Architecturally Controlling Degradation of Polymers with Tissue-Mimetic Mechanical Properties

Polycaprolactone (PCL) is a biodegradable, biocompatible polyester widely used in long-term biomedical implants and drug delivery systems, but its slow degradation rate limits short-term or transient applications. To address this limitation, we developed bottlebrush PCL networks with tunable degradation profiles. The bottlebrush architecture hinders crystallization, suppresses entanglements, and increases strain on cleavable bonds, resulting in inherently strained materials with lower melting temperatures and enhanced softness compared to linear PCL analogs. These networks exhibit tissue-mimetic combination of softness and strain-stiffening. By tailoring the side-chain length, we achieve accelerated and tunable degradation rates. Furthermore, incorporation of hydrophilic side chains enhances water uptake, providing an additional lever to tune degradation kinetics. This work establishes a molecular design framework for engineering PCL-based materials with independently customizable mechanical and degradation properties for next-generation soft tissue scaffolds and resorbable biomedical devices.