title: Preparation and evaluation of MRI detectable poly (acrylic acid) microspheres loaded with superparamagnetic iron oxide nanoparticles for transcatheter arterial embolization.
abstract: To monitor the spatial distribution of embolic particles inside the target tissues during and after embolization, blank poly (acrylic acid) microspheres (PMs) were initially prepared by inverse suspension polymerization method and then loaded with superparamagnetic iron oxide (SPIO) nanoparticles by in situ precipitation method to obtain magnetic resonance imaging (MRI) detectable SPIO-loaded poly (acrylic acid) microspheres (SPMs). The loading of SPIO nanoparticles in SPMs was confirmed by vibrating sample magnetometer, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and infrared spectrum, respectively. The results showed that SPMs exhibited excellent superparamagnetism and the SPIO embedded in SPMs were proved to be inverse spinel magnetite. The content of SPIO loaded in wet SPMs of subgroups of 100-300, 300-500, 500-700 and 700-900μm was measured to be 11.84±0.07, 10.20±0.05, 9.98±0.00 and 8.79±0.01mg/ml, corresponding to the weight percentage in freeze-dried SPMs to be 18.07±0.28%, 18.54±0.13%, 18.66±0.01% and 18.50±0.07%, respectively. The SPMs were spherical in shape, had smooth surface, and were within the size range of clinical demands for embolization. The compression tests indicated that SPMs were more rigid than PMs and commercially used Embospheres (P<0.01). The MRI detectability of SPMs was evaluated with the SPMs embedded in gel phantom in vitro and injected subcutaneously into the back of mice in vivo. Both the results demonstrated that the SPMs could provide distinct negative contrast enhancement and be sensitively detected by T2-weighted MR imaging. All the results show that SPMs are potential MRI detectable embolic microspheres for the future embolotherapy.
authors.affiliation: The State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China; Beijing Key Laboratory of Molecular Pharmaceutics and New Drug Delivery Systems, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China.
authors.forename: Huan
authors.initials: H
authors.lastname: Wang
authors.affiliation: The State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China; Beijing Key Laboratory of Molecular Pharmaceutics and New Drug Delivery Systems, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China.
authors.forename: Xiao-Ya
authors.initials: XY
authors.lastname: Qin
authors.affiliation: The State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China; Beijing Key Laboratory of Molecular Pharmaceutics and New Drug Delivery Systems, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China.
authors.forename: Zi-Yuan
authors.initials: ZY
authors.lastname: Li
authors.affiliation: The State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China; Beijing Key Laboratory of Molecular Pharmaceutics and New Drug Delivery Systems, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China.
authors.forename: Li-Ying
authors.initials: LY
authors.lastname: Guo
authors.affiliation: Department of Nuclear Medicine, Beijing Tsinghua Changgung Hospital, Beijing 100044, China.
authors.forename: Zhuo-Zhao
authors.initials: ZZ
authors.lastname: Zheng
authors.affiliation: Department of Radiology, Peking University Third Hospital, Beijing100191, China.
authors.forename: Li-Si
authors.initials: LS
authors.lastname: Liu
authors.affiliation: The State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China; Beijing Key Laboratory of Molecular Pharmaceutics and New Drug Delivery Systems, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China. Electronic address: tianyuan_fan@bjmu.edu.cn.
authors.forename: Tian-Yuan
authors.initials: TY
authors.lastname: Fan
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D000818:Animals; D003287:Contrast Media / Q000008:administration & dosage / Q000737:chemistry; D004548:Elasticity; D004621:Embolization, Therapeutic / Q000379:methods*; D007279:Injections, Subcutaneous; D060328:Magnetic Phenomena; D008279:Magnetic Resonance Imaging; D058185:Magnetite Nanoparticles / Q000008:administration & dosage / Q000737:chemistry / Q000648:ultrastructure; D008297:Male; D051379:Mice; D008863:Microspheres; D010316:Particle Size; D019047:Phantoms, Imaging
chemical_list: D000180:Acrylic Resins; D003287:Contrast Media; D058185:Magnetite Nanoparticles; C006903:carbopol 940
keywords: Detectability; Embolization; Magnetic resonance imaging; Microspheres; Superparamagnetic iron oxide