| Cancer is one of the major diseases, which is harmful to human health. During the course of therapy, the anticancer drugs plays a key role, mainly through the destruction of the structure and function of DNA to kill tumor cells, but the concentration of local drug through the blood vessels is very limited, and these anticancer drugs to kill tumor cells, at the same time, have a variety of side effects (nephrotoxicity, gastrointestinal toxicity, myelo suppression, etc.). The drug delivery has a special value and significance in making anticancer drugs to play better efficacy, reduced toxicity, safe and effective targeted drug delivery. The hollow magnetic materials have with low density, high surface area, larger internal space, superparamagnetic and surface permeability, as drug carrier material can improve the drug loading capacity, to achieve the targeted administration, sustained release pharmaceutical and reduce the side effects of drugs. Medical polymer materials with excellent biocompatibility, biodegradability, degradation rate have good workability and it can be adjusted. This paper combined the advantages of the hollow magnetic materials and polymer materials prepared the hollow magnetic polymer composite particles (hollow Fe3O4/SiO2@PEG-PLA). And the applications of them in drug delivery were studied.1. Hollow magnetic particle preparation and performance characterization:first polystyrene (PS) microspheres was prepared by dispersion polymerization, then the interfacial deposit was used to prepare Fe3O4/PS composite particles, and PS was used as template. The sol-gel process was used to prepared Fe3O4/SiO2/PS microspheres. Later high temperature calcination maked template PS decomposed, and hollow Fe3O4/SiO2(HMS) was obtained. The infrared (FT-IR), X-ray diffraction (XRD) and transmission electron microscopy (TEM), vibration sample magnetometer(VSM) were used to characterize the morphology and properties of the product. The study showed the method to obtain the hollow magnetic particle of around200nm, obvious hollow structure, good dispersion and superparamagnetism.2. Synthesis of HMS@PEG-PLA:(3-aminopropyl) triethoxysilane (APTES) by a silanization reaction, amine-functionalized HMS (HMS-NH2) nanoparticles were prepared, to made good effect with other organic functional groups. Through the opening ring polymerization with Sn(Oct)2as the catalyst synthetic PEG-PLA and coated HMS microspheres (HMS@PEG-PLA). By FT-IR, XRD, TEM, VSM on the product was characterized. The results show that the microspheres still has the superparamagnetic and good dispersion.3. HMS and HMS@PEG-PLA biocompatility reaserch:L929mouse embryonic fibroblast using MTT colorimetry method to research cell toxicity. MTT experimental results show that both of them showed fairly low cell toxicity, can safely used as drug carrier appling to medical field in human boby.4. The drug release behavior research of HMS and HMS@PEG-PLA:Using them as drug delivery vehicles and the cisplatin (CDDP) as the model drug, the release behavior was researched, we performed vitro drug release studies under physiological conditions, in PBS at37℃for study of drug release behaver. The experimental results show that drug loadings were127μg/mg and172μg/mg respectively, hollow magnetic nanoparticles show higher drug loading rates, and at the same time the drug have obvious slow-release effect and good stability. So the product is expected to be used for targeted drug delivery system. |
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