Gibberellic Acid Surface-Modified Lignin-Derived Nanoparticles as Multifunctional Delivery Systems for Nanoscale CuS to Lettuce (Lactuca sativa): Optimizing Nutrient Uptake and Plant Health

High Resolution Image Download MS PowerPoint Slide Biodegradable nanoparticulate delivery systems for agrochemicals have been explored as alternatives to conventional formulations, but few systems have been engineered for multifunctionality (antioxidant, antibacterial, antifungal, UV-protectant, and growth-regulatory). Here, a biodegradable lignin-based nanodelivery system chemically modified with the plant growth regulator (PGR) gibberellic acid (GA 3 ) was developed to deliver nanoscale copper sulfide (nCuS), a plant nutrient complex with antimicrobial properties. The amphiphilic polymer GA 3 -LN-PLGA was used to synthesize monodisperse (PDI 0.09 ± 0.02), negatively charged (−63.70 ± 5.27 mV), core−shell nanoparticles (NPs) with entrapped nCuS (128.74 ± 0.65 nm). Hydroponic exposure of 250 mg/L GA 3 -LNPs(nCuS) to lettuce ( Lactuca sativa ) increased Cu uptake in roots compared to untreated plants (>30 mg/kg DW), with minimal translocation ( p > 0.5907) to the leaves and mild oxidative stress responses. Protein (Bradford assay) and metabolite (HPLC-DAD) analyses revealed no significant effect of nanoscale exposure with minimal biochemical disruptions. This innovative agrochemical delivery system has the potential to influence plant growth and protection, leading toward improved crop yields.