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The administration of nanoparticles (NPs) first faces the challenges of evading renal filtration and clearance of reticuloendothelial system (RES). After that, NPs infiltrate through the expanded endothelial space and penetrated the dense stroma of tumor microenvironment to tumor cells. As long as possible to prolong the time of NPs remaining in tumor tissue, NPs release active agent and induce pharmacological action. This review provides a comprehensive summary of the physical and chemical properties of NPs and the influence of various biological factors in tumor microenvironment, and discusses how to improve the final efficacy through adjusting the characteristics and structure of NPs. Perspectives and future directions are also provided.
RESUMO
BACKGROUND: Lung uptake during liver scanning has been considered as a passing phenomenon related to several diseases, and especially infectious diseases and malignancy. Some reports have shown diffuse lung uptake during liver scanning of malarial patients. Therefore, we tried to determine the relationship between the abnormalities of the clinical features, including the hematobiochemical indices and the lung uptake during liver scanning, by analyzing the information of the malarial patients. METHODS: We performed 99mTechnethium(Tc)-sulfur colloid liver scanning on 20 of the 45 malarial patients who were admitted from 1999 to 2004. We divided them into two groups, the Lung-Uptake (LU) group and the Non-Lung-Uptake (NLU) group. We analyzed the hematobiochemical indices and clinical features, including the respiratory symptoms, between the two groups. RESULTS: 10 of the 20 malarial patients showed lung uptake on the liver scan. The mean platelet counts were 74,000/L and 165,000/L, respectively, in the LU group and the NLU group (p=0.012). Also, the mean total cholesterol levels were 80.3 mg/dL and 105.7 mg/dL, respectively, in the LU group and the NLU group (p=0.033). The scores ofthe bone marrow (BM) uptake in the LU group were higher than those in the NLU group (p=0.008). Yet the other values such as Hb, ALT, albumin and total bilirubin were not statistically significant, nor were the peak body temperatureand other features. CONCLUSIONS: Half of the patients had lung uptake on the liver scanning, and this may be considered as a characteristic of vivax malaria. The BM uptake during liver scanning in the LU group was more increased, and this is supposed to be a consequence of hyperstimulated reticuloendothelial system, which was accompanied by thrombocytopenia and a lower level of total cholesterol in malarial patients.
Assuntos
Humanos , Bilirrubina , Medula Óssea , Colesterol , Coloides , Doenças Transmissíveis , Fígado , Pulmão , Malária , Malária Vivax , Sistema Fagocitário Mononuclear , Contagem de Plaquetas , TrombocitopeniaRESUMO
Objective To examine the effect of hydroxyethyl starch (HES 6%, 200/0.5) on reticuloendothelial system (RES) function in hemorrhagic shock. Methods Thirty 8 to 12-week-old Wistar rats weighing 250-350g were randomly divided into two groups: HES group ( n = 15) and control group ( n =15) . The animals were anesthetized with intraperitoneal 0.5% pentobarbital sodium 30mg ?kg-1 Bilateral common carotid arteries were exposed and cannulated for MAP monitoring and blood-letting. Blood was gradually removed until MAP dropped to 40mm Hg, which was maintained for 60min. Then same amount of HES (HES group) or Dextran (control group) was infused. The Kupffer cells were separated and purified before hemorrhagic shock (T0), at 12h (T1) 24h (T2) 48h (T3) and 72h (T4) after HES or DEX infusion, when the animals recovered from shock. Phagocytic activity of Kupffer cells (KC) was measured by counting the amount of Latex particles ingested by KC. Results At the same intervals (T1-4) there was no significant difference in phagocytic activity of KC between the two groups. There was no significant difference in phagocytic activity of KC between T0 (baseline) and T1-4 in both groups.Conclusions The phagocytic activity of Kupffer cells in not affected by removed of 20-30% blood volume which was replaced by same amount of HES.
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Rabbits were used in examination of pulmonary coefficient, pulmonary light microscopic examination, coagulation test, blood gas and pH in hemorrhagic shock, blockade of the RES and hemorrhagic shock after blockade of the RES. Our studies indicate that the pulmonary injury was only seen in hemorragic shock after blockade of RES.The portal vein blood in hemorragic shock after the depression of RES was perfused to other rabbits of only depression of RES. Release of leukocytes from the liver and spleen, leukocytes entrapment in the lungs and pulmonary injury were observed in the perfused rabbits. The results suggest that a pathologic factor causing pulmonary injury is present in the portal vein blood of shocked rabbits after the depression of RES.
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Disseminated intravascular coagulation was induced by injection of thrombin and EACA in rats.In the experimental group the rats, after injection of ~(125)I fibrinogen, received thrombin to produce DIC. The control group received saline instead of thrombin. The autoradiographic result indicated that the radioactive microthrombi were mainly situated in the glomeruli of kidney and pulmonary capillaries. By the use of HE and PTAH stain, however, the microthrombi could be found only in the glomeruli of the kidney but not in pulmonary capillaries. This indicated that autoradiography was more sensitive than histochemical and HE methods for detection of thrombi in microcirculation. It was also discovered that the reticuloendothelial cells of liver and spleen phagocytized a large amount of the radioactive materials. The materials might be radioactive fibrin or its monomer because ~(125)I fibrinogen has been attached to thrombin. In addition to these, the epithelium of convoluded tubules of kidney also absorb radioactive materials which might be peptides A and B.