyurethane foam comprising a pore structure configured for cellular infiltration.

In some embodiments, the inner surface of the implant pocket comprises polyurethane foam. In other words, the structural material of the bag may consist essentially of polyurethane foam.

In other embodiments, the foam defining the inner surface of the implant bag and the foam defining the outer surface of the implant bag have a polyurethane backing therebetween. In other words, the bag is constructed of, for example, two pieces of foam-substrate-foam material. The substrate provides strength to the bag.

In some embodiments, the polyurethane foam is affixed to the surface of the implant. In some embodiments, the polyurethane foam is not fixed to the surface of the implant, but is in close contact with the surface of the implant, thereby minimizing the space between the inner surface of the foam pouch and the surface of the implant.

The polyurethane foam may be biodegradable.

In some embodiments, the bag further comprises an inner polyurethane substrate lining the inner surface of the bag.

In another aspect, the present disclosure provides a soft tissue impingement bag, wherein the bag is constructed from:

(a) two or more biodegradable polyurethane foam layers; and

(b) one or more polyurethane substrates;

wherein the polyurethane substrate is located between foam layers; and is

Wherein the foam layer comprises a pore structure configured for cellular infiltration.

Soft tissue implant pouches are advantageous because they minimize capsular contracture during use.

Soft tissue implant bags have many other advantages, including one or more of the following:

pocket conformation to different implant shapes

The pockets minimize the movement and/or rotation and/or dislocation of the implant

Substantially no kinking and overlapping of the outer surface of the bag

Polyurethane foams substantially resist shrinkage in vivo

The polyurethane foam can realize tissue integration

The polyurethane foam can degrade over time, thus eliminating the need for surgical removal

Polyurethane foam is biocompatible.

The implant bag may be formed from one continuous piece of foam that may be molded, formed, or folded to form the bag. Alternatively, it may be formed from more than one foam sheet. When more than one foam sheet is used, the sheets may be fused together near the edges of the foam to form a bag with a seam. In one embodiment, the bonded edge of the bag is outside the bag. In another embodiment, the bonded edge of the bag is inside the bag. The location of the seam can help reduce capsular contracture.

In other embodiments, the seam is neither external nor internal, and does not substantially protrude.

The polyurethane foam may comprise a thermoset polyurethane or may comprise a thermoplastic polyurethane. Preferably, the polyurethane foam comprises a thermoset polyurethane. Preferably, the foam comprises a cross-linked polyurethane.

The polyurethane substrate may comprise a thermoset polyurethane or may comprise a thermoplastic polyurethane. Preferably, the polyurethane substrate comprises thermoplastic polyurethane.

The polyurethane substrate may comprise biodegradable polyurethane or non-degradable polyurethane. The polyurethane substrate may be designed to degrade at a different rate or at substantially the same rate as the polyurethane foam.

As used herein, the term "biodegradable" generally refers to the ability to be broken down in the normal functioning of a living organism/tissue, preferably into harmless, non-toxic or biocompatible products.

In some embodiments, the polyurethane foam may degrade faster than the polyurethane substrate.

In some embodiments, the substrate provides a barrier to cellular infiltration such that when cell growth occurs in the polyurethane foam, it cannot interact with the implant surface.

Soft tissue implant bags may be used as coverings for a variety of implants. The bag can be used as a covering for silicone or saline breast implants.

The polyurethane foam may independently shrink less than 20%, or less than 15%, or less than 10%, or less than 5% in any single surface region after 10 days under in vivo conditions.

The polyurethane foam may independently shrink less than 20%, or less than 15%, or less than 10%, or less than 5% in any single surface region after 20 days under in vivo conditions, or after 60 days under in vivo conditions, or after 90 days under in vivo conditions, or after 120 days under in vivo conditions, or after 200 days under in vivo conditions, or after 1 year under in vivo conditions, or after 2 years under in vivo conditions.

The polyurethane substrate may shrink less than 20%, or less than 15%, or less than 10%, or less than 5% in any single surface region after 10 days under in vivo conditions.

The polyurethane substrate may independently shrink less than 20%, or less than 15%, or less than 10%, or less than 5% in any single surface region after 20 days under in vivo conditions, or after 60 days under in vivo conditions, or after 90 days under in vivo conditions, or after 120 days under in vivo conditions, or after 200 days under in vivo conditions, or after 1 year under in vivo conditions, or after 2 years under in vivo conditions.

The polyurethane foam of the soft tissue implant pocket may have a thickness of about 0.1mm to about 10mm, or about 0.2mm to about 5mm, or about 0.3mm to about 3mm, or about 0.3mm to about 2 mm. The thickness of the foam may be less than about 10mm, or less than about 6mm, or less than about 4mm, or less than about 2mm, or less than about 1mm, or less than about 0.5 mm.

Preferably, the foam has a thickness of 0.3mm to about 3 mm.

The thickness of the polyurethane substrate may be from about 20 μm to about 1000 μm, or from about 50 μm to about 500 μm, or from about 50 μm to about 400 μm.

In some embodiments, the thickness of the foam may be about 0.3mm to about 3mm, and the thickness of the substrate may be about 50 μm to about 400 μm.

In some embodiments, the thickness of the foam may be about 0.3mm to about 1mm, and the thickness of the substrate may be about 100 μm to about 300 μm.

In some embodiments, the foam may be a non-reticulated foam. In some embodiments, the foam may be a reticulated foam. The foam may have interconnected pores. Preferably, the foam is a non-reticulated foam.

As used herein, the term "non-reticulated" polyurethane foam refers to a polyurethane foam that has not undergone a post-manufacture step using chemicals (e.g., alkali solutions), heat (e.g., controlled combustion of hydrogen and oxygen), or solvents to remove the cells and windows.

In some embodiments, the foam may have a density of 3g/100ml to 12g/100ml, or 4g/100ml to 10g/100ml, or 5g/100ml to 8g/100 ml.

In some embodiments, the porosity of the foam may be greater than 50%, or greater than 75%, or from 80% to 95%, or from 95% to 99.9%. It is desirable that the porosity be as high as possible while maintaining other mechanical specifications. If the porosity is too low, the pores may not interconnect. If the porosity is too high, the structural integrity of the foam may be mechanically compromised.

