(Silkothane® Arteriovenous Graft)

SAG (Silkothane® Arteriovenous Graft) is a revolutionary three-layered semi-resorbable vascular prosthesis, which gradually integrates into the body of hemodialytic patients, thanks to the hybrid nature of the Silkothane® material with which it is made.

Integrating the biocompatibility and remodeling capability of silk fibroin with the elasticity and stability of polyurethanes, SAG is an innovative “bionic” solution, which aims to significantly improve the quality of life of an unfortunately growing audience. Today there are over two million people in need of permanent dialysis, a number set to rise due the aging of the population and to the growing incidence of diabetes and hypertension. The goal is to mitigate the trauma of patients, eliminating the many complications related to current therapeutic solutions.

SAG’s biomimetic nanostructure

The game-changing SAG will surpass native fistulae in that it will be available off-the-shelf (thus being promptly applicable to every patient, even in the frail elderly with compromised vasculature), and it will enable early cannulation (i.e. possibility of hemodialysis treatment within 48 hours after implantation, VS 6-8 weeks’ maturation needed for the fistula to be strong enough to be punctured).

SAG will also outperform central venous catheters and currently available early-cannulation arteriovenous grafts, as it will ensure unprecedented hemocompatibility, favorable integration with the host environment, and remodeling, ultimately overcoming issues related to reduced patency and increased infection rates.

In situ tissue engineering

SAG’s unique nanostructure, achieved by means of electrospinning, makes the graft suitable for in vivo colonization and remodeling by host cells and tissues, thus realizing the so-called “in situ tissue engineering” (or “endogenous tissue regeneration”) approach of regenerative medicine.

SAG’s potentialities as vascular access for hemodialysis were successfully verified with in vitro studies (permeability, hemocompatibility, burst pressure, dynamic radial compliance, puncturability)[1] and in a proof-of-concept animal study in sheep (carotid artery-jugular vein shunt)[2]. The clinical efficacy of SAG will be evaluated in the coming months.

[1] A novel hybrid silk-fibroin/polyurethane three-layered vascular graft: towards in situ tissue-engineered vascular accesses for haemodialysis. van Uden S, Vanerio N, Catto V, Bonandrini B, Tironi M, Figliuzzi M, Remuzzi A, Kock L, Redaelli ACL, Greco FG, Riboldi SA. Biomed Mater. 2019 Jan 30; 14(2): 025007. doi: 10.1088/1748-605X/aafc96.

[2] A Novel Hybrid Silk Fibroin/Polyurethane Arteriovenous Graft for Hemodialysis: Proof-of-Concept Animal Study in an Ovine Model. Riboldi SA, Tozzi M, Bagardi M, Ravasio G, Cigalino G, Crippa L, Piccolo S, Nahal A, Spandri M, Catto V, Tironi M, Greco FG, Remuzzi A, Acocella F. Adv Healthc Mater. 2020 Oct; 9(20): e2000794. doi: 10.1002/adhm.202000794. Epub 2020 Sep 11.