阅读说明：本技术 一种phbv提高plla的形状记忆和促成骨效应的方法 (Method for improving shape memory and promoting bone effect of PLLA (PLLA) by PHBV (polyhydroxybutyrate valerate) ) 是由 张彦中 王先流 易兵成 沈炎冰 唐寒 于 2019-11-26 设计创作，主要内容包括：本发明涉及一种PHBV提高PLLA的形状记忆和促成骨效应的方法。该方法通过在左旋聚乳酸PLLA纤维中引入β-羟基丁酸与戊酸酯共聚物PHBV。该方法操作简单,成本低,能有效提高PLLA形状记忆效率和成骨促进作用,为推动和增强PLLA基骨组织工程产品的应用转化与临床功效提供了可能,具有较好的市场应用前景。(The invention relates to a method for improving the shape memory and the bone effect of PLLA by PHBV, which introduces β -hydroxybutyric acid and valerate copolymer PHBV into levorotatory polylactic acid PLLA fiber.)

1. A method for increasing the shape memory of PLLA and promoting bone effect by PHBV features that the copolymer PHBV of β -hydroxy butyric acid and valerate is introduced to the PLLA fibre.

2. The method of claim 1, wherein the PHBV is introduced in the PLLA fiber by electrospinning.

3. The method of claim 2, wherein PLLA-PHBV is dissolved in a solvent to obtain a spinning solution, and then electrospun to obtain PLLA-PHBV ultrafine fibers.

4. The method according to claim 3, wherein the mass ratio of PLLA to PHBV is 9: 1-5: 5; the concentration of PLLA and PHBV in the spinning solution is 8-15% w/v.

5. The method of claim 3, wherein the solvent comprises a mixture of DMF and TCM or/and HFIP.

6. The method according to claim 3, wherein the electrospinning process parameters are: the injection rate is 0.1-3 mL/h, the voltage is 1-20kV, the receiving distance is 0.02-0.2 m, the ambient temperature is 20-60 ℃, and the ambient relative humidity is 20-80%.

7. The method of claim 3, wherein the PLLA-PHBV microfine fiber has a diameter of 500 to 3000 nm.

8. The method of claim 3, wherein the PLLA-PHBV microfine fiber is used for developing and producing bone tissue engineering products.

Technical Field

The invention belongs to the field of preparation of functionalized biomedical fibers, and particularly relates to a method for improving the shape memory and bone effect of PLLA (polylactic acid) by PHBV (polyhydroxybutyrate valerate).

Background

Levorotatory polylactic acid (PLLA), because of its good biocompatibility, workable, high strength and high modulus characteristics, has been widely used in the preparation of bone tissue engineering scaffold, as the tissue substitute of engineering repairs the damaged tissue. In addition, PLLA is a shape memory material and is used in the preparation of vascular stents (Stent). Although PLLA has good biocompatibility, bioabsorbability and shape memory characteristics, its shape transition temperature is high (about 60 ℃ C.), it is not suitable for recovery at body temperature, and the shape recovery efficiency of pure L-PLA (e.g., shape fixation rate R)_fAnd shape recovery ratio R_r) Lower, also poor osteogenic effect without biologically active sites, etc. are common problems that need to be improved by suitable methods.

In general, other monomers are copolymerized with PLLA, such as polyglycolic acid (PGA), polyethylene oxide (PEO), polyethylene glycol (PEG), trimethylene carbonate (TMC) and other polymers, to obtain the shape memory polymer material, so as to realize the glass transition temperature (T) of the polymer material_g) Adjustable (namely the shape deformation temperature interval is adjustable) and the degradation speed is adjustable. However, the improved way of copolymerization of soft and hard segments produces copolymers with low mechanical strength. In addition, inorganic nanoparticles such as hydroxyapatite (HAp), ferroferric oxide (Fe) are used₃O₄) When the material is blended into PLLA material, the shape memory efficiency, the mechanical strength and the biological activity of PLLA can also be improved. However, this approach greatly increases the glass transition temperature of the PLLA, which increases the temperature at which the shape memory effect is activated. Therefore, how to reduce T of PLLA_gThe problem to be solved is that the shape memory performance is improved without reducing the mechanical performance of the material.

β -PHBV is a biodegradable polymer material prepared from starch by fermentation engineering technique, which can be digested by bacteria and decomposed into carbon dioxide, water and biomass under the condition of soil or compost, and is also called green plastic_gLow, the T of PLLA system can be effectively reduced by compounding PLLA with PHBV_g. In addition, PLLA-PHBV is also called as 'bio-alloy' (bio-alloy), and has excellent mechanical property, so that the T of PLLA can be effectively reduced by compounding PLLA and PHBV_gAnd the mechanical property, shape memory efficiency and osteogenesis activity of the PLLA are improved, and the method has important significance for improving the bone regeneration application of PLLA-based tissue engineering products.

Disclosure of Invention

The invention aims to solve the technical problem of providing a method for improving the shape memory of PLLA and promoting the bone effect by PHBV, so as to overcome the defect that the shape memory effect and the bone formation effect of PLLA are poor in the prior art.

