AIM:To study the methods of preparing the magnetic nano-microspheres of Fe2O3 and As2O3/Fe2O3 complexes and their therapeutic effects with magnetic fluid hyperthermia(MFH). METHODS:Nanospheres were prepared by chemica...AIM:To study the methods of preparing the magnetic nano-microspheres of Fe2O3 and As2O3/Fe2O3 complexes and their therapeutic effects with magnetic fluid hyperthermia(MFH). METHODS:Nanospheres were prepared by chemical co-precipitation and their shape and diameter were observed.Hemolysis,micronucleus,cell viability,and LD50 along with other in vivo tests were performed to evaluate the Fe2O3 microsphere biocompatibility.The inhibition ratio of tumors after Fe2O3 and As2O3/Fe2O3 injections combined with induced hyperthermia in xenograft human hepatocarcinoma was calculated. RESULTS:Fe2O3 and As2O3/Fe2O3 particles were round with an average diameter of 20 nm and 100 nm as observed under transmission electron microscope.Upon exposure to an alternating magnetic field(AMF),the temperature of the suspension of magnetic particles increased to 41-51℃,depending on different particle concentrations,and remained stable thereafter.Nanosized Fe2O3 microspheres are a new kind of biomaterial without cytotoxic effects.The LD50 of both Fe2O3 and As2O3/Fe2O3 in mice was higher than 5 g/kg.One to four weeks after Fe2O3 and As2O3/Fe2O3 complex injections into healthy pig livers,no significant differences were found in serum AST,ALT,BUN and Cr levels among thepigs of all groups(P>0.05),and no obvious pathological alterations were observed.After exposure to alternating magnetic fields,the inhibition ratio of the tumors was significantly different from controls in the Fe2O3 and As2O3/Fe2O3 groups(68.74% and 82.79%,respectively; P<0.01).Tumors of mice in treatment groups showed obvious necrosis,while normal tissues adjoining the tumor and internal organs did not. CONCLUSION:Fe2O3 and As2O3/Fe2O3 complexes exerted radiofrequency-induced hyperthermia and drug toxicity on tumors without any liver or kidney damage. Therefore,nanospheres are ideal carriers for tumortargeted therapy.展开更多
Fe3O4 ferrofluids containing monodisperse Fe3O4 nanoparticles with different diameters of 8, 12, 16 and 18nm are prepared by using high-temperature solution phase reaction. The particles have single crystal structures...Fe3O4 ferrofluids containing monodisperse Fe3O4 nanoparticles with different diameters of 8, 12, 16 and 18nm are prepared by using high-temperature solution phase reaction. The particles have single crystal structures with narrow size distributions. At room temperature, the 8-nm ferrofluid shows superparamagnetic behaviour, whereas the others display hysteresis properties and the coercivity increases with the increasing particle size. The spin glass-like behaviour and cusps near 190K are observed on all ferrofluids according to the temperature variation of field-cooled (FC) and zero-field-cooled (ZFC) magnetization measurements. The cusps are found to be associated with the freezing point of the solvent. As a comparison, the ferrofluids are dried and the FC and ZFC magnetization curves of powdery samples are also investigated. It is found that the blocking temperatures for the powdery samples are higher than those for their corresponding ferrofluids. Moreover, the size dependent heating effect of the ferrofluids is also investigated in ac magnetic field with a frequency of 55 kHz and amplitude of 200 Oe.展开更多
基金Supported by The National Natural Science Foundation of China,30770584the State 863 Plan,2002AA302207,2007AA03Z356
摘要AIM:To study the methods of preparing the magnetic nano-microspheres of Fe2O3 and As2O3/Fe2O3 complexes and their therapeutic effects with magnetic fluid hyperthermia(MFH). METHODS:Nanospheres were prepared by chemical co-precipitation and their shape and diameter were observed.Hemolysis,micronucleus,cell viability,and LD50 along with other in vivo tests were performed to evaluate the Fe2O3 microsphere biocompatibility.The inhibition ratio of tumors after Fe2O3 and As2O3/Fe2O3 injections combined with induced hyperthermia in xenograft human hepatocarcinoma was calculated. RESULTS:Fe2O3 and As2O3/Fe2O3 particles were round with an average diameter of 20 nm and 100 nm as observed under transmission electron microscope.Upon exposure to an alternating magnetic field(AMF),the temperature of the suspension of magnetic particles increased to 41-51℃,depending on different particle concentrations,and remained stable thereafter.Nanosized Fe2O3 microspheres are a new kind of biomaterial without cytotoxic effects.The LD50 of both Fe2O3 and As2O3/Fe2O3 in mice was higher than 5 g/kg.One to four weeks after Fe2O3 and As2O3/Fe2O3 complex injections into healthy pig livers,no significant differences were found in serum AST,ALT,BUN and Cr levels among thepigs of all groups(P>0.05),and no obvious pathological alterations were observed.After exposure to alternating magnetic fields,the inhibition ratio of the tumors was significantly different from controls in the Fe2O3 and As2O3/Fe2O3 groups(68.74% and 82.79%,respectively; P<0.01).Tumors of mice in treatment groups showed obvious necrosis,while normal tissues adjoining the tumor and internal organs did not. CONCLUSION:Fe2O3 and As2O3/Fe2O3 complexes exerted radiofrequency-induced hyperthermia and drug toxicity on tumors without any liver or kidney damage. Therefore,nanospheres are ideal carriers for tumortargeted therapy.
摘要Fe3O4 ferrofluids containing monodisperse Fe3O4 nanoparticles with different diameters of 8, 12, 16 and 18nm are prepared by using high-temperature solution phase reaction. The particles have single crystal structures with narrow size distributions. At room temperature, the 8-nm ferrofluid shows superparamagnetic behaviour, whereas the others display hysteresis properties and the coercivity increases with the increasing particle size. The spin glass-like behaviour and cusps near 190K are observed on all ferrofluids according to the temperature variation of field-cooled (FC) and zero-field-cooled (ZFC) magnetization measurements. The cusps are found to be associated with the freezing point of the solvent. As a comparison, the ferrofluids are dried and the FC and ZFC magnetization curves of powdery samples are also investigated. It is found that the blocking temperatures for the powdery samples are higher than those for their corresponding ferrofluids. Moreover, the size dependent heating effect of the ferrofluids is also investigated in ac magnetic field with a frequency of 55 kHz and amplitude of 200 Oe.