Research On The Statistical Mechanics Transport Theoretical Model Of Magnetic Carrier Particles In A Permeable Microvessel

The magnetic targeted drug delivery system has become one of the most attractive strategies of the treatment of tumor due to its high targeting efficiency, low toxicity and non-invasiveness. It can improve the drug concentration of the drug target site, minimize the side effects on healthy tissues and cells and increase the treatment greatly. Thus, it can result in wide range of uses and huge potential market demand.A magnetic drug targeting statistical mechanics transport model in a permeable microvessel is developed first. The flow of blood through a permeable microvascular is described by assuming the blood as a Casson-Newton two-fluid model, and the Darcy model is used to characterize the permeable nature of the inner wall of the microvascular. The coupling effect between the blood flow and interstitial fluid flow is considered by using the Starling assumptions in the model. The random motion of carrier particles in microvascular is described by the Boltzmann equation which includes the elastic collision effect between carrier particles and red blood cells.Then, the distribution of blood flow velocity, blood pressure, interstitial fluid pressure and carrier particles distribution in permeable microvascular are obtained by numerical coupling to solve the magnetic force equation, blood pressure equation, interstitial fluid pressure equation and Boltzmann equation. On this basis, the capture efficiency of the carrier particles is obtained. The present results show that the capture efficiency of the particles will increase with the enhancement of the size of the carrier particles and the external magnetic field intensity. In addition, when the permeability of the inner wall is better and the inlet blood flow velocity is slow, the capture efficiency of the particles will increase as well.Finally, the validity of the model is verified by in vitro experiment, where the influence of the flow rate and the distance between magnet and vascular centerline over the magnetic particle capture efficiency is analyzed. Therefore, the results can provide valuable reference data for the clinical application of magnetic drug targeting method.