Active Targeting Strategies for Improving the Bioavailability of Curcumin: A Systematic Review

Curcumin (CUR) is a bioactive compound with well-documented therapeutic potential in diverse pathological conditions, encompassing intestinal disorders-most notably colonic cancer-as well as extra-intestinal malignancies such as hepatic, breast, and renal tumors. However, the therapeutic efficacy of CUR is severely constrained by its poor aqueous solubility, chemical instability, and consequent low systemic bioavailability. Nano-scaled carriers (nanocurcumin) enhance CUR solubility and membrane permeability through their reduced dimensions and/or specific interactions with membrane constituents. Nevertheless, conventional nanocurcumin formulations, such as unmodified liposomes, nanocapsules, nanogels, and nanofibers, continue to accumulate substantially in non-target tissues because of their lack of disease-specific tropism. This review focuses on the most recent advances in active targeting strategies for nanocurcumin, specifically receptor-mediated cellular targeting for extra-intestinal pathologies and colon-specific ligand-directed delivery for intestinal disorders. Current methodologies for validating the efficacy of engineered nanocurcumin formulations are critically reviewed, and the prevailing limitations alongside prospective future applications of nanocurcumin are delineated and discussed.