Food-grade nanostructured delivery systems for oral administration of astaxanthin: Bioprocessing strategies and therapeutic applications.

Astaxanthin (AXT), a naturally occurring xanthophyll carotenoid with potent antioxidant, anti-inflammatory, and anticancer properties, has garnered significant attention as a multifunctional nutraceutical. However, its poor aqueous solubility, chemical instability, and low gastrointestinal bioavailability have limited its clinical and functional food applications. In recent years, food-grade nanoparticle systems, particularly lipid-based and polymeric nanocarriers, have emerged as promising platforms to enhance the oral bioavailability and targeted delivery of AXT. This review critically explores the latest advances in bioprocessing strategies for the formulation of AXT-loaded nanoparticles using food-safe materials, such as solid lipid nanoparticles, nanostructured lipid carriers, liposomes, protein-based carriers, and biodegradable polymers like chitosan and alginate. Key aspects, including preparation techniques, encapsulation efficiency, physicochemical stability, controlled release, and intestinal absorption mechanisms, are discussed. Furthermore, the review highlights the therapeutic efficacy of nanoparticle-mediated AXT delivery in addressing multiple health targets, such as oxidative stress, chronic inflammation, neurodegeneration, metabolic disorders, and cancer. Regulatory perspectives, safety considerations, and challenges related to industrial scalability are also addressed. Overall, this paper provides a comprehensive overview of food-grade nanocarriers as a transformative approach for the oral delivery of AXT, paving the way for its successful integration into functional foods.