Models and Methods for Local Drug Delivery with Nano/Micro Structured Materials


People involved: Alberto Redaelli, Simone Vesentini, Gianfranco B. Fiore, Monica Soncini, Alfonso Gautieri, Emiliano Votta

Funding source: Italian Institute of Technology

Funding period: 2008 - 2010

Partners: Dipartimento di Matematica, Politecnico di Milano; Dipartimento di Ingegneria Strutturale, Politecnico di Milano.

Micro-structured materials with a controlled degradation profile can be designed to store a drug to be delivered in a desired way after implantation in a biological tissue. This can be used in different contexts, ranging from coating of prostheses and bone inserts for reducing the inflammatory reaction after the implantation up to resorbable stents and to drug delivery devices for use in the brain and in the eye (for instance either from contact lenses or trough laser-activated nanoliposomes). An accurate mathematical modeling of the mass transport accounting for interactions at both the nano and the micro scales with the artificial materials of the device or the adjacent tissue is still missing. This is a challenging task both for physics and mathematics. Indeed, drug delivery from either polymeric or ceramic matrices involves complex phenomena at the nanoscopic and microscopic scales as Brownian ratchet effects, hydrophobic/hydrophilic transitions, phase transitions (solid/liquid) and material erosion. On the nanoscale, by means of atomistic bulk models, it is possible to predict and to tailor the permeability, the diffusion coefficient and the solubility properties of the material with respect to a given solvent molecule. These parameters are then related to the transport and degradation properties of the material at the macro-scale and are incorporated in the mathematical model. In a micro-structured material, both its degradation and its capability to store/release a target drug are driven by the chemical structure of the material. Thus, modeling tools such as molecular dynamics (MD) inclusive of reactive terms and discrete particle dynamics (DPD) are suitable tools to explore the aforementioned properties for a given class of materials of interest.