pH-responsive MOF as Drug Carrier for Controlled Drug Release Studies

Abstract

Metal–organic frameworks (MOFs) are porous materials composed of metal ions or clusters that are connected by organic ligands. These structures are currently being extensively studied as drug delivery systems (DDS) due to their ability to be customized, high capacity for holding cargo, and ease of modification for targeting specific areas and improving stability within the body. Zirconium (Zr) and its metal-organic frameworks (MOFs), especially the well-known Zr terephthalate UiO-66, have been extensively researched due to their outstanding biocompatibility. In this paper, we present a thorough investigation of Zr-MOF in relation to its application in drug delivery. The Zr-MOF is capable of accommodating the drug cisplatin (CP) and can also undergo surface alteration during synthesis, either by coordination modulation or post-synthetic. The FTIR analysis of PEGylated, Silanized Zr-MOF shows a significant peak at 648cm-1 confirming the O-Zr-O bond with peaks at 3648cm-1, 1940cm-1, 1345cm-1, and 1200 cm-1 confirming the O-H of the polymer, C=N vibration, C-N vibration of imidazole and C-O vibration of the composite. Peak at 650cm-1 corresponds to the N-Si-O bond which confirms the incorporation of poly(ethylene) glycol particles inside the MOF structure. Moreover, XRD analysis shows characteristic peak positions at 7.3º, 8.3 º, 11.89 º, and 25.4º indicates a high level of crystallinity in the synthesized product, confirming the presence of UiO66-NH2, APTES and PEG. The drug release study UiO66-NH2 and modified UiO66-NH2 were conducted at acidic, basic, and neutral pH levels over a specific period of time. The highest amount of 90% of Cisplatin was released under acidic circumstances. The strong connections between the modified MOF and the molecules of the CP medication are due to the inclusion of APTES and PEG, causing them to entangle with the drug molecules. Ammino functionalized UiO66 is more effective at transporting the drug Cisplatin (CP) to target sites. The results show that ammino functionalized Zr-MOF is an attractive alternative to UiO-66 for drug delivery.