Bionic hybrid nano-composite scaffold as well as preparation method and application thereof

Abstract

The invention relates to the technical field of biological scaffolds, in particular to a bionic hybrid nano-composite scaffold as well as a preparation method and application thereof. The bionic hybrid nano-composite scaffold provided by the invention has excellent biological activity, antibacterial property and bone repair performance, infection is resisted by combining the potential of antibiotic-free antibacterial nanoparticles (Sr-doped bioactive glass and SrBG) with a microRNA-138 inhibitor, strontium and microRNA-138 can form a synergistic interaction effect, the biological activity and antibacterial property are enhanced, and the biomimetic hybrid nano-composite scaffold has a good application prospect. Meanwhile, osteogenesis and angiogenesis are stimulated based on a gene therapy of microRNA; in addition, the prepared PMMA bone cement not only increases the specific surface area of the bioactive glass, but also enables the PMMA to be more dispersed through crosslinking of the PMMA and the gelatin, so that the action range of active substances is increased, synergistic interaction is formed, and the overall biological activity is further improved.

Description

Technical Field

[0001] The present invention relates to the technical field of biological scaffolds, and particularly to a bionic hybrid nano-composite scaffold, a preparation method thereof, and an application thereof. Background Art

[0002] During the bone regeneration process, bone graft materials may play the following roles according to their characteristics, including: osteogenesis (new bone is produced by living osteoblasts), osteoinduction (the differentiation and generation of osteoblasts are guided), and osteoconduction (bone grows along the material). In recent years, in the research of bone injury repair (especially critical-sized bone defect repair), the construction of biomaterials that simultaneously have good mechanical properties and can simulate osteoconduction and osteoinductive behaviors has received increasing attention. The bionic performance of materials and meeting clinical use scenarios are crucial for the selection of biomaterials for bone substitutes. Combining biomaterials with other biological factors to simulate the natural bone microenvironment and improve the performance of scaffolds, and promoting the integration of bone substitutes into the host system is an important research direction. For example, the combination of bone and bioactive glass and glass ceramics was first published in 1971; the combination of soft connective tissue and 45S5 bioactive glass was discovered in 1981; toxicology and biocompatibility studies (in vitro and in vivo) were published in 1981 to determine the safety of bioactive glass products; the osteostimulatory effect of using bioactive glass particles in bone regeneration was discovered in 1987; In 2000, the FDA approved the use of Grafton for general orthopedic bone grafting in non-weight-bearing areas; in 2004, the FDA approved 45S5 particles for the treatment of dentin hypersensitivity (theophylline).

[0003] The development of new technologies in bone tissue engineering requires the production of macroporous scaffolds with bioactivity and biodegradability. Among many existing bone substitute materials, hydroxyapatite (HA) ceramics are useful bone substitutes, but their degradation degree is the lowest. Tricalcium phosphate is also an alternative bone substitute material, however, it shows poor Ca-P formation ability in vitro and in vivo, although they are biodegradable.

[0004] Bioactive glass has been widely concerned due to its unique advantages. It is usually composed of calcium-containing silicate, and calcium silicate (CaSiO3) was first used for the study of in vitro and in vivo bioactivity. Compared with calcium phosphate, calcium silicate not only has good biocompatibility and biodegradability, but also the gradually released silicon ions and calcium ions accelerate the bone regeneration rate by activating signal pathways related to bone mineralization, bone remodeling, and angiogenesis.

[0005] However, not all types of bioactive glasses are suitable as bone substitute materials. For example, mesoporous bioactive glass (MBG) has excellent bioactivity, biocompatibility, and osteoconductivity and plays an important role in bone tissue regeneration. However, it is difficult to prepare MBG scaffolds with high compressive strength for bone regeneration applications, which greatly hinders its development and use. Although creating glass scaffolds with lower overall porosity or smaller pore sizes can significantly increase compressive strength, it may reduce their suitability for bone regeneration within the scaffolds.

