RETRACTED ARTICLE: A Low Cytotoxic Metal–Organic Framework Carrier: pH-Responsive 5-Fluorouracil Delivery and Anti-Cervical Cancer Activity Evaluation

Abstract

A new porous metal–organic framework (MOF) [Zn2(ad)2(fmdb)(H2O)](DMF)3 (1, DMF = N,N-dimethylformamide) based on zinc(II) ions, biomolecular adenine (Had) and 4,4′-(fluoromethylene)dibenzoic acid (H2fmdb) has been successfully obtained via a one-pot solvothermal reaction. The structural analysis via the single crystal X-ray diffraction reveals that compound 1 locates in the monoclinic space group C2/c and demonstrates a three-dimensional channel-type neutral framework. The as-prepared complex 1 exhibits low toxicity by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium (MTT) assay, revealing its potential application in human health care. In light of its nano-sized channel space and good stability in biological buffers solution, the activated compound 1 (1a) has been applied as a carrier for loading the anticancer drug 5-Fu (5-Fluorouracil) though a simple adsorption process. The successful loading of 5-Fu was confirmed by the gas sorption measurement and the loading capacity was determined by UV–Vis spectroscopy, which reveals a drug loading capacity of 44.6 wt%. The drug delivery in the simulated cancerous tissues (pH = 5.0) exhibited a more complete release in comparison with that in the normal tissues (pH = 7.4), demonstrating the compound 1a could be potentially used as a pH-controlled drug delivery carrier. In connection to these, in vitro anticancer activity of 5-Fu loaded 1a was also evaluated using MTT assays against two human cervical cancer cells HeLa and SiHa.