Biocompatible, shape memory hydrogels hold potential for biomedical applications

08-Jul-13

Scientists at The University of Akron are exploring new biomedical uses for a polymer-based product. The hydrogels exhibit high mechanical properties, excellent recoverable properties, and a unique, free-shapeable property, making them promising replacements for load-bearing soft tissues like cartilage, tendon, muscle and blood vessels. Dr. Jie Zheng, associate professor of chemical and biomolecular engineering, and Dr. Robert Weiss, Hezzleton E. Simmons professor and chair of polymer engineering, are among the most recent to contribute to the growing research of hydrogels, the gelatinous substance that, because of its toughness and plasticity, has several biomedical applications, including cartilage repair, implants for minimally invasive surgery and drug delivery. Since, as Zheng says, "all existing methods to prepare double-network hydrogels involve multiple-step processes, which are tedious and time-consuming," Zheng and his team developed a simple, efficient and one-pot method (in which reactions occur in one as opposed to several pots) to synthesize double-network hydrogels — that is, hydrogels composed of two networks of polymer chains, one rigid, the other ductile. Weiss also has synthesized a tougher brand of hydrogel, a "shape memory hydrogel," which can be bent and stretched and fixed into temporary shapes. When exposed to an external stimulus, such as temperature, light, moisture, or an electric field, shape memory polymers recover their original, permanent shape. Weiss's shape memory hydrogels are thermally actuated, meaning they stretch and change shape when heated, and they retain this temporary shape when cooled. Biocompatible, shape memory hydrogels have the potential to be used for minimally invasive surgery and drug delivery.