CleraFlex Demonstrates Significant Bacterial Burden Reduction in Porcine Burn Infection Study

New peer-reviewed research evaluating CleraFlex™ in a clinically relevant porcine burn wound infection model has been published in the Journal of Burn Care & Research. The study, titled Assessment of Zwitterionic Hydrogels for Antimicrobial Efficacy in a Controlled Porcine Burn Wound Infection Model, evaluated CleraFlex and a zwitterionic hydrogel formulation containing polyhexamethylene biguanide (PHMB) for the management of infected burn wounds.

The study was designed to simulate prolonged field care conditions, where evacuation and access to definitive treatment may be delayed. These scenarios create significant challenges for burn care because surgical debridement and frequent dressing changes may not be readily available, while remaining burn eschar can serve as a source for continued bacterial growth and infection. The need for lightweight, multifunctional wound dressings that can support wound management in resource-limited environments was a key focus of the AFWERX-supported research program.

Burn wounds were inoculated with Pseudomonas aeruginosa and treated with saline, triple antibiotic ointment, CleraFlex, or CleraFlex containing PHMB. CleraFlex significantly reduced Pseudomonas aeruginosa bacterial burden compared with saline-treated wounds despite containing no added antimicrobial active ingredients. Histological analysis also showed reduced inflammatory cell accumulation in wounds treated with the zwitterionic formulations. CleraFlex significantly reduced subcutaneous neutrophil infiltration compared with triple antibiotic ointment, providing additional evidence of a reduced local inflammatory response at the injury site.

Beyond the bacterial and inflammatory findings, the study provided additional insight into how CleraFlex may interact with nonviable burn tissue. Greater epidermal loss was observed in CleraFlex-treated wounds compared with wounds treated with triple antibiotic ointment. In the context of a burn wound, this may reflect enhanced removal of nonviable epidermal tissue and eschar. Because CleraFlex maintains a moist wound environment, these observations are consistent with the potential for the dressing to support autolytic debridement, a process in which the body’s own enzymes and wound fluid help break down and remove devitalized tissue.

The findings are especially notable because CleraFlex alone produced minimal antimicrobial activity in the in vitro zone-of-inhibition assay, a test designed to detect antimicrobial agents that diffuse out of a material and inhibit bacterial growth. CleraFlex does not contain an added antimicrobial drug intended to diffuse from the gel, yet it significantly reduced bacterial burden in the infected porcine wounds. This demonstrates that the observed effect in the wound environment does not depend on the release of a conventional antimicrobial agent.

Based on the well-known antifouling behavior of zwitterionic materials and CleraFlex’s resistance to nonspecific biological adhesion, the researchers proposed that the material may help limit bacterial attachment and biofilm formation, thereby supporting bacterial clearance. These findings are consistent with the broader design of CleraFlex as a zwitterionic wound dressing, combining moisture management with the antifouling properties associated with zwitterionic materials. GelSana is currently conducting additional mechanistic studies to further define how CleraFlex produces these effects in the wound environment.

The research was conducted by Babita Parajuli, MS, Amy Wang, MD, Kelsey Fiddes, DVM, Patrick F. Walker, MD, Timothy S. Horseman, PhD, and David M. Burmeister, PhD, through the Uniformed Services University of the Health Sciences (USU), located on the Walter Reed campus. Members of the research team are also affiliated with USU’s Battlefield Shock and Organ Support Program and the Armed Forces Radiobiology Research Institute, reflecting the team’s broader focus on military trauma, burn care, and translational research.

The work was supported through GelSana’s U.S. Air Force AFWERX Small Business Innovation Research Phase II program, Advancing Military Healthcare: Novel Zwitterionic Hydrogels for Enhanced Wound Healing in Combat-Related Burn Injuries. The broader program evaluated CleraFlex and zwitterionic formulations incorporating therapeutic agents for military burn care, including infection management and use with meshed skin grafts.

This publication builds on research previously recognized by the American Burn Association with the 2026 Robert B. Lindberg Basic Scientist Paper Award. The results provide additional peer-reviewed evidence supporting continued evaluation of CleraFlex for burn wound management, particularly in complex care environments where treatment options and resources may be limited.

GelSana is grateful to Dr. David Burmeister and the entire research team for their continued collaboration in advancing the understanding of zwitterionic wound care technologies.

Read the full publication in the Journal of Burn Care & Research: Assessment of Zwitterionic Hydrogels for Antimicrobial Efficacy in a Controlled Porcine Burn Wound Infection Model