Photoaging of Baby Bottle-Derived Polyethersulfone and Polyphenylsulfone Microplastics and the Resulting Bisphenol S Release.

This study evaluated the release of bisphenol S (BPS) from polyethersulfone (PES) and polyphenylsulfone microplastics (MPs) derived from baby bottles under UV irradiation. Released BPS fluctuates over time because it undergoes photolysis under UV254 irradiation. Under UV365 irradiation, the highest released concentration at 50 °C was 1.7 and 3.2 times that at 35 and 25 °C, respectively, as the activation energy of the photochemical reactions responsible for MP decay was reduced at high temperatures. Low concentrations of humic acid (HA, ≤10 mg·L-1) promote BPS release because HA acts as a photosensitizer. A high concentration of HA (10∼50 mg·L-1) decreases the BPS release because HA shields MPs from light and scavenges reactive radicals that are produced via photochemical reactions. For example, under UV irradiation, hydroxyl radicals (•OH) attack results in the breakage of ether bonds and the formation of phenyl radicals (Ph•) and phenoxy radicals (Ph-O•).The•OH addition and hydrogen extractions further produce BPS from the decayed MPs. A leaching kinetics model was developed and calibrated by the experimental data. The calibrated model predicts the equilibrium level of BPS release from MPs that varies with the surface coverage density of BPS and leaching rate constants. This study provides groundwork that deepens our understanding of environmental aging and the chemical release of MPs.

Quantitative proteomic analysis identified paraoxonase 1 as a novel serum biomarker for microvascular invasion in hepatocellular carcinoma.

This study aimed to identify serum biomarkers for microvascular invasion (MVI) in hepatocellular carcinoma (HCC). MVI is a histological sign of micrometastasis in the liver and is considered as one of the most powerful prognostic factors in HCC. The serum of HCC patients with different vascular invasion statuses was examined by iTRAQ-based proteomic profiling. The expression levels of 24 proteins were associated with the extent of vascular invasion in the pooled samples of 45 HCC cases. Western blot analyses in 90 HCC cases confirmed the correlation of the expression level of paraoxonase 1 (PON1) with the extent of vascular invasion. ELISA assays demonstrated the diagnostic utility of the PON1 level, with the area under curve values of 0.847 and 0.889 for the MVI and gross vascular invasion, respectively, relative to the patients without vascular invasion, in a cohort of 387 additional HCC cases. Immunohistochemistry revealed that PON1 expression in tumor cells was inversely correlated with the extent of vascular invasion in 200 additional HCC cases. In conclusion, using a proteomic approach, we found that serum PON1 was a novel diagnostic biomarker for MVI. The prognostic values of serum PON1 and its possible therapeutic applications are worth further investigation.