[0006] ‌Based on its excellent bioactivity and degradability, 45S5 bioactive glass is expected to be the preferred bioactive glass material for producing macroporous scaffolds that meet the new development needs of bone tissue engineering. However, it is difficult to prepare porous bioactive glass templates (scaffolds) based on bioactive glass 45S5 for bone regeneration. If the melting method is used for preparation, the melting method often results in the formation of low-purity products due to chemical inhomogeneous substances and some contaminants, which may be caused by the primary crystallization process accompanied by precipitation or the presence of unreacted solid chemical substances. Specifically, bioactive glass 45S5 crystallizes during the sintering process; moreover, the finally formed bioactive glass powder has limited porosity and a low specific surface area. If the template method is used for preparation, although the template method is used to grow tubular channels in the material, which can increase the porosity of the obtained scaffold and enhance the interstitial network, the higher porosity will reduce the compressive strength. If the sol-gel method is used for preparation, which is a preparation method catalyzed by acid / alkali, acid / alkali catalytic synthesis is conducive to rapid hydrolysis reactions using strong inorganic acids as catalysts, while alkali catalysis promotes crosslinking and the formation of complex polymer structures, but it is difficult to obtain micro-nano scale bioactive glasses with controllable morphology and uniform particle size. Thus, there are great difficulties in the process of preparing porous bioactive glass scaffolds based on bioactive glass 45S5 for bone regeneration.

[0007] Moreover, to meet the new development needs of bone tissue engineering technologies, bio-scaffolds are also required to have excellent bioactivity, antibacterial properties, and bone repair performance. In recent years, related research on regulating the degradation rate of biomaterials, improving their bioactivity and osteogenic ability through surface functional coating modification, micro-nano structure or porous structure optimization, functional element / small molecule doping, and blend compounding has attracted wide attention. However, there is no clear guidance on how to specifically prepare bio-scaffolds with excellent bioactivity, antibacterial properties, and bone repair performance. Summary of the Invention

[0008] In view of this, the technical problem to be solved by the present invention is to provide a biomimetic hybrid nano-composite scaffold, its preparation method, and application. The biomimetic hybrid nano-composite scaffold provided by the present invention has excellent bioactivity, antibacterial properties, and bone repair performance.

[0009] The present invention provides a bionic hybrid nano-composite scaffold, which is prepared from gelatin, microRNA-138 inhibitor, strontium-doped 45S5 bioactive glass and polymethyl methacrylate (PMMA).

[0010] In the present invention, the strontium-doped 45S5 bioactive glass and PMMA together serve as bone cement components, and the mass ratio of the total mass of the two to the mass of the gelatin and the microRNA-138 inhibitor is 2:2:(0.8-1.2); and the mass ratio of the strontium-doped 45S5 bioactive glass to PMMA is (0.3-0.5):(0.5-0.7). In the strontium-doped 45S5 bioactive glass of the present invention, the doping amount of strontium is (1-5) wt%.

[0011] The strontium-doped 45S5 bioactive glass of the present invention is prepared from tetraethyl orthosilicate, triethyl phosphate, nitric acid, water, calcium nitrate, sodium nitrate and strontium nitrate; the surface of the strontium-doped 45S5 bioactive glass is further coated with hydroxyapatite, forming a core-shell structure with the strontium-doped 45S5 bioactive glass as the core.

[0012] In the bionic hybrid nano-composite scaffold provided by the present invention, on the one hand, the strontium-doped 45S5 bioactive glass and hydroxyapatite form a core-shell structure, and then are made into bone cement with PMMA, increasing the specific surface area of the bioactive glass; on the other hand, strontium in the strontium-doped 45S5 bioactive glass synergizes with microRNA-138, strengthening the bioactivity and antibacterial property and reducing the infection risk at the filling site. In addition, the bone cement crosslinks with gelatin, making PMMA more dispersed, thereby increasing the action range of the active substance, forming a synergistic effect, and further improving the overall bioactivity.

[0013] The present invention also provides a preparation method of the bionic hybrid nano-composite scaffold according to any one of the above technical solutions, including the following steps: mixing gelatin, microRNA-138 inhibitor, strontium-doped 45S5 bioactive glass and PMMA for molding, then performing freeze-drying, and then crosslinking in a crosslinking agent to obtain the bionic hybrid nano-composite scaffold.

