阅读说明：本技术 粘液屏障性能的增强 (Enhancement of mucus barrier performance ) 是由 托马斯·克鲁齐耶 于 2018-04-06 设计创作，主要内容包括：一种组合物或避孕组合物及其用途,该组合物或避孕组合物包含生理学上可接受的载体中的粘膜粘附聚合物,其中粘膜粘附聚合物由4至20个通过醚键、酯键或酰胺键相互连接的单体单元组成,该单体单元选自由氨基官能化的C6糖、C6糖、氨基官能化的C5糖、C5糖、氨基酸、脂肪酸衍生的C6糖和脂肪酸衍生的C5糖组成的清单。(a composition or contraceptive composition comprising a mucoadhesive polymer in a physiologically acceptable carrier, wherein the mucoadhesive polymer is composed of 4 to 20 monomer units linked to each other by ether, ester or amide linkages, the monomer units being selected from the list consisting of amino-functionalized C6 saccharides, C6 saccharides, amino-functionalized C5 saccharides, C5 saccharides, amino acids, fatty acid-derived C6 saccharides and fatty acid-derived C5 saccharides, and uses thereof.)

1. A composition comprising a mucoadhesive polymer and a physiologically acceptable gelling agent, wherein the polymer is composed of 4 to 20 monomer units interconnected by ether, ester or amide linkages, selected from the list consisting of amino functionalized C6 saccharide, C6 saccharide, amino functionalized C5 saccharide, C5 saccharide, amino acid, fatty acid derived C6 saccharide and fatty acid derived C5 saccharide, wherein at least 50% of the monomer units of the mucoadhesive polymer comprise an amino group or at least 50% of the monomer units of the mucoadhesive polymer are selected from the list consisting of alanine, methionine, cysteine, phenylalanine, leucine, valine, isoleucine, fatty acid derived C6 saccharide and fatty acid derived C5 saccharide.

2. The composition of claim 1, wherein the monomeric unit is selected from the group consisting of arginine, lysine, histidine, ornithine, beta-alanine, glycine, serine, threonine, asparagine and glutamine.

3. The composition of claim 1 or 2, wherein the mucoadhesive polymer is selected from the group consisting of polylysine, polyornithine, polyarginine, cationized dialdehyde cellulose (DAC), cationic hydroxyethyl cellulose, chitosan-trimethyl, chitosan-thioglycolic acid, chitosan-iminothiolane, and chitosan-thioacetamidine.

4. The composition of any one of the preceding claims, wherein the mucoadhesive polymer is described by formula (I),

Wherein n is an integer of 2 to 10.

5. The composition of any one of the preceding claims, wherein the pharmaceutically acceptable carrier is water, DMSO, saline, or a combination thereof.

6. A composition for use in therapy comprising a mucoadhesive polymer and a physiologically acceptable gelling agent, the mucoadhesive polymer consisting of 4 to 20 monomer units interconnected by ether, ester or amide linkages, the monomer units being selected from the list consisting of amino-functionalized C6 saccharide, C6 saccharide, amino-functionalized C5 saccharide, C5 saccharide, amino acid, fatty acid-derived C6 saccharide and fatty acid-derived C5 saccharide, wherein at least 50% of the monomer units of the mucoadhesive polymer comprise an amino group or at least 50% of the monomer units of the mucoadhesive polymer are selected from the list consisting of alanine, methionine, cysteine, phenylalanine, leucine, valine, isoleucine, fatty acid-derived C6 saccharide and fatty acid-derived C5 saccharide.

7. The composition for use in therapy according to claim 6, wherein said monomeric unit is selected from the group consisting of arginine, lysine, histidine, ornithine, beta-alanine, glycine, serine, threonine, asparagine and glutamine.

8. The composition for use in therapy according to any one of claims 6 or 7, wherein said mucoadhesive polymer is selected from the group consisting of polylysine, polyornithine, polyarginine, cationized dialdehyde cellulose (DAC), cationic hydroxyethyl cellulose, chitosan-trimethyl, chitosan-thioglycolic acid, chitosan-iminothiolane and chitosan-thioacetamidine.

9. The composition for use in therapy according to any one of claims 6 to 8, wherein the mucoadhesive polymer is described by formula (I),

Wherein n is an integer of 2 to 10.

