Tai-Chi Hydrogel with Chinese Philosophy and Photothermal Properties for Accelerated Diabetic Wound Healing

Abstract Bacterial cellulose (BC) and photothermal hydrogels are widely used currently in wound repair. However, modified and functionalized BC maybe damage the advantages of natural BC that limits its application as a wound dressing, and photothermal hydrogels have problem of secondary damage about overheating during photothermal therapy process. Therefore, we develop a Tai-Chi hydrogel inspired by the Chinese philosophy of “Tai Chi”, which is consist of BC, namely Yin, and polyvinyl alchol/polydopamine (PVA/PDA), namely Yang. Two hydrogels of Tai-Chi hydrogel have opposite properties to selectively cover on healthy skin and the wound, to adjust/balance the wound temperature under NIR irradiation. In vitro experiments demonstrate that mild warm caused by Yang hydrogel under NIR irradiation promote polarization of RAW 264.7 macrophages to M2 phenotype. Tai-Chi hydrogel itself has a significant therapeutic effect on diabetic wound by regulating inflammatory microenvironment. In addition, Tai-Chi hydrogel in combination with NIR irradiation exhibited remarkably therapeutic effect by promoting re-epithelialization and angiogenesis, accelerating collagen deposition and macrophages polarization to M2 phenotype. This work firstly presents the novel strategy in designing functional materials with opposite properties inspired by the philosophy of "Yin-Yang" in “Tai Chi” as diabetic wound dressing.