RESUMEN
BACKGROUND: Based on our previous findings, the mechanical properties of bacterial nanocellulose (BNC) tubes were improved by composite with polyvinyl alcohol (PVA) using phase separation method. However, the biocompatibility of the composite tubes is rarely reported. OBJECTIVE: To evaluate the biocompatibility of BNC and BNC/PVA composite tubes. METHODS: Two types of BNC tubes (S-BNC and D-BNC) with different structures were online prepared in two bioreactors (single-silicone tube bioreactor and double-silicone tubes bioreactor respectively). BNC/PVA composites were prepared based on both BNC tubes using a phase separation method. The hemocompatibility of these tubes including hemolytic ratio, plasma recalcification and platelet adhesion were compared. Living/dead staining method was used to evaluate the cell growth after 3 and 7 days incubation since the endothelial and smooth muscle cells were seeded on the lumen surfaces of the BNC and BNC/PVA composite tubes, respectively. RESULTS AND CONCLUSION: (1) Hemocompatibility: The hemolytic ratios of four kinds of tubes were all below 0.5%. The plasma recalcification time of D-BNC tube was significantly shorter than that of S-BNC tube (P < 0.05). The plasma recalcification processes of two composites were slowed as compared with corresponding BNC tubes (P < 0.05). No significant difference in plasma recalcification was detected between the two composites. The platelets adhered on the inner surface of two pure BNC tubes showed greater deformation and aggregated distribution, which led to the formation of platelet plugs. The platelet adhesion of BNC/PVA composites was dramatically reduced. The D-BNC/PVA composite tube showed more platelet adhesion than the S-BNC/PVA composite tube. (2) Cytocompatibility: Pig iliac endothelial cells could grow on the lumen surface of these four kinds of tubes. And the composites showed better growth as compared with corresponding pure BNC tubes. Human vascular smooth muscle cells could also grow on the lumen surface of four kinds of materials. As compared with the pure BNC tubes, the composites led to improvement in cell growth, and the D-BNC/PVA composite tube showed the best result. To conclude, the BNC/PVA composite tube has good hemocompatibility and cytocompatibility.
RESUMEN
BACKGROUND: There are still no applicable vascular grafts for clinical replacement of the small-diameter blood vessels (< 6 mm). OBJECTIVE: To explore the possibility of bacterial nano-cellulose (BNC)/chitosan (CH) composite tubes as small-diameter artificial blood vessels. METHODS: BNC/CH tubes were fabricated by introducing chitosan (0.5%, 1%, 2%) into BNC tubes. Physicochemical properties of BNC/CH tubes were analyzed including macro-morphology, microstructure, density, water-holding capacity, burst pressure, mechanical properties, blood compatibility and cytocompatibility. RESULTS AND CONCLUSION: The results indicated that, as compared with the BNC tubes, the water permeability of BNC/CH tubes reduced, the density and water-holding capacity increased, as well as the axial and radial mechanical performance was enhanced, but ductility and elasticity of BNC/CH tubes were weakened. Regarding blood compatibility, hemolysis ratios of BNC and BNC/CH met the requirements of medical grade composites, while the plasma recalcification time showed that anticoagulation of BNC/CH tubes was slightly weaker than that of the BNC tubes. Cell compatibility experiments showed that porcine hip artery endothelial cells stably proliferated on the inner surface of both BNC and BNC/CH tubes, but the proliferation was more obvious on the BNC surface than on the BNC/CH surface.