In vitro hemo- and cytocompatibility of bacterial nanocelluose small diameter vascular grafts: Impact of fabrication and surface characteristics

• Published in: PloS one 2020-06, Vol.15 (6), p.e0235168-e0235168
• Main Authors: Wacker, Max, Kiesswetter, Viktoria, Slottosch, Ingo, Awad, George, Paunel-Gorgulu, Adnana, Varghese, Sam, Klopfleisch, Maurice, Kupitz, Dennis, Klemm, Dieter, Nietzsche, Sandor, Petzold-Welcke, Katrin, Kramer, Friederike, Wippermann, Jens, Veluswamy, Priya, Scherner, Maximilian
• Format: Article
• Language: English
• Subjects: Antithrombin; Bacterial proteins; Bamboo; Biocompatibility; Biology and Life Sciences; Biomaterials; Bioreactors; Blood; Cell activation; Cellulose; Coagulation; Complement activation; Deoxyribonucleic acid; DNA; Equipment and supplies; Fabrication; Grafting; Health aspects; Heart surgery; In vitro methods and tests; In vivo methods and tests; Leukocytes; Medical research; Medicine and Health Sciences; Methods; Nanotechnology; Nuclear medicine; Oxygen; Physical Sciences; Platelets; Polyethylene; Polyethylene terephthalate; Polytetrafluoroethylene; Polyvinyl chloride; Radioactivity; Reactive oxygen species; Scanning electron microscopy; Scintigraphy; Surface properties; Surface roughness; Testing; Thrombin; Thrombocytes; Tubes; Vascular grafts
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0235168

There is an increasing need for small diameter vascular grafts with superior host hemo- and cytocompatibilities, such as low activation of platelets and leukocytes. Therefore, we aimed to investigate whether the preparation of bacterial nanocellulose grafts with different inner surfaces has an impact on in vitro host cytocompatibility. We have synthesized five different grafts in a bioreactor, namely open interface surface (OIS), inverted (INV), partially air dried (PAD), surface formed in air contact (SAC) and standard (STD) that were characterized by a different surface roughness. The grafts (length 55 mm, inner diameter 5 mm) were attached to heparinized polyvinyl chloride tubes, loaded with human blood and rotated at 37°C for 4 hours. Then, blood was analyzed for frequencies of cellular fractions, oxidative products, soluble complement and thrombin factors. The results were compared to clinically approved grafts made of polyethylene terephthalate and expanded polytetrafluoroethylene. Additionally, blood platelets were labelled with .sup.111 Indium-oxine to visualize the distribution of adherent platelets in the loop by scintigraphy. SAC nanocellulose grafts with the lowest surface roughness exhibited superior performance with 90% thrombocyte loss. Of note, SAC nanocellulose grafts showed lowest radioactivity with scintigraphy analyses, indicating reduced platelet adhesion. Although the levels of reactive oxygen species and cell free DNA did not differ significantly, the levels of thrombin-antithrombin complexes were lowest in SAC grafts. However, all nanocellulose grafts exhibited enhanced complement activation. The systematic variation of the inner surfaces of BNC vascular grafts significantly improves biocompatibility. Especially, SAC grafts exhibited the lowest loss of platelets as well as leukocytes and additionally significantly diminished activation of the coagulation system. Further animal studies are needed to study in vivo biocompatibilities.