The Research Of Magnetic Drug-carrier Particles For Directional And Local Adipose Tissue Growing

Magnetic carrier particles (MCP) containing Fe₃O₄ have many unique properties such as good biocompatibility, directional reaction to a magnetic field, and can be modified due to the functional group on its surface. MCP are widely studied for their application in biological and medical application such as magnetic resonance imaging(MRI),cell-separation, enzyme immobilization, immunity analysis and detection, drug delivery, biology substance magnetic separation for purification and so on. This study has becoming a hot topic in these years, and many kinds of product have been involved in an increasing number of biological and medical applications.The aim of this thesis is to create a new drug delivery system which will promote the growth of adipose tissue in objective site without usage of any hormone or their similarities. The principle of this study is that the drug A promoting growth of fat can be carried on magnetic particles so that be released in objective site with application of a additional magnetic field. This method is different from those of the products in application in market. The resulting delivery system has obvious advantage over the products in market, so that it should have a potential market and would be beneficial both in economy and society. The idea was not reported in the country or in the world.The thesis mainly contains two parts. Part I is about the preparation of the magnetic particles, changing of the characters mainly charges, defining the conditions for the magnetic particles to carry drug A, and revealing the carrying mechanism. Part II is about researches on stability of the drug carrying ability of the particles, on drug releasing and about the promoting effect on growth of adipose tissue. Partâ…  1. Preparation of the magnetic particles.The magnetic Fe₃O₄ particles with appropriate size were prepared by way of co-precipitation. The co-precipitation is simple in operation with low cost and giving high yield. The size is controllable with this method. The reaction conditions affecting size of the particles were discussed. XRD, VSM,FTIR,Zetasizer revealed that the size of the prepared particles were 50-400nm, which is suitable for the drug delivery and for animal experiments. The magnetic particles were modified to make them to be more stable and to enhance their drug loading capability.2. Research about drug loading capability, loading mechanism and changes of magnetic particles characters.The results showed that the drug loading capability enhanced with increasing of concentrations of drug A. The greatest capacity of drug loading is 15.30(g/g). IR revealed that drug A was linked to magnetic particles through chemical bonds. The size was reduced slightly after drug loading. Although maximized saturation magnetization was reduced from 62.70emu/g to 40.37emu/g, but the particles were still paramagnetic belonging to soft magnetism with well targeting.Part II1. Drug storing stability of the magnetic particlesThe stability were tested in 4°C and room temperature. The results showed that the change of the amount of drug on the particles was 9.5% and 11.6% in 28 days in 4°C and room temperature respectively, so it was concluded that the loading was stable.2. Research about drug releasing.The drug releasing was studied with a model simulating process in vivo in animal. The results showed that drug released steadily from the second day to the fifth day .Such releasing was satisfied with the requirement of this study.3. Research the growth of adipose.The growth of adipose was studied in animal experiments. Female Wistar rats were used to test the growth of adipose. The results showed that the growth of adipose did arises with administration of magnetic particles and adipose occurred in special cites with magnetic field.