Enhancement of oral bioavailability of natural compounds and probiotics by mucoadhesive tailored biopolymer-based nanoparticles: A review

Encapsulation in polymer NPs (NPs) is a well-recognized way to improve the oral bioavailability of hydrophobic and hydrophilic compounds by enhancing their solubility in aqueous medium, to protect them from acid and enzymatic degradation in the gastrointestinal tract, and to favour their permeability across the mucosal membranes. Nanostructures rather than larger delivery systems are also proposed to encapsulate prebiotics, probiotics and natural antimicrobial compounds, as they allow greater penetration of the mucous layer, as well as lower and longer dosages. The NPs with mucoadhesive capacity are designed specifically to increase the residence time at the intestinal absorption sites due to their ability to adhere to the intestinal mucosa. However, they should also be able to penetrate through the mucosa to reach the enterocytes or intestinal absorptive cells. By using the appropriate materials, the size and surface properties of NPs can be routed towards a particular mucus-interaction mechanism. Polymer NPs are widely employed for oral delivery applications in the pharmaceutical industry, since their surface properties are easily tunable to improve mucoadhesive capacity and mucus penetrating ability. Due to their biodegradability, biocompatibility and non-toxicity, biopolymer NPs have gained interest in recent years as mucoadhesive delivery systems for potential food applications. This review aims to promote attention to the use of food-grade biopolymer NPs to increase the bioavailability of natural compounds based on their mucoadhesive potential, and to facilitate the delivery of prebiotics, probiotics and antimicrobials along the gastrointestinal tract. This also includes a previous brief introduction to the complex mucoadhesion mechanism and common evaluation methods for determining mucoadhesiveness in nanoparticulate systems.