交联剂浓度对Pluronic F-127/羧甲基壳聚糖/ZnO水凝胶降解行为的调控及体内外评价

Regulation of Crosslinker Concentration on the Degradation Behavior of Pluronic F-127/Carboxymethyl Chitosan/ZnO Hydrogel and Its Evaluation in Vivo and in Vitro

  • 摘要: 为精准调控可注射温敏水凝胶的降解速率以匹配组织再生进程,本研究以戊二醛为交联剂,制备了0.5wt.%至2.0wt.%四个浓度梯度的Pluronic F-127/羧甲基壳聚糖/ZnO温敏水凝胶,系统考察交联剂浓度对凝胶性能及体内外降解行为的影响。结果表明,随交联剂浓度升高,凝胶化时间从120 s缩短至60 s,平衡溶胀率从55.16%降至23.85%,降解半衰期从4.40天延长至9.31天。皮下植入实验显示体内外降解趋势高度一致。该水凝胶对金黄色葡萄球菌和大肠杆菌的抑菌率均大于95%,细胞活力均高于90%,H&E染色验证了良好的组织相容性。机制分析揭示交联剂浓度通过调控交联键数量、分子扩散阻力及链段降解敏感性三个维度协同决定降解行为。本研究为可注射水凝胶降解行为的定制化调控提供了量化实验依据。

     

    Abstract: In order to precisely control the degradation rate of injectable thermosensitive hydrogels to match the process of tissue regeneration, Pluronic F-127/carboxymethyl chitosan/ZnO thermosensitive hydrogels with four concentration gradients of 0.5wt.% to 2.0wt.% were prepared using glutaraldehyde as the crosslinking agent. The results showed that the gel time was shortened from 120 s to 60 s, the equilibrium swelling rate was reduced from 55.16% to 23.85%, and the degradation half-life was extended from 4.40 days to 9.31 days with the increase of crosslinking agent concentration. The subcutaneous implantation experiment showed a highly consistent degradation trend both in vivo and in vitro. The antibacterial rate of the hydrogel against Staphylococcus aureus and Escherichia coli was more than 95%, and the cell activity was more than 90%. H&E staining verified good histocompatibility. Mechanism analysis reveals that the concentration of crosslinking agents synergistically determines degradation behavior by regulating three dimensions: the number of crosslinking bonds, molecular diffusion resistance, and segment degradation sensitivity. This study provides a quantitative experimental basis for the customized regulation of the degradation behavior of injectable hydrogels.

     

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