(165c) Sprayable, Antimicrobial Hydrogels to Improve Wound Infection Treatment

Burn wounds have high infection rates and pain associated with current treatments; therefore, we aim to develop sprayable, antimicrobial hydrogels to reduce application pain and improve infection treatment. Thermoreversible polymers loaded with antimicrobial agents can be sprayed onto the skin as a liquid at colder temperatures then transition to a gel as it warms on the skin while providing prolonged drug release in the gel state. Poloxamer hydrogels loaded with ciprofloxacin hydrochloride have been developed and evaluated for desirable physical, antimicrobial, and sprayable properties. Many developed formulations have gelation temperatures above room and below skin temperature (21 - 34°C), which is desirable in order to spray while the formulation is a cold liquid and gel once on the warm skin. Using in-line diffusion cells, 50% of the drug is released between 4 and 6 hours. From the drug release experiments, we are also maintaining drug concentrations above the minimum inhibitory concentrations for four common wound pathogens for 18 to 21 hours. The antimicrobial-loaded hydrogels have shown larger zones of bacterial inhibition compared to common topical treatments of burn and chronic wound infections. Through spray pattern analysis, we observed that the type of nozzle, formulation, and distance to a target largely influence the size and shape of the spray pattern, which is important to determine proper dosing of these topical formulations. These results will help guide future development of sprayable, antimicrobial hydrogel treatments to improve current wound infection treatments.