In some embodiments, the average pore size of the foam may be greater than 50 μm, or greater than 75 μm, or greater than 100 μm, or greater than 200 μm, or from 100 to 600 μm, or from 100 to 400 μm.

In some embodiments, the foam has an average pore size of 50 to 600 μm, or 60 to 600 μm, or 70 to 600 μm, or 75 to 400 μm, or 75 to 300 μm, or 100 to 300 μm.

Preferably, the average pore size of the foam is greater than 75 μm, more preferably from about 100 to about 300 μm.

More preferably, the average pore size is from about 100 to about 300 μm.

In some embodiments, the soft tissue implant pocket may include one or more additional layers disposed between the foam and the backing. The one or more other layers may be adhesive layers and/or other foam layers.

In some embodiments, the soft tissue implant pocket is substantially free of aromatic functional groups. As used herein, "substantially free" means that the soft tissue implant pouch comprises less than 0.1 wt%, or less than 0.01 wt%, or less than 0.001 wt%, or 0% aromatic functional groups based on the total weight of the pouch.

The soft tissue implant bag can be of any shape. Preferred shapes include spherical, spheroidal, ovoid, and the like.

Polyurethane foam

Biodegradable polyurethane foams can be biodegraded in living organisms into biocompatible degradation products.

The polyurethane foam may be degradable in vivo. The polyurethane foam may be degradable at a temperature of about 35 ℃ to about 42 ℃.

Polyurethane foams can degrade by hydrolysis. Polyurethane foams can be degraded by hydrolysis of the ester functionality.

Foam polyols

The polyurethane foam may be derived from one or more biodegradable polyols and one or more isocyanates. Alternatively, the polyurethane foam may be derived from a mixture of one or more biodegradable polyols and one or more non-biodegradable polyols and one or more isocyanates. Preferably, the biodegradable polyol is a polyester polyol.

The foam may be derived from one or more biodegradable polyols having a molecular weight of less than or equal to about 2000 daltons, or less than or equal to about 1500 daltons, or less than or equal to about 1300 daltons.

The biodegradable polyol can have a molecular weight of from about 200 to about 2,000 daltons, or from about 200 to about 1,500 daltons, or from about 200 to about 1300 daltons, or from about 600 to about 1500 daltons, or from about 900 to about 1300 daltons.

The biodegradable polyol can have a molecular weight of less than or equal to about 10,000 daltons, or less than or equal to about 8,000 daltons, or less than or equal to about 6,000 daltons, or less than or equal to about 4,000 daltons, or less than or equal to about 2,000 daltons, or less than or equal to about 1,500 daltons, or less than or equal to about 1,000 daltons, or less than or equal to about 800 daltons, or less than or equal to about 600 daltons, or less than or equal to about 500 daltons, or less than or equal to about 400 daltons, or less than or equal to about 350 daltons, or less than or equal to about 300 daltons.

The biodegradable polyol may have a molecular weight of less than 500 daltons, or less than 400 daltons, or less than 350 daltons, or less than 300 daltons.

The biodegradable polyol may be in a liquid state at 20 ℃ and atmospheric pressure. Alternatively, the biodegradable polyol may be in a solid state at 20 ℃ and atmospheric pressure. In some embodiments, the polyol may be in the form of a mixture of a solid and a liquid at 20 ℃.

The biodegradable polyol may be derived from one or more polyol initiators and one or more hydroxy acids, diacids, or cyclic esters and combinations thereof.

In some embodiments, the biodegradable polyol may be derived from one or more polyol initiators and at least one hydroxy acid.

In some embodiments, the biodegradable polyol may be derived from one or more polyol initiators and at least one diacid.

In some embodiments, the biodegradable polyol may be derived from one or more polyol initiators and at least one cyclic ester.

In some embodiments, the biodegradable polyol may be derived from one or more polyol initiators, at least one hydroxy acid, and at least one diacid.

In some embodiments, the biodegradable polyol may be derived from one or more polyol initiators, at least one hydroxy acid, and at least one cyclic ester.

In some embodiments, the biodegradable polyol may be derived from one or more polyol initiators, at least one diacid, and at least one cyclic ester.

In some embodiments, the biodegradable polyol may be derived from one or more polyol initiators, at least one hydroxy acid, at least one diacid, and at least one cyclic ester.

The one or more polyol initiators may be pentaerythritol, trimethylolpropane, glycerol, 1, 4-butanediol, ethylene glycol, sorbitol, glucose, sucrose, 1, 2-propanediol, 1, 3-propanediol, pentanediol, inositol, hexamethylene glycol, heptanediol, octanediol, nonanediol, decanediol, dodecanediol, 2-ethyl-1, 3-hexanediol (EHD), 2, 4-trimethylpentane-1, 3-diol (TMPD), 1, 4-cyclohexanedimethanol, diethylene glycol, dipropylene glycol, and combinations thereof.

Non-limiting examples of hydroxy acids include l-lactic acid, d, l-lactic acid, mandelic acid, phenyllactic acid, hydroxybutyric acid, hydroxyvaleric acid, or glycolic acid, and combinations thereof.

Non-limiting examples of cyclic esters include-caprolactone, glycolide, lactide, mandelate esters, and p-dioxanone, and combinations thereof. Biodegradable polyols can be prepared by ring-opening polymerization or condensation reactions.

Non-limiting examples of diacids include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, and hexadecanedioic acid, and combinations thereof.

The biodegradable polyols may be prepared by ring-opening polymerization and/or condensation reactions.

The one or more non-biodegradable polyols may be polyether polyols. The polyether polyol can be one or more of ethoxylated glycerol, propoxylated glycerol, ethoxylated glycerol-co-propoxylated glycerol, ethoxylated glycerol-propoxylated glycerol block copolymer, ethoxylated pentaerythritol, propoxylated pentaerythritol and propoxylated trimethylolpropane.

The one or more non-biodegradable polyols may have a molecular weight of less than or equal to about 2000 daltons, or less than or equal to about 1500 daltons, or less than or equal to about 1300 daltons.

The molecular weight of the non-biodegradable polyol can be from about 200 to about 2,000 daltons, or from about 200 to about 1,500 daltons, or from about 200 to about 1300 daltons, or from about 600 to about 1500 daltons, or from about 900 to about 1300 daltons.

