An Adeninate-Based Metal-Organic Framework for Antitumour Drug Delivery and Anti-Osteogenic Sarcoma Activity Evolution

Targeted anticancer drug delivery systems (DDSs) have been considered as one of the most important approaches for reducing the side effects and enhancing the therapy effect in cancer treatment. This work presents a targeted anticancer DDS on the basis of a newly synthesised adeninate-based metal-organic framework (MOF) [Zn-2(ad)(2)(AMDB)(H2O)](DMF)(3) (1) with biomolecular adenine (HAd), zinc(ii) ions, and 4,4-(aminomethylene)dibenzoic acid (H(2)AMDB) as the molecular building blocks. The structural analysis via X-ray diffraction technology shows MOF 1 is a channel-type three-dimensional network composed of rod-like Zn-Ad chains. Due to its large inner free spaces and uncoordinated N donor sites functionalised pore surroundings, the antitumour molecule 5-fluorouracil (5-Fu) could be loaded into the pores of 1a (activated 1) though an adsorption process, which shows a moderate high storage capacity of 32 wt-%. At the same time, the pH-dependent delivery of 5-Fu could be achieved in phosphate-buffered saline (PBS) solution. With a lower pH value, the drug release will be enhanced. Furthermore, the invitro antitumour activity of the drug/1a composite has been probed via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay on two human osteogenic sarcoma cells (MG63 and U2OS).