Plant-Derived Nanocarriers for Drug Delivery: A Unified Framework Integrating Extracellular Vesicles, Engineered Phytocarriers, Hybrid Platforms, and Bioinspired Systems

Plant-derived extracellular vesicles (PDEVs), engineered phytosomes, bioinspired polymeric plant-based nanoparticles (PBNPs), hybrid phyto-inorganic nanocomposites, green-synthesized metal nanoparticles, self-assembled nanoarchitectures, and multifunctional composites represent a rapidly advancing class of sustainable, nature-inspired nanocarriers. These platforms combine exceptional biocompatibility, negligible immunogenicity, and renewable sourcing with tunable drug loading, targeted delivery, and controlled release properties. This review synthesizes translational advances from 2020 to 2026, covering scalable isolation/bioprocessing (bioreactors, elicitation), multi-parametric physicochemical/multi-omics characterization, rational engineering/hybridization, and rigorous in vitro/in vivo assessments of uptake, biodistribution, pharmacokinetic (PK), and efficacy. Phytosomes and PBNPs markedly enhance oral bioavailability and targeted delivery of lipophilic phytochemicals, while PDEVs offer unique immunomodulatory, anti-inflammatory, and gene-regulatory activities. Hybrid and green-synthesized systems provide structural stability, redox modulation, and synergistic effects, and self-assembled/multifunctional composites address solubilization barriers with stimuli-responsive design. Early-phase human studies on grapefruit-, ginger-, turmeric-, and ginseng-derived PDEVs report excellent short-term safety, favorable PK, and preliminary bioactivity signals, with no observed immunogenicity or dose-limiting toxicities; however, these trials remain exploratory, constrained by small sample sizes and safety-focused endpoints. Despite challenges, including methodological heterogeneity, variable yields, long-term safety uncertainties (notably for inorganic hybrids), and regulatory ambiguities, emerging strategies such as clustered regularly interspaced short palindromic repeats (CRISPR)-engineered plant line; artificial-intelligence-driven process optimization; standardized guidelines, and integrated clinical, intellectual property, and commercialization frameworks are progressively addressing these barriers. Collectively, these advances position plant-derived nanocarriers as immunologically privileged, eco-friendly alternatives to synthetic and mammalian platforms, laying the foundation for a sustainable era of precision phytomedicine.