Xiong Xike, Sun Jun, Hu Di, Xiao Chao, Wang Jianjun, Zhuo Qiqi, Qin Chuanxiang, Dai Lixing
College of Chemistry, Chemical Engineering and Materials Science, Soochow University Suzhou Jiangsu 215123 People's Republic of China
College of Material Science & Engineering, Jiangsu University of Science and Technology Zhenjiang Jiangsu 212003 People's Republic of China.
RSC Adv. 2020 Sep 23;10(58):35226-35234. doi: 10.1039/d0ra06053d. eCollection 2020 Sep 21.
Shape-memory hydrogels are expected to be used not only in an ordinary environment, but also in some special environments, such as under ultraviolet (UV) irradiation. Developing novel shape-memory polyvinyl alcohol (PVA)/tea polyphenol (TP) hydrogels with UV shielding performance is realistically important in application fields. Herein, we designed functional PVA/TP hydrogels with excellent UV-shielding ability and improved the shape memory on hot water stimuli. This study shows that the abundant hydrogen bonds between PVA and TP are the source of shape memory. The PVA hydrogels with 8 wt% TP loading could approximately recover their original shape after deformation when immersed in water at 50 °C for 30 s. Meanwhile, the hydrogels also had excellent UV shielding capacity. After ageing under UV for 16 days, the observed shape of the hydrogel with 8 wt% TP loading retained 74.7% of the original, and the hydrogel could effectively protect the skin of mice from damage under 10 mW cm UV irradiation. With the understanding of the UV-shielding behavior of hydrogels, this study has been able to generate biomedical materials for human skin protection, specifically skin covering the joint areas, where shape memory of the applied materials is essential.
形状记忆水凝胶不仅有望在普通环境中使用，还能在一些特殊环境中应用，如在紫外线（UV）照射下。开发具有紫外线屏蔽性能的新型形状记忆聚乙烯醇（PVA）/茶多酚（TP）水凝胶在应用领域具有现实意义。在此，我们设计了具有优异紫外线屏蔽能力的功能性PVA/TP水凝胶，并改善了其在热水刺激下的形状记忆性能。本研究表明，PVA和TP之间丰富的氢键是形状记忆的来源。负载8 wt% TP的PVA水凝胶在50℃水中浸泡30 s变形后能大致恢复其原始形状。同时，该水凝胶还具有优异的紫外线屏蔽能力。在紫外线照射下老化16天后，负载8 wt% TP的水凝胶观察到的形状保留了原始形状的74.7%，并且该水凝胶能够有效保护小鼠皮肤在10 mW/cm紫外线照射下免受损伤。随着对水凝胶紫外线屏蔽行为的了解，本研究已能够制备用于人类皮肤保护的生物医学材料，特别是覆盖关节区域的皮肤，在这些部位应用材料的形状记忆至关重要。
