Metrifonate local application for DFU treatment

Diabetic foot ulceration (DFU) is a major problem in diabetic patients as more than 15% of them are expected to develop DFU within their lifetime. Given the severity of the problem and the rather unsatisfactory efficacy of the currently available therapeutic approaches, new, more effective treatments are urgently needed. Single-cell RNA-sequencing (scRNASeq) analysis provides deep insights into cell functions and disease pathophysiology by allowing the profiling of the transcriptomic signatures of individual cells in heterogeneous tissues. A recently completed study in our unit primarily focused on differences between DFU patients who heal their ulcers (Healers) and those who fail to heal them (non-Healers) and investigated molecular changes via scRNASeq analysis of surgically removed DFUs. Our analysis showed enrichment of a unique population of fibroblasts, named Healing Enhancing (HE)-fibroblasts, overexpressing MMP1, MMP3, MMP11, HIF1A, CHI3L1, and TNFAIP6 genes in the Healers. Pathway analysis demonstrated the activation of multiple immune pathways including IL6, HIF1A and ILK signaling in the HE-fibroblasts. By leveraging the above scRNASeq data, we performed an in silico screening of thousands of perturbagens, which indicated that metrifonate, an organophosphate cholinesterase inhibitor that can be used to treat schistosomiasis and has been tested in the past for the treatment of Alzheimer's disease, could be a suitable repurposed drug for DFU management. Subsequent experiments with diabetic db/db mice revealed that alginate gels releasing metrifonate at certain levels markedly enhanced wound healing and these results were confirmed in wounds of human skin that was transplanted onto diabetic nude mice and early pig experiments. Based on these findings, we propose to develop novel treatments for DFU that will be in the form of a wound bandage and will employ new biomaterials that can release appropriate doses of metrifonate in the wound area. The main aims of the current applications are: to develop biomaterials that can provide desirable timed release of appropriate dose of metrifonate, test their efficacy and investigate mechanisms of action of biomaterial-based delivery in wound healing; confirm proof of efficacy in the diabetic Yucatan minipig and corroborate mechanisms of action; and conduct nonclinical IND- enabling studies in preparation for IND filing leading to Phase I/II clinical trials. Successful completion of this project will elucidate the role and mechanisms of action of metrifonate in promoting wound healing in diabetes and will lead to the development of urgently needed novel therapies for the DFU management.