Chitosan-based hydrogels for developing a small-diameter vascular graft: in vitro and in vivo evaluation

Biomed Mater. 2017 Oct 3;12(6):065003. doi: 10.1088/1748-605X/aa78d0.


Aims: Vascular grafts made of synthetic polymers perform poorly in small-diameter applications (cardiac and peripheral bypass). Chitosan is a biocompatible natural polymer that can provide a novel biological scaffold for tissue engineering development. The goal of this study was to demonstrate the biocompatibility of a novel chitosan preparation in vitro and in vivo, and to assess its potential as a scaffold for vascular applications.

Methods and results: A series of experiments of increasing complexity, ranging from in vitro biocompatibility and hemocompatibility tests to in vivo studies in small and large animals (rats and sheep), was performed to provide a comprehensive analysis of chitosan hydrogels' biological properties. In vitro studies established that: (i) chitosan supported human endothelial progenitor cells adhesion, proliferation and resistance to physiological shear stress; (ii) chitosan did not activate platelets, the complement system, or the intrinsic coagulation pathway. In vivo results showed: (iii) no resorption of chitosan and no chronic inflammation at 60 days in a rat heterotopic implantation model (magnetic resonance imaging and histology); (iv) no flow obstruction (Doppler ultrasound) and no thrombus formation (histology and scanning electron microscopy) at 2 h after a carotid arteriotomy repair with chitosan patches in sheep. Finally, two chitosan tubes were implanted as carotid interposition grafts for 3 days in sheep showing that chitosan was strong enough to be sutured, to withstand arterial pressure, and no flow obstruction was observed through this short period.

Conclusion: Chitosan-based hydrogels displayed promising in vitro biocompatibility and hemocompatibility properties as well as in vivo short-term performance.

Publication types

  • Evaluation Study

MeSH terms

  • Animals
  • Cells, Cultured
  • Chitosan / chemistry*
  • Complement Activation*
  • Endothelium, Vascular / cytology
  • Endothelium, Vascular / physiology*
  • Female
  • Humans
  • Hydrogels / chemistry*
  • In Vitro Techniques
  • Platelet Activation*
  • Rats
  • Rats, Wistar
  • Sheep
  • Stress, Mechanical
  • Tissue Engineering / methods*
  • Vascular Grafting*


  • Hydrogels
  • Chitosan