10. A composition for use in therapy according to any one of claims 6 to 9, for use in the treatment of mucosal damage.

11. A contraceptive composition comprising a mucoadhesive polymer and a physiologically acceptable gelling agent, wherein the mucoadhesive polymer is composed of 4 to 20 monomeric units interconnected by ether, ester or amide linkages, said monomeric units being selected from the list consisting of an amino-functionalized C6 saccharide, a C6 saccharide, an amino-functionalized C5 saccharide, a C5 saccharide, an amino acid, a fatty acid-derived C6 saccharide and a fatty acid-derived C5 saccharide, wherein at least 50% of the monomeric units of the mucoadhesive polymer comprise an amino group or at least 50% of the monomeric units of the mucoadhesive polymer are selected from the list consisting of alanine, methionine, cysteine, phenylalanine, leucine, valine, isoleucine, a fatty acid-derived C6 saccharide and a fatty acid-derived C5 saccharide.

12. Use of a mucoadhesive polymer consisting of 4 to 20 monomeric units interconnected by ether, ester or amide linkages, said monomeric units being selected from the list consisting of an amino-functionalized C6 saccharide, a C6 saccharide, an amino-functionalized C5 saccharide, a C5 saccharide, an amino acid, a fatty acid-derived C6 saccharide and a fatty acid-derived C5 saccharide, as a contraceptive, wherein at least 50% of the monomeric units of the mucoadhesive polymer comprise an amino group or at least 50% of the monomeric units of the mucoadhesive polymer are selected from the list consisting of alanine, methionine, cysteine, phenylalanine, leucine, valine, isoleucine, a fatty acid-derived C6 saccharide and a fatty acid-derived C5 saccharide.

13. A kit of parts comprising a composition according to any one of claims 1 to 11 and an applicator.

Technical Field

The present invention relates to compositions comprising mucoadhesive polymers and physiologically acceptable gelling agents, and their use in therapy or contraception. The mucoadhesive polymer may crosslink the mucus layer without coalescing the mucus.

Background

In humans, epithelial surfaces of over 400 square meters are hidden, including in the lungs, gastrointestinal tract and female reproductive tract. Wet epithelial surfaces rely on mucus gels to protect them from dehydration, shear stress and infection. Apart from water, mucus contains mainly mucin biopolymers mixed with proteins, lipids and salts. Mucins are large glycoproteins composed of an extended central protein core densely populated with oligosaccharides that can account for up to 50% of the molecular weight of the molecule. Mucins play a central role in this protective function, resulting in selective filtration based on size exclusion and affinity, preventing many deleterious molecules from reaching the epithelial surface.

However, in some cases, the mucus gel may not properly protect the epithelial cells. For example, dry eye and dry mouth affect at least 8% of the population. Symptoms can be severely uncomfortable due to the loss of hydration and lubrication of these surfaces, and can also pose a health threat due to the increased risk of infection. Inflammatory bowel diseases such as crohn's disease or ulcerative colitis are also associated with failure of the mucin gel to properly protect the epithelial surface from commensal or pathogenic bacteria. Bacterial entry into epithelial cells triggers a difficult to stop inflammatory cycle.

Mucoadhesive polymers have been used for drug delivery due to their adhesive properties. For example, they have been used to deliver drugs to sites of inflammation. Mucoadhesive polymers are often assembled together with drugs into a material or gel, intended to concentrate the drug on the surface of the mucus layer and improve drug delivery.

WO 2004069230 relates to pharmaceutical compositions containing a physiologically active agent, i.e. a drug, and a sustained release or mucoadhesive agent, e.g. chitosan, for prolonged release of the active agent from the composition.

Another use of chitosan is female contraception. CN 102895256 relates to a chitosan gel foaming agent suitable for female contraception and antifungal effect and a preparation method thereof, and belongs to the technical field of foaming agent production. According to this disclosure, chitosan molecules are entrapped in a solid foam matrix in combination with carbomers, which physically prevents the passage of sperm. Mucoadhesive molecules are known to promote the compaction and thickening of mucosal tissue or to enhance barrier function, but use suggests that mucoadhesive polymers and mucus penetrating nanoparticles will crosslink and coalesce mucus. Specifically, when high molecular weight polyacrylic acids such as carbomers are present, the carboxyl functionality in the acrylic acid monomer will form an ionic complex with the basic amino groups in the chitosan chains, resulting in the formation of a highly swollen interpenetrating polymer network. Thus, the coalescence of mucus results in the opening of pores within the mucus and a reduction in the barrier properties of the mucus. Thus, there is a need to improve the cross-linking of mucus without coalescence.

