Methotrexate drug uptake through dimethyl ethylenediamine post-modified metal–organic framework as a carrier: optimization using RSM.

This study reports the performance of Zr-based MOF, UiO-66, modified by Dimethyl Ethylenediamine (UiO-66-mmen) for anticancer methotrexate drug (MTX) uptake. This post-synthetic modified MOF is kind of a support for carrying a medicine in biological media. The surface morphology and characteristics of the modified MOF were analyzed using SEM, EDX, FTIR, PXRD and BET. Also, the optimum values of three effective parameters including pH, MOF dosage and contact time were calculated by response surface methodology (RSM) and central composite design (CCD). The results showed that the best conditions for pH, MOF dosage and time were 3, 0.15 g and 89 min, respectively while MTX uptake efficiency was 88.54%. The results show that the Langmuir isotherm model (q_m = 1000 mg g⁻¹) can better fit the equilibrium data, demonstrating the monolayer adsorption of MTX on UiO-66-mmen. Besides, it was revealed that three predominant mechanisms including H-bonding, interaction between Zr-sites of UiO-66 and carboxyl groups of MTX, and π–π stacking interactions govern MTX uptake on UiO-66-mmen. The kinetic data also exhibited that the Lagergren model is the predominant kinetic model and MTX adsorption on UiO-66-mmen is physical type. Moreover, the thermodynamic analysis proved that MTX uptake is spontaneous, endothermic and physical type. [ABSTRACT FROM AUTHOR]