Bio-compatible Metal-Organic Frameworks as potential drug-carriers

M.C. BERNINI; D. FAIREN-JIMENEZ; P.M. PASINETTI; A.J. RAMIREZ-PASTOR; R. Q. SNURR

Sevilla

Congreso; EUROMAT 2013 European Congress and Exhibition of Advanced Materials and Processes; 2013

The study of the molecular mechanisms that control drug delivery in porous systems is of critical importance to nanomedicine applications, where nanotechnology has the potential to revolutionize cancer diagnosis and therapy by improving the biodistribution of therapeutic agents, so their efficacy can be increased while their toxicity is attenuated. In particular metal-organic frameworks (MOFs) have been recently proposed for drugdelivery applications.1,2 MOFs are obtained by the self-assembly of metal clusters and organic linkers, resulting in tailored nanoporous host materials. By tuning the host/guest interaction, not only varying the pore size but also by functionalizing the building blocks with chemical groups, MOFs have the possibility to control the kinetic release of a therapeutic agent. From the many different MOF structures, a systematic study of their performance in drug delivery and bioimaging is essential to identify promising structures. Simulations provide an outstanding tool to predict the performance of the materials and, like so, to select the optimal structures for a given application. Grand canonical Monte Carlo (GCMC) simulation is the work horse for simulating adsorption in porous materials, predicting and explaining experimental results. However, the simulation of large guest molecules (e.g. a drug) is difficult because of the tight fit of the molecules in the pores. As a consequence, reported modeling studies on drug-porous solid systems are rather scarce, being even more limited when one looks specifically at the family of porous MOFs. In this work, we used GCMC simulations to screen a series of biocompatible MOFs as carrier systems for the model drug ibuprofen (IB), an anti-inflammatory and analgesic drug. We focus on different aspects, such as the drug capacity, the localisation of the adsorption sites, and the drug loading-release dependency on the isosteric heat of adsorption (Qst) and the shape of the adsorption isotherms. Our IB capacities range from 230 to 1900 mg/g, while the Qst varies from 60 to 160 kJ/mol. We have also verified the existence of different anchoring points at the frameworks surfaces, which determines strong interactions that govern the adsorption and release phenomena.