CN211271414U

CN211271414U - Bionic meniscus

Info

Publication number: CN211271414U
Application number: CN201921104380.8U
Authority: CN
Inventors: 敖英芳; 李宗�; 胡晓青; 孙沐阳
Original assignee: Peking University Third Hospital Peking University Third Clinical Medical College
Current assignee: Peking University Third Hospital Peking University Third Clinical Medical College
Priority date: 2019-07-15
Filing date: 2019-07-15
Publication date: 2020-08-18
Anticipated expiration: 2029-07-15

Abstract

The utility model relates to a bionic meniscus, which comprises a polycaprolactone porous bracket used for supporting the bionic meniscus; the fibroin shell layer is coated outside the polycaprolactone porous semi-stent and is used for contacting with a biological tissue body; the fibroin connecting parts are arranged in the pores of the polycaprolactone porous scaffold, and the fibroin connecting parts are adapted to the shapes of the pores. The PCL which is a high polymer material can be biologically degraded in a human body, has good printability and mechanical properties, can provide enough mechanical strength in meniscus tissue engineering, is low in degradation speed, can continuously maintain certain mechanical strength in a tissue replacement process, and protects the mechanical balance of a cartilage surface and a knee joint; as a natural biological material, the fibroin has the advantages of low immunity, excellent biocompatibility, rich sources and the like and good mechanical properties. The bionic meniscus made of PCL and fibroin can be used for repairing a plurality of tissues.

Description

Bionic meniscus

Technical Field

The utility model belongs to the technical field of biomedical materials, especially indicate a bionical meniscus.

Background

In tissue engineering, suitable scaffold materials play a very important role in tissue engineering. Commonly used scaffold materials for repairing menisci are mainly divided into natural and artificially synthesized materials, the natural materials mainly comprise collagen, hyaluronic acid, fibroin, small intestine mucosa, decalcified bone and the like, and the artificially synthesized materials mainly comprise high molecular materials such as Polycaprolactone (PCL), Polyurethane (PU), Polylactic acid (PLA) and the like, and hydrogels such as chitosan, alginate, agarose and the like.

The high molecular synthetic polymer material has sufficient source, strong plasticity and mechanical property which is relatively close to meniscus tissue, and has wide application. Koch et al used a PU scaffold with composite MSCs to repair rabbit 7mm wide lateral meniscal defects with some new tissue ingrowth at 12 weeks. And the PCL scaffold with the composite MSCs is used for repairing the defect of the rabbit medial meniscus, and the regenerated meniscus tissue at 24 weeks is good, so that good biomechanics can be maintained. At present, PCL is taken as a main polymer synthetic material in the field of meniscus tissue engineering, and the PCL has good biological activity, mechanical property and material processing property. The development of electrospinning and 3D printing techniques also makes polymer materials have new breakthrough in the field of tissue engineering, and all parameters and biomechanical strength are closer to those of natural meniscal tissues, so that at present, how to improve the ingrowth of cells on these polymer material scaffolds and how to ensure good and continuous mechanical strength in the process of replacing new tissues still needs to be paid attention.

The natural material has good biocompatibility and certain bioactive components, so the natural material often has a good promotion effect on proliferation and differentiation of cells and secretion of extracellular matrix, but the forming process and the porosity of the natural material are difficult to completely meet the requirements, the components often only comprise one or more of natural menisci, and the mechanical strength of the stent is reduced to some extent. Costa and the like use 3D printing to simulate a human meniscus-shaped fibroin scaffold, have certain mechanical strength, and better in vitro cell activity, but do not perform in vivo experiments. Yuan et al adopt a mixed scaffold of meniscus acellular matrix and bovine decalcified bone to repair the entire medial meniscus of rabbits, with the composition of the nascent tissue very close to that of the natural meniscus tissue at 6 months. Plum and the like use autologous semitendinosus muscle to reconstruct the rabbit medial meniscus, and a good effect is obtained. How to improve the mechanical properties of these natural materials is a problem to be considered further.

However, at present, no report on a bionic meniscus with PCL as a lining and fibroin as a shell exists.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a compound polycaprolactone silk protein's bionical meniscus has good mechanical properties and better ground biocompatibility, can be applied to meniscus tissue engineering's restoration.

The utility model discloses a realize through following technical scheme:

a bionic meniscus comprises a polycaprolactone porous scaffold for supporting the bionic meniscus;

the fibroin shell layer is coated outside the polycaprolactone porous semi-stent and is used for contacting with a biological tissue body;

the hole of the polycaprolactone porous support is internally provided with a fibroin connecting part, and the fibroin connecting part is adapted to the shape of the hole.

