摘要
目的 探讨不同浓度还原氧化石墨烯（rGO）对羧甲基壳聚糖（CMC）支架孔径的调控作用，分析孔径变化与MC3T3-E1细胞增殖之间的关系。方法 采用溶液共混结合冷冻干燥技术，制备rGO质量分数分别为0%、0.5%、1%和2%的CMC-rGO复合支架。通过扫描电镜观察支架微观形貌及孔径分布，使用ImageJ软件测量平均孔径。将MC3T3-E1成骨前体细胞与各组支架共培养，采用CCK-8法检测培养第1、3、5、7天的细胞增殖活性。结果 扫描电镜显示，纯CMC支架孔径小于70μm，结构呈不规则卷曲；0.5%和1% rGO使支架孔径增大至70-120μm，孔壁光滑规整；2% rGO则导致孔径显著减小、结构趋于致密化。CCK-8结果显示，0.5% rGO组细胞活性在各时间点均显著高于纯CMC组（P<0.05），1% rGO组与纯CMC组无显著差异，2% rGO组持续低于纯CMC组（P<0.05）。结论 rGO对CMC支架孔径的调控呈非线性特征，0.5%-1% rGO可形成70-120μm的适宜孔径范围，该结构有利于细胞增殖。0.5%组因孔径分布更为均匀，综合效果最优。本研究为羧甲基壳聚糖基骨修复材料的孔径设计提供了实验依据。
关键词： 羧甲基壳聚糖；还原氧化石墨烯；孔径；细胞增殖
Abstract
Objective To investigate the regulatory effect of different concentrations of reduced graphene oxide (rGO) on the pore size of carboxymethyl chitosan (CMC) scaffolds and to analyze the relationship between pore size changes and MC3T3-E1 cell proliferation. Methods CMC-rGO composite scaffolds with rGO mass fractions of 0%, 0.5%, 1%, and 2% were prepared by solution blending combined with freeze-drying technology. The microstructure and pore size distribution of the scaffolds were observed by scanning electron microscopy, and the average pore size was measured using ImageJ software. MC3T3-E1 osteoblast precursor cells were co-cultured with the scaffolds, and cell proliferation activity was detected by Cell Counting Kit-8 (CCK-8) assay on days 1, 3, 5, and 7. Results Scanning electron microscopy showed that the pure CMC scaffold had a pore size of less than 70 μm with an irregular curled structure. Addition of 0.5% and 1% rGO increased the pore size to 70-120 μm with smooth and regular pore walls, while 2% rGO led to a significant reduction in pore size and structural densification. CCK-8 results showed that cell viability in the 0.5% rGO group was significantly higher than that in the pure CMC group at all time points (P<0.05), the 1% rGO group showed no significant difference compared with the pure CMC group, and the 2% rGO group was consistently lower than the pure CMC group (P<0.05). Conclusion rGO exhibits a nonlinear regulatory effect on the pore size of CMC scaffolds. The 0.5%-1% rGO concentration range forms a favorable pore size range of 70-120 μm, which facilitates cell proliferation. The 0.5% group exhibits more uniform pore size distribution and achieves the best overall effect. This study provides experimental evidence for the pore size design of carboxymethyl chitosan-based bone repair materials.
Key words： Carboxymethyl chitosan; Reduced graphene oxide; Pore size; Cell proliferation
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