Lipid-coated mesoporous silica microparticles for the controlled delivery of β-galactosidase into intestines.

β-Galactosidase has been drawing increasing attention for the treatment of lactose intolerance, but its delivery has been impeded by degradation under gastric conditions. We have demonstrated that the coating of mesoporous silica microparticles (diameter ≈ 9 µm, pore size ≈ 25 nm) with dioleoylphosphatidylcholine membranes significantly improved the loading capability and protected the enzymes from the loss of function under simulated gastric conditions. Once the particles are transferred to simulated intestinal conditions, the digestion of phosphatidylcholine with pancreatin led to the release of functional β-galactosidase.

Silica-based systems for oral delivery of drugs, macromolecules and cells.

According to the US Food and Drug Administration and the European Food Safety Authority, amorphous forms of silica and silicates are generally recognized to be safe as oral delivery ingredients in amounts up to 1500mg per day. Silica is used in the formulation of solid dosage forms, e.g.

Core-shell alginate@silica microparticles encapsulating probiotics.

Lactobacillus rhamnosus GG (LGG) was encapsulated in core-shell alginate-silica microcapsules by coating the electrosprayed ionogel with a silica shell via hydrolysis/condensation of alkoxysilane precursors. The viability of encapsulated LGG highly depends on the mineralisation conditions (in aqueous or organic phases), identified as a critical step. More importantly, due to the unswelling of silica and to its mesoporosity that allows nutriment-metabolite diffusion, it was possible to avoid cell leakage and additionally insure bacterial growth inside the microcapsules.