Dimethyl Sulfoxide-Free Cryopreservation of Human Umbilical Cord Mesenchymal Stem Cells Based on Zwitterionic Betaine and Electroporation

The effective cryopreservation of mesenchymal stem cells (MSCs) is indispensable to the operation of basic research and clinical transplantation. The prevalent protocols for MSC cryopreservation utilize dimethyl sulfoxide (DMSO), which is easily permeable and able to protect MSCs from cryo-injuries, as a primary cryoprotectant (CPA). However, its intrinsic toxicity and adverse effects on cell function remain the bottleneck of MSC cryopreservation. In this work, we cryopreserved human umbilical cord mesenchymal stem cells (UCMSCs) using zwitterionic betaine combined with electroporation without any addition of DMSO. Betaine was characterized by excellent compatibility and cryoprotective properties to depress the freezing point of pure water and balance the cellular osmotic stress. Electroporation was introduced to achieve intracellular delivery of betaine, intending to further provide comprehensive cryoprotection on UCMSCs. Compared with DMSO cryopreservation, UCMSCs recovered from the protocol we developed maintained the normal viability and functions and reduced the level of reactive oxygen species (ROS) that are harmful to cell metabolism. Moreover, the in vivo distribution of thawed UCMSCs was consistent with that of fresh cells monitored by a bioluminescence imaging (BLI) system. This work opens a new window of opportunity for DMSO-free MSC cryopreservation using zwitterionic compounds like betaine combined with electroporation.     

桩西115区块表面活性剂驱技术研究与应用

胜利油田桩西采油厂桩115区块属于高温中低渗油藏,为进一步改善区块注采矛盾,本文通过考察不同浓度4种甜菜碱表面活性剂溶液与桩115区块原油间的界面张力及其在石英砂表面的吸附规律,开发了以甜菜碱表面活性剂为主剂、以碱木素为牺牲剂的低界面张力驱油体系。该体系在石英砂表面的静态吸附量为0.4 mg/g;无需同碱复配,即可使油水界面张力降至5×10-4mN/m。物理模拟实验表明,在水驱后注入0.3 PV冻胶堵剂+0.3 PV低界面张力驱油体系,原油采收率可提高17%。2008年1月在桩115-5井组采用驱替方案进行了现场试验,截止2010年5月净增原油1632 t。图13参7     

聚表二元驱模拟采出液破乳研究

配制长庆北三区聚表二元驱模拟采出液,其中聚丙烯酰胺1000 mg/L、甜菜碱表面活性剂1667 mg/L,含水率10%~50%。在30%含水率模拟采出液、脱水温度55℃、破乳剂加量100 mg/L、脱水时间40 min条件下进行破乳脱水实验,从28种破乳剂中筛选出破乳效果较好的KL-9、KL-10、KL-14磺酸盐型水溶性破乳剂。在破乳剂加量为50 mg/L时,KL-14在45、50、55℃的脱水率分别为92.6%、97.8%和99.9%,均大于KL-9、KL-10,脱水效果最好。在10%、50%含水率模拟采出液中也得到类似的结果。因此,针对10%~50%含水率模拟采出液,最佳破乳剂为KL-14。破乳温度升高,相同破乳剂加量下的脱水率增加;KL-14破乳剂加量增大,相同温度下的脱水率增加;随脱水时间延长,脱水率增大并逐渐稳定。最佳破乳条件为：脱水温度50~55℃、破乳剂加量100 mg/L、脱水时间30 min。     

甜菜碱溶液的界面性能及其在稠油降粘中的应用

为探索稠油乳化降黏过程中乳化剂的构效关系,考察了直链烷基甜菜碱(ASB)、二甲苯基取代甜菜碱(BSB)与稠油的油/水动态界面张力和界面扩张流变参数,测定了甜菜碱溶液与稠油形成的乳状液的稳定性、粒径和黏度。结果表明：甜菜碱分子的亲水基团平铺在界面上,形成具有一定弹性和强度的油/水界面膜,易与稠油形成稳定的O/W乳状液,显著降低了油相黏度。当油/水体积比为1∶1时,2种甜菜碱在质量分数为0.1%～1.0%的范围内,降黏率大于98%。ASB分子与稠油中活性物质混合吸附、协同作用,具有比BSB更高的界面活性和更强的稳定稠油乳状液能力,能在更宽的油/水体积比范围内有效降黏。     

无碱表面活性剂羧基甜菜碱表/界面性能研究

研究了自制的含双键羧基甜菜碱BC的表面性能和无碱条件下与大庆原油间的界面性能。45℃时,BC的临界胶束浓度(C_cmc)为1.02×10^-5mol/L,γ_cmc为29.603 mN/m。油水来源为大庆一厂时,在BC质量分数为0.05%⁰.20%时,BC一元体系、BC/0.09%部分水解聚丙烯酰胺（HPAM）二元体系采出水溶液与原油和模拟原油间的界面张力均达到10^-3mN/m数量级,单一活性剂体系与模拟原油间界面张力降幅大于相应的原油结果,二元体系达到超低界面张力的时间比一元体系长。油水来源为大庆三厂时,BC一元体系采出水溶液与原油达到超低界面张力,且45℃老化160 d的界面张力仍保持在10^-3数量级,稳定性较好。图7表1参10     

