Compliant, Tough, Anti-Fatigue, Self-Recovery, and Biocompatible PHEMA-Based Hydrogels for Breast Tissue Replacement Enabled by Hydrogen Bonding Enhancement and Suppressed Phase Separation

Although hydrogel is a promising prosthesis implantation material for breast reconstruction, there is no suitable hydrogel with proper mechanical properties and good biocompatibility. Here, we report a series of compliant and tough poly (hydroxyethyl methacrylate) (PHEMA)-based hydrogels based on hydrogen bond-reinforcing interactions and phase separation inhibition by introducing maleic acid (MA) units. As a result, the tensile strength, fracture strain, tensile modulus, and toughness are up to 420 kPa, 293.4%, 770 kPa, and 0.86 MJ/m(3), respectively. Moreover, the hydrogels possess good compliance, where the compression modulus is comparable to that of the silicone breast prosthesis (similar to 23 kPa). Meanwhile, the hydrogels have an excellent self-recovery ability and fatigue resistance: the dissipative energy and elastic modulus recover almost completely after waiting for 2 min under cyclic compression, and the maximum strength remains essentially unchanged after 1000 cyclic compressions. More importantly, in vitro cellular experiments and in vivo animal experiments demonstrate that the hydrogels have good biocompatibility and stability. The biocompatible hydrogels with breast tissue-like mechanical properties hold great potential as an alternative implant material for reconstructing breasts.

Automated summary

Compliant and tough poly (hydroxyethyl methacrylate) (PHEMA)-based hydrogels were developed with enhanced hydrogen bond-reinforcing interactions and phase separation inhibition by introducing maleic acid (MA) units. These hydrogels demonstrated high tensile strength, fracture strain, tensile modulus, and toughness, as well as good compliance comparable to silicone breast prosthesis. They also exhibited excellent self-recovery ability and fatigue resistance. Cellular and animal experiments confirmed their biocompatibility and stability, suggesting their potential as an alternative implant material for breast reconstruction.