Sustainable Conversion of Husk into Viscoelastic Hydrogels for Value-Added Biomedical Applications

Natural plants provide a wealth of valuable materials for healthcare, with much of their potential often overlooked in what is commonly considered waste. This study focuses on the Malva Nut Tree (Sterculia lychnophora Hance), whose fruit, PangdaHai (PDH), has long been used in traditional Chinese medicine. By investigating PDH husk's swelling behavior, we efficiently extracted its polysaccharides without harsh chemicals. Using micro-compression, we developed a viscoelastic hydrogel, and through electrostatic crosslinking with chitosan, we further enhanced its mechanical properties. The hydrogel exhibited biocompatibility and accelerated wound healing by promoting keratinocyte migration. Additionally, it outperformed commercial patches as a skin-attached interfacial material for electrocardiography (ECG), demonstrating superior signal-to-noise ratios. Integrated into a 16-channel mesh-electronic device, the hydrogel provided stable performance for in vivo epicardial ECG recording on a beating heart. This research highlights the potential of rigid polysaccharide waste, presenting a sustainable approach to converting plant waste into valuable healthcare materials.