A composite hydrogel scaffold for articular disc regeneration and repair and its preparation method

Abstract

This invention discloses a composite hydrogel scaffold for articular disc regeneration and repair, and its preparation method. The composite hydrogel scaffold comprises a bacterial cellulose membrane and a casing surrounding the bacterial cellulose membrane. The casing is composed of a mixture of hydrogel and bone marrow mesenchymal stem cells. The preparation method of the composite hydrogel scaffold includes: preparing a bacterial cellulose membrane; preparing a hydrogel; mixing the prepared hydrogel with bone marrow mesenchymal stem cells to obtain the casing; placing a freeze-dried bacterial cellulose membrane inside the casing; and finally irradiating the casing with UV light to form the composite hydrogel scaffold. In this invention, the composite hydrogel, when placed at the perforation site of the articular disc, can reduce friction between the disc and condyle, lower stress at the perforation site, and slow down tissue degeneration. Furthermore, it can regenerate and repair damaged articular disc tissue through the hydrogel loaded with bone marrow mesenchymal stem cells.

Description

Technical Field

[0001] This invention relates to the field of biological and chemical materials technology, and in particular to a biological and chemical composite material scaffold for treating articular disc damage and its preparation method. Technical Background

[0002] Temporomandibular disc pathology is a precursor to a series of degenerative changes that can engulf the entire joint; these include disc displacement, thinning, and perforation. Disc perforation can lead to condylar resorption, exacerbating the degenerative changes throughout the joint and severely affecting the patient's oral functions, such as eating and speaking.

[0003] Currently, the mainstream treatment for articular disc perforation is conservative treatment (such as occlusal pads, intra-articular injections, and physical therapy). For severe cases, surgical treatments such as disc reduction and fixation, disc riveting, repair, and replacement are used. Because there is no effective treatment to restore the biological and mechanical function of the damaged articular disc, there is a gap in the treatment options between conservative techniques and surgery.

[0004] A 2019 study reported that scaffold-free implants obtained from cultured porcine chondrocytes were able to repair a relatively small 3 mm temporomandibular joint (TMJ) disc window, and the tensile fracture strength of the newly formed tissue reached 1.1 MPa at 8 weeks post-surgery. However, the mechanical strength of the regenerated tissue was insufficient, and the repair area was limited. Summary of the Invention

[0005] In view of this, the purpose of this invention is to provide a composite hydrogel scaffold for articular disc regeneration and repair and its preparation method, so as to solve the technical problem of the lack of biomaterials suitable for repairing large defects of the temporomandibular joint disc in the prior art.

[0006] The composite hydrogel scaffold for articular disc regeneration and repair of the present invention comprises a bacterial cellulose membrane and a wrapper surrounding the bacterial cellulose membrane, wherein the wrapper is composed of a mixture of hydrogel and bone marrow mesenchymal stem cells.

[0007] The method for preparing the composite hydrogel scaffold for articular disc regeneration and repair according to the present invention includes:

[0008] 1) Preparation of bacterial cellulose membranes:

[0009] xylitol was placed in a culture medium, and a thin film of bacterial cellulose was harvested on the surface of the culture medium. The bacterial cellulose film was then purified, and then washed, sterilized and freeze-dried in sequence.

[0010] 2) Preparation of hydrogel:

[0011] GelMA and HAMA were dissolved in PBS containing phenyllithium (2,4,6-trimethylbenzoyl) phosphate to prepare hydrogels.

[0012] 3) Mix the hydrogel obtained in step 2) with bone marrow mesenchymal stem cells to prepare a package, then transfer the package into a mold, then place the freeze-dried bacterial cellulose membrane from step 1) into the package, and finally irradiate the package with UV to form a composite hydrogel scaffold.

[0013] Furthermore, the culture medium in step 1) contains 0.5% peptone, 2 wt% glucose, 0.27 wt% disodium hydrogen phosphate, 0.5 wt% yeast extract and 0.115 wt% citric acid.

[0014] Furthermore, the purification of the bacterial cellulose membrane in step 1) includes: first purifying the bacterial cellulose membrane with 2wt% NaOH solution at 80℃ for 1h, and then purifying the bacterial cellulose membrane with 1wt% NaClO solution at 80℃ for 30min.

[0015] Furthermore, in step 2), the mass concentration of GelMA is 10%, and the degree of substitution of GelMA is 60K; the mass concentration of HAMA is 0.3%, and the degree of substitution of HAMA is 400K; the mass concentration of PBS containing phenyllithium (2,4,6-trimethylbenzoyl) phosphate is 0.3%.

[0016] Furthermore, the density of bone marrow mesenchymal stem cells in the package described in step 3) is 1*10⁻⁶. 7 per ml.

