Biomedical subjects

Frederic Chaubet

Publications and source records attributed to Frederic Chaubet.

3 recordsLinked to original sources

PubMed2006

The evaluation of a small-diameter polysaccharide-based arterial graft in rats.

Cardiovascular diseases may require surgery such as arterial bypasses that are usually performed with synthetic PTFE and Dacron grafts with diameter above 6mm. For smaller diameter replacement, healthy vascular tissue from the patient is not always available to carry out this type of graft. The purpose of this study was to evaluate the effectiveness of a small-diameter polysaccharide-based scaffold as an alternative arterial replacement. Tubular polysaccharide-based grafts of 2 mm internal diameter were prepared and moulded by a cross-linking technique. Fifteen Wistar adult rats underwent infrarenal aortic bypass with these grafts using microsurgical techniques. Grafts withstood aortic blood pressure and exhibited physiological blood flow, as evaluated with ultrasound techniques and angiographies at 4 and 8 weeks post-surgery. Harvested grafts were morphologically evaluated by light microscopy and immunohistochemistry. Neointima formation at 8 weeks was evidenced through collagen deposition and smooth muscle-like cells circumferential growth on the luminal surface without intimal hyperplasia or aneurysm formation. In conclusion, we described a 2mm polysaccharide-based arterial material being investigated in vivo and demonstrating patency for up to 8 weeks post-surgery with neointima formation and absence of intimal hyperplasia.

Animals↗

PubMed2005

Bovine BMP osteoinductive potential enhanced by functionalized dextran-derived hydrogels.

This study evaluated functionalized dextran-derived hydrogels as BMP carriers using both in vitro and in vivo models. In vitro release kinetics indicated that dextran-derived hydrogels could retain rhBMP-2 growth factor in a variable manner depending on their functionalization ratio. The potential of these hydrogels when combined with extracted bovine BMP to enhance the bone formation was evaluated in a rat ectopic model. The largest osteoinduction was found when using hydrogels exhibiting the highest growth factor retention capacity. In addition, some implanted hydrogels demonstrated a capacity to induce an in-vivo calcification certainly related to their chemical composition. These properties make these materials interesting osteoconductive BMP carriers, allowing to decrease the amount of implanted factor required for bone regeneration.

Animals↗

PubMed2002

Interaction of specifically chemically modified dextrans with transforming growth factor beta1: potentiation of its biological activity.

Transforming growth factor beta (TGFbeta), a potent multifunctional cytokine, is well known to demonstrate heparin binding ability. This study investigated the binding capacity of heparin-like family of chemically modified dextrans to TGFbeta1. Dextran derivatives with various substitution contents in carboxymethyl, benzylamide and sulfate groups were evaluated using a gel mobility shift assay. This structure-function study indicated that a synergistic role of benzylamide and sulfate substituents resulted in an optimal interaction with the growth factor. The effect of these polymers on the biological response of TGFbeta1 was assessed using mink lung epithelial cells transfected with a plasminogen activator inhibitor-1 promoter-luciferase construct (PAI/Luc). When the growth factor was mixed with 250 microg/mL of carboxymethyl-benzylamide-dextran (DCMB) or carboxymethyl-benzylamide-sulfate-dextran (DCMBSu), the luciferase gene expression was enhanced. Only polymers exhibiting TGFbeta1 binding demonstrated a biological potentiating effect. However, this effect was strongly amplified as the cell plating time increased (35-fold increase with a 2 days plating time versus 1.1-fold increase with a 4 hr plating time at a 0.25 ng/mL concentration of TGFbeta1). TGFbeta1 induced the PAI/Luc construct in a dose-dependent fashion but its effect diminished when added to cells previously cultured for 24 and 48 hr. The results indicated that the potentiating effect required a complex formation between TGFbeta1 and polymers, the action of which seeming to locally maintain TGFbeta1 in an active form. TGFbeta isoforms playing a key role in the process of bone repair, specifically designed functionalized dextrans could potentiate the in vivo TGFbeta1 biological effect and be used in the field of wound healing applications.

Animals↗