牙髓组织再生中I型胶原支架最佳浓度的体外研究

目的：探讨牙髓组织再生研究中不同浓度的I型胶原支架对牙髓细胞的分布及数量的影响,确定最佳胶原材料的浓度。方法实验组将10μl移液枪头一端封闭,做为人工根管；对照组为两端开放的10μl移液枪头。体外培养转染绿色荧光蛋白的C57BL/6小鼠牙髓细胞,并将其分别接种于1%,2%和3%的I型胶原支架中,注入10μl的实验组和对照组移液枪头内,于6孔板中培养2周。荧光显微镜下观察牙髓细胞的分布,胰蛋白酶消化后计算各浓度中牙髓细胞的数目。结果对照组各浓度的胶原支架内牙髓细胞均生长良好。实验组1%和2%的I型胶原中的牙髓细胞生长良好,且细胞计数无显著性差异（ P〉0.05）；浓度为3%的胶原中牙髓细胞在人工根管的中、上段少有生长,且与1%和2%的胶原支架中的牙髓细胞数目差异有统计学意义（P〈0.01）。结论 I型胶原支架材料浓度从1%提高到2%,可减少材料的收缩,并能保证细胞生长良好,2%的I型胶原浓度是牙髓组织再生中最佳浓度。

In vitro optimization of collagen I concentration for pulp regeneration

Objective To investigate the optimal concentration of collagen I for the proliferation and distribution of dental pulp cells in pulp regeneration. Methods The 10μl pipette tips were capped to structurally mimic artificial root canals. The bland sterile 10μl pipette tips were used as the control group. GFP positive dental pulp cells were obtained from GFP C57BL/6 mouse. Predetermined amount of GPF positive dental pulp cells were mixed with 1%, 2% and 3% collagen I, respectively. The collagen I gel encapsulated with dental pulp cells were then injected into the artificial root canals and cultured for 2 weeks in 6 wells. The distribution and proliferation of dental pulp cells were observed under fluorescent microscope and the cell amount was also counted. Results The proliferation and distribution had no significant difference in the control group. In artificial root canals, there was no significant difference between 1% and 2% collagen I. However, when the concentration of collagen I increased to 3%, there was only a small fraction of cells survived in the artificial root canals. Conclusion 2% collagen I is the optimal concentration for pulp regeneration.