[Tissue engineering: a new space of scientific expression and technological development for health].
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Animals↗
Biomedical subjects
Charles Baquey
Publications and source records attributed to Charles Baquey.
Old prospects in cardiovascular engineering.
For more than thirty years the thrombogenicity of blood-contacting materials has been deplored. This impotency, combined with inappropriate mechanical properties of these materials, explains the poor patency of medium-sized arterial prostheses and the lack of substitutes for small diameter arteries (psi<or=5 mm). The author here recalls several studies, among many others, which have opened opportunities to improve this situation. However there is a gap which has not been jumped over yet between laboratory experiments and the availability of devices which could be clinically tried. This step clearly needs strong investments from the industry people, and the latter should be encouraged to do so by the public health authorities, as far as they believe that innovation is the condition of therapeutic progress as well as social and economic benefits.
Animals↗
Biocompatibility studies of the Anaconda stent-graft and observations of nitinol corrosion resistance.
PURPOSE: To validate the deployment, in vivo performance, biostability, and healing capacity of the Anaconda self-expanding endoprosthesis in a canine aortic aneurysm model. METHODS: Aneurysms were surgically created in 12 dogs by sewing a woven polyester patch onto the anterior side of the thoracic or abdominal aorta. Anaconda prostheses were implanted transfemorally for prescheduled periods (1 or 3 months). Aneurysm exclusion and stent-graft patency were monitored angiographically. Healing was assessed with histological analysis and scanning electron microscopy (SEM). Textile analysis determined the physical and chemical stability of the woven polyester material, while the biostability of the nitinol wires was evaluated with SEM and spectroscopy. RESULTS: All prostheses were intact at explantation. After 1 month, endothelial-like cells were migrating in a discontinuous manner both proximally and distally over the internal collagenous pannus at the device-host boundary. After 3 months, endothelialization had reached the midsections of the devices, with a thicker collagenous internal capsule. Patches of endothelial-like cells were sharing the luminal surface with thrombotic deposits. However, the wall of the device at the level of the aneurysm was generally poorly healed, with multiple thrombi scattered irregularly over the luminal surface. The polyester fabric was intact except for some filaments that were ruptured adjacent to the sutures and some abrasion caused by the nitinol wires. No evidence of corrosion was found on the nitinol stents. CONCLUSIONS: This Anaconda stent-graft has demonstrated its ability to exclude arterial aneurysms. The device used in this study was an experimental prototype, and the manufacturer has incorporated new immobilization features into the model for clinical use. The constituent materials appear to be suitable in terms of biocompatibility, biofunctionality, and short-term durability.
Alloys↗
Synthesis and evaluation of organosilicon inhibitors of active purine transport in human osteoblasts.
In the search for new compounds that might, once incorporated into biomaterials, stimulate the natural processes of bone regeneration, a new series of silicon-containing alkyl nucleobase analogues has been synthesized. An active hypoxanthine transport process in human osteoblasts was demonstrated, with an apparent Michaelis constant of 2.3 microM and a maximum possible rate of 0.47 pmol s(-1) x 10(6) cell. The synthesized analogues were tested for toxicity in human osteoblasts. Nontoxic analogues were tested in competition transport studies with [(14)C]hypoxanthine. Two of them were found to inhibit the active transport of hypoxanthine in human osteoblasts, with IC(50) values of 6.5 and 11.6 microM.
Adult↗