The aim of this study is to evaluate how treatment with total contact cast (TCC) affects the balance of proteases in diabetic foot ulcers (DFUs) as they heal.This was a prospective observational study of 22 eligible patients with neuropathic plantar DFUs in a hospital-based wound care center. All patients treated with TCC had adequate arterial circulation (ankle-brachial index > 0.75), no sign of infection, and all DFUs were grade 1A according to the University of Texas Diabetic Wound Classification System. Patients had weekly follow-up visits for wound evaluation and reapplication of the TCC. Wound tissues were obtained at baseline (week 0 prior to initial treatment), week 3, week 6, and week 12. Tissue homogenates were analyzed for matrix metalloprotease (MMP) 2, MMP-9, tissue inhibitor matrix metalloproteinase (TIMP) 1, and TIMP-2. Wound measurements were obtained at weekly follow-up visits, and healing rates were calculated by photodigital planimetry.Treatment with TCC for 3 weeks resulted in a 20% decrease in MMP-2 (P = .031) and 44% decrease in MMP-9 (P = .018). By week 6, MMP-2 and MMP-9 levels were reduced by 37% and 55%, respectively. Tissue inhibitor matrix metalloproteinase 1 increased by 42% (P = .033) and TIMP-2 by 44% (P = .04) after 6 weeks of therapy with TCC.This significant and rapid drop of both MMP-2 and MMP-9 strongly suggests a decline of the inflammatory phase and initiation of the proliferation phase.