Single-step deposition of hexamethyldisiloxane surface gradient coatings with a high amplitude of water contact angles over a polyethylene foil

One interesting category of nano- and micro-engineered surfaces is surface gradients, which allow the controlled optimization of biointerfaces at a small scale in an extended area length. Plasma coatings offer a large diversity of functionalities at the nanoscale, accompanied by high chemical stability and adhesion on a variety of substrates at ambient temperature. Atmospheric-pressure plasma-assisted deposition could be employed for the generation of surface gradients on thermosensitive materials. In this study, a corona plasma jet is used to deposit polydimethylsiloxane/SiO2-like surface gradients on polyethylene foil by varying the O2 concentration in the discharge during the movement of the plasma source. We obtained, in a single-step approach, gradient coatings along a length of ∼10 cm, with a gradual variation of both chemistry and surface energy

A new strategy to prevent biofilm and clot formation in medical devices: the use of atmospheric non-thermal plasma assisted deposition of silver-based nanostructured coatings

In industrialized countries, health care associated infections, the fourth leading cause of dis- ease, are a major health issue. At least half of all cases of nosocomial infections are associ- ated with medical devices. Antibacterial coatings arise as an important approach to restrict the nosocomial infection rate without side effects and the development of antibiotic resis- tance. Beside nosocomial infections, clot formation affects cardiovascular medical devices and central venous catheters implants. In order to reduce and prevent such infection, we develop a plasma-assisted process for the deposition of nanostructured functional coatings on flat substrates and mini catheters. Silver nanoparticles (Ag NPs) are synthesized exploit- ing in-flight plasma-droplet reactions and are embedded in an organic coating deposited through hexamethyldisiloxane (HMDSO) plasma assisted polymerization. Coating stability upon liquid immersion and ethylene oxide (EtO) sterilization is assessed through chemical and morphological analysis carried out by means of Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). In the perspective of future clinical appli- cation, an in vitro analysis of anti-biofilm effect has been done. Moreover, we employed a murine model of catheter-associated infection which further highlighted the performance of Ag nanostructured films in counteract biofilm formation. The anti-clot performances coupled by haemo- and cytocompatibility assays have also been performed

Thirty-year patency of a coronary sequential venous bypass graft

Summary. Background: The optimal conduit of second choice in surgical coronary revascularization remains a matter of debate. Radial artery grafts are believed to have a better patency rate than the saphenous vein grafts, although no conclusive results have been reported. This report describes the late result of a coronary revascularization with sequential venous bypass performed 30 years earlier. Methods: An 80-year-old woman was admitted for dyspnoea on exertion and recent-onset angina due to severe aortic valve stenosis. Thirty years earlier, the patient had undergone revascularization with coronary bypass grafting performed using a sequential saphenous vein graft anastomosed on first diagonal branch and on left anterior descending coronary artery. Coronary angiography showed the occlusion of the native left anterior descending artery and the good patency of the previous described sequential vein graft. Results: Surgical inspection confirmed the patency and the soft pliability of the venous graft and the surgeon decided to do not replace the previous graft with a pedicled LIMA (Left Internal Mammary Artery) graft. The patient underwent 21-mm biological Edwards Perimount Magna Ease prosthesis implantation. Postoperative course was uneventful and the patient was discharged on the seventh day after surgery. Conclusions: This case report demonstrated the potential extreme long-term patency of a sequential saphenous vein graft in coronary bypass surgery, raising the question if vein grafts should be really considered the conduits of last resort for coronary artery bypass surgery. Long-term follow-up of randomized trials comparing radial artery versus saphenous vein grafts are warranted in order to give conclusive answers to this ongoing debate