Integrating Hydrogels and Biomedical Plastics via In Situ Physical Entanglements and Covalent Bonding

A robust adhesion strategy is proposed to effectively integrate mechanically dissimilar biomedical plastics and hydrogels. Mechanistic investigations highlight the importance of interfacial physical entanglements and covalent bonding. The hybrid design mitigates foreign body responses associated with rigid plastics in vivo. This innovative approach holds potential for enhancing a variety of polymer-based devices in regenerative medicine and surgical robotics.

Abstract

Both rigid plastics and soft hydrogels find ample applications in engineering and medicine but bear their own disadvantages that limit their broader applications. Bonding these mechanically dissimilar materials may resolve these limitations, preserve their advantages, and offer new opportunities as biointerfaces. Here, a robust adhesion strategy is proposed to integrate highly entangled tough hydrogels and diverse plastics with high interfacial adhesion energy and strength. Systemic investigations on the effects of hydrogel monomer content and crosslink fraction revealed the significant contributions of both polymer physical entanglements and interfacial covalent bonding. This hybrid engineering strategy also enables the plastic-hydrogel composite to attenuate foreign body response caused by pristine rigid plastics in vivo in mice. This versatile materials engineering approach may be broadly applicable to other polymer-based devices commonly used in regenerative medicine and surgical robotics.