A multilayered electrospun graft as vascular access for hemodialysis

Abstract

Despite medical achievements, the number of patients with end-stage kidney disease keeps steadily raising, thereby entailing a high number of surgical and interventional procedures to establish and maintain arteriovenous vascular access for hemodialysis. Due to vascular disease, aneurysms or infection, the preferred access—an autogenous arteriovenous fistula—is not always available and appropriate. Moreover, when replacing small diameter blood vessels, synthetic vascular grafts possess well-known disadvantages. A continuous multilayered gradient electrospinning was used to produce vascular grafts made of collagen type I nanofibers on luminal and adventitial graft side, and poly-ɛ-caprolactone as medial layer. Therefore, a custom-made electrospinner with robust environmental control was developed. The morphology of electrospun grafts was characterized by scanning electron microscopy and measurement of mechanical properties. Human microvascular endothelial cells were cultured in the graft under static culture conditions and compared to cultures obtained from dynamic continuous flow bioreactors. Immunofluorescent analysis showed that endothelial cells form a continuous luminal layer and functional characteristics were confirmed by uptake of acetylated low-density-lipoprotein. Incorporation of vancomycin and gentamicin to the medial graft layer allowed antimicrobial inhibition without exhibiting an adverse impact on cell viability. Most striking a physiological hemocompatibility was achieved for the multilayered grafts.

Influence of Electrical Field Collector Positioning and Motion Scheme on Electrospun Bifurcated Vascular Graft Membranes

“…These values ranged between 985 and 4915 mmHg (except for the case of Kim et al where an extremely thick membrane of 0.33 mm was tested [24]). Previously reported results for SRS suggest that this parameter was determined mostly by membrane thickness [37]. However, in the range of test conditions covered in this study, we did not find such a correlation.…”

Antifungal susceptibility of Candida species to copper oxide nanoparticles on polycaprolactone fibers (PCL-CuONPs)

“…Electrospinning is an effective technique to produce polymer biofilms, which allows the fabrication of continuous filaments at a nano and microscale from natural and synthetic polymers, in this manner increasing the possibility to be like biological and mechanical properties [11]. Polycaprolactone (PCL) is one of the most broadly employed polymers in biomedical applications due to its biocompatibility, biodegradability and physical properties [12,13,14].…”

Additively manufactured small‐diameter vascular grafts with improved tissue healing using a novel SNAP impregnation method

“…Despite the application of sterile surgical techniques, bacterial contamination is considered as a main clinical complication of current synthetic vascular grafts, especially for small‐diameter vascular grafts (SDVGs, <6 mm) which can cause graft failure (Kabirian, Amoabediny, Haghighipour, Salehi‐Nik, & Zandieh‐Doulabi, ; Kabirian, Ditkowski, Zamanian, Heying, & Mozafari, ; Pashneh‐Tala et al, ; Radakovic et al, ; Rao et al, ). Bacteria start to colonize immediately after implantation especially during the critical first 6 hr which is also known as the “decisive period.” Since the management of this period is directly related to success or failure of implantation and the host's defenses are not able to completely combat the infection process during this period (Zilberman & Elsner, ), antimicrobial agents are used in the form of systemic or controlled release systems.…”