Oral absorption mechanisms of polysaccharides and potential as carriers for the construction of nano-delivery systems: A review.

Polysaccharides have garnered increasing attention in recent years for their potential in oral drug delivery within biomaterials and pharmaceuticals, owing to their excellent physicochemical properties, bioactivity, and low toxicity. However, the absorption of polysaccharides encounters multiple challenges posed by the biological, chemical, mechanical, and immune barriers of the intestinal mucosa. Therefore, elucidating the mechanisms by which polysaccharides traverse the intestinal mucosa for oral absorption is essential for their further development and application. Current studies have identified several polysaccharide absorption pathways, including transcellular transport, paracellular transport, M cell and Peyer's patches mediated transport, and intestinal flora mediated transport. Furthermore, numerous studies have demonstrated that polysaccharides can enhance the solubility, gastrointestinal stability, and permeability of small molecule components, which significantly improves their bioavailability. More importantly, nano-delivery systems utilizing polysaccharides as carriers have shown great promise in enhancing the targeting of small molecule components, thereby opening new avenues for drug delivery applications. We hope this review will provide theoretical support and inspiration for a deeper understanding of oral absorption mechanisms and the potential of polysaccharides in the development of nano-delivery systems.