Mechanical properties of a nanoporous membrane used in implantable medical devices. Correlation between experimental characterization and 2D numerical simulation.

Nanoporous membranes are used for the elaboration of implantable medical devices. In order to guaranty their integrity after implantation in a patient body, it is necessary to characterize the microstructure and the mechanical behavior of such membranes. They present randomly distributed pores around 1µm in diameter at the surface. X-ray nanotomography permits to get the geometry of the pores through the thickness with a reduction of the diameter in the core. A multiscale study is done to characterize the membranes: macroscopic tensile tests permit to get the behavior law of the non porous material and in situ tensile tests are carried on in a Scanning Electron Microscope in order to observe the evolution of pores and cracks during loading. A 2D Finite Element Model is also developed in parallel. The confrontation between experiments and numerical simulations permit to validate the accuracy of the model. The latter is then used to simulate several types of loadings considering various pore distributions and sizes.

Triple therapies plus different probiotics for Helicobacter pylori eradication.

The Helicobacter pylori (H. pylori) cure rate following standard triple therapies is decreasing worldwide. Therefore, further approaches aimed to improve standard triple therapy efficacy should be attempted. This prospective, pilot study aimed to evaluate the therapeutic role of either Lactobacillus reuteri (L. reuteri) or a high concentration of probiotics in addition to standard triple therapies for H. pylori eradication. The study enrolled 65 consecutive dyspeptic patients with H. pylori infection. All patients underwent upper endoscopy with gastric biopsies. Patients were assigned to receive one of the following therapies: (a) standard 7-day triple; (b) the same 7-day triple therapy plus L. reuteri supplementation; (c) the same 7-day triple therapy plus a probiotic mixture; and d) a 14-day standard triple therapy plus a probiotic mixture. H. pylori eradication was checked by using a 13C-urea breath test performed 4-6 weeks after treatment. No therapy regimen achieved > 80% eradication rate at both intention-to-treat (ITT) and per protocol (PP) analyses. Although the 14-day therapy plus a probiotic mixture tended to achieve higher eradication rate (71%), no statistically significant difference emerged among the different therapy regimens tested (range: 53-71%). The lowest incidence of side-effects was observed following the 7-day therapy plus L. reuteri (6%) and highest with the 14-day triple therapy plus probiotic mixture (33%), although the difference failed to reach the statistically significance. In conclusion, our data found that 7-14 days triple therapy with or without probiotic supplementation failed to achieved acceptable H. pylori eradication rates.