Orally fed EGCG coronate food released TiO2 and enhanced penetrability into body organs via gut

Owing to unique nano-scale properties, TiO2-NPs (T-NPs) are employed as food-quality enhancers in >900 processed food products. Whereas, epigallocatechin-3-gallate (EGCG), a green tea polyphenol is consumed in traditional brewed tea, globally. Taken together, we aimed to investigate whether human gastric-acid digested T -NPs and complex tea catechins yield ionic species (Ti4+ , Ti3+ etc.) and active EGCG forms to meet favourable conditions for in vivo bio-genesis of EGCG-coronated TiO2-NPs (ET-NPs) in human gut. Secondly, compared to bare-surface micro and nano-scale TiO2, i.e., T-MPs and T-NPs, respectively, how EGCG coronation on ET-NPs in the gut facilitates the modulation of intrinsic propensity of internalization of TiO2 species into bacteria, body -organs, and gut-microbiota (GM), and immune system. ET-NPs were synthesized in non-toxic aqueous solu-tion at varied pH (3-10) and characterised by state-of-the-arts for crystallinity, surface-charge, EGCG-encapsu-lation, stability, size, composition and morphology. Besides, flow-cytometry (FCM), TEM, EDS, histopathology, RT-PCR, 16S-rRNA metagenomics and ELISA were also performed to assess the size and surface dependent ac-tivities of ET-NPs, T-NPs and T-MPs vis-a-vis planktonic bacteria, biofilm, GM bacterial communities and ani-mal's organs. Electron-microscopic, NMR, FTIR, DLS, XRD and EDS confirmed the EGCG coronation, dispersity, size-stability of ET-NPs, crystallinity and elemental composition of ET-NPs-8 and T-NPs. Besides, FCM, RT-PCR, 16S-rRNA metagenomics, histopathology, SEM and EDS analyses exhibited that EGCG coronation in ET-NPs-8 enhanced the penetration into body organs (i.e., liver and kidney etc.) and metabolically active bacterial com-munities of GM.

Automated summary

In this study, ET-NPs were synthesized at different pH values and characterized using advanced techniques. The surface activities of ET-NPs, T-NPs, and T-MPs in planktonic bacteria, biofilm, GM bacterial communities, and animal organs were assessed using flow cytometry, TEM, EDS, histopathology, RT-PCR, 16S-rRNA metagenomics, and ELISA. Electron-microscopic, NMR, FTIR, DLS, XRD, and EDS analyses confirmed the EGCG coronation, dispersity, size-stability of ET-NPs, and crystallinity and elemental composition of ET-NPs-8 and T-NPs. In addition, FCM, RT-PCR, 16S-rRNA metagenomics, histopathology, SEM, and EDS analyses demonstrated that EGCG coronation in ET-NPs-8 enhanced the penetration into body organs and metabolically active bacterial communities of GM.