Modeling and Simulation of Magnetophoresis of Nanoparticles for Magnetic Targeting Applications

Despite numerous studies on drug delivery to the brain there still remain some questions on how can blood brain barrier be overcome in the process of drug transport, and how can drug be targeted and confine within a particular portion of the brain. Drug loaded paramagnetic particle seems to have potential to eliminate the challenges encountered during drug delivery to the central nervous system. Paramagnetic particles, under the effect of external magnetic field, can be used as carriers to effectively transport drugs through cerebrospinal fluid and deliver to the targets without being disturbed by the blood brain barrier and brownian motion. Since the in vivo experiments are expensive and difficult to conduct for such systems, a mechanistic model that can predict the dynamics and distribution of paramagnetic particles is necessary for the optimal design of drug delivery systems. The existing models are applicable to dilute solutions of paramagnetic particles and cannot be extended to concentrated solution, which is generally created near the magnetic targets. Here we present a framework to model magnetophoretic diffusion and convection of paramagnetic particles in a concentrated solution. An analytical solution to the magnetic field-driven transport of particles in 1-D and 3D were developed with application to drug delivery through cerebrospinal fluid. This solution gives rise to concentration profiles of the paramagnetic nanoparticle. The effect of activity coefficient was investigated. Invitro experimental study of paramagnetic nanoparticle transport in a tube was used to back up our model prediction. The result obtained from our model and experiment show that paramagnetic nanoparticle can be confined in a particular domain of the central nervous system (CNS) which will aid the delivery and targeting of drug to the domain.