Solid lipid nanoparticles: a sustainable platform for smart delivery of agrochemicals in crop production

Abstract

Agriculture, a cornerstone of our global food supply, is constantly evolving with new technologies that improve productivity, sustainability and environmental protection. Despite their widespread use, conventional agricultural inputs face critical challenges, including rapid degradation, poor bioavailability, non-targeted delivery and environmental contamination. Nanotechnology-based delivery systems have shown promise in increasing agricultural productivity and mitigating environmental impacts. Since the 1990s, solid lipid nanoparticles (SLNs) composed of solid lipids, such as waxes, glycerides and fatty acids, have emerged as innovative delivery systems to deliver various active molecules. Compared with alternative delivery systems, SLNs offer several benefits, including polymer-based nanoparticles, liposomal carriers and lipid emulsions. SLNs enter plant systems through multiple pathways, including foliar penetration via cuticles and stomata and root uptake through apoplastic and symplastic transport. These versatile entry routes enhance the delivery of nutrients and agrochemicals, contributing to more efficient and sustainable agricultural practices. This review provides a comprehensive analysis of SLN fabrication methods, including ultrasonication, high-pressure homogenization, microemulsion, solvent evaporation, solvent diffusion, solvent injection and double emulsion, alongside solid lipid-based nanoscale templates for active ingredient incorporation. It also highlights the physicochemical properties of lipids used in SLNs, evaluates the advantages and limitations of various SLN formulations and systematically explores their integration into agricultural systems. By enhancing input efficiency, reducing environmental impact and enabling targeted delivery of bioactive compounds, SLNs represent a transformative approach to sustainable agriculture. Their continued development and application hold significant promise for advancing food security and ecological resilience in future farming practices.