Precision-Porous PolyHEMA-Based Scaffold as an Antibiotic-Releasing Insert for a Scleral Bandage

Combat-related penetrating ocular injuries have become a common form of battlefield injury in modern warfare and can lead to potentially devastating visual impairments. Prompt stabilization of the wounded globe via prevention of infection and fibrosis enhances the probability of a successful outcome after professional medical treatment. In this study, a norfloxacin-releasing poly(hydroxyethyl methacrylate)-based insert was designed and fabricated as a part of scleral bandage to prevent development of infection and scar formation. First, a sphere-templating technique was applied, during which 2-hydroxyethyl methacrylate monomer was photocopolymerized with acrylic acid and/or 4-fluorostyrene at different molar ratios to generate poly(hydroxyethyl methacrylate)-based porous scaffolds of various compositions with interconnected, monodisperse, 38 μm diameter pores. The scaffolds were then loaded with norfloxacin via swelling in drug-saturated solutions of various solvents, such as water, acetone, chloroform and ethanol, and the effect of the scaffold composition and the swelling solvent on norfloxacin uptake was explored. An in vitro drug release study was then conducted to explore the release kinetics of norfloxacin from the drug-loaded scaffolds, with the aim to find the optimal scaffold composition to provide release of norfloxacin over a 1 week period. The antibacterial potential of the optimal composition norfloxacin-loaded scaffold to inhibit the growth of the relevant clinical pathogens Staphylococcus epidermidis and Pseudomonas aeruginosa during a 1 week period was evaluated in vitro using a continuous culture flow cell system and a soft agar overlay plate assay.