Disclosure of Invention

Therefore, in this context, it is an object of the present invention to provide mucoadhesive polymers which can crosslink the mucus layer without coalescing the mucus. The present inventors have surprisingly found that a mucoadhesive polymer consisting of 4 to 20 monomer units interconnected by ether, ester or amide linkages, wherein the monomer units are selected from the list consisting of amino functionalized C6 saccharide, C6 saccharide, amino functionalized C5 saccharide, C5 saccharide, amino acid, fatty acid derived C6 saccharide and fatty acid derived C5 saccharide, wherein at least 50% of the monomer units of the mucoadhesive polymer comprise an amino group or at least 50% of the monomer units of the mucoadhesive polymer are selected from the list consisting of alanine, methionine, cysteine, phenylalanine, leucine, valine, isoleucine, fatty acid derived C6 saccharide and fatty acid derived C5 saccharide, achieves an enhanced effect. In a first aspect, the present invention relates to a composition comprising a mucoadhesive polymer as defined above and a physiologically acceptable gelling agent. In a further aspect, the invention relates to a composition comprising a mucoadhesive polymer as defined above and a physiologically acceptable gelling agent for use in therapy, for example for treating mucosal lesions. In a further aspect, the present invention relates to a contraceptive composition comprising a mucoadhesive polymer as defined above and a physiologically acceptable gelling agent. In another aspect, the invention relates to a kit of parts comprising a composition comprising a mucoadhesive polymer as defined above, a physiologically acceptable gelling agent and an applicator.

The small size of the polymer advantageously allows the molecules to diffuse within the mucus. The improved diffusion of mucoadhesive polymers into the mucosa allows for cross-linking of mucus layers over large thicknesses without coalescing of mucus. Small mucoadhesive polymers complex with mucus, thereby blocking the pores of the network and enhancing its barrier properties. In addition, small size polymers are generally more soluble under conditions suitable for delivery to the mucosa of a subject than larger size polymers. Thus, the mucoadhesive polymer may be more efficiently delivered to the mucosa, which in turn allows for stronger, and thus more efficient, crosslinking than can be achieved using larger mucoadhesive polymer molecules. The mucoadhesive polymer may generally be cationic, e.g. at least 50% of the monomers have positively charged amino groups, or hydrophobic, e.g. at least 50% of the monomers have hydrophobic side chains. The effective duration of the cross-linked mucus is determined by the biological renewal time of the mucus, which can vary according to different organs of the body, such as the eye, respiratory tract, oral cavity or reproductive tract. The crosslinking time may be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 hours, 1, 2, 3 days or even up to 10 days.

Thus, mucoadhesive polymers will provide a more reliable barrier effect that prevents cells and microorganisms such as bacteria, viruses and sperm from penetrating the cross-linked mucus and diffusing into the mucosa. Accordingly, one aspect of the present invention is a composition, such as a contraceptive composition, for use in the prevention of pregnancy and/or Sexually Transmitted Infections (STIs).

By combining with a physiologically acceptable gelling agent, the contact area between the composition and the mucus is maximized. The increased contact area can help ensure that a maximum amount of mucoadhesive polymer can diffuse into the mucus layer and change its properties. Also contributing to the increased diffusion is the high density of the composition. By having a high composition density, preferably similar to that of water, such as a semi-solid gel, the applied composition can change shape and encapsulate the entire surface of the cervical inlet.

In addition, the present invention provides contraceptive compositions that are free of hormones or chemicals that have undesirable side effects. Undesirable effects may include embolism, migraine or minor side effects, such as affecting the menstrual cycle. The effective time of the mucoadhesive polymers according to the invention is determined by the renewal time of the mucus, which means that the contraceptive effect is temporary. The contraceptive dissolves after an effective time without affecting fertility. The time for adequate contraception is affected by several factors, such as the time for biological renewal of mucus, the concentration of mucoadhesive polymers, etc., and is maintained for a period of time, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 hours, 1, 2, 3 days, or even up to 10 days, which is sufficient to prevent sperm cells from entering the cervix. By preventing sperm from entering the cervix, the acidic environment of the vagina will reduce sperm motility and weaken the sperm such that it cannot fertilize the egg. Under natural conditions, sperm cells need to enter the cervix within minutes before surviving. A single application achieves a complete contraceptive effect, which means that a non-consecutive use of the contraceptive composition may provide the same protection as a consecutive use.

A single application achieves a complete contraceptive effect, which means that a temporary contact of cervical mucus with the contraceptive composition provides the same complete protection as a continuous contact of cervical mucus.

