基于OPA三元缩合反应的多功能抗菌水凝胶敷料的构建及体外性能研究

Construction and in vitro evaluation of a multifunctional antibacterial hydrogel dressing based on OPA-mediated ternary condensation

摘要

目的: 旨在开发一种集快速成型、强效黏附、可控自降解、荧光可视化及广谱抗菌于一体的无抗生素多功能抗菌水凝胶敷料并对其体外性能进行系统验证。方法: 通过将邻苯二甲醛(o-phthalaldehyde，OPA)、四臂聚乙二醇巯基(tetra-PEG-SH)和四臂聚乙二醇氨基(tetra-PEG-NH₂)聚合物前驱体溶液混合后的三元缩合反应，制备出一种超快原位形成的异吲哚交联水凝胶敷料(命名为OSN)。通过调控OPA与前驱溶液的摩尔比(0.5∶1∶1、1∶1∶1、2∶1∶1)，制备了3种水凝胶(OSN-1、OSN-2、OSN-3)。综合运用扫描电镜、流变学测试、力学性能分析、紫外/荧光光谱、细胞实验(CCK-8、活/死染色、划痕实验)及抗菌评价(菌落计数、扫描电镜、生物膜染色、流式细胞术)等手段，对其成胶性能、微观结构、力学强度、自降解行为、生物相容性及抗菌活性等进行系统表征。结果: OSN水凝胶可在10 s内快速原位成型，形成均匀的三维网络结构，且提高OPA比例可加速凝胶化并赋予水凝胶自降解特性，其中OSN-3在24 h内完全降解。该水凝胶展现出良好的组织黏附强度和生物相容性，能促进成纤维细胞L929迁移，并对耐甲氧西林金黄色葡萄球菌和大肠杆菌均表现出强效抗菌活性，能有效破坏细菌生物膜。此外，水凝胶在降解过程中伴随异吲哚环断裂导致的蓝色荧光减弱与消失，具备了降解过程可视化的潜力。结论: 成功构建了一种基于OPA三元缩合反应的无抗生素抗菌OSN水凝胶敷料，该敷料集可注射、快速成型、强效黏附、可控自降解、荧光可视化与广谱抗菌功能于一体，且生物相容性良好，为开发无抗生素的智能伤口管理策略提供了一种新颖且有潜力的解决方案。

Abstract

Objective: This study aimed to develop an antibiotic-free，multifunctional antibacterial hydrogel dressing that integrates rapid gelation，robust tissue adhesion，controllable self-degradation，fluorescence-enabled visualization，and broad-spectrum antibacterial activity，and to systematically evaluate its in vitro performance. Methods: An ultrafast in situ-forming isoindole-crosslinked hydrogel dressing，designated OSN，was fabricated through a ternary condensation reaction initiated by mixing precursor solutions of o-phthalaldehyde(OPA)，four-arm poly(ethylene glycol)thiol(tetra-PEG-SH)，and four-arm poly(ethylene glycol)amine(tetra-PEG-NH₂). By varying the molar ratio of OPA to the two polymer precursors(0.5∶1∶1，1∶1∶1，and 2∶1∶1)，three hydrogels，denoted OSN-1，OSN-2，and OSN-3，were prepared. Their gelation behavior，microstructure，mechanical properties，self-degradation profile，biocompatibility，and antibacterial activity were systematically characterized using scanning electron microscopy，rheological analysis，mechanical testing，UV-visible/fluorescence spectroscopy，cell-based assays(including CCK-8，live/dead staining，and scratch wound assays)and antibacterial evaluations(including colony counting，scanning electron microscopy，biofilm staining and flow cytometry). Results: The OSN hydrogels formed rapidly in situ within 10 s and exhibited a homogeneous three-dimensional network architecture. Increasing the OPA content accelerated gelation and imparted self-degradable behavior to the hydrogel matrix，with OSN-3 undergoing complete degradation within 24 h. The hydrogels demonstrated favorable tissue-adhesive strength，together with good biocompatibility. They also promoted the migration of L929 fibroblasts and exhibited potent antibacterial activity against both methicillin-resistant Staphylococcus aureus and Escherichia coli，effectively disrupting bacterial biofilms. In addition，degradation of the hydrogel was accompanied by attenuation and eventual disappearance of blue fluorescence，attributable to cleavage of the isoindole ring，indicating the potential for fluorescence-based visualization of the degradation process. Conclusion: This study successfully developed an antibiotic-free antibacterial OSN hydrogel dressing based on OPA-mediated ternary condensation. The resulting dressing combines injectability，rapid gelation，strong tissue adhesion，controllable self-degradation，fluorescence-enabled visualization，and broad-spectrum antibacterial activity，while maintaining good biocompatibility. These findings provide a novel and promising strategy for the development of antibiotic-free intelligent wound-management strategies.

关键词

OPA三元缩合反应 / 自降解 / 抗菌水凝胶敷料 / 异吲哚结构 / 感染性伤口

Key words

OPA-mediated ternary condensation / self-degradation / antibacterial hydrogel dressing / isoindole structure / infected wounds

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基金资助

甘肃省科技计划项目(自然科学基金)(24JRRF008)

青岛市医疗卫生科研项目(2024-WJKY193)

酒泉市科技计划项目(2025MA1020)