[0017] The beneficial effects of this invention are:

[0018] 1. The composite hydrogel used for regeneration and repair of temporomandibular joint disc perforation in this invention, when placed at the perforation site of the joint disc, can reduce friction between the disc and condyle, reduce stress at the perforation site and slow down tissue degeneration. Furthermore, it can also regenerate and repair damaged joint disc tissue through hydrogel loaded with bone marrow mesenchymal stem cells.

[0019] 2. The composite hydrogel used in this invention for the regeneration and repair of temporomandibular joint disc perforation is suitable for repairing large defects in the temporomandibular joint disc. Attached Figure Description

[0020] Figure 1 This is a photograph of a composite hydrogel scaffold. The figures are labeled: 1-bacterial cellulose membrane, 2-encapsulation material. Detailed Implementation

[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0022] Example 1: This example describes a composite hydrogel scaffold for articular disc regeneration and repair, which includes a bacterial cellulose membrane 1 and a wrapper 2 encapsulated outside the bacterial cellulose membrane. The wrapper is composed of a mixture of hydrogel and bone marrow mesenchymal stem cells.

[0023] Example 2: Preparation of the composite hydrogel scaffold for articular disc regeneration and repair described in Example 1, comprising:

[0024] 1) Preparation of bacterial cellulose membranes:

[0025] The xylitol bacteria are placed in a culture medium containing 0.5% peptone, 2 wt% glucose, 0.27 wt% disodium hydrogen phosphate, 0.5 wt% yeast extract, and 0.115 wt% citric acid. Of course, in practice, the components and their concentrations in the culture medium can be appropriately modified when preparing it; any culture medium that allows xylitol bacteria to reproduce well is suitable.

[0026] A thin film of bacterial cellulose is harvested from the surface of the culture medium. The bacterial cellulose membrane is then purified, followed by washing, sterilization, and freeze-drying. In this step, the purification of the bacterial cellulose membrane includes: first purifying the membrane with 2wt% NaOH solution at 80℃ for 1 hour, and then purifying it with 1wt% NaClO solution at 80℃ for 30 minutes. Of course, in practice, the materials used for purifying the bacterial cellulose membrane, the purification temperature, and the purification time can be changed as needed, as long as the purification of the bacterial cellulose membrane is achieved.

[0027] 2) Preparation of hydrogel:

[0028] Hydrogels were prepared by dissolving GelMA and HAMA in PBS containing phenyllithium (2,4,6-trimethylbenzoyl) phosphate.

[0029] The GelMA used in this step has a mass concentration of 10% and a degree of substitution of 60K; the HAMA has a mass concentration of 0.3% and a degree of substitution of 400K; and the PBS contains 0.3% lithium phenyl (2,4,6-trimethylbenzoyl) phosphate. Of course, in practice, the mass concentrations and degrees of substitution of GelMA and HAMA can be adjusted as needed, as long as the strength of the cured hydrogel meets the requirements.

[0030] 3) The hydrogel obtained in step 2) is mixed with bone marrow mesenchymal stem cells to prepare a capsule. The capsule is then transferred to a mold, and the freeze-dried bacterial cellulose membrane from step 1) is placed inside the capsule. Finally, the capsule is irradiated with UV light to form a composite hydrogel scaffold. The density of bone marrow mesenchymal stem cells in the capsule in this step is 1*10⁻⁶. 7The density of bone marrow mesenchymal stem cells in the package can be any other value in practice, as long as it can achieve a good effect in repairing damaged articular disc tissue in actual application.

[0031] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for preparing a composite hydrogel scaffold for temporomandibular joint disc regeneration and repair, characterized in that: include: 1) Preparation of bacterial cellulose membranes: Xylitol was added to the culture medium, and a thin film of bacterial cellulose was harvested on the surface of the culture medium. The bacterial cellulose membrane was then purified, and then washed, sterilized and freeze-dried in sequence. 2) Preparation of hydrogel: GelMA and HAMA were dissolved in PBS containing phenyllithium (2,4,6-trimethylbenzoyl) phosphate to prepare hydrogels; 3) Mix the hydrogel obtained in step 2) with bone marrow mesenchymal stem cells to prepare a package, then transfer the package into a mold, then place the freeze-dried bacterial cellulose membrane from step 1) into the package, and finally irradiate the package with UV to form a composite hydrogel scaffold. The culture medium in step 1) contains 0.5% peptone, 2 wt% glucose, 0.27 wt% disodium hydrogen phosphate, 0.5% wt% yeast extract and 0.115 wt% citric acid; The purification of bacterial cellulose membrane in step 1) includes: first purifying the bacterial cellulose membrane with 2 wt% NaOH solution at 80℃ for 1 h, and then purifying the bacterial cellulose membrane with 1 wt% NaClO solution at 80℃ for 30 min. The density of bone marrow mesenchymal stem cells in the package described in step 3) is 1*10⁻⁶. 7 per ml.

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