Development of Biocompatible Iron-Carboxylate Metal Organic Frameworks for pH-Responsive Drug Delivery Application.

Metal organic frameworks (MOFs), MIL-101-Fe (Materials of Institute Lavoisier), have been synthesized by solvothermal method. The as-synthesized MIL-101-Fe particles are observed to have hexagonal shaped morphology with average particle size ranging from 480 to 500 nm. The functionalization of the surface of as-synthesized MIL-101-Fe particles was done with the integration of amine group into the framework to facilitate the conjugation of the drug and other entities. Further, the drug conjugated MOF particles were coated with polyethyleneglycol (PEG) layer so as to extend the drug release time by controlling the faster pH mediated MOF degradation in biological buffers. pH dependent drug release study of the MOF particles was carried out at 3 different pH values, i.e., 5, 6 and 7.4. The drug release profiles showed that the drug released from NH₂-MIL-101-Fe takes less time which was further increased after coating the NH₂-MIL-101-Fe with polyethyleneglycol (PEG@Drug@NH₂-MIL-101-Fe). This confirmed that PEG coated particles have great stability for drug delivery application.