Expression Of Tissue Matrix Metalloproteinase-1 (MMP-1) In Neuropathic Diabetic Foot Ulcers with Delayed Healing: Cross-Sectional Study

Background: Matrix metalloproteinases (MMPs) are characteristic of chronic wounds. That can affect the healing process. Therefore, we aimed to evaluate the immunoreactivity of tissue MMP-1 to histopathological analysis of delayed healing in neuropathic diabetic foot ulcers (DFUs). Methods: This cross-sectional research included 21 diabetic patients with neuropathic foot ulcers who did not achieve at least a 50% decrease in the surface area of the ulcer after four weeks of standard treatment. Infected or ischemic ulcers were excluded. Following the debridement, two biopsies were collected from the base and the edge of the ulcer for histopathological assessment. The analysis focused on cellularity (involving fibroblasts and macrophages), vascular proliferation, inflammation, and collagen maturation. The evaluation of MMP-1 immunoreactivity was categorized as follows: 0 for no staining, 1 for mild staining, 2 for moderate staining, and 3 for strong staining. Results: MMP-1 was found in 33.3% of ulcer bases and 52.4% at edges. A significant negative correlation was noted between ulcer surface area and MMP-1 expression in the base. Pathological evaluation indicated moderate cellularity in bases (85%) and edges (52%), with moderate vascular proliferation (71% for base, 52% for edge). Additionally, 38% of bases and 76% of edges lacked inflammatory cells, while mature collagen was present in 85% of bases and all edges. Conclusion: Reduced tissue MMP-1 levels contribute to the slow healing of DFUs, which are characterized by high mature collagen, low cellularity, and chronic inflammation. Further trials are needed to explore MMP-1’s potential as a treatment to enhance wound healing