Biomedical subjects

Cédric Boura

Publications and source records attributed to Cédric Boura.

3 recordsLinked to original sources

PubMed2006

Influence of polyelectrolyte multilayer films on the ICAM-1 expression of endothelial cells.

Recently, the use of polyelectrolyte films has been suggested as a new versatile technique of surface modification aimed at tissue engineering. In the present study, we evaluated the expression of intercellular adhesion molecule (ICAM)-1 of endothelial cells (ECs) seeded on two types of polyelectrolyte multilayer films either terminated by poly(D-lysine) (PDL) or poly(allylamine hydrochloride) (PAH). This work showed that chemical stimulations with tumor necrosis factor (TNF)-alpha induced the ICAM-1 expression of ECs differently depending largely on the film architecture employed. Compared with PAH-ending films, the PDL-ending ones upregulated the ICAM-1 expression of the ECs after a prolonged exposition to TNF-alpha, rendering this film type less favorable in tissue engineering. Cytochalasin D (an F-actin disrupting agent) showed the involvement of the cytoskeleton in the upregulation of ICAM-1 for cells deposited on films terminated by PDL. The PAH-ending films did not perturb the ICAM-1 expression of ECs and might thus enhance the seeding of ECs in vascular engineering.

Cells, Cultured↗

PubMed2005

Endothelial cell--interactions with polyelectrolyte multilayer films.

The seeding of endothelial cells (ECs) on biomaterial surfaces became a major challenge, allowing to improve the non-thrombogenic properties of these surfaces. Recently, the use of polyelectrolyte films has been suggested as a new versatile technique of surface modification aimed at tissue engineering. In this study, we evaluate the adhesion properties of ECs on two types of polyelectrolyte films ending either by poly(D-lysine) (PDL), or poly(allylamine hydrochloride) (PAH), and compared them to data obtained on PDL or PAH monolayers, glass and fibronectin (Fn)-coated glass. ECs seeded on polyelectrolyte films showed a good morphology, allowing ECs to resist physiological shear stress better compared to ECs seeded on glass or Fn. The expression of beta1 integrins was slightly lower on polyelectrolyte films than on control surfaces. However, the phosphorylation of focal adhesion kinase, involved in the transduction of adhesion signal, was not modified on PAH ending films compared to control surfaces; whereas it became lower on PDL ending films. Finally, PAH ending films improve strongly ECs adhesion without disturbing the adhesion mechanism, necessary for the development of a new endothelium. These types of films or similar build-ups could thus be used in the future as a way to modify surfaces for vascular tissue engineering.

Actins↗

PubMed2003

Volume expansion with modified hemoglobin solution, colloids, or crystalloid after hemorrhagic shock in rabbits: effects in skeletal muscle oxygen pressure and use versus arterial blood velocity and resistance.

Therapeutic goals for hemorrhagic shock resuscitation are the increase of cardiac output and oxygen delivery. The possibility exists that because of microcirculatory effects, different volume expanders result in different tissue oxygen delivery and oxygen use. In a rabbit model of resuscitation from hemorrhagic shock (50% blood loss), we compared the effects of an hemoglobin-based O2-carrying solution (HbOC) with those elicited by albumin, hydroxyethyl starch (HES), or saline on systemic hemodynamics, skeletal muscle O2 pressure (PtiO2), and interstitial concentration of lactate (LACi) through the combined implantation of a microdialysis probe and a sensitive O2 electrode into the hind limb. Hemorrhagic shock induced a 50% decrease in mean arterial pressure (MAP), femoral artery blood flow (BF), and PtiO2. After resuscitation, there were statistically significant differences among the volume expanders. The increase in MAP was faster with HbOC and colloids, and slower with saline, mainly obtained by vasoconstriction for HbOC and by increased BF with albumin and HES. The maximum MAP values were significantly higher for HbOC compared with the other volume expanders. HbOC and colloids induced a faster increase in PtiO2 as compared with saline, but maximum PtiO2 values were not different among the volume expanders. Tissue oxygen use as estimated by LACi increased transiently at the beginning of volume expansion with similar maximum values. Animals resuscitated with saline had significantly higher LACi concentrations after the onset of volume expansion as compared with HbOC but not with colloids. Our results demonstrate that there are measurable differences in MAP and BF upon resuscitation with the four different solutions and there is a slower increase in tissue PtiO2 with saline than with colloids associated with significantly increased LACi consistent with delayed reoxygenation upon resuscitation with saline.

Animals↗