Bio-based nanomaterials in drug delivery: An updated review

Bio-based nanomaterials have emerged as promising drug delivery platforms due to their biocompatibility, biodegradability, and ability to enhance therapeutic performance. Conventional drug delivery systems are often limited by poor drug solubility, rapid degradation, low bioavailability, and nonspecific distribution, particularly for natural bioactive compounds such as polyphenols, alkaloids, and terpenoids. Recent advances in nanotechnology have enabled the development of bio-based nanocarriers capable of improving drug stability, controlled release, intracellular transport, and site-specific delivery. This review provides an updated overview of natural nanomaterials used in drug delivery, including polysaccharide-, protein-, lipid-, and green-synthesized inorganic nanocarriers. Major delivery platforms such as nanoliposomes, micelles, nanosuspensions, solid lipid nanoparticles, and polymeric nanostructures are discussed alongside their mechanisms of action, including passive targeting via the enhanced permeability and retention (EPR) effect, ligand-mediated active targeting, and stimuli-responsive drug release. The review further examines recent applications in cancer therapy, gastrointestinal disorders, delivery of natural bioactive compounds, vaccines, gene therapy, and neurological diseases. In addition to highlighting therapeutic advantages, this review critically discusses current translational challenges, including large-scale manufacturing, batch reproducibility, long-term safety, biodistribution, immunogenicity, and regulatory limitations. A key contribution of this review is the integration of comparative analysis and translational perspectives across major bio-based nanocarrier systems, highlighting the need for standardized evaluation frameworks and scalable production strategies. Future research should focus on reproducible green synthesis methods, quantitative benchmarking, advanced characterization approaches, and clinically relevant validation studies to accelerate the translation of natural nanomaterials into pharmaceutical applications.