新型壳聚糖-胶原支架与牙周膜细胞的生物相容性

背景：目前胶原作为牙周组织工程支架材料仍具有机械强度差、降解速度快等缺点，将其与壳聚糖复合可改善上述问题。 目的：评估新型壳聚糖-胶原支架材料的体外生物相容性。 方法：通过MTT法评估100%，75%，50%，25%壳聚糖-胶原支架材料浸提液对人牙周膜细胞的毒性。选择第4-6代生长状态良好的人牙周膜细胞与壳聚糖-胶原支架共培养，观察细胞在支架上的生长情况，并检测与壳聚糖-胶原支架复合培养前后人牙周膜细胞碱性磷酸酶活性的变化。 结果与结论：新型壳聚糖-胶原支架具有双层结构，一侧表面致密，一侧表面疏松多孔。MTT法检测不同浓度材料浸提液毒性评级为0或1级。扫描电子显微镜及组织学观察可见细胞在壳聚糖-胶原支架上增殖良好，且致密层可起屏障膜作用，阻挡细胞进入支架内部；复合培养24 h后，人牙周膜细胞的碱性磷酸酶活性与复合培养前无明显差异(P > 0.05)，复合培养48，72 h后人牙周膜细胞的碱性磷酸酶活性高于复合培养前(P < 0.05)。以上结果提示新型壳聚糖-胶原支架具有良好的生物相容性及屏障功能，可进一步应用于牙周组织工程的研究。

Biocompatibility of a novel chitosan-collagen scaffold and periodontal ligament cells

BACKGROUND: At present, collagen as a material in periodontal tissue engineering has some disadvantages such as poor mechanical strength and rapid degradation speed. Collagen combined with chitosan can improve above-mentioned problems. OBJECTIVE: To evaluate the biocompatibility of a novel chitosan-collagen scaffold in vitro. METHODS: Cytotoxicity of the extract of chitosan-collagen scaffold in different concentrations (100%, 75%, 50%, 25%) was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Human periodontal ligament cells at 4-6 passages were cocultured with the chitosan-collagen scaffold. Cell growth on the scaffold was observed. Changes in alkaline phosphatase activity were detected in periodontal ligament cells before and after coculture. RESULTS AND CONCLUSION:The novel chitosan-collagen scaffold was made up of double layers with one dense layer and another loose layer. The grade of the cytotoxicity of the scaffold was from 0 to 1. Scanning electron microscope and histological observation demonstrated that cells grew well on the chitosan-collagen scaffold; the dense layer could prevent cells to migrate into the scaffold. There were no significant differences in alkaline phosphatase activity in human periodontal ligament cells before and 24 hours after combined culture (P > 0.05). Alkaline phosphatase activity in human periodontal ligament cells was greatly higher at 48 and 72 hours after combined culture compared with that before culture (P < 0.05). Above results indicated that the novel chitosan-collagen scaffold has a good biocompatibility and barrier function, and potential as a scaffold for periodontal tissue engineering.