Study On Folic Acid-Modified Magnetic Mesopourous Silica Loaded Nanoparticles

All kinds of cancer rates remain high and increasing at an alarming rate during the past several decades.Although enormous efforts have been made in comprehensive treatment for this diease,little or no survival improvement was obtained.According to the report from National Cancer Institute（NCI）in USA,nanobiotechnology has tremendous potential for cancer prevention,diagnosis,and treatment.magnetic mesoporous silica nanoparticles surface functional groups with folic acid conjugated with target specificity,can selectively bind with over-expressed antigents or receptors on the surface of cancer cells,make it easy to infiltrate into the cell and control drug release.In this paper,Fe₃O₄magnetic nanoparticles were prepared by hydrothermal method with the main raw materials of ferric chloride,and the particle size was uniform,about70～120nm.Using the sol-gel method and improved stober method out of the Fe₃O₄@meso-SiO₂composite nanoparticles,and through infrared spectrum,scanning electron microscopy（sem）and transmission electron microscopy（sem）to confirm mesoporous silica successfully coated on the surface of ferroferric oxide nanoparticles;X-ray diffraction determined that the original crystal type did not change;The specific surface area of nitrogen adsorption was 204.57 m²/g,and the average pore diameter was4.5nm.Levomisole was used as a model drug,and the drug loading capacity of magnetic mesoporous silica nanoparticles with folic acid modified was 19.38%,and the encapsulation efficiency was 55.35%.In vitro release of Fe₃O₄@meso-SiO₂-FA nanoparticles by dialysis method,it could be seen that the insoluble drug levamisole was acid soluble to p H,the lower of the p H value of the buffer medium,the more drug released.The greater the drug load,the faster of the drug release;Compared with free drugs,Fe₃O₄@meso-SiO₂-FA nanoparticles could reduce the sudden release effect and slow release of drugs and the nanoparticles modified by folic acid were more targeted.The MCF-7 cytotoxicity of blank nanoparticles before and after folic acid modification was investigated by MTT,the results showed that the concentration of under50 ug/m L,there was no obvious toxicity for cell as a carrier material;When the concentration was higher than that of 50 ug/m L,the toxicity of the nanoparticles modified by folic acid was lower than that of unmodified blank nanoparticles.Also The effects of different concentrations of nanoparticles on the survival rate of MCF-7 tumor cells were investigated,draw the conclusion that:with the increase of drug concentration,the cell survival rate decreases but still can achieve 65%above,which improve levamisole and cannot be used separately as anticancer drugs.The pharmacokinetic characteristics of levamisole in rats were studied by using the established HPLC analysis method,the results showed that the selected method of chosen well in specificity,precision and recovery of the method are accord with the requirement of determination of biological sample analysis,the blood drug concentration-time curve showed that the Fe₃O₄@meso-SiO₂-FA nanoparticles could significantly extend the residence time of drugs in rats,had good sustained release effect,could better improve the therapeutic effect of drugs,decrease the number of medications,and had the vital significance to improve the patient compliance.