Macroporous Poly(hydroxyethyl methacrylate) Hydrogels as Removable Antibiotic-Capture Liners for Endotracheal Tubes Designed to Prevent Ventilator-Associated Pneumonia

Abstract

Ventilator-associated pneumonia (VAP) is a life-threatening condition most frequently associated with the use of endotracheal tubes (ETs). This study describes the development of macroporous p(HEMA) hydrogels as removable antimicrobial liners for ETs to help prevent VAP. Hydrogels were prepared by free-radical polymerisation using varying sodium chloride concentrations and 40% or 60% w/w water. Increasing NaCl concentration enhanced porosity but reduced mechanical strength and improved swelling and gentamicin loading of hydrogels containing 60% w/w but not 40% w/w water. Gentamicin release was more controlled at lower NaCl concentrations, whereas hydrogels with higher porosity promoted rapid release. The formulation containing 60% w/w water and 0.1 M NaCl provided the best balance of mechanical integrity, drug uptake, sustained antimicrobial activity, and reduced bacterial adherence. Nebulisation studies showed that gentamicin-loaded hydrogels eradicated adherent bacteria and prevented recovery of viable organisms after repeated bacterial challenges. These findings indicate that macroporous p(HEMA) hydrogel liners offer a promising strategy for reducing endotracheal tube-associated infection.