Antibiotic eluting collagen-based hydrogel improves wound healing in a biofilm challenged murine stented wound model

Biofilm-colonized chronic wounds are difficult to treat due to a constantly evolving microbiome. In this study, a cHG augmented with antibiotics was examined for the topical treatment of biofilm-challenged wounds in vivo. Two studies were performed in series using a murine stented wound model. Mice were divided into four groups: control (wound only), infection only (IO), infection + cHG (IcHG), and infection + cHG + antibiotics (IcHG + Abx). We first examined Pseudomonas aeruginosa biofilms treated with gentamicin, and then MRSA biofilms treated with clindamycin. Wound healing was assessed using photography, immunohistochemistry, and histology. Systemic symptoms were monitored with hematological laboratory tests. Pseudomonas aeruginosa infected wounds treated with cHG + Abx healed faster and were protected from bacteremia. In the MRSA infected mice, wound treatment significantly affected the outcome, explaining 5.56% of total variance (ANOVA: F(3, 366) = 17.38, p < 0.0001). Additionally, infected wounds treated with cHG + Abx demonstrated less inflammatory tissue and accelerated closure rate on day 8 (76.53% ± 7.43% vs 48.40% ± 4.95%, p < 0.0001) and day 14 (96.00% ± 3.07% vs 82.38% ± 8.24%, p = 0.003), as compared to the infection only wounds. cHG offers a biocompatible, topical option with dual functionality: antibiotic augmentation to target biofilm pathogens, and a collagen-rich dressing to accelerate wound healing.