聚磺酸甜菜碱的合成及在棉织物抗菌整理中应用

为实现棉织物的高效持久抗菌功能,制备了一种聚磺酸甜菜碱(PSPB)抗菌整理剂并将其应用于棉织物的抗菌整理。通过单因素分析法,探讨了PSPB质量浓度、浴比、浸泡时间、烘焙温度与烘焙时间对棉织物抑菌圈大小的影响,得到抗菌整理的优化工艺;采用活菌计数法对经优化工艺整理的棉织物进行抗菌性能及耐洗牢度测试。结果表明,抗菌整理的优化工艺条件为:PSPB质量浓度54 g/L,浴比1∶30,浸泡时间50 min,烘焙温度170 ℃,烘焙时间150 s。红外光谱与扫描电镜表征证实PSPB成功合成且成功接枝到棉纤维表面。整理后织物对大肠杆菌与金黄色葡萄球菌的抑菌率分别为99.87%、99.99%,且具有优异的耐洗性能。织物断裂强力及白度测试结果表明,PSPB抗菌棉织物的强力与白度均满足服用要求。     

三甲铵乙内酯(甜菜碱)的合成

介绍了以氯乙酸钠和三甲胺为原料合成三甲铵乙内酯（甜菜碱）的方法,以室温为起始反应温度反应０．５ｈ,然后分别于５０℃～５５℃和８０℃～８５℃反应１ｈ,以强酸性阳离子交换树脂为反应液的分离提纯物质。其收率超过９７％,产品纯度达到９８．５％。该法具有操作简便、反应时间短、反应条件温和、产品纯度高等优点。     

甜菜碱提高LO2细胞中抗氧化酶的表达水平

该研究探究了甜菜碱(BET)对人正常肝细胞LO2细胞中超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GPx)、过氧化氢酶(CAT)mRNA水平的影响及机制.使用实时荧光定量、蛋白质免疫印迹和酶联免疫吸附法检测细胞内抗氧化酶的mRNA水平,以及Nrf2-Keap1-ARE通路的相关指标.经不同浓度的BET处理12 h后,...     

Large‐scale anaerobic degradation of betaine

Betaine, also known as N,N,N‐trimethyl glycine, is a soluble nitrogenous compound present at significant concentrations in sugar‐beet molasses. Molasses is used as substrate in a wide range of industrial fermentations, for example, alcohol, acid and yeast cell production. Betaine is not consumed to any significant extent during these fermentations and appears to largely pass through the subsequent processing stages, becoming an important constituent of the wastewater produced by these industries. The present study confirmed that betaine is present in large amounts in sugar‐beet molasses (up to 6% w/w) and in the effluent of processes using sugar‐beet molasses as substrate (up to 4.5 g dm⁻³). Betaine appeared to be almost completely degraded in the two full‐scale anaerobic treatment plants sampled. This was confirmed by anaerobic activity tests performed with both acclimated and unacclimated anaerobic sludge. The results obtained suggest the possible involvement of a multistep degradation process, with the likelihood of a nitrogen‐containing intermediate. Finally, although not totally discountable, betaine degradation does not appear to be coupled to sulfate reduction during treatment of high‐sulfate wastewaters. © 1999 Society of Chemical Industry     

Biodegradable Amphoteric Surfactants in Titration-Ultrasound Formulation of Oil-in-Water Nanoemulsions: Rational Design,Development, and Kinetic Stability

Amphoteric amphiphilic compounds, due to their unique properties, may represent a group of safe and biocompatible surface-active agents for effective colloidal stabilization of nanoformulations. For this reason, the aim of this work was to develop and characterize the oil-in-water nanoemulsions based on two betaine-derived surfactants with high biodegradability, i.e., cocamidopropyl betaine and coco-betaine. In the first step, we investigated ternary phase diagrams of surfactant-oil-water systems containing different weight ratios of surfactant and oil, as the betaine-type surfactant entity (S), linoleic acid, or oleic acid as the oil phase (O), and the aqueous phase (W) using the titration-ultrasound approach. All the received nanoemulsion systems were then characterized upon droplets size (dynamic light scattering), surface charge (electrophoretic light scattering), and morphology (transmission electron as well as atomic force microscopy). Thermal and spinning tests revealed the most stable compositions, which were subjected to further kinetic stability analysis, including turbidimetric evaluation. Finally, the backscattering profiles revealed the most promising candidate with a size <200 nm for potential delivery of active agents in the future cosmetic, pharmaceutical, and biomedical applications.