DIELECTROPHORETIC ASSEMBLY OF DRUG-LOADING NANOPARTICLES WITH DRUG-ELUTING STENTS

ZHU Shucun YI Hong NI Zhonghua

(Department of Mechanical Engineering, Southeast University, Nanjing 210096 )

Abstract: A novel drug-loading method using dielectrophoretic self-organization is proposed to solve the local drug-loading of intravascular stents studded with microprobes. Based on dielectrophoretic assembly mechanism, the dimensionless dielectro-phoretic force and the governing equation of motion for a particle, the drug-loading model of intravascular stents by dielec-trophoresis is built for finite element analysis of the dielectrophoretic force distribution and the motion trajectories of particles in the problem space. The influence of the relative particle/electrode position and Brownian motion on the assembly efficiency is also discussed. It is proved that the assembly scheme using dielectrophoresis is feasible in theory. Finally, upon the results of the simulation, theoretical predictions of the particle response under the electric fields are experimentally confirmed by the drug-loading testing platform. Results show that for 4.4 m latex beads suspended in de-ionized (DI) water, when the value (peak-to-peak) of the applied voltage is 10 V and the AC frequency is in the range of 0.1～1.0 MHz, the particles begin to move towards the electrodes drived by positive dielectrophoretic force, and when the AC frequency is 500 kHz, the motion rate of particle reaches the highest level.

Key words: Nano-dielectrophoresis Drug-loading nanoparticles Brownian motion Drug-eluting stents

CLC No: TP271 

教育部科学技术研究(106083)和江苏省自然科学基金(BK2005072, BK2006709)资助项目. Received 20051102, received in revised form 20060530