Optimization of Protein Immobilization in Microfludic Devices for Circulating Tumor Cell Capture

The isolation of metastatic circulating tumor cells (CTCs) within the blood using microfluidic devices is a promising method for the detection of cancer. In this study, protein patterning of endothelial-leukocyte adhesion molecule-1 (E-selectin) and anti-epitheal-cell-adhesion-molecule (Anti-EpCAM) within microfluidic channels is utilized to improve the capture efficiency. To create this protein patterning the protein immobilization method must first be optimized to allow for maximum capture of CTCs and minimal increase in the flow rate of cells through the device due to added coating thickness. Proteins are immobilized in alternating regions using photo-initiated graft polymerization of polyacrylic acid (PAA) and a silanization reaction. Using interferometer measurements and fluorescent tagging, PAA height was minimized and protein immobilization was optimized.

Conformational Search on the Lewis X Structure by Molecular Dynamic: Study of Tri- and Pentasaccharide

Carbohydrates play vital roles in many biological processes, such as recognition, adhesion, and signalling between cells. The Lewis X determinant is a trisaccharide fragment implicated as a specific differentiation antigen, tumor antigen, and key component of the ligand for the endothelial leukocyte adhesion molecule, so it is necessary or essential to determine and to know their conformational and structural properties. In this work, conformational analysis was performed using molecular dynamics (MD) simulation with the AMBER10 program package in order to study the dynamic behavior of of the Lewis X trisaccharide (β-D-Gal-(1,4)-[α-L-Fuc-(1,3)]-β-D-GlcNAc-OMe) and the Lewis X pentasaccharide (β-D-Gal-(1,4)-[α-L-Fuc-(1,3)]-β-D-GlcNAc-(1,3)-β-D-Gal-(1,4)-β-D-Glu-OMe) in explicit water model at 300 K for 10 ns using the GLYCAM 06 force field.

E-Selectin Expression Increased in Human Ruptured Cerebral Aneurysm Tissues

Objectives:The purpose of the present study is to investigate the expression of inflammation factor endothelial-leukocyte adhesion molecule (E-selectin, CD62E) in cerebral aneurysm walls and its relationship with aneurysm rupture.Methods:Cerebral aneurysm tissue samples were collected at the time of surgical clipping of nine patients with history of subarachnoid hemorrhage, and then compared with control artery tissues from the superficial temporal arteries (STA) of five patients with intracranial tumors. Immunohistochemistry (IHC) was performed to reveal and localize E-selectin expression in the aneurysms and artery tissues. Western blot analysis was used to relatively quantify the level of E-selectine protein expression in cerebral aneurysms when compared with normal arteries.Results:E-selectin was detected in the wall of all the aneurysm tissue samples and was rarely found in normal control arteries by IHC, and it was concentrated in proliferating and disorganized epithelia cells. Moreover, with the Western blot method, the E-selectin protein level increased significantly in aneurysm tissues compared to normal STA.Conclusions:E-selectin might be an important factor involved in the process of cerebral aneurysm formation and rupture, by promoting inflammation and weakening cerebral artery walls.