Functionalization of Magnetic Nanoparticles with Dendritic鈥揕inear鈥揃rush-Like Triblock Copolymers and Their Drug Release Properties

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• 作者：Xiaohua He ; Xiaomeng Wu ; Xin Cai ; Shaoliang Lin ; Meiran Xie ; Xinyuan Zhu ; Deyue Yan
• 刊名：Langmuir
• 出版年：2012
• 出版时间：August 14, 2012
• 年：2012
• 卷：28
• 期：32
• 页码：11929-11938
• 全文大小：493K
• 年卷期：v.28,no.32(August 14, 2012)
• ISSN：1520-5827

文摘

Novel water-soluble dendritic鈥搇inear鈥揵rush-like triblock copolymer polyamidoamine-b-poly(2-(dimethylamino)ethyl methacrylate)-b-poly(poly(ethylene glycol) methyl ether methacrylate) (PAMAM-b-PDMAEMA-b-PPEGMA)-grafted superparamagnetic iron oxide nanoparticles (SPIONs) were successfully prepared via a two-step copper-mediated atom transfer radical polymerization (ATRP) method. The macroinitiators were immobilized on the surface of Fe₃O₄ nanoparticles via effective ligand exchange of oleic acid with the propargyl focal point PAMAM-typed dendron (generation 2.0, denoted as propargyl-D_2.0) containing four carboxyl acid end groups, following a click reaction with 2鈥?azidoethyl-2-bromoisobutylate (AEBIB). PDMAEMA and PPEGMA were grown gradually from nanoparticle surfaces using the 鈥済rafting from鈥?approach, which rendered the SPIONs soluble in water and reversed aggregation. To the best of our knowledge, this is the first report that describes the functionalization of magnetic nanoparticles with dendritic鈥搇inear鈥揵rush-like triblock copolymers. The modified nanoparticles were systematically studied via TEM, FT-IR, DLS, XRD, NMR, TGA, and magnetization measurements. DLS measurement confirmed that the obtained dendritic鈥搇inear鈥揵rush-like triblock copolymer-grafted SPIONs had a uniform hydrodynamic particle size of average diameter less than 30 nm. The dendritic鈥搇inear鈥揵rush-like triblock copolymer-grafted SPIONs possessed excellent biocompatibility by methyl tetrazolium (MTT) assays against NIH3T3 cells and hemolysis assays with rabbit erythrocytes. Furthermore, an anticancer drug, doxorubicin (Dox), was used as a model drug and loaded into the dendritic鈥搇inear鈥揵rush-like triblock copolymer-grafted SPIONs, and subsequently, the drug releases were performed in phosphoric acid buffer solution pH = 4.7, 7.4, or 11.0 at 37 掳C. The results verify that the dendritic鈥搇inear鈥揵rush-like triblock copolymer-grafted SPIONs possess pH-responsive drug release behavior. The Dox dose of the loaded and free drug required for 50% cellular growth inhibition was 2.72 and 0.72 渭m/mL, respectively, according to MTT assay against a Hella cell line in vitro. Therefore, on the basis of its biocompatibility and drug release effect, the modified SPION could provide a charming opportunity to design some excellent drug delivery systems for therapeutic applications.