Bioprinted Symbiotic Dressings: A Lichen-Inspired Approach to Diabetic Wound Healing with Enhanced Bioactivity and Structural Integrity

Providing oxygen and preventing infection at wound sites are effective ways to heal diabetic chronic wounds. Inspired by natural lichens, a bioprinted biogenic hydrogel (BBH) containing microalgae and probiotics is developed for diabetic chronic wound therapeutics, which offers prolonged biogenetic oxygen supply by microalgae and infection inhibition by probiotics. The rational design of symbiotic BBH with customizable structure and microorganism composition enhances wound resilience against elevated glucose levels and hypoxia, leading to the increased migration ability of fibroblasts and the angiogenic potential of human umbilical vein endothelial cells. Notably, BBH-treated diabetic wounds exhibit dense vascular distribution, reduced hypoxia levels and inflammatory responses, and enhanced epithelial differentiation and keratinization abilities. Consequently, the BBH achieves rapid tissue repairing within 3 d and restores approximately 90% of the whole skin structure within 12 d. This work presents an engineered platform for regulating biological microenvironment of diabetic wounds and provides insights for developing bioprinted hybrid microorganism systems.