Biomacromolecules, Vol.21, No.9, 3795-3806, 2020
Dual Cross-linked HHA Hydrogel Supplies and Regulates M Phi 2 for Synergistic Improvement of Immunocompromise and Impaired Angiogenesis to Enhance Diabetic Chronic Wound Healing
Immunocompromise and impaired angiogenesis of diabetes lead to chronic inflammation when wounds occur, which is the primary reason for the long-term incurable nature of diabetic chronic wounds. Herein, a high-molecular-weight hyaluronic acid (HHA) hydrogel is developed to supply and regulate M2 phenotype macrophages (M Phi 2) for synergistic improvement of immunocompromise and impaired angiogenesis. M Phi 2 are seeded on the Cu-HHA/PVA hydrogels prepared by Cu2+ cross-linking of low degree and physical cross-linking (one freeze-thaw cycle and unique lyophilization) to form Cu-HHA/PVA@M Phi 2 hydrogels. The Cu-HHA/PVA@M Phi 2 hydrogel can directly supply the M Phi 2 in the wound site, maintain the consistent phenotype of loaded M Phi 2, and transform the M1 phenotype macrophages (M Phi 1) in the wound bed to M Phi 2 by HHA. Furthermore, Cu2+ could be released from the hydrogels to further stimulate angiogenesis, thus accelerating the wound-healing phase transition from inflammation to proliferation and remodeling. The average wound area after the 0.5Cu-HHA/PVA@M Phi 2 (ionic cross-linking degree 0.5%) treatment was much smaller than that of other diabetic groups at day 12 and close to that of the wild nondiabetic control group. Therefore, this facile hydrogel strategy with multiple modulation mechanisms of immunocompromise and angiogenesis may act as a safe and effective treatment strategy for a diabetic chronic wound.