Study On The Super Paramagnetic Isoniazid Sulfate-loaded PELA Microsphere

The nanospheres of super paramagnetic is the Fe3O4 nanoparticles size below 30 nm ,the thermal vibration energy is overcome the magnetic attraction, showing super paramagnetic. It have a strong magnetic response under the magnetic field. But when out of magnetic field ,the magnetic soon disappear.Super paramagnetic magnetic microsphere is one of the magnetic targeting drug delivery system. It is a microspheres which contains the nanospheres of super paramagnetic magnetic. The microspheres with good magnetic compliance which can be applied magnetic field guidance to the focus area ,However, without external magnetic field they have well distributed.As a good carrier of microspheres,PELA is PEG-PLA Polymer copolymer which have biodegradable and biocompatible characteristics. In this study, isoniazid is the model drug which will combine with Fe3O4 nanoparticles of superparamagnetic, and use the PELA as carrier materials, preparation of superparamagnetic isoniazid PELA microspheres (SPI-PELA-MS). The Preparation of SPI-PELA-MS,the drug release in vivo and in vitro,the targeting of SPI-PELA-MS are be research.PART 1 The Preparation and characterization of Fe3O4 nanospheres of superparamagneticThe Fe3O4 nanospheres of super paramagnetic were prepared by chemical coprecipitation. It is characterized from the appearance, traits of magnetic induction. The Fe3O4 nanospheres of super paramagnetic is black uniform suspension, size range of about 15-20nm, saturation magnetization 21.431emu / g.PART 2 The Preparation of superparamagnetic isoniazid PELA microspheres (SPI-PELA-MS)SPI-PELA-MS is prepared by double-emulsion/solvent evaporation method . Study some factors which affect technic of preparation, such as Concentration of PVA , PELA concentration, Speed of viscolizer and so on. In this part UV method is established to determinate the encapsulation efficiency and drug loading. SPI-PELA-MS of Optimal Preparation : The average encapsulation efficiency is 62.35%, the average drug loading is 5.01%, the average intensity of magnetic response is 2.17 emu / g, the average particle size is 2.7μm. Study the stability of. SPI-PELA-MS in different temperatures . -4℃is the best for stability. PART 3 Study the drug release of SPI-PELA-MS In vivoStudy the drug release of SPI-PELA-MS In vitro. Observed three groups of drug release: A group, superparamagnetic isoniazid PELA microspheres; B group, isoniazid PELA microspheres. A, B groups are affect by oscillating magnetic field for 15 minutes before each sample. C group, isoniazid PELA microspheres, without oscillating magnetic field, as a blank. The results show that whit the affect by oscillating magnetic field, A group of drug release was significantly higher than B group.PART 4 Study the drug release of SPI-PELA-MS In vitro and targetingStudy the drug release of SPI-PELA-MS in vivo by injecting of muscles( isoniazid/rabbit weight=10mg/1kg) . A group, superparamagnetic isoniazid PELA microspheres; B,C group, isoniazid PELA microspheres. From 15min to 11 hours 17 sampling points have been set. three group get plasma 1.0ml on each sampling point. On 10 sampling points, before getting sampling, A, B groups were affect by oscillating magnetic field for 15 minutes. The results show that the oscillating magnetic field by the interference, can increase the drug from SPI-PELA-MS in the release. Targeting study,Venous injection of SPI-PELA-MS to Rabbit, affect by oscillating magnetic field. observed by MRI, The results is that SPI-PELA-MS have characterization of Targeting.