[0014] Specifically, in the present invention, strontium-doped 45S5 bioactive glass and PMMA are first compounded to obtain bone cement; then the bone cement is mixed and molded in an aqueous solution of microRNA-138 inhibitor and gelatin and left overnight at (0 to 4) °C to gel to obtain the molded material, and then the molded material is freeze-dried, and finally the freeze-dried material is soaked in a cross-linking agent solution for cross-linking to obtain a biomimetic hybrid nanocomposite scaffold. The freeze-drying in the present invention specifically is: first freezing at (-30 to -10) °C for (46 to 50) h, then freezing at (-90 to -70) °C for (22 to 26) h, and finally freeze-drying at (-60 to -40) °C for (46 to 50) h. The temperature of the cross-linking in the present invention is room temperature, specifically (20 to 30) °C, preferably 25 °C; the time of the cross-linking is (22 to 26) h. The cross-linking agent in the present invention is selected from at least one of glutaraldehyde, genipin, anthocyanin, and hexamethylene diisocyanate. The dosages of the gelatin, microRNA-138 inhibitor, strontium-doped 45S5 bioactive glass, and PMMA in the present invention are the same as above and will not be elaborated. The biomimetic hybrid nanocomposite scaffold obtained in the present invention is the same as the foregoing and will not be elaborated.

[0015] The strontium-doped 45S5 bioactive glass of the present invention is prepared in the same manner as described above, and specifically obtained by the following steps: hydrolyzing 45S5 bioactive glass, tetraethyl orthosilicate, nitric acid and water, then carrying out polycondensation on the obtained materials and triethyl phosphate, and then mixing the obtained materials with calcium nitrate, sodium nitrate and strontium nitrate for static aging to obtain strontium-doped 45S5 bioactive glass. Specifically, in the present invention, 45S5 bioactive glass and tetraethyl orthosilicate are successively added to an aqueous nitric acid solution for hydrolysis, then triethyl phosphate is added to the obtained materials for polycondensation, and then calcium nitrate, sodium nitrate and strontium nitrate are respectively added thereto at intervals of (18-22) min for mixing, and then static aging is carried out to obtain strontium-doped 45S5 bioactive glass. Based on 10 g of 45S5 bioactive glass, the dosage ratios of tetraethyl orthosilicate, nitric acid and water in the present invention are (14-18) mL: (1-2) mL: (15-25) mL, the dosage of triethyl phosphate is (0.1-1) mL, and the dosage ratios of calcium nitrate, sodium nitrate and strontium nitrate are (8-12) g: (5-7) g: (0.4-2.5) g. The hydrolysis temperature in the present invention is (20-30) °C, and the hydrolysis time is (50-70) min; the polycondensation temperature is (20-30) °C, and the polycondensation time is (20-30) min; the static aging time is (90-100) h. After the static aging in the present invention, drying is further included, and the drying is specifically: first drying at (65-75) °C for (22-26) h, and then drying at (110-130) °C for (46-50) h.

[0016] The present invention also provides the application of the bionic hybrid nanocomposite scaffold described in any of the above technical solutions or the bionic hybrid nanocomposite scaffold obtained by the preparation method described in any of the above technical solutions as a hard tissue repair material, soft tissue repair material, vascular stent or artificial joint prosthesis.

[0017] The present invention provides a bionic hybrid nanocomposite scaffold and its preparation method and application. The present invention uses the freeze-drying method to prepare a novel hybrid nanocomposite based on gelatin / microRNA-138 inhibitor / Sr-doped 45S5 bioactive glass nanoparticles crosslinked with PMMA. By utilizing the potential of antibiotic-free antibacterial nanoparticles (Sr-doped bioactive glass, SrBG) in combination with microRNA-138 inhibitor to combat infection, strontium and microRNA-138 can form a synergistic effect, enhancing bioactivity and antibacterial properties. At the same time, microRNA-based gene therapy stimulates osteogenesis and angiogenesis. In addition, it is made into PMMA bone cement, which not only increases the specific surface area of bioactive glass, but also the crosslinking of PMMA and gelatin makes PMMA more dispersed, thereby increasing the scope of action of active substances and forming a synergistic effect, further improving the overall bioactivity.

