Chonbuk National University

About: Chonbuk National University is a education organization based out in Jeonju, South Korea. It is known for research contribution in the topics: Apoptosis & Nanofiber. The organization has 14820 authors who have published 28884 publications receiving 554131 citations.

Deposition of nanomaterials: A crucial step in biosensor fabrication

Abstract: Biosensor development includes the deposition of (nano)materials onto a conductive electrode surface, which is a crucial step for obtaining improved performance from the constructed biosensors. Various methods have been used to create a successful matrix of (nano)materials that ensures proper contact between the material and electrode surface. The purpose of (nano)material deposition is to provide a high surface area to improve the electroanalytical performance of biosensors by supporting the stable immobilization of enzymes in a more significant quantity as well as enhancing the catalytic or bioaffinity features. For decades, researchers have been using increasingly advanced methods not only for improving sensing performance, but also for improving stability, reproducibility, and mass production. In this review, we summarized the methods used for (nano)material deposition onto an electrode surface for efficient biosensor fabrication. An enhanced and optimized (nano)material deposition method is crucial for the mechanical stability and fabrication reproducibility of electrodes when designing a suitable biosensing device. In addition, we discussed the problems faced during biosensor application as well as the present challenges and prospects for superior deposition methods.

Hypoxia Enhances Lysophosphatidic Acid Responsiveness in Ovarian Cancer Cells and Lysophosphatidic Acid Induces Ovarian Tumor Metastasis In vivo

Abstract: Lysophosphatidic acid (LPA) is elevated in ascites of ovarian cancer patients and stimulates growth and other activities of ovarian cancer cells in vitro . Tissue hypoxia is a critical factor for tumor aggressiveness and metastasis in cancers. We tested whether the ascites of ovarian cancer is hypoxic and whether hypoxia influences the effects of LPA on ovarian cancer cells. We found that ovarian ascitic fluids were hypoxic in vivo . Enhanced cellular responsiveness to LPA, including migration and/or invasion of ovarian cancer cells, was observed under hypoxic conditions. This enhancement could be completely blocked by geldanamycin or a small interfering RNA targeting hypoxia-inducible factor 1α (HIF1α). LPA-induced cell migration required cytosolic phospholipase A 2 (cPLA 2 ) and LPA stimulates cPLA 2 phosphorylation in a HIF1α-dependent manner under hypoxia conditions. Furthermore, we show for the first time that exogenous LPA enhances tumor metastasis in an orthotopic ovarian cancer model and HIFα expression in tumors. 17-Dimethylaminoethylamino-17-demethoxygeldanamycin (an inhibitor of the heat shock protein 90) effectively blocked LPA-induced tumor metastasis in vivo. Together, our data indicate that hypoxic conditions are likely to be pathologically important for ovarian cancer development. HIF1α plays a critical role in enhancing and/or sensitizing the role of LPA on cell migration and invasion under hypoxic conditions, where cPLA 2 is required for LPA-induced cell migration. (Cancer Res 2006; 66(16): 7983-90)