A Stellera chamaejasme-derived multifunctional biocomposite with antibacterial, mosquito-repellent, and biodegradable properties.

The increasing threat of healthcare-associated infections and mosquito-borne diseases demands new materials that combine antimicrobial protection, insect repellency, and biocompatibility. Here, we convert Stellera chamaejasme L. (SC), an ecologically harmful invasive weed, into a multifunctional biocomposite (SCZrB/WPU) by integrating SC root fibers, bamboo waste, zirconium phosphate (ZrP), and waterborne polyurethane (WPU). The resulting material exhibits >99.99% antibacterial efficacy against S. aureus and E. coli, and >89.5% repellency against Aedes albopictus. It releases only 0.14 mg L-1 formaldehyde, well below the most stringent indoor air quality standards. The biocomposite is fully biodegradable in soil (69.1% mass retention after 60 days) with no microplastic residues. Moreover, the composite fiberboard showed excellent water resistance, UV stability, and flame retardancy. With a flexural strength of 30.22 MPa, it can serve as a sturdy yet decomposable support in temporary medical facilities and infection-control barriers for public health applications. This work transforms an ecological liability into a sustainable material for public health and environmental barrier applications, offering a circular solution for low-resource settings where both infection and vector control are critical.