The invention provides a method for improving the shape memory of PLLA and promoting bone effect by PHBV, which introduces β -hydroxybutyric acid and valerate copolymer PHBV into levorotatory polylactic acid PLLA fiber.

PHBV was introduced in PLLA fibers by electrospinning.

Dissolving PLLA and PHBV in a solvent to obtain a spinning solution, and then electrospinning to obtain the PLLA-PHBV superfine fiber.

The mass ratio of the PLLA to the PHBV is 9: 1-5: 5.

The concentration of PLLA and PHBV in the spinning solution is 8-15% w/v.

The solvent is not limited, and preferably, the solvent comprises a mixture of DMF and TCM or/and HFIP.

The technical parameters of the electrospinning are not limited, and preferably, the technical parameters of the electrospinning are as follows: the injection rate is 0.1-3 mL/h, the voltage is 1-20kV, the receiving distance is 0.02-0.2 m, the ambient temperature is 20-60 ℃, and the ambient relative humidity is 20-80%.

The diameter of the PLLA-PHBV superfine fiber is 500nm to 3000 nm.

The shape transition temperature range of the PLLA-PHBV superfine fiber is 40-60 ℃.

Shape fixation rate (R) of the PLLA-PHBV superfine fiber_f) And shape recovery ratio (R)_r)≥99％。

The PLLA-PHBV superfine fiber is used for developing and producing bone tissue engineering products.

Aiming at the problem that the shape memory effect and the osteogenesis effect of PLLA are poor, the invention provides a method for preparing brand-new T by combining the advantages of PLLA and PHBV and using an electrospinning technology and a one-step method_gThe superfine fiber film with reduced content, enhanced mechanical property, improved shape memory efficiency and excellent osteogenic property can imitate the nano-micron fiber structure of natural extracellular matrix and provide ideal microenvironment for cell growth, proliferation and osteogenic differentiation.

Advantageous effects

(1) The invention combines the advantages of the bionic technology and the Shape Memory Polymers (SMPs) to prepare the shape memory fiber scaffold with the imitated natural extracellular matrix, which can provide an ideal microenvironment for the growth, proliferation and differentiation of cells;

(2) when the shape memory superfine fiber film is applied to bone tissue engineering, the minimally invasive implantation of the bracket (the temporary shape and the permanent shape are reasonably preset to ensure that the bracket is easy to implant and then returns to the permanent shape under the action of body temperature or an external heat source), the biodegradation, the osteogenesis activity and other capabilities can be realized, the biomechanical stimulation can be continuously provided, and the problem of stress shielding is solved;

(3) the invention can rapidly, massively and efficiently prepare the PLLA-PHBV shape memory material with the fiber structure by a one-step method, has simple process and high efficiency, and can effectively reduce the T of the PLLA_gThe brittleness of the PLLA is reduced, the shape memory efficiency and the osteogenesis performance of the PLLA are improved, the possibility is provided for promoting and enhancing the application transformation and clinical efficacy of PLLA-based bone tissue engineering products, and the PLLA-based bone tissue engineering products have good market application prospects.

Drawings

FIG. 1 is a scanning electron micrograph of a PLLA-PHBV (9:1) shape memory material having a fibrous structure according to example 1;

FIG. 2 is a scanning electron micrograph of a PLLA-PHBV (8:2) shape memory material having a fibrous structure according to example 2;

FIG. 3 is a scanning electron micrograph of a PLLA-PHBV (7:3) shape memory material having a fibrous structure according to example 3;

FIG. 4 is a scanning electron micrograph of a PLLA-PHBV (6:4) shape memory material having a fibrous structure of example 4;

FIG. 5 is a summary of the shape transition temperatures of the PLLA-PHBV shape memory materials having a fibrous structure of examples 1-4;

FIG. 6 is the shape memory test results for the PLLA-PHBV (9:1) shape memory material with fiber architecture of example 1;

FIG. 7 is the shape memory test results for the PLLA-PHBV (8:2) shape memory material with fiber architecture of example 2;

FIG. 8 is the shape memory test results for the PLLA-PHBV (7:3) shape memory material with fiber architecture of example 3;

FIG. 9 is the shape memory test result of the PLLA-PHBV (6:4) shape memory material with fiber structure of example 4;

FIG. 10 is a graph of the staining of the alkaline phosphatase (ALP) after 14 days of the mesenchymal stem cells (BMSCs) of bone marrow on the PLLA-PHBV (7:3) shape memory material with fibrous structure of example 3;

FIG. 11 is a graph of Alizarin Red (ARS) staining 14 days after bone marrow mesenchymal stem cells (BMSCs) on PLLA-PHBV (7:3) shape memory material with fibrous structure in example 3.

Detailed Description

The invention will be further illustrated with reference to the following specific examples. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Further, it should be understood that various changes or modifications of the present invention may be made by those skilled in the art after reading the teaching of the present invention, and such equivalents may fall within the scope of the present invention as defined in the appended claims.