The mucoadhesive polymer is composed of 4 to 20 monomer units interconnected by ether, ester or amide linkages. In addition, the polysaccharide monomers may be linked by ether, ester and/or acetal linkages. In one embodiment of the invention, at least 50% of the monomers of the mucoadhesive polymer comprise amino groups. In another embodiment of the invention, at least 50% of the monomers of the mucoadhesive polymer comprise hydrophobic groups. The amino groups render the mucoadhesive polymers alkaline, which facilitates their binding to the mucosa. The basic amino groups in particular provide more effective crosslinking. Furthermore, when at least 50% of the monomers of the mucoadhesive polymer comprise hydrophobic groups, the mucoadhesive polymer may also adhere to and diffuse into the mucosa to cross-link the mucosa without coalescing the mucosa.

In the context of the present invention, amino is-NH₂In which one or two hydrogen atoms may beSubstituted with a group R, or the amino group may be a quaternary amino group having 3R groups. R may be selected from C_1-4Alkyl, optionally substituted by one or more-OH, -SH or-NH₂And when more than one R is present on the same nitrogen atom, they may be the same or different. Provided that R has 4 or fewer carbon atoms, particularly when the hydrogen atoms of R are substituted by one or more-OH, -SH, or-NH groups₂When substituted, the amino group is typically basic. Longer alkyl chains, for example, amino groups having 5 or more carbon atoms, tend to mask the basicity of the amino group, and in the context of the present invention, amino groups with alkyl groups of 5 or more carbon atoms are not counted as amino groups. Likewise, the sugar may also contain an amide group, e.g., -CONHCH₃or-NHCHO, but in the context of the present invention these groups are not counted as amino groups.

The mucoadhesive polymer may be a polysaccharide in which the C6 or C5 saccharides are linked to each other by ether linkages. The monomers of the C6 and C5 sugars may be linked by any ether linkage, for example, C1 and C4, which may link two adjacent C6 sugars, or C1 and C6, which may link two adjacent C6 sugars. Specifically, when the monomer is a C6 sugar such as glucose, then the monomer, e.g., glucose monomer, can be linked by a β (1-4) linkage. In one embodiment, the mucoadhesive polymer is comprised of 4 to 20 β (1-4) linked glucose monomers, wherein at least 50% of the glucose monomers comprise amino groups, e.g., -NH₂. The amino group may be attached to any carbon atom of the glucose monomer, for example C2 or C3. In the amino group, one or two hydrogen atoms may be substituted by a group R, which may be selected from C_1-4Alkyl, optionally substituted by one or more-OH, -SH or-NH₂And (4) substitution.

In a preferred embodiment, the mucoadhesive polymer is chitosan, wherein at least 50% of the glucose monomers have-NH₂And wherein less than 20% of the glucose monomers have-CONHCH₃A group. Chitosan may also be referred to as being at least 50% deacetylated. Other embodiments of mucoadhesive polymers include cationized dialdehyde cellulose (DAC), cationic hydroxyethyl cellulose, chitosan-trimethyl (trimethyl chitosan, chitosan-trimethyl)l), chitosan-thioglycolic acid, chitosan-iminothiolane (iminothiolane) or chitosan-thioacetamidine.

With respect to the cationized dialdehyde cellulose and the cationic hydroxyethyl cellulose, it is understood that at least 50% of the glucose monomers in the dialdehyde or hydroxymethyl cellulose are aminated by the cationic amine, and thus the polysaccharide is cationic.

In one embodiment of the invention, at least 50% of the monomer units are sugar monomers derived from fatty acids. In the context of the present invention, fatty acids are considered to be hydrophobic groups. Any fatty acid is suitable for use in the present invention, but the fatty acid is preferably naturally occurring and biodegradable. Preferred fatty acids have from 6 to 22 carbon atoms, especially an even number of carbon atoms, and the fatty acid may contain one or more double bonds. The fatty acid is preferably linked to the sugar monomer via an ester linkage.

In another embodiment of the invention, the mucoadhesive polymer is a peptide molecule of 4 to 20 amino acids in length, which is linked by amide bonds. When the mucoadhesive polymer comprises amino acids, any amino acid may be included, as long as optionally at least 50% of the amino acids carry a basic group, or as long as at least 50% of the amino acids carry a hydrophobic group. Mucoadhesive polymers are not limited to naturally occurring amino acids, but it is preferred that the amino acids are non-toxic and are subject-tolerant. It is preferred that the mucoadhesive polymer does not contain a D-amino acid, but that any amino acid contained in the mucoadhesive polymer is an L-amino acid. Generally, the following amino acids are considered basic: arginine, lysine, histidine, ornithine and beta-alanine, and in one embodiment, the mucoadhesive polymer is a 4 to 20 amino acid polypeptide wherein at least 50% of the amino acids are selected from the list consisting of arginine, lysine, histidine, ornithine and beta-alanine. The remaining amino acids may be selected from any amino acid, for example any of the 20 amino acids defined by the genetic code, but are in particular glycine, serine, threonine, asparagine and glutamine. Specific embodiments of mucoadhesive polymers include polylysine, polyornithine, and polyarginine. The advantage of using basic amino acids is their good solubility in aqueous solutions.

