Injectable, strong and bioadhesive catechol-chitosan hydrogels physically crosslinked using sodium bicarbonate

Fast-gelling chitosan thermosensitive hydrogels have proven to be excellent matrices for targeted drug-delivery and cell therapy. In this work, we demonstrate the possibility of designing injectable bioadhesive hydrogels with a high gelation rate by modifying chitosan with catechol (cat-CH) and using sodium bicarbonate (SHC) as a gelling agent. Cat-CH/SHC hydrogels gel under 5 min at 37 degrees C and reach a high secant modulus after 24 h (E = 90 kPa at 50% strain). Besides, they show significantly higher adhesion to tissues than chitosan hydrogels thanks to the combination of catechol grafting and physical crosslinking. Their pH and osmolality stayed inside the physiological range. While biocompability tests will be mandatory to conclude regarding their potential for drug or cell encapsulation, these hydrogels uniquely combine physiological compatibility, injectability, fast gelation, good cohesion, and bioadhesion.

快速凝胶化的壳聚糖温敏水凝胶已被证明是用于靶向给药和细胞治疗的优良基质。在这项工作中，我们通过用儿茶酚（cat - CH）修饰壳聚糖并使用碳酸氢钠（SHC）作为胶凝剂，证明了设计具有高凝胶化速率的可注射生物粘附水凝胶的可能性。Cat - CH / SHC水凝胶在37℃下5分钟内凝胶，并在24小时后达到较高的正割模量（在50%应变下E = 90 kPa）。此外，由于儿茶酚接枝和物理交联的共同作用，它们对组织的粘附性明显高于壳聚糖水凝胶。它们的pH值和渗透压保持在生理范围内。虽然生物相容性测试对于确定它们在药物或细胞包封方面的潜力是必不可少的，但这些水凝胶独特地结合了生理相容性、可注射性、快速凝胶化、良好的内聚性和生物粘附性。