The long-term goal of this work is to develop a treatment for chronic wounds that will prevent wound biofilm and facilitate healing. Chronic wounds affect approximately 6.5 million patients in the US with annual treatment cost up to $50 billion. Despite high treatment costs, approximately 30% of patients will not heal using existing interventions and many wounds progress to serious infections, including amputations. The involvement of drug resistant organisms and multispecies biofilms is gaining recognition as an important factor in wound chronicity. There are currently no therapeutic options to address these issues. New therapeutics are urgently needed to reduce pain, improve functional outcomes, and improve quality of life for those with chronic wounds. The goal of this work is to develop an antimicrobial wound treatment based on an engineered cationic antimicrobial peptide called ASP-1 that is effective against biofilm and conducive to healing. ASP-1 displays potent activity against biofilms of both gram positive and gram negative bacteria, including multi-drug resistant organisms (DROs) over a broad range of pH and in the presence of proteins. Chitosan hydrogels containing ASP-1 will be developed for primary wound application to establish feasibility for efficacy and safety using both in vitro and animal models. The composition of hydrogels developed will be tailored to achieve a duration of ASP-1 release exceeding 3 days, which will be measured by RP-HPLC. The efficacy of hydrogels will be established first using in vitro biofilm models where challenge durations will extend over 3 day periods and biofilms tested will include methicillin resistant Staphylococcus aureus (MRSA), Acinetobacter baumannii, and Pseudomonas aeruginosa. The hydrogels will be evaluated for biocompatibility using direct contact cytotoxicity assays. These assays will be conducted for both primary human dermal fibroblasts and keratinocytes. Finally, both safety and efficacy of the ASP- 1 Hydrogel will be evaluated using a porcine model of excisional MRSA wound infection. This model will be utilized to conduct an early dose range evaluation. A commercial silver based product will be included for comparison in both the in vitro an animal studies. Successful completion of this project will demonstrate feasibility for an ASP-1 Hydrogel that provides broad spectrum antibiofilm coverage and overcomes the biocompatibility and cytotoxicity limitations associated with silver and other antiseptic products. If successful, this product will have a significant impact on reducing morbidity and improving the quality of life of patients with chronic wounds.
The goal of this project is to develop a product that will be used to treat chronic and infected wounds. The product will fill a critical gap in the need for antimicrobial treatments that are biocompatible and supportive of healing. If successful, the product is expected to have a substantial impact on the treatment and quality of life of patients with chronic wounds by reducing infection, pain, amputation risks, and treatment costs.