In another embodiment, the mucoadhesive polymer is a peptide molecule of 4 to 20 amino acids in length, wherein at least 50% of the amino acids carry a hydrophobic group, the amino acids being selected from the list consisting of: alanine, methionine, cysteine, phenylalanine, leucine, valine and isoleucine. The remaining amino acids may be selected from the list consisting of: glycine, serine, threonine, asparagine, and glutamine. In one embodiment, the mucoadhesive polymer comprises amino acids and at least 50% of the amino acids are selected from the group consisting of arginine, lysine, histidine, ornithine and beta-alanine, or 50% of the amino acids carry a hydrophobic group and are selected from the group consisting of arginine, lysine, histidine, ornithine and beta-alanine. The use of amino acids or hydrophobic amino acids is advantageous because they are biodegradable and the protein-peptide interaction between mucin and polymers can enhance mucosal adhesion. In addition, the amino acid polymer can be recombinantly produced using bacteria or synthetically produced.

In a further embodiment, the mucoadhesive polymer comprises two saccharide monomers, e.g., C6 and/or C5 saccharide monomers and an amino acid if at least 50% of the monomers are basic, e.g., carry an amino group, or at least 50% of the monomers are hydrophobic, e.g., carry a hydrophobic group.

In another embodiment, the polymer consists of 20 or preferably 10 or 8 monomer units, which ensures that the polymer is small enough to diffuse deep into the mucus gel and large enough to form a tight cross-linked network. Tight means impermeable to microorganisms or sperm cells.

In a further embodiment, the mucoadhesive polymer is selected from polymers having a low molecular weight, which should have a Degree of Polymerization (DP) providing a molecular weight in the range of 0.5 to about 5kDa, which ensures that the mucoadhesive polymer forms a stable complex with mucus. In a preferred embodiment, the mucoadhesive polymer is chitosan, and the preferred DP of chitosan provides a molecular weight in the range of 0.5 to about 3.5kDa, more preferably in the range of 0.7 to 2kDa, most preferably about 1.5 kDa.

In another aspect, the invention is a kit of parts comprising a composition comprising a mucoadhesive polymer and a physiologically acceptable gelling agent, such as a contraceptive composition as described above, and an applicator. In one embodiment, the applicator is a delivery device similar to tampons known for use by a method in which an applicator containing a composition in gel form, e.g., a contraceptive composition, containing a mucoadhesive polymer and a physiologically acceptable gelling agent as described above is inserted into the vagina. The gel is deployed from the applicator and the gel is applied to cervical mucus, and the mucus is cross-linked by the mucoadhesive polymer. In one embodiment, the applicator is a container that contains the contraceptive composition, e.g., as a contraceptive composition, and which may be emptied by an emptying mechanism. In another embodiment, the container resembles a balloon, which contains the composition under a first condition and is removed under a second condition to administer the composition. In yet another embodiment, a kit comprises a mucoadhesive polymer and a physiologically acceptable gelling agent in a composition for treating mucosal lesions and an applicator, wherein the applicator is a container from which the composition is released in the form of a liquid or drops.

Drawings

FIG. 1 schematic representation of mucin gel droplets in chitosan solution and cryo SEM images of the surface of complexes of chitosan DP8, DP52 and DP 100.

Figure 2. quantitative bar graph of the amount of chitosan involved in complexing with purified mucin drops.

FIG. 3. Bar graph showing diffusion of fluorescently labeled dextran in mucin droplet/chitosan complex.

FIG. 4 histological image of HT29-MTX cultures cultured on porous membranes. (A) Young, 7-day-old cultures showed a multi-layered structure. (B) After 30 days of incubation, these become polarized and are coated with a layer of adherent mucus (blue staining). (C) Bar graph of metabolic activity of young HT29-MTX cells after exposure to various concentrations of chitosan solution. (D) Bar graph of the metabolic activity of mature HT29-MTX after exposure to 5mg/mL chitosan solution.

FIG. 5 is a graph showing the output of flow cytometry of HT29-MTX cells exposed to fluorescently labeled dextran (column A) or cholera toxin subunit B (column B). The three conditions tested were HT29-MTX with a mucus layer for 30 days of growth (line I), HT29-MTX without a mucus layer and treated with chitosan for 7 days of growth (line II), and HT29-MTX with a mucus layer and treated with chitosan for 30 days of growth (line III).

