Study On The Targeting Delivery Of Magnetic Nanoparticles And Its Application On Lung Targeting

The magnetic targeted drug delivery system is one of the most attractive strategiesdue to its non-invasiveness, high targeting efficiency and minimizing the toxic sideeffects on healthy cells and tissues. Magnetic drug targeting therapy can be used for themedical treatment of various diseases, especially cancer. If combined with theinhalation aerosol, this technique can cure the diseases of the respiratory tract and lungs.It could result in wide range of uses and the huge potential market demand.The purpose of the dissertation is to optimize the targeting delivery of magneticdrug-loaded particles in respiratory tract. First, we used Metropolis Monte Carlo methodto simulate the magnetic nanoparticles aggregation in uniform magnetic field. Theparticles will form the chain-like clusters, branched clusters and looped clusters aligningin the orientation external magnetic field. Then the quasi-Halbach permanent magnetarray was designed and constructed, which used to magnetic particle aggregation asexternal magnetic field generation device. Based on the coupled physics field ofmagnetic field and fluid field, the motion of magnetic aerosol particles in Y-shape tubewas studied in different condition of external field.The main research works of the dissertation include:(1) We used Metropolis Monte Carlo method to simulate the magneticnanoparticles aggregation in uniform magnetic field. From small to large diameters thedistribution of orientations approach the orientation of magnetic field direction step bystep, the larger one forms chain-like clusters, smaller size forms clusters with branchedand looped shapes. An analysis of total particles system energy with Monte Carlo stepswas conducted.(2) The magnetic field distribution around Halbach magnet has single-sided feature,which could improve the utilization efficiency of magnetic field energy. We examinedthree evaluation factors，such as magnetic field strength, the effectiveness of magneticfield strength parameters and lateral uniformity of magnetic force parameters. Theresults demonstrate the Halbach magnet array than normal magnet is more than twoorders of magnitude improvement for the three factors. And, the three evaluation factorspresented in thesis can provide methods available for performance evaluation of a typetargeting delivery magnet system.(3) The calculation model of coupled magneto-fluid field was introduction based on based on gas-solid two-phase flow model with sparse solid-phase. The methodologyof our research is based on analysis of relationship of between flow velocity and flowrate, flow rate and pressure analysis. In summary, after imposing a magnetic field thevelocity decreases and the pressure drop increases at the target position as the magneticfield intensity increases. Thus concentration of magnetic aerosol particles near themagnet side has risen. The directed flow of magnetic aerosol particle flow is changedwith the distance with magnet. Volume fraction of different can also cause changes inthe velocity difference. After the comparisons of single magnet and Halbach magnetarray, the Halbach magnet is2-3times that of a single magnet about the capacity offluid acceleration.(4) Derived from3.5cm Halbach magnet array can provide a difference of morethan2times the aggregation, and along with the atomizing time of growth, aggregationdifference is more obvious from the results of in vitro experiments. Judging from theexperimental results on rat inhalation, add field group the iron content of the right andleft sides of the lungs than in the normal group and without magnetic field group, thegroups iron content was significant difference (P <0.01), and the left and rightsignificantly different on both sides, the difference is more than2times. From thehistology of rat lung lobe analysis, we can clearly see the difference of the magneticnanoparticles deposited on different the lung tissue.