Polyurethane–polyvinylpyrrolidone iodine blends as potential urological biomaterials

Biomaterial-centred infections are major complications of implanted and indwelling medical devices like urological and venous catheters with significant economic consequences and increased patient morbidity. In the present study, polyurethane (PU) blends comprising the polymeric complex of polyvinylpyrrolidone iodine (PVPI) were developed. The developed PU/PVPI blends were extensively characterized for both surface and thermal properties using contact angle, ATR-FTIR, SEM-EDAX, TGA and DSC analyses. The suitability of the developed blends as urinary tract biomaterial was evaluated using bacterial adhesion (both qualitative and quantitative), protein adsorption and salt encrustation studies. The PU blends with PVPI exhibited reduced protein adsorption and excellent antimicrobial efficacy against the three clinically relevant bacteria, viz. Staphylococcus aureus, Staphylococcus epidermidis and Pseudomonas aeruginosa. A progressive increase in the antiadhesive and antimicrobial efficacy was observed with the increase in PVPI concentration from 0.5 to 1.5% w/w in the PU/PVPI blends. The developed blends showed a strong resistance towards salt encrustation process as the deposition of the salts, namely struvite and hydroxyapatite, which usually forms the major components of urinary tract encrustation, was significantly reduced on PU/PVPI blends. Due to the combined antiadhesive, antimicrobial and encrustation-resistant properties, along with good stability these PU/PVPI blends can offer a promising strategy to reduce medical device-associated infections.