Figure 6 (a) shows a bar graph of quantification of the amount of chitosan involved in complexation with mature HT29-MTX cultures overlaid with mucus layer. Confocal images of chitosan-FITC deposition of HT29-MTX cell layer and top, and cross-sectional views of all three chitosans (B) DP8, (B') DP52 and (B ") DP 100.

FIG. 7 optical microscope (10 × Objective) images taken after 3min, 12min, 30min and 50min of contact between mucoadhesive amino acid polymer and mucin gel.

FIG. 8 phase microscope images of porcine gastric mucin complexed or not with chitosan placed in sperm solution.

FIG. 9.A) macroscopic image of 4. mu.L mucin gel dripped into chitosan solution. B) Confocal fluorescence image of complex boundaries using fluorescein-labeled chitosan.

FIG. 10 measurement of fluorescence intensity of chitosan oligomers permeating capillaries containing ovulated human cervical mucus.

Fig. 11 sperm penetration data measured as sperm count and penetration distance per field of view for two replicates of human cervical mucus.

FIG. 12 shows the toxicity of chitosan oligomers on sperm cells, expressed by the loss of motility (%), and velocity (. mu.m/s) through progressive motility (%).

Detailed Description

The subject of the present invention relates to a composition comprising a mucoadhesive polymer and a physiologically acceptable gelling agent, wherein the mucoadhesive polymer is composed of 4 to 20 monomer units interconnected by ether, ester or amide bonds, the monomer units being selected from the list consisting of amino functionalized C6 saccharide, C6 saccharide, amino functionalized C5 saccharide, C5 saccharide, amino acid, fatty acid derived C6 saccharide and fatty acid derived C5 saccharide, wherein at least 50% of the monomer units of the mucoadhesive polymer comprise amino groups or at least 50% of the monomer units of the mucoadhesive polymer are selected from the group consisting of alanine, methionine, cysteine, phenylalanine, leucine, valine, isoleucine, fatty acid derived C6 saccharide and fatty acid derived C5 saccharide. Mucoadhesive polymers may be used as contraceptives, and in another aspect, the invention relates to contraceptive compositions having a mucoadhesive polymer and a gelling agent.

In another aspect of the invention, a composition comprising a mucoadhesive polymer and a physiologically acceptable gelling agent is used in therapy, the mucoadhesive polymer being composed of 4 to 20 monomer units interconnected by ether, ester or amide linkages, the monomer units being selected from the list consisting of amino-functionalized C6 saccharide, C6 saccharide, amino-functionalized C5 saccharide, C5 saccharide, amino acid, fatty acid-derived C6 saccharide and fatty acid-derived C5 saccharide, wherein at least 50% of the monomer units of the mucoadhesive polymer comprise amino groups or at least 50% of the monomer units of the mucoadhesive polymer are selected from the list consisting of alanine, methionine, cysteine, phenylalanine, leucine, valine, isoleucine, fatty acid-derived C6 saccharide and fatty acid-derived C5 saccharide.

The composition comprising the mucoadhesive polymer and the physiologically acceptable gelling agent may be part of a kit further comprising an applicator. The applicator may be used to apply the composition to a surface, such as the cervix.

The mucoadhesive polymer may be administered in a physiologically acceptable carrier, which ensures that the mucoadhesive polymer is soluble under the conditions of its use and that the mucoadhesive polymer is uniformly distributed in the target area. By uniformly distributed herein is meant that the targeted mucus region is subjected to at least a minimum amount of composition, determinable to the skilled person, with sufficient mucoadhesive polymer to diffuse into the mucus and enhance the mucus barrier.

Physiologically acceptable carriers refer to non-toxic compounds that are neither chemically nor physically toxic to the human or animal organism or biological process at effective doses.

In one embodiment, the pharmaceutically acceptable carrier is water, DMSO, saline, or a combination thereof.

Mucoadhesion is described herein as an interfacial force that holds two biomaterials together, such as an attractive force between the biomaterials and mucus or mucosa. Thus, by mucoadhesive polymer is meant a polymer that is attractive to mucus or mucous membranes.

Mucus is a protective covering of all epithelial surfaces that keeps the epithelial layer moist and prevents the invasion of microorganisms into the epithelial cells. Since mucus entraps microorganisms and facilitates their distal transport, natural protection is achieved. When referring to the barrier effect achieved by mucoadhesive polymers, it is an enhancement of mucus due to cross-linking of the polymers. The effect of the enhanced barrier is based on the tightness of the cross-linked mucus against diffusion, and the length of time the mucus is enhanced by the complex mucoadhesive polymers. The latter results from the natural renewal time of mucus cells from the mucosa to remove mucus containing cross-linked polymers.

