Lipid-Based Nanosystems to Enhance the Bioaccessibility and Bioavailability of Algal Lipids

Lipid-based nanosystems (LBNs) present a promising opportunity to harness algae-derived lipids for food and nutraceutical applications, addressing the growing consumer demand for natural and safe ingredients. Algal lipids have attracted increasing attention due to their sustainability and composition in bioactive lipids, particularly omega-3 and omega-6 polyunsaturated fatty acids and polar lipids. However, their poor aqueous solubility, susceptibility to oxidation, and variable bioaccessibility restrict their effective application in food systems. LBNs, including nanoliposomes, nanoemulsions, solid lipid nanoparticles, nanostructured lipid carriers, and self-nanoemulsifying systems, have been proposed to improve the delivery of algal lipids by improving their solubilization, protecting them from gastrointestinal degradation, and potentially enhancing their intestinal absorption. This review critically examines and integrates the available evidence from in vitro digestion models, cellular and ex vivo assays, as well as in vivo studies, to provide insights into how LBNs modulate bioaccessibility, intestinal absorption, bioavailability, and downstream biological activities of algal lipids. Key methodological limitations and knowledge gaps that currently hinder definitive conclusions are also discussed, with the aim of guiding future research toward more robust and translatable evidence in this field and to support the development and application of algal lipid-loaded nanosystems in functional foods, nutraceuticals, and clinical nutrition.