Dual layer-coating of PDMS to prevent calcification and bacterial infection for the potential use of urinary tract biomaterials

Abstract

Polydimethylsiloxane (PDMS) is widely used in medical devices because of its exceptional properties. However, challenges, such as biofouling and bacterial infections, arise from their hydrophobic nature, especially in devices intended for the urinary tract. To address these issues, this study pioneered a surface modification strategy aimed at enriching PDMS with both hydrophilicity and antifouling attributes, making it ideal for urinary tract device applications. We introduced a novel dual-layer coating process, initially grafting a hydrogel-like poly(acrylic acid) (PAA) layer onto PDMS through benzophenone-mediated photoinitiated polymerization to enhance surface hydrophilicity. Subsequently, polyethyleneimine (PEI) was covalently bonded to the PAA layer, ensuring the formation of a stable antifouling surface that prevented bacterial adhesion and calcium deposition. This method guarantees a robust coating that performs consistently across various environmental conditions, including the fluctuating pH levels typical of the urinary tract. Comprehensive surface characterization validated the substantial improvements in hydrophilicity along with significant reductions in bacterial adhesion and calcium deposition. The innovative PAA/PEI dual-layer coating demonstrated marked superiority over conventional uncoated and single-layer-coated PDMS samples, offering a promising solution for enhancing the safety and efficacy of PDMS-based urinary tract devices. The implications of this study extend beyond immediate applications and provide valuable insights into the domains of biomaterials and medical device engineering.