[0018] Experiments show that the present invention combines microRNA-138 inhibitor and strontium with composite bioactive glass to form a bionic hybrid nanocomposite scaffold with good anti-infection performance and bioactivity. Specifically, the addition of strontium element and microRNA inhibitor plays a synergistic role. 45S5 bioactive glass and hydroxyapatite form a core-shell structure and are prepared into PMMA cement dispersed in gelatin. The three processes form a synergistic effect, enhancing relevant properties. After adding strontium and microRNA inhibitor to modify and functionalize the surface of polymethyl methacrylate PMMA bioactive glass, the number of living cells increased by 2 times after 48 hours, and the synergy of microRNA-138 inhibitor in the composite scaffold is significantly better than that of other similar inhibitors. Brief Description of the Drawings

[0019] Figure 1 Bioactivity test diagram of microspheres obtained with 0 g of strontium nitrate added;

[0020] Figure 2 Bioactivity test diagram of microspheres obtained with 0.46 g of strontium nitrate added;

[0021] Figure 3 Bioactivity test diagram of microspheres obtained with 1.38 g of strontium nitrate added;

[0022] Figure 4 Bioactivity test diagram of microspheres obtained with 2.31 g of strontium nitrate added;

[0023] Figure 5 Bioactivity diagram of the bionic nanocomposite scaffold obtained in Comparative Example 1 of the present invention;

[0024] Figure 6This is the bioactivity diagram of the bionic nano-composite scaffold obtained in Comparative Example 2 of the present invention. Detailed implementation mode

[0025] The present invention discloses a bionic hybrid nano-composite scaffold, a preparation method thereof, and an application thereof. Those skilled in the art can draw on the content of this article and appropriately improve the process parameters to achieve it. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art, and they are all regarded as included in the present invention. The method and application of the present invention have been described through preferred embodiments, and those related can obviously make changes or appropriate alterations and combinations to the methods and applications in this article without departing from the content, spirit, and scope of the present invention to implement and apply the technology of the present invention.

[0026] The present invention studied the properties of bioactive glass and scaffolds through the following methods:

[0027] (1) The bioactivity of bioactive glass in simulated body fluid (SBF) was studied by Fourier transform infrared spectroscopy (FTIR) of the samples before and after soaking.

[0028] (2) The antibacterial properties of the composite bioactive glass and the bionic hybrid nano-composite scaffold were studied.

[0029] (3) The effects of the composite bioactive glass scaffold on proliferation, osteogenic differentiation, and angiogenesis potential were studied, specifically in vitro osteogenic activity and in vitro angiogenesis activity detection.

[0030] Among them, for the in vitro osteogenic activity detection reference: Bone marrow mesenchymal stem cells (BMSCs) were seeded on the bottom of a 24-well plate, and 5 mg of the scaffold sample was embedded in the upper part of the Transwell system. Both the cells and the scaffold were soaked in osteogenic induction medium (50 μg / mL ascorbic acid, 10 nM dexamethasone, and 10 mM β-glycerophosphate), and the medium was changed every other day. After 7 days of culture, the expression of osteogenic genes, including Runt-related transcription factor 2 (RUNX2), osteocalcin (OCN), ALP, and Osterix, was quantitatively evaluated. Cell lysis and total RNA extraction were performed using TRIzol reagent (Invitrogen, USA). Subsequently, the extracted RNA was reverse transcribed into complementary DNA (cDNA) using a commercial kit (Takara, Japan) and RT-PCR quantitative analysis was carried out. The specific primer sequences used are listed in detail in Table 1.

[0031] Table 1

[0032]

[0033] In vitro angiogenesis activity detection reference: Measured by the scratch test. Bone marrow mesenchymal stem cells (BMSCs) were cultured in the lower chamber of the transwell system, and the scaffold was placed in the upper chamber for subsequent detection. After cell confluence, a 200 μL pipette tip was used to make a uniform scratch to evaluate the migration of BMSCs. Subsequently, images were collected after 24 hours using Image J software for quantitative evaluation.

