Mechano-adaptive microgel-integrated (MA-MI) polycarbonate polyurethane composites with superior load-bearing and self-replenishing hydration lubrication performance

MA-MI strategy is proposed to fabricate PCU composites. • Dynamic hydrogen bonding and microgels synergistically enable self-adaptive lubrication. • PCU/MG shows excellent durability under long-term and high-load sliding. Polymeric elastomers are widely used in biomedical devices and implants. However, their inherent surface hydrophobicity hinders the formation of stable lubricating films in aqueous environments, leading to severe friction and wear. Here, we present a mechano-adaptive and microgel-integrated (MA-MI) strategy for fabricating polycarbonate polyurethane (PCU) composites (PCU/MG) that combine high load-bearing capacity with effective hydration lubrication. By incorporating controlled amounts of microgels into a dynamic hydrogen-bonded matrix, the mechanical properties and wettability are simultaneously tuned. Cyclic compression tests show that the PCU/MG-1:1 composite retains nearly 100% of its original strength and over 85% of its energy dissipation capacity after 200 cycles. Under aqueous sliding, friction-induced exposure of embedded microgels triggers localized hydration, generating a self-replenishing hydration layer and rolling lubrication components in situ. As a result, the composite exhibits low friction, load-adaptive lubricity, and stable lubrication across a wide range of aqueous environments. The PCU/MG-1:1 composite achieves an over 80% reduction in steady-state wear rate after 10,000 sliding cycles compared with short-term tests. This MA-MI strategy overcomes the longstanding trade-off between load-bearing capacity and surface lubricity in conventional polymeric elastomers, providing a promising route toward durable self-lubricating biomedical materials.