High Contrast Detection of Carotid Neothrombus with Strong Near-Infrared Absorption Selenium Nanosphere Enhanced Photoacoustic Imaging.

Background: Carotid artery thrombosis is the leading cause of stroke. Since there are no apparent symptoms in the early stages of carotid atherosclerosis onset, it causes a more significant clinical diagnosis. Photoacoustic (PA) imaging provides high contrast and good depth information, which has been used for the early detection and diagnosis of many diseases. Methods: We investigated thrombus formation by using 20% ferric chloride (FeCl3) in the carotid arteries of KM mice for the thrombosis model. The near-infrared selenium/polypyrrole (Se@PPy) nanomaterials are easy to synthesize and have excellent optical absorption in vivo, which can be used as PA contrast agents to obtain thrombosis information. Results: In vitro experiments showed that Se@PPy nanocomposites have fulfilling PA ability in the 700 nm to 900 nm wavelength range. In the carotid atherosclerosis model, maximum PA signal enhancement up to 3.44, 4.04, and 5.07 times was observed by injection of Se@PPy nanomaterials, which helped to diagnose the severity of carotid atherosclerosis. Conclusion: The superior PA signal of Se@PPy nanomaterials can identify the extent of atherosclerotic carotid lesions, demonstrating the feasibility of PA imaging technology in diagnosing carotid thrombosis lesion formation. This study demonstrates nanocomposites and PA techniques for imaging and diagnosing carotid thrombosis in vivo.

Celastrol induces apoptosis in hepatocellular carcinoma cells via targeting ER-stress/UPR.

Hepatocellular carcinoma (HCC) is one of the most serious and deadly diseases worldwide with limited options for effective treatment. Biomarker-based active compound targeting therapy may shed some light on novel drugs for HCC. The endoplasmic reticulum (ER) stress and unfolded protein response (UPR) play important roles in the regulation of cell fate and have become novel signaling targets for the development of anticancer drugs. Celastrol, a triterpene from traditional Chinese medicine, has been reported to possess anti-tumor effects on various cancers. We, along with several other research groups, have recently reported that UPR was induced by celastrol in several different cancers, including hepatocellular carcinoma. However, UPR status in HCC still remains unclear. The role of ER stress and autophagy in response to celastrol also has yet to be elucidated. Our results demonstrated that celastrol could cause G2/M phase rest and inhibit proliferation in HepG2 and Bel7402. Exposure to celastrol resulted in the activation of the intrinsic apoptotic pathway, via ER stress and the UPR. In murine syngeneic model studies celastrol inhibited H22 tumor growth via the induction of ER stress and apoptosis. Our study suggests that celastrol is a potential drug for HCC therapy via targeting ER-stress/UPR.

Phytotoxic Mechanism of Nanoparticles: Destruction of Chloroplasts and Vascular Bundles and Alteration of Nutrient Absorption.

This study focused on determining the phytotoxic mechanism of CeO2 nanoparticles (NPs): destroying chloroplasts and vascular bundles and altering absorption of nutrients on conventional and Bt-transgenic cottons. Experiments were designed with three concentrations of CeO2 NPs including: 0, 100 and 500 mg·L(-1), and each treatment was three replications. Results indicate that absorbed CeO2 nanoparticles significantly reduced the Zn, Mg, Fe, and P levels in xylem sap compared with the control group and decreased indole-3-acetic acid (IAA) and abscisic acid (ABA) concentrations in the roots of conventional cotton. Transmission electron microscopy (TEM) images revealed that CeO2 NPs were absorbed into the roots and subsequently transported to the stems and leaves of both conventional and Bt-transgenic cotton plants via xylem sap. In addition, the majority of aggregated CeO2 NPs were attached to the external surface of chloroplasts, which were swollen and ruptured, especially in Bt-transgenic cotton. The vascular bundles were destroyed by CeO2 nanoparticles, and more damage was observed in transgenic cotton than conventional cotton.