Abstract
This study compares the biotribological and structural behavior of PVA and pHEMA hydrogels under conditions simulating the cartilage environment to understand the lubrication mechanisms. PVA samples exhibited very low apparent friction coefficients and high-water uptake due to their hydrophilic, hydroxyl-rich network. In contrast, pHEMA hydrogels showed higher friction but substantially enhanced wear resistance, particularly under extended sliding against rough counterfaces. While PVA offers excellent lubrication performance, its wear stability remains limited. On the other hand, the low wear observed in pHEMAdespite its higher frictionsuggests strong structural resilience, making it a promising platform for further tailoring toward cartilage-mimicking applications. The results highlight the importance of balancing interfacial lubrication and mechanical durability when designing hydrogel-based cartilage replacements.