Preparation Of Silver Nanoparticles Gelatin/Alginate Scaffold And Experimental Study Of Repairing Skull Defect

Objective: To investigate the effects of different content of AgNPs on the physicochemical and biological properties of Gel / Alg scaffolds and the osteogenic properties of AgNPs-Gel / Alg scaffolds in bone defects of rabbit skull.Methods: 1.Gelatin / Alginate(Gel / Alg)scaffolds with different concentrations of silver nanoparticles(AgNPs)were prepared by vacuum freeze-drying method,which were 0 μM,200 μM,400 μM and 600 μM respectively.2.Scanning electron microscopy(SEM)was used to observe the scaffold structure and measure its pore size,and the water absorption and porosity of scaffold materials were measured by weighing method and medium soaking method respectively.3.CCK-8 method was used to measure the proliferation rate of cells on scaffolds.4.Establish a rabbit skull defect model,and detect the osteogenic effect of AgNPs in the scaffold material by postoperative imaging and histological analysis.Results: The pore size and porosity of scaffolds with different concentrations of AgNPs were higher than those of the control group(Gel / Alg)(P < 0.05),and with the increase of AgNPs concentration,the pore size and porosity of scaffolds increased accordingly.The water absorption of three kinds of AgNPs-Gel / Alg scaffolds was higher than that of the control group(Gel / Alg),the difference was statistically significant(P < 0.05),and the water absorption of 400 μM AgNPs-Gel / Alg scaffolds was higher than that of200 μM AgNPs-Gel / Alg scaffolds(P < 0.05).At the same time point,the degradation rate of three AgNPs-Gel / Alg scaffolds was significantly higher than that of the control group(P < 0.05),and the degradation rate of 400 μM AgNPs-Gel / Alg scaffolds was significantly higher than that of 200 μM AgNPs-Gel / Alg scaffolds(P < 0.05).On the3 rd,5th and 7th day,the proliferation activity of MC3T3-E1 in 200 μM AgNPs-Gel / Alg scaffolds was significantly higher than that in the control group(Gel / Alg)(P < 0.05).At4 w and 8 w,Micro-CT quantitative analysis showed that the amount of new bone around the scaffold in the group with AgNPs was higher than that in the control group(Gel /Alg),and the amount of new bone around 200 μM AgNPs-Gel / Alg scaffold was significantly higher than that of other groups(P < 0.05);at 4 w,Masson staining showedthat there were a lot of collagen fibers around the scaffold in the group with AgNPs,but less in the control group(Gel / Alg).With the increase of time,there were more and more cord-like collagen fibers around the scaffold in the group with AgNPs.Conclusion: 1.AgNPs-Gel / Alg scaffolds have good biocompatibility.2.AgNPs has an effect on the physical and chemical properties of Gel / Alg scaffolds,200 μM AgNPs-Gel / Alg scaffold is more suitable for bone tissue engineering.3.AgNPs-Gel/Alg scaffold can promote the repair of rabbit skull defect,which further proves osteogenic effect that AgNPs has in vivo.