以壳聚糖和明胶为复合生物墨水3D打印的脊髓仿生支架及其生物相容性研究

Study on the biocompatibility of spinal cord high biomimetic scaffold 3D printed with chitosan and gelatin composite bioink

目的:探究3D打印脊髓仿生支架的复合生物墨水配方及生物相容性和可靠性评估。方法:利用3D打印技术,以壳聚糖(chitosan,C)和明胶(gelatin,G)为基础复合生物墨水,比较不同配比复合生物墨水的理化性能:孔隙率、溶胀率、流变性能、降解速率、力学性能分析。通过优化打印参数,打印出特定空间构型的脊髓外形仿生支架。接着运用仿生支架材料浸提液与SH-SY5Y细胞共培养方法,通过扫描电子显微镜和CCK-8实验评估该支架材料的细胞毒性及其对细胞增殖能力的影响。结果:通过比较最终选择4%浓度的C和6%浓度G(4C6G)组为最适的复合生物墨水配方并进行后续的研究。在打印速度1.5 mm/s、压强0.09~0.11 MPa、层厚0.1 mm、间距1 mm、针头0.11 mm的参数下,可以实现打印出5 mm×5 mm×0.9 mm尺寸的蝴蝶形状高保真度的脊髓仿生支架。扫描电子显微镜可见SH-SY5Y细胞黏附在支架内部,并且能正常生长;CCK-8结果显示,浸提液无细胞毒性。结论:以C和G为复合生物墨水有望成为脊髓损伤修复仿生支架的原材料。

Objective:To explore the formulation and biocompatibility and reliability evaluation of composite bioink for 3D printed spinal cord bionic stent.Methods:Chitosan(C)and gelatin(G)were used as composite bioink by 3D printing technology.The physicochemical properties of composite bioinks with different ratios were compared,including porosity,swelling rate,rheological properties,degradation rate and mechanical properties.By optimizing the printing parameters,the spinal cord shape bionic stent with specific spatial configuration was printed.Then,the bionic scaffold extract was co-cultured with SH-SY5Y cells,and the cytotoxicity of the scaffold and its effect on cell proliferation were evaluated by scanning electron microscopy and CCK-8 assay.Results:By comparing the final selection of 4%concentration of C and 6%concentration of G(4C6G)group as the most suitable compound bioink formulation,and the follow-up study was carried out.Under the parameters of printing speed of 1.5 mm/s,pressure of 0.09-0.11 MPa,layer thickness of 0.1 mm,spacing of 1 mm and needle of 0.11 mm,the butterfly shape high-fidelity spinal cord bionic scaffold of 5 mm×5 mm×0.9 mm can be printed.Scanning electron microscopy showed that SH-SY5Y cells adhered to the interior of the scaffold and could grow normally.CCK-8 results showed that the extract had no cytotoxicity.Conclusion:C and G bioink is expected to be the raw material of bionic stent for spinal cord injury repair.