In vitro fecal fermentation of acylated porous Canna edulis starch and corresponding stabilized Pickering emulsions.

In this study, acylated porous Canna edulis starch with varying degrees of substitution (DS) were prepared and employed for stabilizing Pickering emulsions. Subsequently, the fermentation characteristics of them were investigated. Enzymatically produced porous starch (PS) was esterified with acetic, propionic, butyric, or valeric anhydrides, yielding acetylated (PSA-0.116), propionylated (PSP-0.163), butyrylated (PSB-0.304), and valerylated PS (PSV-0.462) with different DS. Scanning electron microscopy revealed the presence of pores and surface micro-particles in the modified PS, confirming successful esterification through characteristic peaks in 1H NMR and a CO peak at 1736 cm-1 in the FT-IR spectrum. With increasing DS, starch exhibited reduced crystallinity (PSV, 26.61 %), elevated resistant starch content (PSV, 91.63 %), and a higher contact angle (PSV, 87.13°). Acylated PS particles effectively stabilized Pickering emulsions. Pickering emulsions stabilized by acylated PS with higher DS exhibited higher emulsification index and smaller droplet sizes. In vitro fermentation of acylated PS and corresponding stabilized Pickering emulsions fostered short-chain fatty acid production, boosted the relative abundance of beneficial bacteria (Bifidobacterium, Prevotella, etc.) while inhibited the growth of harmful bacteria (Escherichia-Shigella, Comamonas, etc.), maintaining the intestinal microbiota balance. These findings support the potential applications of acylated PS and corresponding stabilized Pickering emulsions in functional foods and drug delivery.

Mucus-penetrating dendritic mesoporous silica nanoparticle loading drug nanocrystal clusters to enhance permeation and intestinal absorption.

Multiple gastrointestinal barriers (mucus clearance and epithelium barrier) are the main challenges in the oral administration of nanocarriers. To achieve efficient mucus penetration and epithelial absorption, a novel strategy based on mesoporous silica nanoparticles with dendritic superstructure, hydrophilicity, and nearly neutral-charged modification was designed. The mPEG covalently grafted dendritic mesoporous silica nanoparticles (mPEG-DMSNs) had a particle size of about 200 nm and a loading capacity of up to 50% andrographolide (AG) as a nanocrystal cluster in the mesoporous structure. This dual strategy of combining with the surface topography structure and hydrophilic modification maintained a high mucus permeability and showed an increase in cell absorption. The mPEG-DMSN formulation also exhibited effective transepithelial transport and intestinal tract distribution. The pharmacokinetics study demonstrated that compared with other AG formulations, the andrographolide nanocrystals-loaded mPEG-DMSN (AG@mPEG-DMSN) exhibited much higher bioavailability. Also, AG@mPEG-DMSN could significantly improve the in vitro and in vivo anti-inflammatory efficacy of AG. In summary, mPEG-DMSN offers an interesting strategy to overcome the mucus clearance and epithelium barriers of the gastrointestinal tract.