Research Projects

Blood-contacting medical devices such as catheters and extracorporeal tubing often suffer from two major complications; thrombosis and bacterial infections, which lead to device failure, high healthcare costs. Conventional approaches using anticoagulant drugs (e.g., heparin) and antibiotics come with limitations such as bleeding risks, bacterial resistance, and systemic side effects. In recent years, metal-phenolic-amine (MPA) coatings have emerged as promising surface-modification strategies that provide both antibacterial and antithrombogenic properties. These coatings are typically based on small molecules like gallic acid and cystamine assembled with metals such as Cu2+. However, such systems suffer from issues like limited durability, uncontrolled leaching, and lack of tunability in structure and function. This project proposes the design and synthesis of random copolymers with gallol and amino acid pendants to address these limitations. The copolymers with gallol moieties are expected to provide strong metal coordination with antioxidant properties, and the amino acid pendants will introduce amine functionalities to promote crosslinking, enhance adhesion, and offer pH-responsive behavior. The copolymers will be synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization, allowing precise control over molecular weight, narrow dispersity (Ð), functional group density along the copolymer chain, and composition. The resulting copolymers will be used to coat poly(vinyl chloride) (PVC) substrates via a simple dip-coating process, followed by metal ion complexation using Cu2+, Fe3+, or Zn2+. The ultimate goal is to create a stable, biofunctional metal-polymer network directly on the device surface. These coatings are expected to resist bacterial colonization, minimize platelet adhesion, and remain stable under physiological conditions due to their durable, non-leaching, and tunable polymer structure. In this proposal, our primary research objectives are: (i) design and synthesis of random copolymers with gallol and amino acid pendants, (ii) develop and optimize metal-coordinated coatings on PVC tubing, (iii) evaluate surface morphology, chemical composition, and metal retention, (iv) test biological functions, such as nitric oxide (NO) release (Cu-based), antibacterial activity, hemocompatibility, and cytocompatibility, and (v) compare performance with conventional MPA coatings. The innovation of this work lies in the integrated approach to engineer a polymeric alternative to small-molecule MPA coatings, providing improved durability, reduced leaching, and modularity for different metal ions. The study introduces amino acid-based units in the copolymer architectures, enabling pH responsiveness and enhanced adhesion. The proposed platform is versatile and can be tailored for diverse medical applications requiring antimicrobial, anticoagulant, or anti-inflammatory surfaces.