Zein coated calcium carbonate nanoparticles for the targeted controlled release of model antibiotic and nutrient across the intestine

Abstract In this study, a novel bio-inspired method was used to synthesize calcium carbonate nanoparticles (CaCO3 NPs) using gelatin as a template for the co-delivery of vitamin D and amoxicillin. The synthesized CaCO3 NPs were characterized using Transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Thermogravimetric analysis (TGA) and Brunauer-Emmett-Teller (BET). XRD and TEM confirmed nanocrystalline nature of CaCO3 in size range of 10-15 nm. Further, CaCO3 NPs encapsulated with vitamin D, coated with zein and finally loaded with amoxicillin as a model drug. The release study of vitamin D and amoxicillin was performed in the simulated gastric fluid (SGF) (pH 1.2) and simulated intestinal fluid (SIF) (pH 6.8) and (pH 7.4) at 37 °C temperature. The encapsulation of hydrophobic vitamin D in CaCO3 NPs with an external zein coating approach enhances their controlled and sustained release property at the target site. The role of gelatin molecule in the synthesis of nano-sized CaCO3 was demonstrated using CD spectroscopy. MTT assay was performed on zein coated CaCO3 NPs at varying concentrations on kidney (HEK) and liver (Hep G2) cell lines after 24 hours exposure to ensure its biocompatibility.