The molecular weight of the non-biodegradable polyol can be less than or equal to about 10,000 daltons, or less than or equal to about 8,000 daltons, or less than or equal to about 6,000 daltons, or less than or equal to about 4,000 daltons, or less than or equal to about 2,000 daltons, or less than or equal to about 1,500 daltons, or less than or equal to about 1,000 daltons, or less than or equal to about 800 daltons, or less than or equal to about 600 daltons, or less than or equal to about 500 daltons, or less than or equal to about 400 daltons, or less than or equal to about 350 daltons, or less than or equal to about 300 daltons.

The molecular weight of the non-biodegradable polyol may be less than 500 daltons, or less than 400 daltons, or less than 350 daltons, or less than 300 daltons.

The biodegradable polyol renders the foam biodegradable. Polyols can be prepared by condensation or ring-opening polymerization using a high proportion of initiator (or starter) to control molecular weight. The amount of initiator may be from 1 mole of initiator per 200g of polyol to 1 mole of initiator per 5000g of polyol, or from 1 mole of initiator per 500g of polyol to 1 mole of initiator per 2000g of polyol. Non-limiting examples of suitable monomers for the initiator include pentaerythritol (4 arm), trimethylolpropane (3 arm), glycerol (3 arm), 1, 4-butanediol (2 arm), inositol (6 arm). Mixtures of initiators may be used. Mixtures of polyols may be used. It may be preferable to minimize the number of ingredients. However, in some cases, it may be advantageous to use more than one polyol or more than two. The hydroxyl functionality of the polyol can be 2 or greater. When polyols having only monohydroxy functionality are used in large amounts, sufficient foam may not be produced. However, small amounts may be used to adjust the properties of the foam, for example, the addition of several percent of a monohydroxy compound having a long chain lipophilic chain may affect the hydrophobicity/hydrophilicity of the foam.

The degradation rate of the foam can be controlled by varying the ratio of biodegradable polyol to non-biodegradable polyol. By reducing or eliminating non-biodegradable polyols from the formulation, faster degrading foams may be produced, which may be desirable in certain applications. Monomer selection may also affect the rate of degradation due to kinetic differences in the rate of hydrolysis of different ester bonds.

Biodegradable and non-biodegradable polyols have different functions in the foam of soft tissue implant pouches. The non-biodegradable polyol may be selected from polyether polyols such as ethoxylated glycerol, propoxylated glycerol and ethoxylated glycerol-co-propoxylated glycerol. Such non-biodegradable polyols can stabilize the foam by introducing non-biodegradable functionality. In addition, they may provide a mechanism to control the hydrophilic/hydrophobic balance by, for example, ethoxylate/propoxylate content. They may also improve foam resiliency by lowering the glass transition temperature (Tg).

Biodegradable polyols may be solids at lower molecular weights than non-biodegradable polyols, for example, polycaprolactone diol having a molecular weight of 500 is a solid at room temperature while polypropylene glycol remains liquid to a higher molecular weight. The high molecular weight non-biodegradable liquid polyol can act as a "filler" to reduce the isocyanate content, thereby reducing the possibility of scorching due to excessive exothermic reactions during foam production.

The biodegradable polyol may be derived from one or more polyol initiators and at least one hydroxy acid and/or cyclic ester. In the event that the non-biodegradable polyether fails to sufficiently lower the Tg, the biodegradable polyol may contribute to lowering the Tg. The polyol may be a 3-arm glycerol-initiated polyol based on caprolactone and one of glycolic acid or lactic acid. The amount of CL (LA and/or GA) may influence the glass transition as well as the degradation time. More caprolactone will lower the Tg and increase the degradation time. The molecular weight may be 800-. The molecular weight may be low enough to become liquid, but high enough to avoid scorching without requiring large amounts of isocyanate to react.

Foamed isocyanates

The polyurethane from which the foam layer is made may be derived from one or more biodegradable polyols and one or more isocyanates. The molar ratio of isocyanate functional groups to hydroxyl and other isocyanate-reactive functional groups (isocyanate index) of the resulting foam may be less than or equal to 1.0, or less than or equal to 0.9, or less than or equal to 0.8, or less than or equal to 0.7, or less than or equal to 0.6. The isocyanate index may be 0.4 to 1.0, or 0.6 to 0.9.

The polyurethane foam may be derived from a polyol and an isocyanate, the isocyanate content (i.e., the content of NCO functional groups) being less than 20 wt.%, or less than 19 wt.%, or less than 18 wt.%, or less than 17 wt.%, or less than 16 wt.%, or less than 15 wt.%, or less than 14 wt.%, or less than 13 wt.%, or less than 12 wt.%, or less than 11 wt.%, or less than 10 wt.%, or less than 9 wt.%, or less than 8 wt.%, based on the total weight of the polyol and the isocyanate. The isocyanate content of the foam may be from 5% to 20%, or from 8% to 17%, or from 11% to 14%, based on the total weight of the polyol and the isocyanate.

It is generally believed that degradation products of aliphatic isocyanates, such as Ethyl Lysine Diisocyanate (ELDI), are more biocompatible than degradation products of aromatic diisocyanates. Thus, isocyanates such as Hexamethylene Diisocyanate (HDI) and ELDI may be particularly suitable. Isophorone diisocyanate (IPDI) may also be used, but may impart a higher glass transition temperature, which may cause the foam to harden. Combinations of isocyanates may be used and may be preferred in some cases, for example, the glass transition may be adjusted by a combination of HDI and IPDI. Trimethylhexamethylene diisocyanate, 1, 4-butane diisocyanate, methyllysine diisocyanate (MLDI) and other isocyanates commonly used in polyurethane synthesis may also be suitable.

Lowering the isocyanate index results in a softer and weaker foam, and thus faster degradation. Increasing the isocyanate index may increase the degradation time but may result in a stronger foam.

Biodegradable polyurethane foam is advantageous because it can be designed to include resilience, resistance to premature degradation, resistance to shrinkage, protection from excessive acidic degradation products, biocompatibility, controlled water absorption, compatibility with other polyurethane layers, and the ability to readily incorporate additives during synthesis. The foam may be soft and adapted to the desired shape.

The foam may be designed to degrade at a particular rate. They may be designed to maintain structural integrity for more than, for example, three months, or they may be designed to maintain structural integrity as low as, for example, several days, or even one or two days.

