Engineering of bacterial cellulose-based vascular grafts for small-diameter applications

Cardiovascular diseases remain the leading cause of mortality worldwide, necessitating advanced revascularization strategies such as coronary artery bypass grafting (CABG). While autologous vessels like the saphenous vein are commonly used, their limited availability, their potential maladaptation to the arterial environment, and the suboptimal performance of synthetic alternatives underscores the urgent demand for innovative small-diameter grafts. Grafts made of Bacterial Cellulose (BC), synthesized by Acetobacter xylinum, have gained attention due to its excellent biocompatibility, mechanical integrity, and in vivo patency. However, clinical translation is hindered by inconsistent fabrication processes that result in graft mismatched dimensions and variable mechanical performance. This study presents an optimized and reproducible culture method for producing BC-based grafts with clinically relevant dimensions (4 mm inner diameter and 15 cm length). The grafts were evaluated morphologically, biologically and mechanically according to ISO-10993 and ISO-7198 standards, using human saphenous veins as a benchmark. While the veins exhibited high variability in structure (inner diameter: 2.6 ± 0.7 mm; outer diameter: 4.9 ± 1.3 mm) and performance (e.g., burst pressure: 577.4 ± 631.3 mmHg), the BC grafts demonstrated consistent morphology (inner diameter: 4.00 mm; outer diameter: 4.92 ± 0.10 mm) and favorable and more reproducible mechanical properties (e.g. burst pressure: 306.6 ± 96.04 mmHg). In vitro assays confirmed effective bacterial residue removal, low thrombogenicity and preserved the biocompatibility of the cellulose network. Subcutaneous implantation of BC grafts induced a mild inflammatory response, and showed no signs of calcification, in contrast to Gore-tex implants. These findings emphasize the potential of BC grafts as reliable, scalable, and clinically relevant alternatives for vascular substitutes, including pediatric applications, and underscore the importance of standardized production for translational success.