Akkus Anna, Tyler Rakim, Schiraldi David, Roperto Renato, Faddoul Fady, Teich Sorin
School of Dental Medicine, Department of Comprehensive Care, Case Western Reserve University, Cleveland, Ohio 44106, USA.
School of Engineering, Department of Macromolecular Science, Case Western Reserve University, Cleveland, Ohio 44106, USA.
J Clin Exp Dent. 2017 Jul 1;9(7):e875-e878. doi: 10.4317/jced.53465. eCollection 2017 Jul.
Bio cellulose is a byproduct of sweet tea fermentation known as kombusha. During the biosynthesis by bacteria cellulose chains are polymerized by enzyme from activated glucose. The single chains are then extruded through the bacterial cell wall. Interestingly, a potential of the Kombucha's byproduct bio cellulose (BC) as biomaterial had come into focus only in the past few decades. The unique physical and mechanical properties such as high purity, an ultrafine and highly crystalline network structure, a superior mechanical strength, flexibility, pronounced permeability to gases and liquids, and an excellent compatibility with living tissue that reinforced by biodegradability, biocompatibility, large swelling ratios.
The bio-cellulose film specimens were provided by the R.P Dressel dental materials laboratory, Department of Comprehensive Care, School of Dental Medicine, Case Western Reserve University, Cleveland, US. The films were harvested, washed with water and dried at room temperature overnight. 1wt% of PEG-2000 and 10wt% of NaOH were added into ultrapure water to prepare PEG/NaOH solution. Then bio-cellulose film was added to the mixture and swell for 3 h at room temperature. All bio-cellulose film specimens were all used in the TA Instruments Q500 Thermogravmetric Analyzer to investigate weight percent lost and degradation. The TGA was under ambient air conditions at a heating rate of 10ºC/min.
PEG control exhibited one transition with the peak at 380ºC. Cellulose and cellulose/ PEG films showed 3 major transitions. Interestingly, the cellulose/PEG film showed slightly elevated temperatures when compared to the corresponding transitions for cellulose control. The thermal gravimetric analysis (TGA) degradation curves were analyzed. Cellulose control film exhibited two zero order transitions, that indicate the independence of the rate of degradation from the amount on the initial substance. The activation energies for three transitions for cellulose and cellulose/PEG showed increasingly higher values for the transitions at higher temperatures. TGA, Bio-cellulose, PEG.
生物纤维素是甜茶发酵的副产品，称为康普茶菌。在生物合成过程中，细菌纤维素链由活化葡萄糖中的酶聚合而成。然后单链通过细菌细胞壁挤出。有趣的是，康普茶的副产品生物纤维素（BC）作为生物材料的潜力仅在过去几十年才受到关注。其独特的物理和机械性能包括高纯度、超细且高度结晶的网络结构、优异的机械强度、柔韧性、对气体和液体的显著渗透性，以及通过生物降解性、生物相容性、大溶胀率增强的与活组织的优异相容性。
生物纤维素膜标本由美国克利夫兰凯斯西储大学牙科学院综合护理系的R.P Dressel牙科材料实验室提供。将膜收获，用水洗涤并在室温下过夜干燥。将1wt%的PEG - 2000和10wt%的NaOH加入超纯水中制备PEG/NaOH溶液。然后将生物纤维素膜加入混合物中并在室温下溶胀3小时。所有生物纤维素膜标本均用于TA仪器Q500热重分析仪中研究失重和降解情况。热重分析在环境空气条件下以10℃/分钟的加热速率进行。
PEG对照显示出一个转变，峰值在380℃。纤维素和纤维素/PEG膜显示出3个主要转变。有趣的是，与纤维素对照的相应转变相比，纤维素/PEG膜显示出温度略有升高。对热重分析（TGA）降解曲线进行了分析。纤维素对照膜表现出两个零级转变，这表明降解速率与初始物质的量无关。纤维素和纤维素/PEG的三个转变的活化能在较高温度下的转变中显示出越来越高的值。TGA，生物纤维素，PEG。
