A novel hybrid silk-fibroin/polyurethane three-layered vascular graft: towards in situ tissue-engineered vascular accesses for haemodialysis

Biomed Mater. 2019 Jan 30;14(2):025007. doi: 10.1088/1748-605X/aafc96.

Abstract

Clinically available alternatives of vascular access for long-term haemodialysis-currently limited to native arteriovenous fistulae and synthetic grafts-suffer from several drawbacks and are associated to high failure rates. Bioprosthetic grafts and tissue-engineered blood vessels are costly alternatives without clearly demonstrated increased performance. In situ tissue engineering could be the ideal approach to provide a vascular access that profits from the advantages of vascular grafts in the short-term (e.g. early cannulation) and of fistulae in the long-term (e.g. high success rates driven by biointegration). Hence, in this study a three-layered silk fibroin/polyurethane vascular graft was developed by electrospinning to be applied as long-term haemodialysis vascular access pursuing a 'hybrid' in situ engineering approach (i.e. based on a semi-degradable scaffold). This Silkothane® graft was characterized concerning morphology, mechanics, physical properties, blood contact and vascular cell adhesion/viability. The full three-layered graft structure, influenced by the polyurethane presence, ensured mechanical properties that are a determinant factor for the success of a vascular access (e.g. vein-graft compliance matching). The Silkothane® graft demonstrated early cannulation potential in line with self-sealing commercial synthetic arteriovenous grafts, and a degradability driven by enzymatic activity. Moreover, the fibroin-only layers and extracellular matrix-like morphology, presented by the graft, revealed to be crucial in providing a non-haemolytic character, long clotting time, and favourable adhesion of human umbilical vein endothelial cells with increasing viability after 3 and 7 d. Accordingly, the proposed approach may represent a step forward towards an in situ engineered hybrid vascular access with potentialities for vein-graft anastomosis stability, early cannulation, and biointegration.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biocompatible Materials / chemistry
  • Blood Coagulation Tests
  • Blood Vessel Prosthesis*
  • Bombyx
  • Cell Adhesion
  • Cell Survival
  • Electrochemistry
  • Fibroins / chemistry*
  • Hemolysis
  • Human Umbilical Vein Endothelial Cells
  • Humans
  • Inflammation
  • Permeability
  • Polyurethanes / chemistry*
  • Renal Dialysis / instrumentation*
  • Renal Dialysis / methods
  • Stress, Mechanical
  • Sutures
  • Tensile Strength
  • Tissue Engineering / methods*
  • Vascular Access Devices*

Substances

  • Biocompatible Materials
  • Polyurethanes
  • Fibroins