Preparation Of Tissue Engineered Bacterial Cellulose Tube And Preliminary Evalluation Of Biocompatibility In Vitro

Bacterial cellulose is a kind of gelatinous substance which is synthesized by Acetobacter. Bacterial cellulose is widely applied in tissues engineering field, especially in the research of vessel scaffold, because of its three dimensional nano-networks structure, good mechanical properties and biocompatibility. However, lack of bacterial cellulase and absence of strong acid or base environments cause bacterial cellulose not easy to be degraded in body. Sodium periodate has ability to oxidize cellulose and improve its degradability. The aim of this study is to explore the degradability of cellulose which is oxidized by sodium periodate, and whether it has potential application as vascular tissue engineering scaffolds.First part of this study was to compare the degradability of modified bacterial cellulose with that of non-modified bacterial cellulose. Bacterial cellulose was treated by different concentration of sodium periodate with different hours. After bacterial cellulose was oxidized, aldehyde content was determinated in order to understand the relationship between oxidizability and different reaction conditions. Then modified bacterial cellulose was degraded by simulated body fluid for the purpose of understanding whether oxidized bacterial cellulose had better degradability than non-oxidized bacterial cellulose. Subsequently, microstructure, equilibrium water content, porosity of wet film and tensile strength were measured respectively in order to realize the influence of different oxidation degree on these properties of bacterial cellulose. Biocompatibility of oxidized bacterial cellulose was evaluated by the test of in vitro cytotoxicity and hemolysis test. Further, optimal oxidizability was screened. Second part of this study was to synthesize small caliber bacterial cellulose tube by using batch closed method, and to explore the influence of culture condition on synthesizing bacterial cellulose tube.Result:oxidized bacterial cellulose had better degradability than non-oxidized bacterial cellulose. After determining microstructure, equilibrium water content, porosity of wet film and tensile strength, we discovered that microstructure would shrink with the oxidation degree deepening, but nanometer fibrils could be found out. The change of microstructure bring about the change of equilibrium water content, porosity of wet film and tensile strength, while did not affect its research on tissue engineering. Group A(dialdehyde concentration:9.80%±0.0101),B(dialdehyde concentration:11.02%±0.0114),C(dialdehyde concentration:22.27%±0.0177)were screened by cytotoxicity test and hemolysis test, and these three groups(A,B,C) were confirmed having good biocompatibility. So these three groups had the potential application as vascular tissue engineering scaffolds.Synthesizing small caliber bacterial cellulose tube was feasible by using batch closed culture method, and the tube had high equilibrium water content, porosity of wet film.In summary, degradability of bacterial cellulose could be improved through oxidation modification, but different oxidizability will lead to the change of property and cytotoxicity. In this study, Group A,B,C with lower oxidizability had better biocompatibility and degradability than non-oxidized bacterial cellulose, which had the potential application as vascular tissue engineering scaffolds. In the research of synthesizing small caliber bacterial cellulose tube, small caliber bacterial cellulose tube with high equilibrium water content and porosity of wet film were obtained.The future work mainly includes the improvement of the thickness of small caliber bacterial cellulose tube and the screening of optimal oxidizability for purpose of construction of tissue engineering blood vessel.