Objective To evaluate pharmacodynamics of prepared long-circulating superparamagnetic iron oxide (SPIO) liposomes. Methods Control and experimental groups were established after adding SPIO or long-circulating SPIO liposomes as agents. (1)Macrophages experiment in vitro: the RAW 264.7 macrophage cell strains were recovered, cultured and seeded in the culture plate at a density of 2.5×105 cells/well until they reached 80%-90% confluence. The intracellular Fe uptake of control and experimental group cells were quantified by Ferrozine assay after incubation with different concentrations of drugs. Factorial design analysis of variance was used as statistics method. Prussian blue staining method was used to detect staining of experimental cells.(2)Drug biodistribution in mice: C57BL/6J(n=6) were classified into blank control group (n=2), control group(n=2) and experimental group(n=2).Saline, SPIO and long circulating SPIO were injected via the tail vein in the blank control group, control group and experimental group respectively. Then distribution of drugs in the body was observed by pathological examination.(3) MR imaging of tumor-bearing nude mice: 20 BALB/c nude mice bearing lung cancer models were established and classified into control group and experimental group. After administration of drugs, all animals underwent MR scanning. Signal intensities of livers and tumors were measured, SNR-time dynamic curves were drew. Covariance analysis was used to compare post-enhanced SNR at the 12th hour. (4)Cytotoxicity studies (MTT): cytotoxicity of both drugs on human liver cell line HL-7702 was studied, and statistically analyzed using factorial design analysis of variance. Results (1) Macrophages experiment in vitro: The nanoparticle uptake by macrophage cells evaluated by ferrozine assay showed the uptake of blank SPIO was higher than long-circulating SPIO liposomes. Compared with the blank control group, there was strong blue staining in the macrophages with Prussian staining in the control group and little blue staining in the experimental group. (2) Drug biodistribution in mice: for blue stained cells composed of iron particles, the amounts in the liver, spleen, lung, kidney of the control group were more than those in the experimental group. (3) MR imaging of tumor-bearing nude mice: the non-enhanced SNR of livers and tumors in the control group and experimental group were 31.47 ± 0.56, 30.89 ± 1.41, 58.41 ± 0.61, 58.44 ± 1.08, respectively. After injecting of contrast agents, SNR of livers and tumors in the control group and experimental group were 17.00 ± 0.96, 22.29 ± 0.73, 58.50 ± 0.63, 52.47 ± 1.18, respectively. The covariance analysis showed that SNR of the livers in the control group after 12 hours was significantly lower than the experimental group (F=167.022, P=0.000); while the SNR of the tumors in the experimental group was significantly lower than the control group (F=266.106, P=0.000).(4) Cytotoxicity of nanoparticles by MTT method: the viability of HL-7702 cells tend to decrease with the increase of Fe concentration. Cytotoxicity in the long-circulating SPIO liposomes was lower than the SPIO(F=2256.204,P=0.000). Conclusions Long-circulating SPIO liposomes we prepared reveal suitable sizes, even distribution, and good anti-macrophage ability in vitro and in vivo. They have long circulation characteristic and T2 negative enhancement effect in the transplanted lung cancers, while they still maintain low cytotoxicity.

Objective To observe the value of myocardial contrast echocardiography(MCE)combined with speckle tracking imaging(STI)for evaluating the protective effect of 2-aminoethoxydiphenyl borate(2-APB)on heart of arsenic poisoned rats.Methods Forty rats were randomly divided into low-and high-dose 2-APB intervention after arsenic trioxide(ATO)poisoned group(2-APBL group and 2-APBH group),simple ATO poisoned group(ATO group),simple 2-APB intervention group(2-APB group)and control group(each n=8).5 mg/kg ATO were intraperitoneally injected in 2-APBL group,2-APBH group and ATO group,while equal dose physiological saline were injected in 2-APB group and control group,respectively.Then 2,4 and 4 mg/kg 2-APB were intraperitoneally injected in 2-APBL group,2-APBH group and 2-APB group,while equal doses physiological saline were injected in ATO group and control group,respectively.MCE and STI were performed,serum myocardial injury markers were tested,sarcoplasmic reticulum Ca2+-ATPase(SERCA)was examinated,and finally myocardial pathological examination was performed.The above indexes were compared among groups and between each 2 groups,and correlation analysis was performed.Results Significant differences of left ventricular fractional shortening(LVFS),left ventricular ejection fraction(LVEF),wash in slope(WIS),peak intensity(PI),WIS×PI,area under the curve(AUC),global circumferential strain(GCS)in each layer of myocardium,as well as glutamic-oxaloacetic transaminase(GOT),creatine kinase(CK),lactate dehydrogenase(LDH)and SERCA were found among 5 groups(all P＜0.05).The above indexes substantially increased or decreased sequentially ATO group,2-APBL group,2-APBH group and 2-APB group/control group(all P＜0.05).WIS,PI,WIS × PI and GCS of rat endo-myocardium,GSC of mid-myocardium and GCS of epi-myocardium all positively correlated with SERCA(r=0.874,0.893,0.920,0.916,0.848,0.783,all P＜0.05).Conclusion MCE combined with STI,especially WISXPI and GCS of endo-myocardium could be used to evaluate the protective effect of 2-APB on heart of arsenic poisoned rats.

Objective:To evaluate the effect of 2-aminoethoxydiphenyl-borate (2-APB) on cardiac dysfunction in arsenic poisoning rats by stratified strain technique.Methods:Thirty-two 12-week-old SD rats were randomly divided into control group ( n=8) and arsenic exposure group ( n=24). After 12 weeks of arsenic exposure, arsenic exposure group was divided into three groups: natural recovery group ( n=8), low-dose intervention group (n=8) and high-dose intervention group ( n=8). The rats were treated with 2-APB for 21 days. After the last administration, the routine parameters and the layered strain parameters were measured by ultrasonic instrument. Then the rats were killed and their blood and myocardial samples were obtained. The levels of serum creatine kinase isoenzyme (CK-MB) and lactate dehydrogenase (LDH) were tested, and the morphological changes of cardiomyocytes were observed by HE staining. Results:Left ventricular ejection fraction (LVEF), left ventricular short axis shortening (LVFS), global circumferential strain of subendocardial myocardium (GCS-endo), global circumferential strain of middle myocardium (GCS-mid), global circumferential strain of subepicardial myocardium (GCS-epi) and circumferential strain rate of left ventricular segments (SrC) in the natural recovery group were lower than those in the control group ( P<0.05), while serum CK-MB and LDH were higher than those in the control group ( P<0.05). Some ultrasonic parameters and biochemical indexes in the low and high dose intervention groups were improved in varying degrees compared with the natural recovery group ( P<0.05). The correlation between GCS-endo and CK-MB was the highest ( r=-0.931, P<0.05). Myocardial HE staining showed that the degree of myocardial cell swelling and necrosis were reduced, and erythrocyte exudation was reduced in the low and high dose intervention groups compared with the natural recovery group. Conclusions:The stratified strain technique can be used to evaluate the protective effect of 2-APB on cardiac dysfunction in arsenic poisoning rats, and GCS-endo may be one of its sensitive indexes.