Bacterial cellulose as a potential vascular graft: Mechanical characterization and constitutive model development

Abstract

Bacterial cellulose (BC) is a polysaccharide produced by Acetobacter Xylinum bacteria with interesting properties for arterial grafting and vascular tissue engineering including high-burst pressure, high-water content, high crystallinity, and an ultrafine highly pure fibrous structure similar to that of collagen. Given that compliance mismatch is one of the main factors contributing to the development of intimal hyperplasia in vascular replacement conduits, an in depth investigation of support mechanical properties of BC is required to further supporting its use in cardiovascular-grafting applications. The aim of this study was to mechanically characterize BC and also study its potential to accommodate vascular cells. To achieve these aims, inflation tests and uniaxial tensile tests were carried out on BC samples. In addition, dynamic compliance tests were conducted on BC tubes, and the results were compared to that of arteries, saphenous vein, expanded polytetrafluoroethylene, and Dacron grafts. BC tubes exhibited a compliance response similar to human saphenous vein with a mean compliance value of 4.27 × 10(-2) % per millimeter of mercury over the pressure range of 30-120 mmHg. In addition, bovine smooth muscle cells and endothelial cells were cultured on BC samples, and histology and fluorescent imaging analysis were carried out showing good adherence and biocompatibility. Finally, a method to predict the mechanical behavior of BC grafts in situ was established, whereby a constitutive model for BC was determined and used to model the BC tubes under inflation using finite element analysis.

Bioactive 3D-Shaped Wound Dressings Synthesized from Bacterial Cellulose: Effect on Cell Adhesion of Polyvinyl Alcohol Integrated In Situ

“…This was more distinctive for BC (Figure 2(b)), which showed a nonlinear response (toe-in region) as has been described elsewhere [48,49]. This region results from the gradual stretching of cellulose fibres upon loading, which is analogous to the function of collagen fibrils [48].…”

Cellulose-based materials as scaffolds for tissue engineering

“…At the same time, they supported the development of a layer of vascular smooth muscle cells. These tubes were therefore considered to be suitable for engineering small-caliber vascular grafts (Zahedmanesh et al 2011).…”

A multiscale mechanobiological modelling framework using agent-based models and finite element analysis: application to vascular tissue engineering

“…The python code could automatically detect the new luminal surface and apply the pressure and pore pressure boundary condition to the new surface following each iteration. The tube was 8 mm long with a thickness of 0.673 mm and a luminal diameter of 4.18 mm, which was chosen based on dimensions of bacterial cellulose tubes used in (Zahedmanesh et al 2011) which have shown good potential for vascular tissue engineering. The model was discretised by 190 elements longitudinally and 62 elements radially.…”