[0034] The present invention will be further elaborated below in conjunction with embodiments:

[0035] Example 1

[0036] Preparation of a novel hybrid nanocomposite based on gelatin / microRNA-138 inhibitor / Sr-doped 45S5 bioactive glass nanoparticles:

[0037] (1) Preparation of bioactive glass-hydroxyapatite (SrBG&HA) microspheres with different strontium doping amounts:

[0038] ① Preparation of microspheres obtained with 0 g of strontium nitrate added:

[0039] Step 1: Bioactive glass (BG) particles were synthesized by the sol-gel method. Using the synthesized bioactive glass for further experiments, specifically, first 0.5 mL of nitric acid (HNO3, 65%) was added to 19.5 mL of distilled water (H2O) and stirred for 10 min. Then, 10 g of the above-synthesized bioactive glass, 16.7 mL of tetraethyl orthosilicate (TEOS, Si(OC2H5)4) were successively added to the acidic solution, and acid hydrolysis was carried out by stirring at 25 °C for one hour. 1.5 mL of triethyl phosphate (TEP, (C2H5)3PO4) was added, and polycondensation was continued by stirring at 25 °C for 25 min.

[0040] Step 2: Then, at time intervals of 20 min for each component, 10.5 g of calcium nitrate (Ca(NO3)2) and 6.72 g of sodium nitrate (NaNO3) were added respectively. Then the whole material was stirred for 1 hour and stored at room temperature for 96 hours. After 96 h, the obtained gel was first placed in an oven at 70 °C for 24 h, and then kept at 120 °C for 48 h to obtain microspheres with strontium-doped bioactive glass (SrBG) as the core and hydroxyapatite (HA) as the shell. The strontium doping amount in the finally obtained microspheres was 0 wt%.

[0041] ② Preparation of microspheres obtained with 0.46 g of strontium nitrate added:

[0042] Prepare according to the method of ①, and the difference from ① is only that: in step 2, 10.5 g of calcium nitrate (Ca(NO3)2), 6.45 g of sodium nitrate (NaNO3), and 0.46 g of strontium nitrate (Sr(NO3)2) are added respectively. The strontium doping amount in the finally obtained microspheres is 1 wt%.

[0043] ③ Preparation of microspheres obtained by adding 1.38 g of strontium nitrate:

[0044] Prepare according to the method of ①, and the difference from ① is only that: in step 2, 10.5 g of calcium nitrate (Ca(NO3)2), 5.9 g of sodium nitrate (NaNO3), and 1.38 g of strontium nitrate (Sr(NO3)2) are added respectively. The strontium doping amount in the finally obtained microspheres is 3 wt%.

[0045] ④ Preparation of microspheres obtained by adding 2.31 g of strontium nitrate:

[0046] Prepare according to the method of ①, and the difference from ① is only that: in step 2, 10.5 g of calcium nitrate (Ca(NO3)2), 5.35 g of sodium nitrate (NaNO3), and 2.31 g of strontium nitrate (Sr(NO3)2) are added respectively. The strontium doping amount in the finally obtained microspheres is 5 wt%.

[0047] Culture the above-obtained microspheres with different strontium doping amounts in SBF solution to test their bioactivity and antibacterial properties. Among them, sample 0 represents the microspheres obtained by adding 0 g of strontium nitrate, sample 1 represents the microspheres obtained by adding 0.46 g of strontium nitrate, sample 2 represents the microspheres obtained by adding 1.38 g of strontium nitrate, and sample 3 represents the microspheres obtained by adding 2.31 g of strontium nitrate. The bioactivity of each obtained microsphere is as Figures 1 to 4 shown, Figure 1 is the bioactivity test chart of the microspheres obtained by adding 0 g of strontium nitrate, Figure 2 is the bioactivity test chart of the microspheres obtained by adding 0.46 g of strontium nitrate, Figure 3 is the bioactivity test chart of the microspheres obtained by adding 1.38 g of strontium nitrate, Figure 4 is the bioactivity test chart of the microspheres obtained by adding 2.31 g of strontium nitrate; the antibacterial properties of each obtained microsphere are shown in Table 2;

[0048] Table 2

[0049]

[0050] (2) Preparation of PMMA cement containing SrBG&HA:

[0051] Prepare SrBG&HA microspheres with 1.38 g of strontium nitrate added by the method in (1).