Under the conditions of ASTM F1635, the polyurethane foam may degrade such that the mass of the foam is reduced by about 10% to about 90% over a period of less than one year.

Alternatively, the quality of the foam may be reduced by about 10% to about 90% within 11 months, or within 10 months, or within 9 months, or within 8 months, or within 7 months, or within 6 months, or within 5 months, or within 4 months, or within 3 months, or within 2 months, or within 1 month.

Under the conditions of ASTM F1635, the degradation rate can be controlled by varying the nature and proportions of the components of the polyurethane foam. Thus, the polyurethane can be designed to degrade over a specific period of time. This is advantageous in providing a material that degrades partially, completely or substantially completely over a specified period of time, for example, when the functional aspects of the polyurethane foam layer are no longer needed.

This is particularly useful where the polyurethane is used for in vivo applications, as the polyurethane may not need to be surgically removed from the patient.

The degradation rate of the foam can be controlled by varying the ratio of biodegradable polyol to non-biodegradable polyol or by the choice of monomers. By reducing or eliminating non-biodegradable polyols from the formulation, faster degrading materials may be produced, which may be desirable in certain applications.

The foam may be derived from at least one prepolymer, which may be prepared by contacting one or more biodegradable polyols and/or one or more polyol initiators with one or more polyisocyanates. Non-limiting examples of polyol initiators are, for example, pentaerythritol, trimethylolpropane, glycerol, 1, 4-butanediol and inositol, ethylene glycol, sorbitol, glucose, sucrose, 1, 2-propanediol and mixtures thereof. The foam may be derived from a mixture of the prepolymer thus formed and other polyisocyanates. The foam may comprise less than 50 weight percent prepolymer and greater than 50 weight percent polyisocyanate, based on the total weight of these ingredients. The foam may comprise less than 30 weight percent prepolymer and greater than 70 weight percent polyisocyanate, based on the total weight of these ingredients. Foams prepared in this manner can advantageously have a high strength and a fine cell structure.

The foam may be derived from a biodegradable polyol having a molecular weight of less than or equal to about 1300 daltons, and a polyisocyanate having an isocyanate (NCO) content of less than 20 wt.%, or less than 19 wt.%, or less than 18 wt.%, or less than 17 wt.%, or less than 16 wt.%, or less than 15 wt.%, or less than 14 wt.%, or less than 13 wt.%, or less than 12 wt.%, or less than 11 wt.%, or less than 10 wt.%, or less than 9 wt.%, or less than 8 wt.%, based on the total weight of the polyol and the polyisocyanate.

The foam may be derived from biodegradable and non-biodegradable polyols wherein the biodegradable polyol has a molecular weight of less than or equal to about 1300 daltons and from polyols and polyisocyanates having an isocyanate (NCO) content of less than 20 wt.%, or less than 19 wt.%, or less than 18 wt.%, or less than 17 wt.%, or less than 16 wt.%, or less than 15 wt.%, or less than 14 wt.%, or less than 13 wt.%, or less than 12 wt.%, or less than 11 wt.%, or less than 10 wt.%, or less than 9 wt.%, or less than 8 wt.%, based on the total weight of the polyol and polyisocyanate.

The foam may be derived from a biodegradable polyol having a molecular weight of less than or equal to about 1300 daltons, and a polyisocyanate having an isocyanate (NCO) content of less than 20 wt%, or less than 19 wt%, or less than 18 wt%, or less than 17 wt%, or less than 16 wt%, or less than 15 wt%, or less than 14 wt%, or less than 13 wt%, or less than 12 wt%, or less than 11 wt%, or less than 10 wt%, or less than 9 wt%, or less than 8 wt%, based on the total weight of the polyol and polyisocyanate, and a molar ratio of isocyanate functional groups to hydroxyl and other isocyanate-reactive functional groups (isocyanate index) of less than or equal to 1.0.

The foams can be derived from biodegradable and non-biodegradable polyols wherein the molecular weight of the biodegradable polyol is less than or equal to about 1300 daltons and from polyols and polyisocyanates having an isocyanate (NCO) content of less than 20 wt.%, or less than 19 wt.%, or less than 18 wt.%, or less than 17 wt.%, or less than 16 wt.%, or less than 15 wt.%, or less than 14 wt.%, or less than 13 wt.%, or less than 12 wt.%, or less than 11 wt.%, or less than 10 wt.%, or less than 9 wt.%, or less than 8 wt.%, based on the total weight of the polyol and polyisocyanate, and the molar ratio of isocyanate functional groups to hydroxyl and other isocyanate-reactive functional groups (isocyanate index) is less than or equal to 1.0.

Various additives known in the art of polyurethane foam technology and tissue engineering may be added to the foam. These additives may be added during or after foam synthesis. In some cases, the additives may react during foam synthesis and be covalently incorporated into the foam. Exemplary additives include antimicrobial agents, plasticizers, cell openers, antioxidants, antistatic agents, catalysts, fillers, flame retardants, softeners/tougheners, cell control agents, mold release agents, stabilizers, fillers, dyes, pigments, pigment dispersants, solvents, anesthetics, cells, enzymes, proteins, growth factors, growth inhibitors, hemostatic agents, and bioactive agents (e.g., drugs). The additives may or may not be chemically bonded to the foam.

Catalyst and process for preparing same

There are many catalysts known in the art of polyurethane synthesis that can be used to prepare the polyurethanes of the present disclosure. Various catalysts may be used in the preparation of the composition, which may provide different attributes. For example, dibutyltin Dilaurate (DBTL), stannous octoate, and amine catalysts such as DABCO. Bismuth, zinc and titanium based catalysts are also known to be effective in catalyzing carbamate formation and exhibit low toxicity. COSCAT Z-22 is a zinc-based catalyst and is an example of a catalyst that can be used that has low toxicity and can provide effective results. Catalysts containing mercury and lead are effective, but are considered toxic (non-biocompatible) and therefore unsuitable. Combinations of catalysts are known to be effective. Minimization of the amount of catalyst is also desirable.

Surface active agent

The function of the surfactant (stabilizer, blowing agent) is to help prevent the bubbles in the foam from collapsing as they form during the reaction, which allows the bubbles to rise and produce a stable foam, which can then cure.

