Xiang Dongfang, Wu Xin, Cao Wei, Xue Bin, Qin Meng, Cao Yi, Wang Wei
Key Laboratory of Intelligent Optical Sensing and Integration, National Laboratory of Solid State Microstructure, and Department of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, China.
Shenzhen Research Institute of Nanjing University, Shenzhen, China.
Front Chem. 2020 Jan 28;8:7. doi: 10.3389/fchem.2020.00007. eCollection 2020.
Hydrogels with photo-responsive mechanical properties have found broad biomedical applications, including delivering bioactive molecules, cell culture, biosensing, and tissue engineering. Here, using a photocleavable protein, PhoCl, as the crosslinker we engineer two types of poly(ethylene glycol) hydrogels whose mechanical stability can be weakened or strengthened, respectively, upon visible light illumination. In the photo weakening hydrogels, photocleavage leads to rupture of the protein crosslinkers, and decrease of the mechanical properties of the hydrogels. In contrast, in the photo strengthening hydrogels, by properly choosing the crosslinking positions, photocleavage does not rupture the crosslinking sites but exposes additional cryptical reactive cysteine residues. When reacting with extra maleimide groups in the hydrogel network, the mechanical properties of the hydrogels can be enhanced upon light illumination. Our study indicates that photocleavable proteins could provide more designing possibilities than the small-molecule counterparts. A proof-of-principle demonstration of spatially controlling the mechanical properties of hydrogels was also provided.
具有光响应机械性能的水凝胶已在生物医学领域得到广泛应用，包括生物活性分子递送、细胞培养、生物传感和组织工程。在此，我们使用可光裂解蛋白PhoCl作为交联剂，设计了两种聚乙二醇水凝胶，其机械稳定性在可见光照射下可分别被削弱或增强。在光弱化水凝胶中，光裂解导致蛋白交联剂断裂，水凝胶的机械性能下降。相反，在光强化水凝胶中，通过适当选择交联位置，光裂解不会使交联位点断裂，而是暴露出额外的隐蔽反应性半胱氨酸残基。当与水凝胶网络中的额外马来酰亚胺基团反应时，水凝胶的机械性能在光照下可得到增强。我们的研究表明，与小分子交联剂相比可光裂解蛋白能提供更多的设计可能性。还提供了对水凝胶机械性能进行空间控制的原理验证演示。