[0052] The microspheres were mixed with PMMA for compounding to prepare PMMA cement doped with 40 wt% SrBG&HA microspheres.

[0053] (3)Preparation of bionic hybrid nanocomposite scaffolds:

[0054] Scaffolds were prepared by the freeze-drying method. An aqueous gelatin solution was prepared at 25 °C. The microRNA inhibitor was added to the gelatin solution at a ratio of PMMA cement doped with 40 wt% SrBG&HA microspheres: gelatin: microRNA-138 inhibitor of 2:2:1 by mass, and stirred for 10 min. Then the PMMA cement doped with 40 wt% SrBG&HA microspheres obtained in (2) was added to the gelatin solution and stirred for 1.5 h. After that, the mixture was molded and gelled overnight at 2 °C. The molded material was first frozen at -20 °C for 48 h, and then transferred to -80 °C for continued freezing for 24 h. Subsequently, the nanocomposite was freeze-dried in a freeze-dryer at -50 °C for 48 h to obtain a porous nanocomposite. Then the sample was immersed in an ethanol solution of 0.5% glutaraldehyde (% volume / volume) for 24 h for crosslinking to obtain a bionic hybrid nanocomposite scaffold.

[0055] Test the bioactivity, antibacterial property, sustained-release duration, in vitro osteogenic activity and in vitro angiogenesis activity of the bionic hybrid nanocomposite scaffold. Among them, the bioactivity can be referred to Figure 3 (Since the only difference between the scaffold and the microspheres is the dispersion method, the bioactivity spectra are the same), the sustained-release duration (the duration for slowly releasing the active ingredient) is 22 d, and the antibacterial property, in vitro osteogenic activity and in vitro angiogenesis activity are shown in Table 3.

[0056] Table 3

[0057]

[0058] Comparative Example 1

[0059] PMMA cement containing SrBG&HA was prepared according to the same method as in Example 1 to obtain PMMA cement doped with 40 wt% SrBG&HA microspheres.

[0060] The scaffolds were prepared by freeze-drying method. An aqueous gelatin solution was prepared at 25 °C. The PMMA cement doped with 40 wt% SrBG&HA microspheres was added to the gelatin solution and stirred for 1.5 h. Then the mixture was molded and gelled overnight at 2 °C. The molded material was first frozen at -20 °C for 48 h and then transferred to -80 °C for continued freezing for 24 h to obtain the nanocomposite. Subsequently, the nanocomposite was freeze-dried in a freeze-dryer at -50 °C for 48 h to obtain the porous nanocomposite. Then the sample was immersed in an ethanol solution of 0.5% glutaraldehyde (% volume / volume) for 24 h for crosslinking to obtain the biomimetic nanocomposite scaffold.

[0061] The bioactivity, antibacterial property, slow-release duration, in vitro osteogenic activity and in vitro angiogenesis activity were tested. Among them, the bioactivity is as Figure 5 shown, Figure 5 which is the bioactivity diagram of the biomimetic nanocomposite scaffold obtained in Comparative Example 1 of the present invention; the slow-release duration (the duration for slowly releasing the active ingredient) is 22 d, and the antibacterial property, in vitro osteogenic activity and in vitro angiogenesis activity are shown in Table 4.

[0062] Table 4

[0063]

[0064] Comparative Example 2

[0065] The PMMA cement containing SrBG&HA was prepared by the same method as in Example 1 to obtain the PMMA cement doped with 40 wt% SrBG&HA microspheres.

[0066] The scaffolds were prepared by freeze-drying method. An aqueous gelatin solution was prepared at 25 °C. The microRNA inhibitor was added to the gelatin solution at a ratio of gelatin:microRNA-145 inhibitor of 2:1 (wt% / wt%) and stirred for 10 min. Then the PMMA cement doped with 40 wt% SrBG&HA microspheres was added to the gelatin solution and stirred for 1.5 h. Then the mixture was molded and gelled overnight at 2 °C. The molded material was first frozen at -20 °C for 48 h and then transferred to -80 °C for continued freezing for 24 h to obtain the nanocomposite. Subsequently, the nanocomposite was freeze-dried in a freeze-dryer at -50 °C for 48 h to obtain the porous nanocomposite. Then the sample was immersed in an ethanol solution of 0.5% glutaraldehyde (% volume / volume) for 24 h for crosslinking to obtain the biomimetic hybrid nanocomposite scaffold.

