Ref HAL: hal-00717362_v1
DOI: 10.1016/j.irbm.2012.01.007
Résumé: La pose chirurgicale de prothèses afin de pallier les descentes d'organes de la zone pelvienne ou pariétale est une opération de plus en plus fréquente et requière l'implantation de plus de 1 200 000 dispositifs médicaux annuellement. Or, les cas de complications et de réinterventions chirurgicales restent très élevés, principalement dus aux infections associées à une réponse inflammatoire importante, ainsi qu'aux érosions, expositions et migrations des prothèses. Ces travaux présentent différentes stratégies permettant d'apporter des propriétés de résistance à l'infection et de suivi postopératoire à l'aide d'une visibilité en IRM à des treillis. Pour cela, un enrobage de polymères dégradables (polyesters) piégeant des antibiotiques est créé à l'aide d'un aérographe autour des filaments des treillis tout en conservant leurs aspects morphologiques et leurs propriétés mécaniques. Cet enrobage temporaire permet une libération prolongée de principes actifs inhibant l'adhésion bactérienne, la formation de biofilm et la prolifération bactérienne périprothétique pendant plus de trois jours in vitro. Parallèlement, des polymères contenant des agents de contraste greffés sur leur squelette carboné ont été utilisés comme agent d'enrobage, afin d'apporter des propriétés de visibilité en IRM aux treillis. In vitro, ces treillis enrobés induisent un signal significatif en IRM expérimentale (7 Tesla) et présentent une très bonne stabilité de l'agent de contraste, quelle que soit la technique de stérilisation employée. Surgical operations for soft tissue reinforcement (i.e. pelvic organs prolapse or abdominal hernias) are common procedures and require annually at least 1,200,000 of prostheses. Unfortunately, postoperatory complications and reinterventions are still important, mainly due to infection, inflammation, erosion, exposition or meshes migration. We present here several strategies to bring to meshes anti-infective resistance and clinical follow-up capability through an MRI visible material. A coating of the mesh by degradable polymers (polyesters) trapping antibiotics was created using an airbrushing technique, without modifying dramatically the morphology and the mechanical properties of the meshes. This temporary drug reservoir-coating allows a sustained release of the drugs and hamper in vitro bacterial contamination and biofilm formation on the meshes, associated to a large periprosthetic microorganism growth inhibition for a minimum of three days. Simultaneously, magnetic resonance contrast

Ref HAL: hal-00680748_v1
DOI: 10.1016/j.actbio.2011.11.009
Résumé: A great deal of effort has been made since the 1990s to enlarge the field of magnetic resonance imaging. Better tissue contrast, more biocompatible contrast agents and the absence of any radiation for the patient are some of the many advantages of using magnetic resonance imaging (MRI) rather than X-ray technology. But implantable medical devices cannot be visualized by conventional MRI and a tool therefore needs to be developed to rectify this. The synthesis of a new MRI-visible degradable polymer is described by grafting an MR contrast agent (DTPA-Gd) to a non-water-soluble, biocompatible and degradable poly(ecaprolactone) (PCL). The substitution degree, calculated by 1H nuclear magnetic resonance and inductively coupled plasma-mass spectrometry, is close to 0.5% and proves to be sufficient to provide a strong and clear T1 contrast enhancement. This new MRI-visible polymer was coated onto a commercial mesh for tissue reinforcement using an airbrush system and enabled in vitro MR visualization of the mesh for at least 1 year. A stability study of the DTPA-Gd-PCL chelate in phosphate-buffered saline showed that a very low amount of gadoliniumwas released into the mediumover 52 weeks, guaranteeing the safety of the device. This study shows that this new MRI-visible polymer has great potential for the MR visualization of implantable medical devices and therefore the post-operative management of patients.

Ref HAL: hal-00625737_v1
DOI: 10.1002/marc.2011100235
Résumé: A new strategy for the synthesis of polyamides frompolyesters of hydroxyl-containing amino acids using a multi O

Ref HAL: hal-00536858_v1
DOI: 10.1002/pola.24400
Résumé: Novel 5-Z-amino-d-valerolactone (5-NHZ-VL) was synthesized with aim to prepare degradable polyesters and copolyesters having amino pendant groups. Following a straightforward and efficient synthetic pathway, 5-NHZ-VL was obtained in only two steps and up to 50 % yield. The monomer was fully characterized by 1H NMR, 13C NMR, ESI mass spectrometry and HPLC. Various conventional conditions were tested for this lactone ring opening polymerization and led to the novel corresponding poly(5-NHZ-VL) (Mn = 7000 g/mol ; PD = 1.2). Following this homopolymerization, 5-NHZ-VL was copolymerized with e-caprolactone to generate a family of copolyesters with an amino-group content ranging from 10 to 80 %. Finally, the polyelectrolyte poly(5-NH3+-VL) was recovered by removal of the protecting group under acidic conditions and integrity of the polyester backbone was confirmed by 1H NMR.

Ref HAL: hal-00626439_v1
DOI: 10.1002/pola.23652
Résumé: A novel method is proposed to access to new poly(a-amino-e-caprolactoneco-e-caprolactone) using poly(a-iodo-e-caprolactone-co-e-caprolactone) as polymeric substrate. First, ring-opening (co)polymerizations of a-iodo-e-caprolactone (aIeCL) with e-caprolactone (eCL) are performed using tin 2-ethylhexanoate (Sn(Oct)2)as catalyst. (Co)polymers are fully characterized by 1H NMR, 13C NMR, FTIR, SEC, DSC, and TGA. Then, these iodinated polyesters are used as polymeric substrates to access to poly(a-amino-e-caprolactone-co-e-caprolactone) by two different strategies. The first one is the reaction of poly(aIeCL-co-eCL) with ammonia, the second one is the reduction of poly(aN3eCL-co-eCL) by hydrogenolysis. This poly(a-amino-e-caprolactone-co-e-caprolactone) (FaNH2eCL \ 0.1) opens the way to new cationic and watersoluble PCL-based degradable polyesters.