Articles by Christophe Chaubaroux in JoVE
Multi-Scale Modification of Metallic Implants With Pore Gradients, Polyelectrolytes and Their Indirect Monitoring In vivo Nihal E. Vrana1, Agnes Dupret-Bories1,2, Christophe Chaubaroux1, Elisabeth Rieger1,2, Christian Debry1,2, Dominique Vautier1,3, Marie-Helene Metz-Boutigue1,3, Philippe Lavalle1,3 1Biomatériaux et Bioingénieriee, INSERM, 2Service Oto-Rhino-Laryngologie, Hôpitaux Universitaires de Strasbourg, 3Faculté de Chirurgie Dentaire, Université de Strasbourg In this video, we will demonstrate modification techniques for porous metallic implants to improve their functionality and to control cell migration. Techniques include development of pore gradients to control cell movement in 3D and production of basement membrane mimics to control cell movement in 2-D. Also, a HPLC-based method for monitoring implant integration in-vivo via analysis of blood proteins is described.
Other articles by Christophe Chaubaroux on PubMed
Modification of Macroporous Titanium Tracheal Implants with Biodegradable Structures: Tracking in Vivo Integration for Determination of Optimal in Situ Epithelialization Conditions Biotechnology and Bioengineering. Aug, 2012 | Pubmed ID: 22331657 Previously, we showed that macroporous titanium implants, colonized in vivo together with an epithelial graft, are viable options for tracheal replacement in sheep. To decrease the number of operating steps, biomaterial-based replacements for epithelial graft and intramuscular implantation were developed in the present study. Hybrid microporous PLLA/titanium tracheal implants were designed to decrease initial stenosis and provide a surface for epithelialization. They have been implanted in New Zealand white rabbits as tracheal substitutes and compared to intramuscular implantation samples. Moreover, a basement membrane like coating of the implant surface was also designed by Layer-by-Layer (LbL) method with collagen and alginate. The results showed that the commencement of stenosis can be prevented by the microporous PLLA. For determination of the optimum time point of epithelialization after implantation, HPLC analysis of blood samples, C-reactive protein (CRP), and Chromogranin A (CGA) analyses and histology were carried out. Following 3 weeks the implant would be ready for epithelialization with respect to the amount of tissue integration. Calcein-AM labeled epithelial cell seeding showed that after 3 weeks implant surfaces were suitable for their attachment. CRP readings were steady after an initial rise in the first week. Cross-linked collagen/alginate structures show nanofibrillarity and they form uniform films over the implant surfaces without damaging the microporosity of the PLLA body. Human respiratory epithelial cells proliferated and migrated on these surfaces which provided a better alternative to PLLA film surface. In conclusion, collagen/alginate LbL coated hybrid PLLA/titanium implants are viable options for tracheal replacement, together with in situ epithelialization.
Collagen-based Fibrillar Multilayer Films Cross-linked by a Natural Agent Biomacromolecules. Jul, 2012 | Pubmed ID: 22662909 Surface functionalization plays an important role in the design of biomedical implants, especially when layer forming cells, such as endothelial or epithelial cells, are needed. In this study, we define a novel nanoscale surface coating composed of collagen/alginate polyelectrolyte multilayers and cross-linked for stability with genipin. This buildup follows an exponential growth regime versus the number of deposition cycles with a distinct nanofibrillar structure that is not damaged by the cross-linking step. Stability and cell compatibility of the cross-linked coatings were studied with human umbilical vein endothelial cells. The surface coating can be covered by a monolayer of vascular endothelial cells within 5 days. Genipin cross-linking renders the surface more suitable for cell attachment and proliferation compared to glutaraldehyde (more conventional cross-linker) cross-linked surfaces, where cell clumps in dispersed areas were observed. In summary, it is possible with the defined system to build fibrillar structures with a nanoscale control of film thickness, which would be useful for in vivo applications such as inner lining of lumens for vascular and tracheal implants.
Protein Capsules Assembled Via Isobutyramide Grafts: Sequential Growth, Biofunctionalization, and Cellular Uptake ACS Nano. Sep, 2012 | Pubmed ID: 22950440 We report the sequential assembly of proteins via the alternating physical adsorption of human serum albumin (HSA) and chemical grafting with isobutyramide (IBAM) or bromoisobutyramide (BrIBAM) groups. This approach, performed on silica template particles, leads to the formation of noncovalent protein films with controlled growth at the nanometer scale. Further, after template removal, hollow protein capsules with tunable wall thicknesses and high mechanical stability are obtained. The use of BrIBAM, compared to IBAM grafts, leads to significantly thicker capsule walls, highlighting the influence of the bromine atoms in the assembly process, which is discussed in terms of a theoretical model of noncovalent interactions. Another feature of the process is the possibility to functionalize the HSA capsules with other biologically active macromolecules, including enzymes, polysaccharides, or DNA plasmids, demonstrating the versatility of this approach. We also report that BrIBAM-HSA and IBAM-HSA capsules display negligible cytotoxicity in vitro with HeLa cells and that their cellular uptake is dependent on the thickness of the capsule walls. These findings support the potential use of these protein capsules in tailored biological applications such as drug delivery.