Preparation Of Copper Sulfide/Graphene Oxide/Chitosan/Nano-Hydroxyapatite Composite Scaffolds And Study Of Osteogenic Antibacterial Properties

Purpose:Aiming at the synergic problem of antibacterial and bone repair in infected bone defects,the feasibility analysis of the synergic photothermal antibacterial and promoting bone repair of chitosan(CS)/nano-hydroxyapatite(nHA)bone scaffolds with composite copper sulfide(CuS)/graphene oxide(GO)nanosheets was discussed.Method:1.CuS/GO NSs were synthesized from GO and CuS nanosheets by hydrothermal method,and then CS/nHA and CGCHs scaffolds were synthesized after the composite of CS and nHA substrate materials.CuS/GO NSs were detected and characterized by transmission electron microscopy(TEM),X-ray diffraction(XRD)and Fourier transform infrared spectroscopy(FTIR),and the microstructure and composition of scaffold materials were observed and analyzed by scanning electron microscopy(SEM).The absorption peak of CuS/GO NSs and the temperature rise and cooling curves under infrared spectrum were measured to calculate the photothermal conversion rate and detect the photothermal performance of CGCHs scaffolds.2.The biocompatibility and blood compatibility of scaffold materials were evaluated by CCK-8 method,staining of live/dead cells,hemolysis test,and cell adhesion test.The angiogenesis of scaffolds was evaluated by cell migration and tube formation experiments.Alkaline phosphatase(ALP)activity and alizarin red staining were used to evaluate the effect of materials on osteoblast differentiation.Cell immunofluorescence staining and RT-qPCR were used to detect the effect of materials on the expression of osteogenic genes.3.Skull defect model of SD rats was used to evaluate the osteogenic properties of the scaffolds in vivo.The antibacterial effect of the scaffolds combined with photoheat was evaluated by constructing infectious bone defects in the tibia of SD rats.Results:1.CuS/GO composite nanosheets were synthesized successfully,and CGCHs nanocomposite scaffolds were synthesized using CS/nHA as the substrate.The results of transmission electron microscopy showed that CuS nanosheets were evenly dispersed on the surface of GO nanosheets,the XRD pattern indicated that the characteristic peaks of CuS/GO were basically coincident with the positions of standardized samples,and FTIR spectra showed that the functional groups of CuS/GO and GO were basically similar.CuS/GO nanosheets have excellent photothermal conversion performance in near-infrared light(808 nm,1 W/cm2),and the composite CGCHs scaffold materials also continue to have strong photothermal performance.Sem results showed that all scaffolds had good porosity and swelling capacity.2.CS/nHA and CGCHs scaffolds(200 ug/mL)have good biocompatibility and blood compatibility;Canalization experiments showed that CGCHs scaffolds could promote cell migration and canalization.A series of in vitro osteogenic experiments showed that both CS/nHA and CGCHs scaffolds had a certain ability to promote osteogenesis.In vitro antibacterial experiments showed that CS/nHA and CGCHs scaffolds had certain antibacterial ability.The antibacterial effect of CGCHs was stronger,and the antibacterial activity of CS/NHA and CGCHS scaffolds could be enhanced by combined photothermal treatment.3.The skull defect experiment of SD rats showed that,compared with the blank control group,both CS/nHA and CGCHs scaffolds had the ability to promote bone repair,among which CGCHs had the strongest ability.The experimental results of infective tibial defects in SD rats showed that both CS/nHA and CGCHs scaffolds had certain antibacterial activity in vivo,and the antibacterial activity of CGCHs combined with photoheat was particularly prominent.Conclusion:CS/nHA scaffolds with CuS/GO nanosheets have ideal biocompatibility under certain concentration,and have the ability to promote angiogenesis and osteogenic differentiation in vivo and in vitro,as well as the synergistic antibacterial performance of combined photothermal.In particular,CGCHs antibacterial bone scaffolds with excellent photothermal anti-infection and osteogenic functions are expected to provide new strategies and new ideas for the clinical treatment of infectious bone defects.