[Characterization and Exposure Risk Assessment of Non-phthalate Plasticizers in House Dust from Guangzhou].

Although non-phthalate plasticizers are widely used in various consumer products as substitutes for phthalates, currently little is known about their environmental occurrence and the risks of human exposure. To characterize the pollution and human exposure risk in indoor environments, house dust samples collected from 83 households in Guangzhou were analyzed for twelve typical non-phthalate plasticizers. Results showed that dioctyl terephthalate (DEHT), trioctyl trimellitate (TOTM), acetyl lemon tributyl ester (ATBC), heptylnonyl adipate, di(2-ethylhexyl) adipate, and trioctyl trimellitate were detected in all samples. The total concentrations of non-phthalate plasticizers ranged from 22.4 to 615 µg ·g-1 with a median of 101 µg ·g-1. DEHT had the highest concentrations (9-487 µg ·g-1), followed by TOTM (0.3-87 µg ·g-1) and ATBC (1.7-50 µg ·g-1). Daily intakes via dust ingestion for adults and children were estimated based on the dust concentrations. The total daily intake of children was 367 ng ·(kg ·d)-1, which was 8-9 times higher than that of adults[43 ng ·(kg ·d)-1]. Further risk assessment through the hazard quotient approach showed that the exposure of adults and children to non-phthalic plasticizers via dust ingestion was within an acceptable risk range.

In vivo imaging in tumor-bearing animals and pharmacokinetics of PEGylated liposomes modified with RGD cyclopeptide / 药学学报

The hydroxycamptothecin (HCPT) PEGylated liposomes (HCPT-LP) were modified with RGD cyclopeptide formed the tumor-targeting liposomes (HCPT-RGD-LP). HCPT-LP and HCPT-RGD-LP were injected intravenously with single dose of 5 mg x kg(-1) to rats. The drug concentration in plasma was determined and the pharmacokinetic behaviour was compared. The HCPT distribution in heart, liver, spleen, lung, kidney and plasma of mice was investigated following intravenous administration of HCPT-LP and HCPT injection. The nude mice implanted human hepatoma HepG2 cells were studied by in vivo imaging. The fluorescent probe was DiR and the nude mice were injected with DiR PEGylated liposomes (DiR-LP) and DiR-LP modified with RGD cyclopeptide (DiR-RGD-LP). The results showed that there was no significant difference (P > 0.05) of main pharmacokinetic parameters t1/2beta, CL, V(c), AUC(0-48 h), AUC(0-inifinity), MRT(0-48 h), MRT(0-infinity) between HCPT-RGD-LP and HCPT-LP. HCPT-LP had a remarkably better long-circulating effect than HCPT injection in mice and the concentration of HCPT was highest in liver. The DiR accumulation in tumors of DiR-RGD-LP was higher than that of DiR-LP by the visualized fluorescence of in vivo imaging. It indicated that such PEGylated liposomes modified with RGD cyclopeptide could improve the tumor targeting efficacy.