Living Chinese Herbal Scaffolds from Microfluidic Bioprinting for Wound Healing

Biological scaffolds have been widely employed in wound healing applications, while their practical efficiency is compromised by insufficient oxygen delivery to the 3-dimensional constructs and inadequate nutrient supply for the long-term healing process. Here, we present an innovative living Chinese herbal scaffold to provide a sustainable oxygen and nutrient supply for promoting wound healing. Through a facile microfluidic bioprinting strategy, a traditional Chinese herbal medicine (Panax notoginseng saponins [PNS]) and a living autotrophic microorganism (microalgae Chlorella pyrenoidosa [MA]) were successfully encapsulated into the scaffolds. The encapsulated PNS could be gradually released from the scaffolds, which promoted cell adhesion, proliferation, migration, and tube formation in vitro. In addition, benefiting from the photosynthetic oxygenation of the alive MA, the obtained scaffolds would produce sustainable oxygen under light illumination, exerting a protective effect against hypoxia-induced cell death. Based on these features, we have demonstrated through in vivo experiments that these living Chinese herbal scaffolds could efficiently alleviate local hypoxia, enhance angiogenesis, and thereby accelerate wound closure in diabetic mice, indicating their great potential in wound healing and other tissue repair applications.