Magnetizable stent-grafts enable endothelial cell capture

Abstract

Emerging nanotechnologies have enabled the use of magnetic forces to guide the movement of magnetically-labeled cells, drugs, and other therapeutic agents. Endothelial cells labeled with superparamagnetic iron oxide nanoparticles (SPION) have previously been captured on the surface of magnetizable 2205 duplex stainless steel stents in a porcine coronary implantation model. Recently, we have coated these stents with electrospun polyurethane nanofibers to fabricate prototype stent-grafts. Facilitated endothelialization may help improve the healing of arteries treated with stent-grafts, reduce the risk of thrombosis and restenosis, and enable small-caliber applications. When placed in a SPION-labeled endothelial cell suspension in the presence of an external magnetic field, magnetized stent-grafts successfully captured cells to the surface regions adjacent to the stent struts. Implantation within the coronary circulation of pigs (n=13) followed immediately by SPION-labeled autologous endothelial cell delivery resulted in widely patent devices with a thin, uniform neointima and no signs of thrombosis or inflammation at 7 days. Furthermore, the magnetized stent-grafts successfully captured and retained SPION-labeled endothelial cells to select regions adjacent to stent struts and between stent struts, whereas the non-magnetized control stent-grafts did not. Early results with these prototype devices are encouraging and further refinements will be necessary in order to achieve more uniform cell capture and complete endothelialization. Once optimized, this approach may lead to more rapid and complete healing of vascular stent-grafts with a concomitant improvement in long-term device performance.

Electrospun Produced 3D Matrices for Covering of Vascular Stents: Paclitaxel Release Depending on Fiber Structure and Composition of the External Environment

“…Recently, electrospun matrices were suggested as coatings for bare-metal esophageal [11] and vascular stents [12]. The high incidence of restenosis requires the reassessment and improvement of current practices for the remodeling of stented arterial regions with bare-metal stents [13].…”

Biocompatible Carbon-Based Coating as Potential Endovascular Material for Stent Surface

“…Surface modification technologies can be divided into two main categories: passive and bioactive material surface and coatings [ 18 ]. Passive approaches are aimed at modification of surface chemistry or material physical structure [ 19 ]. Bioactive strategies employ either permanent immobilization of an active agent or local drug delivery [ 20 ].…”

Vascular Stents Coated with Electrospun Drug-Eluting Material: Functioning in Rabbit Iliac Artery

“…DESs coated by electrospinning with biostable or biodegradable polymers able to release anti-inflammatory preparations, cytostatics, anticoagulants, ligands for endothelization, and so on have been used to restore the vascular lumen [ 17 , 23 , 28 , 47 , 49 , 50 ]. The authors of all papers note that the stents of this type are most promising healthcare products, which improve endothelialization and reduce inflammation and clotting depending on the fillers used.…”

“…The experimental esophageal and vascular stents thus coated were manufactured [ 25 , 26 , 27 ]. In particular, the PK Papyrus (Biotronik, Berlin, Germany) stent is used in clinical practice; in this stent, the electrospun polymeric coating acts as a graft for hermetic sealing of coronary artery lesions [ 28 , 29 ]. The use of electrospinning for coating stents indeed looks very attractive as this method makes it possible to produce coatings from fibers with a diameter of several tens of nanometers to several micrometers, fabricate such fibers of synthetic and natural polymers or their mixtures, introduce various drugs into the fibers, and form layers with the help of successive or concurrent production of different types of fibers [ 30 , 31 , 32 , 33 , 34 ].…”