A porous Zn-based metal-organic framework for pH and temperature dual-responsive controlled drug release.

A porous metal-organic framework Zn-TBDA (TBDA = 4′-(1H-tetrazol-5-yl) -[1,1′-biphenyl]-3,5-dicarboxylic acid) with one-dimensional channels has been synthesized from zinc ions and bifunctional ligands. The negligible cytotoxicity of Zn-TBDA is confirmed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium (MTT) assay and microscopy observation. The anticancer drug methotrexate (MTX) is loaded into Zn-TBDA successfully via in-situ encapsulation and the loading capability reaches about 12.59 wt% in resulting composite MTX-encapsulated Zn-TBDA. Under different physiological microenvironments, MTX-encapsulated Zn-TBDA exhibits sensitive pH and temperature dual-responsive release manners, revealing its practical value as a smart drug carrier with controlled release in certain site and improved therapeutic efficacy without any additional external fields. [ABSTRACT FROM AUTHOR]