The surfactant may be a siloxane-ether copolymer, a fluoro-ether copolymer, or other amphiphilic compound comprising a hydrophobic portion and a hydrophilic portion. There are many commercially available surfactants developed specifically for polyurethane foams. The amount is 0.01 to 1.5 mass% of the whole formulation. Preferred amounts are 0.01% to 0.20% of the formulation. The most suitable amount depends on the molecular weight, composition and type of surfactant, and the remainder of the formulation-some formulations may be more hydrophobic and some more hydrophilic, and thus different amounts of stabilization may be required. Useful surfactants can be simple block copolymers and brush copolymers. It is clear to the skilled person to vary the concentration of the surfactant and to determine which concentration is most effective in stabilizing the foam layer.

Foaming agent

The foam may be foamed by any method known in the art. The blowing agent may be generated during foam formation and/or may be added as one or more other ingredients. Water may be used in the formulation to react with the isocyanate to form urea linkages and CO₂A gas. CO 2₂The gas will bubble and blow out the foam. E.g. temperature, mixingThe selection of both the synthetic and surfactant may affect the size of the bubbles (cell size). Commercially, the pore size of polyurethane foams ranges from microcellular (low density shoe soles) to open cell, macroporous foams (e.g., in filter or foam mattresses). The desired porosity can be obtained by using from 0.1 to 4% by weight of water, preferably from 1.0 to 1.5% by weight of water, in the entire formulation. This results in a suitable level of foaming. Less water results in a denser foam. Higher amounts of water may be useful, but there is a limit in that mechanical properties are negatively affected and scorch may become possible.

Pentane and other low boiling hydrocarbons are also suitable as blowing agents. Foams produced in this manner may advantageously be free of urea due to the absence of water. Ideally, the absence of water reduces the amount of isocyanate required for reaction in the formulation, which therefore reduces the amount of heat generated when producing the foam. This is particularly advantageous in large scale preparations where the heat of reaction may be more difficult to dissipate from the foam.

The foam layers may independently comprise any one or more of the features disclosed herein in any combination.

Preparation of polyurethane foams

The foam can be prepared simply by a one-pot process. All ingredients may be combined and mixed with or without heat and the foam will be produced and cured. Alternatively, the foam may be prepared by any continuous or semi-continuous process well known in the art.

In one embodiment, one or more polyols or polyol initiators are first treated with a polyisocyanate to form a prepolymer. The prepolymer is then treated with other ingredients to form a foam. In another embodiment, other polyisocyanates than those used to form the prepolymer may be used.

In another embodiment, all of the ingredients except the polyisocyanate ingredient are mixed together to form one part. The polyisocyanate is then added to start the reaction. This is advantageous because both parts are stable before mixing together.

The foam may be prepared in a solvent-free process.

The foam may advantageously be prepared by a one-pot batch procedure, which may not require isolation or purification of intermediate materials. The foam can be prepared from low cost raw materials.

Reticulation

In some cases, it may be advantageous to reticulate the foam. Reticulation results in the removal of the cell windows, thereby increasing the amount of open cell material. This may be advantageous when fluid transport is required. This can be done in a special chamber (reticulated chamber) where hydrogen and oxygen are introduced into the foam and ignited to destroy and remove any aperture windows.

A cell opener may be added to the foam mixture to disrupt the pore structure, for example during foaming, to produce a foam with a natural sponge structure. The cell opener may reduce the tightness and shrinkage of the foam, resulting in a dimensionally stable foam having interconnected pores. Polyurethane foam cell openers and other reactive ingredients are discussed, for example, in Szycher, M, Szycher's Handbook of Polyurethanes, CRC Press, New York, N.Y.,9-6to 9-8 (1999). Suitable cell openers for use include powdered divalent metal salts of long chain fatty acids having from about 1 to 22 carbon atoms. Divalent metal salts of stearic acid, such as calcium stearate and magnesium stearate, are examples of cell openers. The concentration of the cell opener in the resin mixture may be about 0.1 wt% to 7.0 wt% or about 0.3 wt% to 1 wt%.

Bioactive agents

A bioactive agent may optionally be added to the foam mixture. As used herein, the term "biological activity" generally refers to an agent, molecule, or compound that affects a biological or chemical event in a subject.

Polyurethane substrate

When a polyurethane substrate is present, it may consist of more than one layer. For example, the substrate may be a laminate of two or more sheets of the same or different polyurethanes.

The substrate may comprise a biodegradable polyurethane. The substrate may be derived from one or more polyols, one or more isocyanates, and one or more chain extenders. The chain extender may be biodegradable or non-biodegradable.

In some embodiments, the substrate comprises an oriented polyurethane.

In some embodiments, the substrate comprises a biaxially oriented polyurethane.

In some embodiments, the oriented polyurethane is annealed.

The backing should be flexible enough to conform to the foam shape of the soft tissue implant bag. The substrate may be comprised of one or more polyurethane layers.

The substrate may be biodegradable or non-biodegradable, but should preferably be biocompatible.

The substrate may be a woven or non-woven layer of fibres, for example obtainable by electrospinning.

A substrate having a thickness of 50 to 400 μm provides a good balance between strength (increasing with thickness), permeability (decreasing with thickness) and handling (stiffening with increasing thickness). In addition, if the substrate is too thick, the quality of the substrate may become too high compared to the quality of the foam.

In some embodiments, the substrate may be porous. Porosity may be imparted by introducing one or more openings in the substrate prior to constructing the laminate. Preferably, the openings are sized to allow cellular fluids to pass therethrough.

In some embodiments, the size of the opening may be from about 0.1mm to about 5mm, preferably from about 1mm to about 5 mm.

Preferably, the distance between the respective openings may be about 0.5mm to 5mm, more preferably about 1mm to about 3 mm. Most preferably about 2 mm. The opening is configured to allow tissue to grow through the membrane and vascularization to occur throughout the implant pouch.

The soft tissue implant pocket may include a biocompatible and/or biodegradable adhesive between the foam and the backing.

In other embodiments, no adhesive may be used, and the substrate may be fused directly to the foam.

The polyurethane substrate may be derived from:

one or more chain extenders represented by formula (1) or formula (2)

Wherein R is₁、R₂And R₃Independently selected from C optionally having substituents_1-20Alkylene and optionally substituted C_2-20An alkenylene group;

one or more aliphatic polyester polyols; and

one or more aliphatic diisocyanates.

