Research and clinical translation of trilayer stent-graft of expanded polytetrafluoroethylene for interventional treatment of aortic dissection

Abstract

The aortic dissection (AD) is a life-threatening disease. The transcatheter endovascular aortic repair (EVAR) affords a minimally invasive technique to save lives of these critical patients, and an appropriate stent-graft gets to be the key medical device during an EVAR procedure. Herein, we report a trilayer stent-graft and corresponding delivery system used for the treatment of the AD disease. The stent-graft is made of nitinol stents with an asymmetric Z-wave design and two expanded polytetrafluoroethylene (ePTFE) membranes. Each of inner and outer surfaces of the stent-graft was covered by an ePTFE membrane, and the two membranes were then sintered together. The biological studies of the sintered ePTFE membranes indicated that the stent-graft had excellent cytocompatibility and hemocompatibility in vitro. Both the stent-graft and the delivery system exhibited satisfactory mechanical properties and operability. The safety and efficacy of this stent-graft and the corresponding delivery system were demonstrated in vivo. In 9 canine experiments, the blood vessels of the animals implanted with the stent-grafts were of good patency, and there were no thrombus and obvious stenosis by angiography after implantation for 6 months. Furthermore, all of the 9 clinical cases experienced successful implantation using the stent-graft and its post-release delivery system, and the one-year follow-ups indicated the preliminary safety and efficacy of the trilayer stent-graft with an asymmetric Z-wave design for interventional treatment.

Stereo Coverage and Overall Stiffness of Biomaterial Arrays Underly Parts of Topography Effects on Cell Adhesion

“…Cell–material interactions are critical for tissue regeneration. − Cells respond to various material cues, cell cues and soluble factors. − As material cues are concerned, surface topography and matrix stiffness are two physical factors which always exist more or less. The present study distinguishes itself as the focus understanding of a part of topological effect in light of overall stiffness effect.…”

Achieving Long-Acting Local Analgesia Using an Intelligent Hydrogel Encapsulated with Drug and pH Regulator

“…Biomaterials have various applications in the fields of tissue replacement, tissue engineering, regenerative medicine, and drug delivery. − Carriers such as liposomes, nanoparticles, and microspheres have been used to encapsulate local anesthetics for developing long-acting analgesia formulations. , However, besides the relatively low encapsulation efficiency of drugs and complex preparation methods of these formulations, those particles are, unlike our in situ -formed physical hydrogel, not easy to retain in the injection site, and thus, these particle-form formulations exhibit limited long-term efficacy as usual. A star local anesthetic formulation with the trade name Exparel is BUP multivesicular liposome, which is used via surgical site infiltration .…”

Recent advances in regenerative biomaterials

“…In addition to hydrogels composed of cross-linked polymer networks, most of polymers exhibit excellent processability into various macroscopic physical forms. For example, poly(methyl methacrylate), named bone cement, has been used as a filling material to achieve bone repairing [ 157–159 ]; synthetic polyetheretherketone (PEEK) has been applied in orthopedics [ 160 ]; polytetrafluoroethylene has been used as an implantable material owing to its excellent biocompatibility and mechanical properties [ 161 ]. Besides the nonbiodegradable polymers as mentioned above, biodegradable polymers have been used in clinic [ 162 ].…”