[0067] The bioactivity, antibacterial property, slow-release duration, in vitro osteogenic activity and in vitro angiogenesis activity were tested. Among them, the bioactivity is as Figure 6 shown, Figure 6Biological activity diagram of the bionic nanocomposite scaffold obtained in Comparative Example 2 of the present invention. The sustained release duration (the duration for slowly releasing the active ingredient) is 22 days, and the antibacterial property, in vitro osteogenic activity and in vitro angiogenesis activity are shown in Table 5.

[0068] Table 5

[0069]

[0070] Characterization of the synthesized bioactive glass found that doping 3 wt% of strontium Sr into the structure of 45S5 bioactive glass prepared by the sol-gel method optimized its biocompatibility and antibacterial properties. In addition, it was observed that it had antibacterial properties against both Gram-positive and Gram-negative bacteria. It can be seen that the combined use of bioactive glass and microRNA-138 inhibitor can improve cell activity and cell adhesion.

[0071] The above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, making equivalent replacements or changes should be covered within the protection scope of the present invention.

Claims

1. A bionic hybrid nanocomposite scaffold, characterized in that, It is prepared from gelatin, microRNA-138 inhibitor, strontium-doped 45S5 bioactive glass and PMMA.

2. The bionic hybrid nanocomposite scaffold according to claim 1, wherein The mass ratio of the total mass of the strontium-doped 45S5 bioactive glass and PMMA to the mass of the gelatin and the microRNA-138 inhibitor is 2:2:(0.8~1.2); The mass ratio of the strontium-doped 45S5 bioactive glass to PMMA is (0.3~0.5):(0.5~0.7).

3. The bionic hybrid nanocomposite scaffold according to claim 1, characterized in that, The doping amount of strontium in the strontium-doped 45S5 bioactive glass is (1~5) wt%.

4. The bionic hybrid nanocomposite scaffold according to claim 1, characterized in that, The surface of the strontium-doped 45S5 bioactive glass is coated with hydroxyapatite.

5. A preparation method of a bionic hybrid nanocomposite scaffold, characterized in that, It includes the following steps: Gelatin, microRNA-138 inhibitor, strontium-doped 45S5 bioactive glass and PMMA are mixed and molded, then freeze-dried, and then cross-linked in a cross-linking agent to obtain a biomimetic hybrid nanocomposite scaffold.

6. The preparation method according to claim 5, characterized in that, The mass ratio of the total mass of the strontium-doped 45S5 bioactive glass and PMMA to the mass of the gelatin and the microRNA-138 inhibitor is 2:2:(0.8~1.2); The mass ratio of the strontium-doped 45S5 bioactive glass to PMMA is (0.3~0.5):(0.5~0.7).

7. The preparation method according to claim 5, characterized in that, The doping amount of strontium in the strontium-doped 45S5 bioactive glass is (1~5) wt%.

8. The preparation method according to claim 5, wherein The strontium-doped 45S5 bioactive glass is prepared by the following steps: 45S5 bioactive glass, tetraethyl orthosilicate, nitric acid and water are hydrolyzed, then the obtained materials and triethyl phosphate are polycondensed, and then the obtained materials are mixed with calcium nitrate, sodium nitrate and strontium nitrate and left to stand for aging to obtain strontium-doped 45S5 bioactive glass.

9. The preparation method according to claim 8, characterized in that, The temperature of the hydrolysis is (20~30) °C, and the time of the hydrolysis is (50~70) min; The temperature of the polycondensation is (20~30) °C, and the time of the polycondensation is (20~30) min; The time of the standing aging is (90~100) h.

10. Application of the biomimetic hybrid nanocomposite scaffold according to any one of claims 1 to 4 or the biomimetic hybrid nanocomposite scaffold obtained by the preparation method according to any one of claims 5 to 9 as a hard tissue repair material, soft tissue repair material, vascular stent or artificial joint prosthesis.

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