Keratin-Silver Nanoparticle Composite (Keratin-AgNPs) Derived from Poultry Feathers and Hylocereus megalanthus Peel for Antimicrobial and Ecotoxicological Applications: The increasing demand for sustainable nanomaterials has encouraged the development of multifunctional biopolymer-based systems with biomedical and environmental applications. In this study, a keratin-silver nanoparticle composite (Keratin-AgNPs) was synthesized using keratin extracted from poultry feathers and green-synthesized silver nanoparticles (AgNPs) obtained from Hylocereus megalanthus (pitahaya peel) extract. Keratin extraction was optimized through sulfitolysis using response surface methodology (RSM), achieving an extraction yield of 89% under optimal conditions (pH 9, 70 °C, 6 h). AgNPs synthesis was optimized at 34.8 °C, 39.2 min, and pH 8, producing stable nanoparticles with an average hydrodynamic size of 72.1 nm, PDI of 0.210, and zeta potential of -36.8 mV. Physicochemical characterization using FTIR, UV-Vis, DLS, TEM, SEM, Raman spectroscopy, and TGA confirmed keratin structural preservation, nanoparticle formation, colloidal stability, and favorable morphological features. The Keratin-AgNPs composite exhibited enhanced antimicrobial activity against Staphylococcus aureus, moderate antibacterial effects against Escherichia coli, and concentration-dependent antifungal activity against Aspergillus niger. Ecotoxicological evaluation using Daphnia magna, Artemia salina, and Lactuca sativa suggested low-to-moderate toxicity under controlled exposure conditions, supporting environmental compatibility compared with free nanoparticles. Compostability assessment further demonstrated favorable degradation behavior, highlighting the potential of Keratin-AgNPs as a sustainable nanomaterial aligned with green chemistry and circular economy principles for biomedical, antimicrobial, and environmentally responsible applications.

Teodora Lloclla Aguilar is a researcher, university lecturer, and environmental project developer in chemistry, nanotechnology, environmental science, and sustainable technologies. She is a PhD candidate in Chemistry at the National University of Engineering (UNI), Peru, and holds a Master’s degree in Chemical Engineering from the National University of Callao (UNAC). Her research interests include green chemistry, biomaterials, ecotoxicology, environmental monitoring, wastewater treatment, and sustainable nanotechnology. She has participated in multidisciplinary research and innovation projects and received national and international awards in environmental entrepreneurship and sustainability.