Physical entanglement improves the anti-adsorption and super-lubricity properties of polyacrylamide-based hydrogels for biomedical applications

Though hydrogels have been widely employed in clinical applications, the bio-fouling problem and poor tribological performance have become one of the crucial limitations. In this study, we innovatively explore physically entangled hydrogels to achieve superior anti-adsorption and lubrication performance and prepare a soft and stretchable hydrogel catheter. The albumin adsorption mass is as low as 0.014 μg/mm2, a 97% reduction in protein adsorption mass compared to widely recognized zwitterionic materials. These advantages stem from the numerous physical entanglements in the hydrogel. First, the thicker hydration layer arising from elevated monomer density minimizes contact between proteins and polymer chains; second, binding the soft suspension chain to the hydrogel surface prevents the chains from bonding to proteins in solution. By utilizing physically entangled hydrogels with soft and tough characteristics, the fabricated hydrogel catheters with anti-protein adsorption possess superlubricating properties in serum (friction coefficient: 5.7 × 10−3). The physically entangled hydrogel demonstrates a promising approach that can enhance both the anti-adsorption and super-lubricity properties, with the aim of extending the service life of medical devices and improving patient comfort.