| Bacterial cellulose (BC) and BC/fibrin composites were prepared and the static and dynamic mechanical properties were investigated to assess their suitability to artificial blood vessel applications. An important prerequisite for such applications is the ability to replicate the biological and mechanical properties of the blood vessels; and since published scientific works had observed both BC and fibrin to be biologically compliant, only mechanical properties were investigated in this study. Firstly, preparations of BC, BC/fibrin composites and their crosslinked counterparts were performed. BC/fibrin composites of varying compositions were produced by immersing never-dried-BC into fibrin/ionic liquid/DMSO solution in varied durations. The composite compositions were predicted from a calibration method based on calibration samples, FTIR data and Beer's law. Crosslinking was done by glutaraldehyde-treatment. Secondly, characterizations of static and dynamic mechanical properties were carried out by tensile test and cyclic loading test, respectively. The static test provided the data for the analysis of strength, modulus and elongation while the dynamic test for viscoelasticity and durability. The BC/fibrin composites and crosslinked BC had improved mechanical properties compared to their native components, however only the crosslinked BC/fibrin composites exhibited comparable strength, modulus, viscoelasticity and durability to the bovine blood vessel, indicating that the crosslinked composites were promising materials for artificial blood vessel applications. Additionally, the modification of fibrin content in the composites resulted in the modification of mechanical properties; such was desirable because real blood vessels exist in wide range of mechanical properties. The interactions and morphologies of the interfaces between BC and fibrin were investigated in relation to mechanical properties. The occurrence of crosslinking was believed to afford effective reinforcement in the BC/BC and/or BC/fibrin interfaces which imparted the significant mechanical improvement to the composites. The positive results obtained from the assessment of mechanical properties indicated that BC/fibrin composites are good potential artificial blood vessel materials. In the future, if an in vivo test will prove affirmative results, BC/fibrin composites, which have widely available resources and can be produced by simple method, may be used as blood vessel replacement material. |