Number average molecular weight (M) of polyurethane substrate_w) May be up to 200,000 daltons, or up to 150,000 daltons, or up to 100,000 daltons, or up to 60,000 daltons, or up to 40,000 daltons, or up to 20,000 daltons.

Number average molecular weight (M) of polyurethane substrate_w) May be from 2,000 to 200,000 daltons, or from 5,000 to 150,000 daltons, or from 10,000 to 100,000 daltons, or from 20,000 to 100,000 daltons, or from 2,000 to 60,000 daltons, or from 2,000 to 40,000 daltons, or from 2,000 to 20,000 daltons.

Number average molecular weight (M) of polyurethane_n) May be up to 100,000 daltons, or up to 75,000 daltons, or up to 50,000 daltons, or up to 30,000 daltons, or up to 20,000 daltons, or up to 10,000 daltons. Preferably, the number average molecular weight of the polyurethane is from 50,000 to 100,000 daltons.

Polydispersity (M) of the polyurethane_w/M_n) May be 1.0 to 4.0, or 1.0 to 3.5, or 1.5 to 3.0. Preferably, the polydispersity is from 1.0 to 2.0.

Substrate polyol

The molecular weight of the polyol can be from about 200 to about 2,000 daltons, or from about 200 to about 1,500 daltons, or from about 200 to about 1,300 daltons.

The molecular weight of the polyol may be less than or equal to about 10,000 daltons, or less than or equal to about 8,000 daltons, or less than or equal to about 6,000 daltons, or less than or equal to about 4,000 daltons, or less than or equal to about 2,000 daltons, or less than or equal to about 1,500 daltons, or less than or equal to about 1,000 daltons, or less than or equal to about 800 daltons, or less than or equal to about 600 daltons, or less than or equal to about 500 daltons, or less than or equal to about 400 daltons, or less than or equal to about 350 daltons, or less than or equal to about 300 daltons.

The molecular weight of the polyol may be less than 500 daltons, or less than 400 daltons, or less than 350 daltons, or less than 300 daltons.

The polyol may be in a liquid state at 20 ℃ and atmospheric pressure. Alternatively, the polyol may be in a solid state at 20 ℃ and atmospheric pressure.

The polyol may be derived from one or more diol initiators and one or more hydroxy acids, diacids, or cyclic esters and combinations thereof.

In one embodiment, the polyol may be derived from one or more diol initiators and at least one hydroxy acid.

In one embodiment, the polyol may be derived from one or more diol initiators and at least one diacid.

In one embodiment, the polyol may be derived from one or more diol initiators and at least one cyclic ester.

In one embodiment, the polyol may be derived from one or more diol initiators, at least one hydroxy acid, and at least one diacid.

In one embodiment, the polyol may be derived from one or more diol initiators, at least one hydroxy acid, and at least one cyclic ester.

In one embodiment, the polyol may be derived from one or more diol initiators, at least one diacid, and at least one cyclic ester.

In one embodiment, the polyol may be derived from one or more diol initiators, at least one hydroxy acid, at least one diacid, and at least one cyclic ester.

Non-limiting examples of the one or more diol initiators include ethylene glycol, 1, 3-propanediol, 1, 2-propanediol, 1, 4-butanediol, pentanediol, hexamethylene glycol, heptanediol, octanediol, nonanediol, decanediol, dodecanediol, 2-ethyl-1, 3-hexanediol (EHD), 2, 4-trimethylpentane-1, 3-diol (TMPD), 1, 4-cyclohexanedimethanol, diethylene glycol, dipropylene glycol, and combinations thereof. Non-limiting examples of diacids include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, and hexadecanedioic acid, and combinations thereof. Non-limiting examples of hydroxy acids include l-lactic acid, d, l-lactic acid, mandelic acid, phenyllactic acid, hydroxybutyric acid, hydroxyvaleric acid, or glycolic acid, and combinations thereof. Non-limiting examples of cyclic esters include-caprolactone, glycolide, lactide, mandelate esters, and p-dioxanone, and combinations thereof. The polyols may be prepared by ring-opening polymerization or condensation reactions or by both ring-opening polymerization and condensation reactions.

Chain extender for substrates

In some embodiments, R of formulas (1) and (2)₁、R₂And R₃Independently selected from C optionally having substituents_1-6Alkylene and optionally substituted C_2-6An alkenylene group.

The term "optionally substituted" means that a group may or may not be further substituted with a substituent selected from C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, halogen C1-6 alkyl, halogen C2-6 alkenyl, halogen C2-6 alkynyl, hydroxy, C1-6 alkoxy, C2-6 alkenyloxy, halogen C1-6 alkoxy, halogen alkenyloxy, nitro C1-6 alkyl, nitro C2-6 alkenyl, nitro C-6 alkynyl, nitroheterocyclyl, amino, C1-6 alkylamino, C1-6 dialkylamino, C2-6 alkenylamino, C2-6 alkynylamino, acyl, alkenylacyl, alkynylacyl, acylamino, diacylamino, acyloxy, C1-6 alkylsulfonyloxy, heterocyclyl, heterocyclyloxy, C1-6 alkylsulfonyloxy, C, One or more groups of heterocyclylamino, halogenoheterocyclyl, C1-6 alkylsulfophenyl, alkoxycarbonyl, mercapto, C1-6 alkylthio, acylthio, phosphorus-containing group, and the like. Preferred optional substituents are methyl, ethyl, propyl, butyl and phenyl.

The chain extender of formula (1) or formula (2) is preferably 3-hydroxypropyl hydroxy-acetate, 2-hydroxyethyl 6-hydroxy-hexanoate, 4-hydroxybutyl 6-hydroxy-hexanoate, ethylene glycol succinic diester diol, ethylene glycol fumaric diester diol, glycolic acid-ethylene glycol dimer, lactic acid-ethylene glycol dimer and mixtures thereof.

The chain extender of formula (1) or formula (2) may be prepared from one or more diols and one or more hydroxy acids and/or cyclic esters.

