Defensin Peptide Hydrogel Accelerates Diabetic Wound Healing by Fighting Infection and Inflammation

Alginate-based hydrogels provided sustained hBD-2 release for over 3 days with stable properties across pH 6-8. In vitro, hBD-2 hydrogels showed excellent biocompatibility and superior cell migration promotion compared to PP4-3.1 hydrogels. In a diabetic mouse wound model, hBD-2 hydrogels significantly: accelerated wound closure, improved re-epithelialization and tissue remodeling, reduced microbial wound load, decreased M1-like macrophages and M1/M2 ratio (shifting toward anti-inflammatory phenotype), reduced CD3+ cells, lowered reactive oxygen species levels, and increased neovascularization and collagen deposition.

Alginate hydrogels were designed to deliver two AMPs (hBD-2 and PP4-3.1). Physical characterization included rheology, swelling, porosity, and release kinetics. In vitro testing assessed biocompatibility and cell migration. hBD-2 hydrogels were tested in a streptozotocin-induced diabetic mouse wound model, with outcomes including wound closure rate, histological maturation, microbial load, inflammatory markers (macrophage phenotype, CD3+ cells), ROS levels, neovascularization, and collagen deposition.

Diabetic foot ulcers affect approximately 25% of diabetes patients and cause over 100,000 amputations annually in the US alone. Current treatments fail to address all the factors that impair healing. This hBD-2 hydrogel simultaneously fights infection, calms inflammation, reduces oxidative damage, and promotes tissue repair — a multi-pronged approach matching the complexity of diabetic wound pathology.

The convergence of antimicrobial peptides and advanced hydrogel biomaterials represents a new generation of wound care. Unlike traditional antibiotics, defensin peptides have immunomodulatory properties that go beyond killing bacteria. This study demonstrates that harnessing these dual functions in a sustained-release system can address the root causes of impaired diabetic wound healing — a concept applicable to other chronic wound types.

This is a preclinical study using a mouse diabetic wound model. Mouse wound healing differs from human (contraction vs granulation). The streptozotocin model mimics type 1 diabetes more than type 2, which causes most diabetic foot ulcers. Specific wound closure rates and statistical comparisons were not detailed in the abstract. Long-term outcomes and comparison to existing clinical wound treatments were not assessed.