Peng Qiongyao, Wu Qiuqiu, Chen Jingsi, Wang Tao, Wu Meng, Yang Diling, Peng Xuwen, Liu Jifang, Zhang Hao, Zeng Hongbo
Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada.
Sixth Affiliated Hospital of Guangzhou Medical University, Qingyuan People's Hospital, Guangzhou Medical University, Guangdong 511500, China.
ACS Appl Mater Interfaces. 2021 Oct 13;13(40):48239-48251. doi: 10.1021/acsami.1c13744. Epub 2021 Oct 2.
Underwater adhesion is a great challenge for the development of adhesives as the attractive interfacial intermolecular interactions are usually weakened by the surface hydration layer. The coacervation process of sessile organisms like marine mussels and sandcastle worms has inspired substantial research interest in the fabrication of long-lasting underwater adhesives, but they generally suffer from time-consuming curing triggered by surrounding environmental changes and cannot reserve the adhesiveness once damaged. Herein, an instant and repeatable underwater adhesive was developed based on the coacervation of tannic acid (TA) and poly(ethylene glycol)--poly(propylene glycol)--poly(ethylene glycol) (PEG-PPG-PEG, F68), which was driven by hydrogen-bonding interaction, and the hydrophobic cores of F68 micelles offered an additional cross-linking to enhance the mechanical properties. The TA-F68 coacervates could be facilely painted on different substrates, exhibiting robust and instant underwater adhesion (with adhesion strength up to 1.1 MPa on porcine skin) and excellent repeatability (at least 1000 cycles), superior to the previously reported coacervates. Due to the biological activities of TA, the underwater adhesive displayed innate anticancer and antibacterial properties against different types of cancer cells and bacteria, showing great potential for diverse biomedical applications, such as injectable drug carriers, tissue glues, and wound dressings.
水下粘附对于粘合剂的开发而言是一项巨大挑战，因为有吸引力的界面分子间相互作用通常会被表面水化层削弱。海洋贻贝和沙堡蠕虫等固着生物的凝聚过程激发了人们对制造持久水下粘合剂的浓厚研究兴趣，但它们通常存在因周围环境变化引发的固化耗时问题，并且一旦受损就无法保留粘性。在此，基于单宁酸（TA）与聚（乙二醇）-聚（丙二醇）-聚（乙二醇）（PEG-PPG-PEG，F68）的凝聚作用开发了一种即时且可重复使用的水下粘合剂，该凝聚作用由氢键相互作用驱动，F68胶束的疏水核心提供了额外的交联以增强机械性能。TA-F68凝聚物可以轻松地涂覆在不同基材上，表现出强大且即时的水下粘附力（在猪皮上的粘附强度高达1.1 MPa）和出色的可重复性（至少1000次循环），优于先前报道的凝聚物。由于TA的生物活性，这种水下粘合剂对不同类型的癌细胞和细菌具有天然的抗癌和抗菌特性，在诸如可注射药物载体、组织胶水和伤口敷料等多种生物医学应用中显示出巨大潜力。
