Biomedical Engineering, College of Engineering, Texas A&M University, College Station, Texas, USA.
Chemical Engineering, College of Engineering, Texas A&M University, College Station, Texas, USA.
J Biomed Mater Res A. 2023 Oct;111(10):1577-1587. doi: 10.1002/jbm.a.37556. Epub 2023 May 18.
Granular hydrogels are a promising biomaterial for a wide range of biomedical applications, including tissue regeneration, drug/cell delivery, and 3D printing. These granular hydrogels are created by assembling microgels through the jamming process. However, current methods for interconnecting the microgels often limit their use due to the reliance on postprocessing for crosslinking through photoinitiated reactions or enzymatic catalysis. To address this limitation, we incorporated a thiol-functionalized thermo-responsive polymer into oxidized hyaluronic acid microgel assemblies. The rapid exchange rate of thiol-aldehyde dynamic covalent bonds allows the microgel assembly to be shear-thinning and self-healing, with the phase transition behavior of the thermo-responsive polymer serving as secondary crosslinking to stabilize the granular hydrogels network at body temperature. This two-stage crosslinking system provides excellent injectability and shape stability, while maintaining mechanical integrity. In addition, the aldehyde groups of the microgels act as covalent binding sites for sustained drug release. These granular hydrogels can be used as scaffolds for cell delivery and encapsulation, and can be 3D printed without the need for post-printing processing to maintain mechanical stability. Overall, our work introduces thermo-responsive granular hydrogels with promising potential for various biomedical applications.
颗粒状水凝胶是一种有前途的生物材料，可用于广泛的生物医学应用，包括组织再生、药物/细胞递送和 3D 打印。这些颗粒状水凝胶是通过将微凝胶通过阻塞过程组装而成的。然而，目前连接微凝胶的方法通常由于依赖后处理通过光引发反应或酶催化进行交联而限制了其使用。为了解决这个限制，我们将巯基功能化的热响应聚合物掺入氧化透明质酸微凝胶组装体中。硫醇-醛动态共价键的快速交换率允许微凝胶组装体具有剪切稀化和自修复特性，热响应聚合物的相转变行为作为二级交联，以在体温下稳定颗粒状水凝胶网络。这种两阶段交联系统提供了优异的可注射性和形状稳定性，同时保持机械完整性。此外，微凝胶的醛基作为持续药物释放的共价结合位点。这些颗粒状水凝胶可用作细胞递送和封装的支架，并且可以在不需要后印刷处理来维持机械稳定性的情况下进行 3D 打印。总的来说，我们的工作介绍了具有广泛生物医学应用前景的热响应颗粒状水凝胶。