The sum of the thickness of the upper shell and the thickness of the lower shell of the fibroin shell layer is less than the thickness of the polycaprolactone porous scaffold.

The pore diameters of the pores of the polycaprolactone porous scaffold are different.

The pores of the polycaprolactone porous scaffold are irregular in shape.

The inner surface of the fibroin shell layer and the outer surface of the polycaprolactone porous scaffold are both non-smooth surfaces.

The polycaprolactone porous semi-scaffold is characterized in that a structural model of a meniscus is prepared by adopting SolidWork software, and the structural model is led into a 3D printer to prepare the polycaprolactone porous scaffold with a half-moon-shaped bionic structure.

The structural model is based on the anterior angle data of the meniscus of the original organism, the body data of the meniscus, the inner edge thickness of the meniscus posterior angle, the outer edge thickness of the meniscus posterior angle and the distance between the inner edge and the outer edge of the meniscus posterior angle.

The utility model has the advantages that:

(1) PCL is a polymeric material approved by FDA and biodegradable in human body, so it is suitable for being used as raw material of biological scaffold. Due to good printability and mechanical properties, the meniscal tissue engineering plastic can provide enough mechanical strength in meniscal tissue engineering, is slow in degradation speed, can continuously maintain certain mechanical strength in the tissue replacement process, and protects the mechanical balance of the articular cartilage surface and the knee joint.

(2) The fibroin which is a natural biological material not only has the advantages of low immunity, good biocompatibility, rich sources and the like, but also has good mechanical properties which are not possessed by most natural biological materials; fibroin biomaterials are currently FDA approved for use in certain medical products, including sutures and surgical meshes, and can be processed into a variety of materials. The research shows that the good mechanical strength of the fibroin is endowed by a large number of beta sheet secondary structures which are arranged regularly and have strong interaction. Therefore, the PCL is used as the inner liner and the fibroin is used as the outer shell to manufacture the mixed 3D scaffold, so that the PCL-fibroin composite scaffold has a great application prospect and can be used for repairing a plurality of tissues.

Drawings

FIG. 1 is a schematic view from left to right of a single fibroin biomimetic meniscus, a single PCL biomimetic meniscus and a PCL/SF composite biomimetic meniscus under a corresponding electron microscope;

FIG. 2 is a schematic partial transverse cross-sectional view of FIG. 1, taken in cross-section generally parallel to the overall shape of the biomimetic meniscus;

FIG. 3 is a schematic longitudinal cross-sectional view of FIG. 1, taken in a vertical cross-section;

FIG. 4 shows tensile moduli of a simple fibroin biomimetic meniscus, a simple PCL biomimetic meniscus, and a PCL/SF composite biomimetic meniscus, respectively;

FIG. 5 shows the compression moduli of a simple fibroin biomimetic meniscus, a simple PCL biomimetic meniscus, and a PCL/SF composite biomimetic meniscus, respectively;

fig. 6 is an interfacial shear force test of polycaprolactone and fibroin, and fibroin can effectively reduce friction between the scaffold and the cartilage surface, which is very important for cartilage protection.

Description of the reference numerals

1 fibroin shell layer, 2 polycaprolactone porous support, 3 pores and 4 fibroin connecting parts.

Detailed Description

The technical solutions of the present invention are described in detail below by way of examples, which are only exemplary and can be used only for explaining and explaining the technical solutions of the present invention, but should not be construed as limiting the technical solutions of the present invention.

As shown in fig. 1 to 3, the present application provides a biomimetic meniscus comprising a polycaprolactone porous scaffold 2 for support of the biomimetic meniscus.

The fibroin shell layer 1 is coated outside the polycaprolactone porous bracket 2 and is used for contacting with a biological tissue body;

and fibroin connecting parts 4 are arranged in the pores 3 of the polycaprolactone porous scaffold, and the fibroin connecting parts are adapted to the shapes of the pores. The pore sizes of the pores of the polycaprolactone porous scaffold are not the same. The pores of the polycaprolactone porous scaffold are irregular in shape, so that the surface area for cell adhesion can be greatly increased.

The sum of the thickness of the upper shell and the thickness of the lower shell of the fibroin shell layer is less than the thickness of the polycaprolactone porous scaffold. The inner surface of the fibroin shell layer and the outer surface of the polycaprolactone porous support are both non-smooth surfaces, so that the stability of the combination of the polycaprolactone porous support and the fibroin shell layer is improved.

