Evaluation of iron transport from ferrous glycinate liposomes using Caco-2 cell model.

BACKGROUND: Iron fortification of foods is currently a strategy employed to fight iron deficiency in countries. Liposomes were assumed to be a potential carrier of iron supplements. OBJECTIVE: The objective of this study was to investigate the iron transport from ferrous glycinate liposomes, and to estimate the effects of liposomal carriers, phytic acid, zinc and particle size on iron transport using Caco-2 cell models. METHODS: Caco-2 cells were cultured and seeded in DMEM medium. Minimum essential medium was added to the basolateral side. Iron liposome suspensions were added to the apical side of the transwell. RESULTS: The iron transport from ferrous glycinate liposomes was significantly higher than that from ferrous glycinate. In the presence of phytic acid or zinc ion, iron transport from ferrous glycinate liposomes and ferrous glycinate was evidently inhibited, and iron transport decreased with increasing phytic acid concentration. Iron transport was decreased with increase of particle size increasing of ferrous glycinate liposome. CONCLUSION: Liposomes could behave as more than a simple carrier, and iron transport from liposomes could be implemented via a mechanism different from the regulated non-heme iron pathway.

A Fluorescence Biosensor for Detection of Mercury Ion Based on Oligonucleotide / 分析化学

A simple,fast and highly sensitive fluorescence analysis method for detection of mercury ion was developed based on N-methyl-mesoporphyrin IX (NMM)/G-quadruplex DNA system and specific T-Hg-T mismatches.In this strategy,a large number of thymine was introduced into guanine-rich oigonucleotides which could form G-quadruplex.In the presence of Hg2+,guanine-rich oigonucleotides and complementary strand could form double-stranded DNA molecule by specific T-Hg-T mismatch pair,leading to destruction of G-quadruplex DNA structure.In the absence of Hg2+,guanine-rich oigonucleotides spontaneously formed G-quadruplex DNA structure that could bound NMM to generate intense fluorescence.Based on the above facts,a sensitive fluorescence biosensor for determination of Hg2+ was fabricated.And the optimal conditions for Hg2+ determination were as follows:buffer solution pH of 6.7,20 mmol/L KCl and 2.5 μmol/L NMM in buffer and incubation for 2 h.Under the optimal conditions,the fluorescence intensity signal change (F0-F) and the Hg2+ concentration exhibited a linear correlation within 50 nmol/L to 1000 nmol/L range with a low detection limit of 22.8 nmol/L (3σ).The biosensor exhibited good selectivity toward common metal ions.The developed method was successfully employed to detect Hg2+ in tap water with recovery of 106.1％-107.8％.