Shelf-Stable Antibiotic Hybrid Exosomes for the Topical Treatment of Wound Infections

With an estimated 2.8 million antibiotic resistant infections in the United States each year, multidrug-resistant bacterial pathogens are becoming serious and urgent threats. Of these bacteria, the ESKAPE pathogens pose significant risks to wounded military personnel, resulting in hospitalization and delays in returning to active duty. The current standard of care for combat-related wounds in soldiers unable to take oral regimens is intravenous administration of antibiotics. This approach leads to systemic toxicity and development of drug resistance. Topical, locally administered formulations have the potential to address these challenges but are associated with low tissue penetration and adverse reactions such as skin irritation. To address the need for a safe and effective topical antibiotic formulation, Luna Labs USA, LLC and STTR partners at the University of Miami are developing biopolymer-stabilized, antibiotic-loaded exosomes. Specifically, hybrid exosomes are synthesized by combining endogenous exosomes with synthetic liposomes to controllably form stable drug-loaded delivery vehicles. The resultant vesicles are then formulated with biopolymers into a dry format that can be easily transported into deployed settings. Upon hydration at the point of care, the polymers form a loose hydrogel network that can be topically applied across wounds to prevent infection. In Phase I, reproducibility, feasibility, and antimicrobial activity of the formulation were demonstrated in vitro against ESKAPE pathogens. Phase II will include formulation optimization and multiple in vivo studies aimed at demonstrating safety and efficacy to support preclinical validation.