The thickness of the mucus layer on the mucosa is different and based on different biological factors, such as part of the body, animal species, age or disease outbreak, and therefore the thickness affected by the mucoadhesive polymer depends on these factors and may vary from a few microns to several hundred microns. The thickness of the complexed mucus and thus the barrier effect required to prevent the diffusion of foreign substances into the mucosa depends on the use of mucoadhesive polymers. One thickness of the barrier layer may be impermeable to relatively large cells such as sperm, however a more compact barrier layer may be required to be impermeable to bacteria or viruses or other microorganisms or infections.

Small mucoadhesive polymers are composed of 4 to 20 monomer units, which are interconnected by ether, ester or amide linkages. The monomeric units are selected from the list consisting of amino-functionalized C6 saccharide, C6 saccharide, amino-functionalized C5 saccharide, C5 saccharide, amino acid, fatty acid-derived C6 saccharide, and fatty acid-derived C5 saccharide, wherein at least 50% of the monomeric units of the mucoadhesive polymer comprise amino groups or at least 50% of the monomeric units of the mucoadhesive polymer are selected from the list consisting of alanine, methionine, cysteine, phenylalanine, leucine, valine, isoleucine, fatty acid-derived C6 saccharide, and fatty acid-derived C5 saccharide.

Small polymers herein are polymers having a low Degree of Polymerization (DP), such as 20 monomers or less, preferably in the range of 5 to 20, such as a DP of 8, and a molecular weight below 5kDa, preferably in the range of 0.7 to 2kDa, such as 1.5 kDa.

The small size of the polymer ensures that the polymer is soluble under the conditions of use and that the polymer can diffuse through the pores of the mucus and form a thick and tight barrier.

The mucoadhesive polymer should be stable in the environment of the targeted mucosa, which may be in the range of low pH, e.g. of the stomach or of the abdominal cavity of women, to neutral or weakly alkaline pH in the cells. The mucoadhesive polymers are therefore stable in the pH range of 1-8. Depending on the pH environment, different types and sizes of polymers may be used. For example, DP8 chitosan is soluble at alkaline pH, whereas DP52 chitosan and DP100 are only soluble at pH < 6.

Diffusion of the polymer occurs when the mucoadhesive polymer and physiologically acceptable gelling agent adhere to mucus. Mucoadhesive polymers may be used in therapy because of their low degree of polymerization and degree of acetylation which provide good mucoadhesion. This allows the polymer to diffuse into the mucus and temporarily block the pores of the mucus. This occurs due to temporary cross-linking of the mucus, which is governed by the normal turnover time of the mucus and the biodegradability of the mucoadhesive polymer. Thus, the effective cross-linking time may be adjusted by subjecting the mucus to different mucoadhesive polymer concentrations, such as for example concentrations of 1 to 100mg/mL, such as 5 mg/mL.

Mucoadhesive polymers, due to their adhesive properties and small size, can penetrate mucus and diffuse to the mucus surface to form a thick layer. Small mucoadhesive polymers then complex with the mucus, thereby blocking the pores of the network, providing the mucus with enhanced barrier properties. When mucus is enhanced, it is impermeable to particles and prevents, for example, externally introduced liquids, particles, and cells, such as sperm, from passing through. The complex formed in the mucus can target cells of a certain size and is therefore impermeable to viral particles in the range of 20-30nm, mycoplasma in the range of 0.3 microns, bacteria in the range of 0.5 to 5 microns, or sperm in the range of 3 microns.

The composition of the invention comprising a mucoadhesive polymer and a pharmaceutically acceptable gelling agent is a contraceptive agent, since the treated mucus is temporarily impermeable to sperm. A contraceptive effect in connection with the present invention refers to a reversible and temporary pregnancy prevention due to a non-surgical, hormone-free and non-coherent barrier effect achieved by a single use, meaning that the contraceptive effect is achieved by one application and does not need to be produced in a certain concentration over a certain time as a pill.

The composition of the invention comprising a mucoadhesive polymer and a pharmaceutically acceptable gelling agent is a contraceptive agent, since the treated mucus is temporarily impermeable to sperm. A contraceptive effect in connection with the present invention refers to a reversible and temporary pregnancy prevention effect due to a stable non-surgical, hormone-free and non-coherent barrier effect achieved within minutes of contact of cervical mucus with the solution and within hours with or without further contraceptive action. This effect is achieved by a single use, which means that a contraceptive effect is achieved by one application without the need to maintain a certain concentration over a period of time.