Non-limiting examples of the one or more diols include ethylene glycol, 1, 3-propanediol, 1, 2-propanediol, 1, 4-butanediol, pentanediol, hexamethylene glycol, heptanediol, octanediol, nonanediol, decanediol, dodecanediol, 2-ethyl-1, 3-hexanediol (EHD), 2, 4-trimethylpentane-1, 3-diol (TMPD), 1, 4-cyclohexanedimethanol, diethylene glycol, dipropylene glycol, and combinations thereof. Non-limiting examples of hydroxy acids include l-lactic acid, d, l-lactic acid, mandelic acid, phenyllactic acid, hydroxybutyric acid, hydroxyvaleric acid, or glycolic acid, and combinations thereof. Non-limiting examples of cyclic esters include-caprolactone, glycolide, lactide, mandelate esters, and p-dioxanone, and combinations thereof.

The polyurethane may further comprise one or more aliphatic polyol chain extenders which are not hydrolytically degradable under in vivo conditions. For example, the polyurethane may further comprise one or more diol chain extenders which do not comprise ester functional groups in its backbone. Preferably, the non-degradable chain extender is an alkane diol having up to 30 carbon atoms, such as ethylene glycol, 1, 3-propanediol, 1, 2-propanediol, 1, 4-butanediol, pentanediol, hexamethylene glycol, heptanediol, nonanediol, dodecanediol, 2-ethyl-1, 3-hexanediol (EHD), 2, 4-trimethylpentane-1, 3-diol (TMPD), 1, 6-hexanediol, 1, 4-cyclohexanedimethanol, diethylene glycol, dipropylene glycol, and mixtures thereof.

Substrate diisocyanate

The aliphatic diisocyanate is preferably 4,4' -methylenedicyclohexyl diisocyanate (HMDI), 1, 6-Hexane Diisocyanate (HDI), 1, 4-Butane Diisocyanate (BDI), L-Lysine Diisocyanate (LDI), ethyl-L-lysine diisocyanate (ELDI), methyl-L-lysine diisocyanate (MLDI), 2,4, 4-trimethylhexamethylene diisocyanate, other similar diisocyanates, and mixtures thereof.

It is generally believed that degradation products of aliphatic isocyanates, such as Ethyl Lysine Diisocyanate (ELDI), are more biocompatible than degradation products of aromatic diisocyanates. Thus, isocyanates such as Hexamethylene Diisocyanate (HDI) and ELDI may be particularly suitable. Isophorone diisocyanate (IPDI) can also be used. Combinations of isocyanates may be used, which may be preferred in some cases-for example, the glass transition may be adjusted by a combination of HDI and IPDI. Trimethylhexamethylene diisocyanate, 1, 4-butane diisocyanate, methyllysine diisocyanate (MLDI), and other isocyanates commonly used in polyurethane synthesis may also be suitable.

Degradation of the substrate polyurethane

The polyurethane may comprise hard segments and soft segments. The ratio of hard segments to soft segments affects the melting point of the polyurethane.

The hard segment content (% HS) of the polyurethane, i.e., the total content of ingredients derived from the chain extender of formula (1) or formula (2) and the isocyanate, expressed in weight percent, may be from 2 to 100 weight percent, or from 5 to 80 weight percent, or from 10 to 70 weight percent.

The soft segment content (% SS) of the polyurethane (i.e., the weight percentage of the ingredients derived from the polyester polyol) can be 5% to 98%, and in some embodiments, at least 25% or at least 40%.

In some embodiments, the polyurethane comprises hard segments and soft segments, wherein the hard segment content (% HS) of the polyurethane is less than 60%, preferably 30% to 60%.

The amount of chain extender of formula (1) or formula (2) in the polyurethane can be varied to vary the non-degradable length of the continuous urethane in the hard segment. For example, the molecular weight of the non-degradable length of the hard segment may be from 100 to 10,000 daltons, or from 200 to 5,000 daltons, or from 400 to 2,000 daltons, or from 200 to 700 daltons, or from 320 to 700 daltons.

Under the conditions of ASTM F1635, the substrate polyurethane can degrade such that the number average molecular weight (M) of the polyurethane_n) A 10% to 90% reduction in time within a year.

The substrate polyurethane may be degradable in vivo. The polyurethane may be degradable at a temperature of 35 to 42 ℃.

Alternatively, the number average molecular weight (M) of the polyurethane_n) The reduction can be 10% to 90% within 11 months, or within 10 months, or within 9 months, or within 8 months, or within 7 months, or within 6 months, or within 5 months, or within 4 months, or within 3 months, or within 2 months, or within 1 month.

Under the conditions of ASTM F1635, the degradation rate can be controlled by varying the nature and proportions of the polyurethane components. Thus, the polyurethane can be designed to degrade within a specific time. This is advantageous in providing a material that degrades partially, completely or substantially completely at a particular time, for example, when the functional aspects of the polyurethane are no longer needed.

Melting Point

The melting point of the polyurethane of the substrate may be 60 ℃ to 190 ℃. The melting point may be from 60 ℃ to 180 ℃, or from 60 ℃ to 170 ℃, or from 60 ℃ to 160 ℃, or from 60 ℃ to 150 ℃, or from 60 ℃ to 140 ℃, or from 60 ℃ to 130 ℃, or from 60 ℃ to 120 ℃, or from 60 ℃ to 110 ℃, or from 60 ℃ to 100 ℃, or from 60 ℃ to 90 ℃, or from 60 ℃ to 80 ℃, or from 60 ℃ to 70 ℃.

When a significant melting transition occurs, the melting point can be determined by differential scanning calorimetry. Other techniques known to those skilled in the art, such as dynamic mechanical thermal analysis, may also be used.

Adhesive agent

Various adhesives may be utilized to secure the substrate to the foam. The adhesive layer may be a fused layer or a discontinuous layer. Suitable adhesives include, but are not limited to, solvent-based adhesives, latex adhesives, pressure sensitive adhesives, hot melt adhesives, and reactive adhesives, such as a biodegradable or non-biodegradable thermosetting polyurethane reactive mixture. Suitable pressure sensitive adhesives include, but are not limited to, pressure sensitive adhesives made from acrylics, natural latex, styrene butadiene rubber, and reclaimed rubber. Suitable hot melt adhesives include, but are not limited to, polyamides, polyolefins, and poly (ethylene-co-vinyl acetate).

In one embodiment, the substrate itself may be an adhesive. In other embodiments, the structural layer may be fused directly to the foam without the use of an adhesive.

The biodegradable polyurethanes of the substrates disclosed herein can degrade by in vivo hydrolysis.

