Plant Lipid Droplets and Derived Lipidic Nano-Assemblies: Structure, Biogenesis and Pharmaceutical Applications

Lipid droplets (LDs) serve as the primary storage site for neutral lipids in plant cells, with growing evidence supporting many additional biological roles, such as in lipid homeostasis, signalling, trafficking, inflammatory responses and inter-organelle communication. While the biogenesis and structure of LDs in seeds and other plant tissues have been well-documented, the full range of their functions has yet to be elucidated. Plant LDs encapsulate a hydrophobic neutral lipid core, enveloped by a phospholipid monolayer embedded with specific proteins. Despite their tissue-specific diversity, a range of methods for LD isolation from plant materials has been established, facilitating lipidomic and proteomic characterisation. This knowledge has facilitated studies into the potential applications of LDs, particularly in pharmaceutical biotechnology. This review explores the multifunctional nature and biogenesis of plant LDs, highlights recent advances in LD fractioning from plant materials, explores factors affecting their stability, and discusses the potential of mimicking natural LDs using artificial lipid nano-droplets (ALNDs) and similar synthetic lipid-based formulations. It also underscores the significance of LD-based delivery systems in pharmaceutical applications, emphasising their emerging potential in enhancing drug solubility, bioavailability and targeted delivery. Finally, future research directions are highlighted, focusing on scaling up LD isolation, optimising ALND and other formulations, and investigating their pharmacokinetics and long-term stability for more widespread clinical applications.