The application provides a 3D printing manufacturing method of a bionic meniscus of composite polycaprolactone/fibroin, wherein the molecular weight of Polycaprolactone (PCL) is 80000, and fibroin is self-made.

3D printing related apparatus and printing conditions:

a printer: 3D Bioplotter (envisionTEC, Germany)

Needle diameter: 300 um; melting temperature: 130 ℃; air pressure: 8.0 bar.

1. Fibroin solution extraction

(1) 2L of ultrapure water was added to a large beaker, boiled and weighed to 4.24g of Na₂CO3₃Slowly pouring the mixture into the container;

(2) pouring 10g of cut silkworm cocoons into boiling water, soaking for 30min and fully stirring to completely dissolve sericin in the silkworm cocoons in an alkaline solution;

(3) taking out the cotton-shaped residual substances (fibroin) after 30min, cooling with ultrapure water, extruding out excessive water, putting into a big beaker, adding 1L of ultrapure water, stirring for 30min, extruding out water, and repeating the above operation for 2-3 times;

(4) taking out the fibroin, spreading on an aluminum foil, and airing in a ventilated place overnight;

(5) according to the fibroin: lithium bromide (LiBr) ═ 1: weighing LiBr with corresponding mass according to the weight ratio of 4, preparing 9.3M LiBr aqueous solution by using water, and pouring the prepared LiBr aqueous solution onto the fibroin to ensure that the fibroin is completely covered by the solution;

(6) heating the mixed solution to 60 ℃, and keeping for 4 hours until the fibroin is completely dissolved and is transparent amber;

(7) subsequently, the above solution was dialyzed with ultrapure water for 3 days, and the dialyzed solution was centrifuged at a low temperature for 20min (4 ℃, 9000rpm), the first supernatant was removed and centrifuged again, and then the second supernatant, i.e., the fibroin solution, was stored in a refrigerator at 4 ℃ in a sealed state.

2. Preparation of polycaprolactone pore scaffold

According to the method, the anterior angle, the body part, the thickness of the inner edge and the outer edge of the posterior angle and the distance between the inner edge and the outer edge of the posterior angle are measured by the rabbit inner side meniscus for the test, a unified structural model of the meniscus is prepared by adopting SolidWork software, the structural model is led into a 3D printer, and the PCL pore support with the half-moon-shaped bionic structure is prepared.

3. Preparation of biomimetic meniscus

Casting the prepared fibroin solution on a polycaprolactone pore scaffold, pre-freezing at-20 ℃ overnight, and freeze-drying in a vacuum drier at-20 ℃ for later use.

Characterization and identification of biomimetic menisci, as shown in fig. 4-6:

(a) and (3) detection by a scanning electron microscope: the surface of the stent was examined using Hitachi S-4800.

(b) And (3) mechanical property detection: the tensile and compressive moduli of the holder were measured using an Shimadzu AG-IS type electronic universal material tester.

Under an electron microscope, the composite bionic meniscus can effectively generate a complex structure of big holes and small holes, and the surface area of cell adhesion is greatly improved. The application of the 3D printing technology can well solve the problems of the bionic property and the porosity of the meniscus.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. A bionic meniscus is characterized by comprising a polycaprolactone porous scaffold for supporting the bionic meniscus;

2. The biomimetic meniscus of claim 1, wherein the sum of the thickness of the superior shell and the thickness of the inferior shell of the fibroin shell is less than the thickness of the polycaprolactone porous scaffold.

3. The biomimetic meniscus of claim 1, wherein the pores of the polycaprolactone porous scaffold are not the same pore size.

4. The biomimetic meniscus of claim 1, wherein the pores of the polycaprolactone porous scaffold are irregularly shaped.

5. The biomimetic meniscus of claim 1, wherein both the inner surface of the fibroin shell and the outer surface of the polycaprolactone porous scaffold are non-smooth surfaces.

6. The biomimetic meniscus according to claim 1, wherein the polycaprolactone porous scaffold is prepared by preparing a structural model of the meniscus using SolidWork software and introducing the structural model into a 3D printer to prepare a polycaprolactone porous scaffold of a biomimetic structure in a meniscus shape.

7. The biomimetic meniscus of claim 6, wherein the structural model is derived from anterior angle data for the meniscus for the primitive organism, body data for the meniscus, inner edge thickness of the meniscus posterior angle, outer edge thickness of the meniscus posterior angle, and distance between the inner and outer edges of the meniscus posterior angle.