Swelling and erosion assisted sustained release of tea polyphenol from antibacterial ultrahigh molecular weight polyethylene for joint replacement

The considerable hazard posed by periprosthetic joint infections underlines the urgent need for the rapid advancement of in-situ drug delivery systems within joint materials. However, the pursuit of sustained antibacterial efficacy remains a formidable challenge. In this context, we proposed a novel strategy that leverages swelling and erosion mechanisms to facilitate drug release of drug-loaded ultrahigh molecular weight polyethylene (UHMWPE), thereby ensuring its long-lasting antibacterial performance. Polyethylene oxide (PEO), a hydrophilic polymer with fast hydrating ability and high swelling capacity, was incorporated in UHMWPE alongside the antibacterial tea polyphenol (epigallocatechin gallate, EGCG as representative). The swelling of PEO enhanced water infiltration into the matrix, while the erosion of PEO balanced the release of the encapsulated EGCG, resulting in a steady release. The behavior was supported by the EGCG release profiles and the corresponding fitted release kinetic models. As demonstrated by segmented antibacterial assessments, the antibacterial efficiency was enhanced 2 to 3 times in the PEO/EGCG/UHMWPE composite compared to that of EGCG/UHMWPE. Additionally, the PEO/EGCG/UHMWPE composite exhibited favorable biocompatibility and mechanical performance, making it a potential candidate for the development of drug-releasing joint implants to combat prosthetic bacterial infections.