Metal-organic-frameworks for biomedical applications in drug delivery, and as MRI contrast agents

Intelligent anticancer drug delivery performances of two poly(N-isopropylacrylamide)-based magnetite nanohydrogels

This article evaluates the anticancer drug delivery performances of two nanohydrogels composed of poly(N-isopropylacrylamide-co-itaconic anhydride) [P(NIPAAm-co-IA)], poly(ethylene glycol) (PEG), and Fe₃O₄ nanoparticles. For this purpose, the magnetite nanohydrogels (MNHGs) were loaded with doxorubicin hydrochloride (DOX) as a universal anticancer drug. The morphologies and magnetic properties of the DOX-loaded MNHGs were investigated using transmission electron microscopy (TEM) and vibrating-sample magnetometer (VSM), respectively. The sizes and zeta potentials (ξ) of the MNHGs and their corresponding DOX-loaded nanosystems were also investigated. The DOX-loaded MNHGs showed the highest drug release values at condition of 41 °C and pH 5.3. The drug-loaded MNHGs at physiological condition (pH 7.4 and 37 °C) exhibited negligible drug release values. In vitro cytotoxic effects of the DOX-loaded MNHGs were extensively evaluated through the assessing survival rate of HeLa cells using the MTT assay, and there in vitro cellular uptake into the mentioned cell line were examined using fluorescent microscopy and fluorescence-activated cell sorting (FACS) flow cytometry analyses. As the results, the DOX-loaded MNHG1 exhibited higher anticancer drug delivery performance in the terms of cytotoxic effect and in vitro cellular uptake. Thus, the developed MNHG1 can be considered as a promising de novo drug delivery system, in part due to its pH and thermal responsive drug release behavior as well as proper magnetite character toward targeted drug delivery.

A 3D metal–organic framework with dual-aerial-octahedral trinucleate building units: synthesis, structure and fluorescence sensing properties

JLNU-2 can be used to detect nitrobenzene with high selectivity, sensitivity, anti-interference ability and recyclability through tracing the fluorescence quenching behaviour.

Gate-opening upon CO2 adsorption on a metal–organic framework that mimics a natural stimuli-response system

A dynamic d-champhorate-based protuberant-grid-type framework, undergoes gate opening and closing processes that were triggered by the stimuli of the adsorption or desorption of CO₂. It is able to specifically recognize CO₂ over than N₂ and H₂ and shows a high CO₂ uptake of 90 mg g⁻¹ under 35 bar at 298 K.