Explore Novel Hydrogelable Covalent Conjugates of Caprylic Acid to Amplify its Bactericidal and Pro-healing Capability for Accelerated Healing of Infected Wounds - ABSTRACT Millions of Americans suffer infected wounds (IWs), particularly diabetic IWs (dIWs), resulting in immense medical and economic burdens. Antimicrobial resistance has severely limited available treatments, with Staphylococcus aureus (SA) and Pseudomonas aeruginosa (PA) as predominant pathogens forming biofilms that hinder healing. Current therapies fail to eradicate biofilms or restore tissue repair. Our long-term goal is to develop therapeutics that both eliminate infection and re-establish regeneration. Caprylic acid (C8), an eight- carbon fatty acid, exhibits strong bactericidal, immunomodulatory, and pro-healing properties but is rapidly cleared and unable to support tissue scaffolding. To overcome these limitations, we developed hydrogel- forming covalent C8–tripeptide conjugates (CONJs). These self-assembling amphiphiles form tunable, shear- thinning gels that flow into irregular wound cavities, kill bacteria within biofilms, and sustain C8 release during biodegradation. Central hypothesis: Self-assembling, gel-forming CONJs−covalently linking C8 with gelling- aid tripeptides−amplify C8’s bactericidal, immunomodulatory, and pro-healing functions, eradicate biofilms, shifting wound immunity toward regeneration and resolution, and restore healing in dIWs. Objective: To explore tunable CONJ gels as novel multifunctional therapeutics that restore healing without the toxicity, tissue incompatibility, or limited efficacy of current single-function modalities. We propose two aims. Aim 1: Engineer and benchmark wound-compatible CONJ gels; explore how gel chemical composition influences mechanical properties and cytocompatibility. Aim 2: Evaluate therapeutic efficacy, biodegradation/C8-release, and immunomodulation to identify the most effective CONJ gels for amplifying C8’s bactericidal, immunomodulatory, and pro-healing properties in dIWs. A) Test CONJ gels in vitro for MRSA and PA biofilm eradication. B) Develop treatment regimens using the two lead CONJ gelators identified from our pilot study, Aim 1, and Aim 2a to eliminate MRSA/PA infection and restore healing in db/db diabetic mouse model. C) Define gel biodegradation and C8 release in wounds by LC-MS/MS. D) Assess immunomodulation in human blood immunocytes and mouse dIWs, including potential shifts toward reparative immunity [↑ M2-like macrophages (Mɸs) and regenerative pro-resolving factors, ↓ inflammatory factors/M1-like Mɸs).Overall Impact: This R21 will 1) deliver novel self-assembling, gel-forming CONJs that amplify C8’s bactericidal, immunomodulatory, and pro-healing functions to restore healing in infected diabetic wounds; 2) provide insights on chemical and mechanical parameters driving CONJ gel efficacy; and 3) advance a new biomaterial platform that transforms short-lived bioactives into long-acting, multifunctional gels as therapeutics. The most effective CONJ gels have strong potential for translating into safer, more effective, and user-friendly therapeutics for infected diabetic wounds. Our team brings proven expertise in developing CONJ gels and evaluating their antibacterial and wound-healing properties.