Manufacture of implant bags

In one embodiment, the soft tissue implant bag may be manufactured as follows: folding the polyurethane foam sheet as disclosed herein, heat seals the edges to fuse them together, but leaves an opening sized for introduction of the selected implant.

In another embodiment, the soft tissue implant bag may alternatively be manufactured as follows: the edges of the two polyurethane foam sheets are heat sealed together to fuse them together, but leaving an opening sized for introduction of the selected implant.

In another embodiment, the soft tissue implant bag may alternatively be manufactured as follows: the two oversized sheets are heat sealed so that the heat seal follows between 50-80% of the circumference of the circle, and then the remainder of the circumference is cut off.

Sealing may be achieved by a combination of heat and pressure.

In another embodiment, the soft tissue implant bag may be manufactured as follows: a sheet of polyurethane foam that has been laminated with a polyurethane backing is folded as disclosed herein, heat sealing the edges so as to fuse them together, but leaving an opening sized for introduction of the selected implant.

The folding may be such that the substrate is located inside or outside the resulting bag. In the case of a substrate located outside the bag, the bag can conveniently be turned inside out so that the substrate is located inside the bag.

The substrate may be laminated to the foam and then formed into a pocket such that there are substantially no gaps (e.g., bubbles) between the materials.

The foam layer and the substrate layer may have substantially equal length and width dimensions.

The substrate may be laminated to the foam via interaction between the materials by applying heat or pressure or a combination of heat and pressure. Alternatively, the substrate may be covalently bonded to the foam. In alternative and/or other embodiments, the substrate may be laminated to the foam layer by means of a suitable adhesive according to any of the above embodiments.

In another embodiment, an implant pocket may be formed by fusing a layer of foam on each side of a substrate to form a foam-substrate-foam construction. The resulting construction can be folded and the sides fused together to leave an opening through which the implant can be introduced. The resulting bag includes inner and outer foam surfaces and a substrate therebetween. The substrate may add structural strength.

The substrate may be formed by melt pressing.

The melt-pressing may be performed at a temperature of 100 to 200 ℃.

Melt pressing may be performed at a pressure of up to 30 t.

Melt pressing may be performed between two smooth or substantially smooth sheets. Melt pressing may be performed between two PTFE sheets (e.g., glass fiber reinforced PTFE sheets).

Fusing of the substrate to the foam can be performed without the application of pressure.

The fusing may be performed by applying heat to the surface of the substrate, for example by exposing the second main surface to a temperature of 100 to 200 ℃.

The fusing may be performed for a period of 5 seconds to minutes, preferably 15 seconds to 90 seconds.

In another aspect of the present disclosure, there is provided a method of making a soft tissue implant pocket comprising the steps of:

(a) folding a polyurethane foam sheet as disclosed herein such that the edges of the sheet are substantially aligned; and

(b) the aligned edges are heat sealed leaving an opening sized for introduction of the implant.

In some embodiments, heat sealing is combined with cutting to provide a final implant bag.

In other embodiments, the cutting may be performed after the heat sealing.

In another aspect of the present disclosure, there is provided a method of making a soft tissue implant pocket comprising the steps of:

(a) placing the first polyurethane foam sheet on the second polyurethane foam sheet such that edges of the sheets are substantially aligned; and

(b) the aligned edges are heat sealed leaving an opening sized for introduction of the implant.

In another aspect of the present disclosure, there is provided a method of making a soft tissue implant pocket comprising the steps of:

(a) folding the foam/substrate laminate such that the edges of the laminate are substantially aligned, as disclosed herein; and

(b) the aligned edges are heat sealed leaving an opening sized for introduction of the implant.

In another aspect of the present disclosure, there is provided a method of making a soft tissue implant pocket comprising the steps of:

(a) folding the foam/substrate/foam laminate such that the edges of the laminate are substantially aligned, as disclosed herein; and

(b) the aligned edges are heat sealed leaving an opening sized for introduction of the implant.

In another aspect of the present disclosure, there is provided a method of making a soft tissue implant pocket comprising the steps of:

(a) placing the first polyurethane foam/substrate laminate on the second polyurethane foam/substrate laminate such that edges of the laminates are substantially aligned; and

(b) the aligned edges are heat sealed leaving an opening sized for introduction of the implant.

In any one or more of the methods disclosed herein, the foam layers can be bonded to each other or to the substrate by ultrasonic welding. This is a particularly useful method of bonding layers using an orientation substrate.

In another aspect of the present disclosure, there is provided a use of a soft tissue implant pocket as disclosed herein to reduce or eliminate capsular contracture.

In another aspect of the disclosure, a method of reducing or eliminating capsular contracture is provided, comprising placing an implant in a soft tissue implant pocket as disclosed herein, sealing the pocket, and implanting the pocket in a subject.

Other features and advantages of the present disclosure will be understood by reference to the following drawings and detailed description.

Drawings

Fig. 1 is a schematic view of a soft tissue implant bag according to one embodiment of the present disclosure.

Fig. 2 is a schematic view of a soft tissue implant bag according to another embodiment of the present disclosure.

Detailed Description

The following is a detailed description of the disclosure provided to assist those skilled in the art in practicing the disclosure. Modifications and variations of the embodiments described herein may be made by those of ordinary skill in the art without departing from the spirit or scope of the disclosure.

Although any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present disclosure, the preferred methods and materials are now described.

It must also be noted that, as used in the specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a chain extender" may include more than one chain extender and the like.

Throughout the specification the terms "comprises" or "comprising" or grammatical variations thereof are to be taken as specifying the presence of the stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof not specifically mentioned.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

Unless otherwise indicated or apparent from the context, as used herein, the term "about" is to be understood as being within the normal tolerance of the art, e.g., within two standard deviations of the mean. "about" can be understood as being within 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%, 0.1%, 0.05% or 0.01% of the stated value. All numbers provided herein in the specification and claims can be modified by the term "about" unless the context clearly dictates otherwise.

Ranges provided herein are to be understood as shorthand for all values within the range. For example, a range of 1 to 50 can be understood to include any number, combination of numbers, or subrange from the group comprising 1,2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, or 50.

The main components and features for preparing one or more embodiments of the soft tissue implant pouches disclosed herein are discussed in detail in the following sections.