Study Of Invitro And Invivo Toxicity And Lung Targeted Functions Of Superparamagnetic Iron Oxide Nanoparticles

Objective:To prepare the SPIONs modified by chitosan or sodiumoleate and investigate their invitro and invivo toxicity and lung targetedfunctions.Methods:1The SPIONs were prepared by coprecipitation and theirproperties were measured. A549cells were treated by the SPIONs andprussian blue staining was performed. SPIONs of different concentrationswere added and MTT assay was used to detect the effect of SPIONs on cellproliferation. The activity of LDH in the supernatant was tested.Furthermore, cell apoptosis was analyzed by DAPI staining.2Fifty four SD rats were divided into three groups including controlgroup, chitosan-SPIONs group and sodium oleate-SPIONs group. The ratswere exposed to SPIONs by intratracheal instillation. General condition ofthe rats was observed.Six rats of each group were killed at24h,72h and14days after exposure. The major blood biochemical indicators were analyzedwith an automatic biochemical analyzer. The total cells and neutrophil cells of BALF were counted. The pathological changes of lungs were observedwith HE Staining.3The magntic field strength was measured. Fifteen SD rats weredivided into three groups including control group, with magnetic fieldgroup and without magnetic field group. The rats inhaled thechitosan-SPIONs and Halbach magnetic field was put at the position of theright lung.The iron content was measured with orthophenanthrolene andthe prussian blue staining of the pathological sections of lungs were used tofind the difference of iron content of the left and right lungs.Results:1(1)The SPIONs both exhibited structure of spherecrystallization with a diameter of20-30nm and they could enter A549cellsin the cytoplasmic region.(2)MTT assay result showed that chitosan-SPIONs hardly affected cell survival rate while sodium oelate modifiedSPIONs ranging from100to200μg/mL inhibited the proliferation of A549cells on24h and72h(Ｐ<0.05).(3)The activity of LDH in the supernatantof cells treated with100μg/mL and200μg/mL sodium oleate-SPIONs washigher than the control group and the groups treated with the sameconcentration of chitosan-SPIONs(Ｐ<0.05).(4)The typical displays forapotosis, such as nuclear shrinkage and fragmentation were mostlyobserved in cell treated with sodium oelate modified SPIONs and theirapoptosis rate was higher than the control group(Ｐ<0.05).2(1)Only two blood biochemical indicators (12h TP and14day ALP)had differences with the control group.（2）Total cells and neutrophilcells in BALF of experimental groups were higher than the control groupon24h and72h(Ｐ<0.05) and that of sodium oleate-SPIONs group wereobviously higher than chitosan-SPIONs group(Ｐ <0.05). HE stainingshowed that inflammation were both observed in the experimental groups.And the sodium oleate-SPIONs group was more serious than thechitosan-SPIONs group. The lung injures of chitosan-SPIONs group weregradually reduced over time.3(1)Measurement of the magntic field strength showed that theHalbach magnetic field exhibited a tapered magntic field.(2)The ironcontent measurement and the prussian blue staining of the pathologicalsections of lungs both showed that the iron content of right lung was higherthan the left lung(Ｐ<0.05).The iron conent of group with magnetic fieldand without magnetic field group were both higher than the controlgroup(Ｐ<0.05). The iron conent of right lung of group with magnetic fieldwas higher than the left lung(Ｐ<0.05).(3)There were a lot of blue particleson the sections of right lung which were rare on the left lung.Conclusions:Chitosan modified SPIONs have less cytotoxicity andlung toxicity than sodium oleate modified SPIONs. The chitosan-SPIONsdistributed more at the lung which added on the magntic field.