To evaluate the cytocompatibil ity of Arg-Gly-Asp-recombinant spider silk protein (pNSR16) / poly vinyl alcohol (PVA) through in vitro cytotoxicity experiment and cell-material co-culture experiment. Methods pNSR16/PVA scaffold and its extraction were prepared by using solvent casting/particulate leaching method, and NIH-3T3 cells were cultivated with the extraction in vitro. The cytotoxicity of scaffold was analyzed using MTT assay 1, 3 and 5 days after culture. Scanning electron microscope and HE staining observation were conducted 2, 4 and 6 days after culturing NIH-3T3 cells on the pNSR16/PVA scaffold. Immunohistochemistry detection was performed 6 days after co-culture. Adhesion, growthand expression of the cells on the scaffold were observed. Results The cytotoxicity of pNSR16/PVA scaffold was in grade 0. Scanning electron microscope observation: the cells covered the surface of the scaffold and were arranged in a directional manner 4 days after co-culture. HE staining: the cells adhered to and grew on the surface of scaffold, and migrated into the scaffold with the increase of culture duration. Immunohistochemistry detection: bFGF was secreted by NIH-3T3 cells, and the cells differentiated normally. Conclusion pNSR16/PVA scaffold has a satisfactory cytocompatibil ity and may be an ideal tissue engineered scaffold materia
Objective To develop three-dimensional (3D) porous nanofiber scaffold of PLGA-silk fibroincollagen and to investigate its cytocompatibil ity in vitro. Methods Method of electrostatic spinning was used to prepare 3D porous nanofiber scaffold of PLGA-silk fibroin-collagen (the experimental group) and 3D porous nanofiber scaffold of PLGA (the control group). The scaffold in each group was observed by scanning electron microscope (SEM). The parameters of scaffold fiber diameter, porosity, water absorption rate, and tensile strength were detected. SC harvested from the bilateral brachial plexus and sciatic nerve of 8 SD suckl ing rats of inbred strains were cultured. SC purity was detected by S-100 immunohistochemistry staining. The SCs at passage 4 (5 × 104 cells/mL) were treated with the scaffold extract of each group at a concentration of 25%, 50%, and 100%, respectively; the cells treated with DMEM served as blank control group. MTT method was used to detect absorbance (A) value 1, 3, 5, and 7 days after culture. The SC at passage 4 were seeded on the scaffold of the experimental and the control group, respectively. SEM observation was conducted 2, 4, and 6 days after co-culture, and laser scanning confocal microscope (LSCM) observation was performed 4 days after co-culture for the growth condition of SC on the scaffold. Results SEM observation: the scaffold in two groups had interconnected porous network structure; the fiber diameter in the experimental and the control group was (141 ± 9) nm and (205 ± 11) nm, respectively; the pores in the scaffold were interconnected; the porosity was 87.4% ± 1.1% and 85.3% ± 1.3%, respectively; the water absorption rate was 2 647% ± 172% and 2 593% ± 161%, respectively; the tensile strength was (0.32 ± 0.03) MPa and (0.28 ± 0.04) MPa, respectively. S-100 immunohistochemistry staining showed that the SC purity was 96.5% ± 1.3%. MTT detection: SC grew well in the different concentration groups and the control group, the absorbance (A) value increased over time, significant differences were noted among different time points in the same group (P lt; 0.05), and there was no significant difference between the different concentration groups and the blank control group at different time points (P gt; 0.05). SEM observation: in the experimental group, SC grew well on the scaffold, axon connection occurred 4 days after co-culture, the cells prol iferated massively and secreted matrix 6 days after co-culture, and the growth condition of the cells was better than the control group. The condition observed by LSCM 4 days after co-culture was the same as that of SEM. Conclusion The 3D porous nanofiber scaffoldof PLGA-silk fibroin-collagen prepared by the method of electrostatic spinning is safe, free of toxicity, and suitable for SC growth, and has good cytocompatibil ity and proper aperture and porosity. It is a potential scaffold carrier for tissue engineered nerve.