Sodium alginate based piezoelectric hydrogel for promoting healing of infected wounds at movable parts

The frequent movement is an obstacle to the healing of wounds at movable parts. It would be highly beneficial if this characteristic could be utilized to accelerate wound healing process. Herein, we developed a sodium niobate (NNO) hydrogel (NNO-Gel) for promoting healing process of wounds at movable parts based on its photodynamic and piezoelectric properties. NNO-Gel is formed through incorporating NNO into polyvinyl alcohol‑sodium alginate hydrogel using calcium chloride as a cross-linking agent. NNO-Gel could not only produce reactive oxygen species for bacteria inactivation with simulated sunlight irradiation, but also generate electric field for promoting cell migration and proliferation through the frequent movement of necks. With simulated sunlight irradiation, NNO-Gel could kill 95.6 % ± 1.4 % of bacteria, 9.3 % higher than NNO nanomaterials. The cell proliferation rate reaches 148.41 ± 6.37 % by NNO nanomaterials with ultrasound irradiation through activating and phosphorylating phosphoinositide 3-kinase and protein kinase B. For infected neck wounds, NNO NMs and NNO-Gel show 23.6 ± 5.1 % and 25.3 ± 6.1 % higher healing rate than PBS treated ones. The development of NNO-Gel provides an opportunity for transforming the negative frequent movement which prevents wound healing into motive power for promoting healing of wound at movable parts, as well as the possibility of clinic applications for piezoelectric nanomaterials.