The temporary effect indicates that the effect of the mucoadhesive polymer is reversible when applied to mucus. The rate at which reversion occurs depends on the amount of polymer diffusing into the mucus and the biological turnover time of the mucus itself.

in the context of the present invention, lesion (loss) refers to any impairment or undesirable change in tissue structure or composition. This may occur anywhere in the human or animal body, including soft tissue injuries, skin injuries, intestinal injuries and any injury to mucosal tissue, such as lung or other organs or intraabdominal tissue, such as, but not limited to, the cervix, vagina and/or uterus.

FIG. 1 is a schematic representation of mucin gel drops in chitosan solution and a frozen SEM image of the surface of chitosan DP8, DP52 and DP100 complexes.

Figure 2 shows quantification of the amount of chitosan involved in the complexation with purified mucin drops.

figure 3 shows the diffusion of fluorescently labeled dextran in the mucin droplet/chitosan complex. (D) Diffusion front travel speed of dextran 70 KDa.

FIG. 4 shows the toxicity of chitosan solution on HT29-MTX cells. Histology of HT29-MTX cultures cultured on porous membranes. (A) The 7-day-old culture showed a multilayer structure. (B) After 30 days of culture, these become polarized and covered with a layer of adherent mucus (blue staining). (C) Metabolic activity of HT29-MTX cells 7 days after exposure to various concentrations of chitosan solution. (D) Metabolic activity of mature HT29-MTX after exposure to 5mg/mL chitosan solution.

FIG. 5 shows the results of flow cytometry analysis of HT29-MTX cells exposed to fluorescently labeled dextran (column A) or cholera toxin subunit B (column B). The three conditions tested were HT29-MTX with a mucus layer for 30 days of growth (line I), HT29-MTX without a mucus layer and treated with chitosan for 7 days of growth (line II), and HT29-MTX with a mucus layer and treated with chitosan for 30 days of growth (line III).

FIG. 6 shows the results of quantification of the amount of chitosan involved in complexation with mucus layer-covered mature HT29-MTX cultures. Confocal images of chitosan-FITC deposition of HT29-MTX cell layer and top, and cross-sectional views of all three chitosans (B) DP8, (B') DP52 and (B ") DP 100.

Figure 7 shows the effect of low or high molecular weight mucoadhesive polymers on mucin gels. A4. mu.L droplet of purified porcine gastric mucin was placed in a solution of poly-L-arginine (PLA, DP11 corresponding to 1.9kDa, 5mg/mL), poly-L-lysine (PLL, DP11 corresponding to 1.6kDa, 5mg/mL) or poly-L-lysine (PLL, DP 400 corresponding to 66kDa, 5 mg/mL). Mucin droplets were observed under a microscope (10 × objective). Three images were taken after 3 minutes, 12 minutes, 30 minutes and 50 minutes of contact. Small polyamino acids are clearly deep cross-linked mucin, while large polyamino acid polymers alter the structure of mucin droplets and make them significantly dense or coalesce.

FIG. 8 shows a 4. mu.L drop of purified porcine gastric mucin complexed or uncomplexed using chitosan solution (DP8, 5mg/mL) in sperm solution. The image was recorded after 2 minutes. The complexed mucin does not allow sperm cells to penetrate the shell, while the uncomplexed mucin droplets allow sperm cells to penetrate the gel.

Fig. 9 shows the complexation of porcine gastric mucin gel (10mg/mL, pH 6) with high molar mass chitosan (550kDa, degree of deacetylation 98%) at 2.5mg/mL pH 5.5 and shows a macroscopic image of 4 μ L mucin gel dropped into the chitosan solution after 1 hour of complexation (drop size about 800 μm) and a confocal fluorescence image of the complex boundary of chitosan labeled with fluorescein. Larger chitosans are able to bind but are unable to penetrate the viscous droplets.

FIG. 10 shows the penetration of fluorescein-labeled chitosan oligomer (molar mass 1.4kDa, degree of deacetylation 89%) into ovulated human cervical mucus.

FIG. 11 shows the effect of adding oligochitosan (CO, molar mass 1.4kDa, degree of deacetylation 89%) dissolved in water at pH 5.5 on sperm penetration in human cervical mucus.

FIG. 12 shows chitosan oligomer pairs dissolved in water (H)₂O), Phosphate Buffered Saline (PBS) or sperm cells in Semen Buffer (SB) (2.5mg/mL, 1.4kDa molar mass, 89% deacetylation).