利用响应面法优化鳗弧菌载体疫苗MVAV6203A-1冷冻干燥保护剂配方

应用单因素试验、复合保护剂组合试验和响应面分析法,对鳗弧菌载体疫苗MVAV6203A-1冷冻干燥的保护剂配方进行筛选和优化。试验结果表明,众多保护剂中半乳糖、海藻糖和脱脂牛奶的组合使用,能够显著提高细胞对冷冻干燥环境的耐受力。以冻干后的细胞存活率为响应值,响应面法优化的结果为:半乳糖4.6%、海藻糖2.3%、脱脂牛奶10.2%,以优化的最佳配方进行的3次重复冻干试验,细胞平均存活率可达77.3%。优化的保护剂配方适用于鳗弧菌载体疫苗的冻干生产。     

两种大豆蛋白-磷脂酰胆碱纳米乳液粉末化特性研究

将超声处理及高压均质后的纳米乳液,直接利用真空冷冻干燥法制备了大豆蛋白-磷脂酰胆碱的乳化粉末,并进一步通过扫描电子显微镜、激光粒径分析仪、红外光谱等手段对真空冷冻干燥粉末以及复原乳液的物理化学等特性进行研究。研究发现冻干粉末复原乳液水复溶性良好,基本保持了与原始乳液相同的纳米级粒径。扫描电子显微镜及冻干粉末的粒径分布显示超声和高压均质制备的纳米乳液粉末结构致密均匀,表面无裂缝和孔隙,且高压均质制备粉末的表面更为平整,粒径分布总体呈现单峰分布,粒径平均值仅为6.13μm。使用超声和高压均质制备的纳米乳液冻干粉末的包埋产率和效率均达到90%以上,同时超声制备的纳米乳液冻干粉末更有利于β-胡萝卜素的包埋,更好地防止β-胡萝卜素损失。采用红外光谱学实验验证后发现,高压均质制备纳米乳液粉末的蛋白α-螺旋与β-折叠结构含量较低。与大豆蛋白-磷脂酰胆碱纳米乳液相比,真空冷冻干燥粉末的储藏稳定性及货架期显著提高。     

海藻糖在双歧杆菌冻干菌粉制备和保藏中生物保护作用的初探

对新型保护剂海藻糖在长双歧杆菌（Ｂｉｆｉｄｏｂａｃｔｒｅｒｉｕｍ ｌｎｇｕｍ）冻干菌粉制备和保藏中的生物保护作用进行了初步研究。结果表明：４种双糖保护剂中,涨藻糖的细胞冻干存活率分别是蔗糖的６倍和麦芽的４．５倍（Ｐ〈０．０１）,而且显著高于乳糖（Ｐ〈０．０５）;４种复合保护剂中添加海藻糖后,细胞冻干存活率均显著提高（Ｐ〈０．０１）;海藻糖还可明显改善冻干菌粉的细胞贮藏稳定性,延长活菌保藏期。     

农产品干燥技术的应用与发展

介绍了干燥技术的应用状况,并对3种干燥方法进行了比较,着重论述了冷冻干燥技术的应用特点及其发展现状。     

Canine platelet transfusions

Objective – To review potential platelet storage options, guidelines for administration of platelets, and adverse events associated with platelet transfusions. Data Sources – Data sources included original research publications and scientific reviews. Human Data Synthesis – Transfusion of platelet concentrates (PCs) plays a key role in the management of patients with severe thrombocytopenia. Currently PCs are stored at 22°C under continuous gentle agitation for up to 5 days. Chilling of platelets is associated with rapid clearance of transfused platelets, and galactosylation of platelets has proven unsuccessful in prolonging platelet survival. Although approved by the American Association of Blood Banks, cryopreservation of human platelets in 6% DMSO largely remains a research technique. Pre‐storage leukoreduction of PCs has reduced but not eliminated acute inflammatory transfusion reactions, with platelet inflammatory mediators contributing to such reactions. Veterinary Data Synthesis – Canine plateletpheresis allows collection of a concentrate with a high platelet yield, typically 3–4.5 × 10¹¹ versus <1 × 10¹¹ for whole blood‐derived platelets, improving the ability to provide sufficient platelets to meet the recipient's transfusion needs. Cryopreservation of canine platelets in 6% DMSO offers immediate availability of platelets, with an acceptable posttransfusion in vivo platelet recovery and half‐life of 50% and 2 days, respectively. While data on administration of rehydrated lyophilized platelets in bleeding animal models are encouraging, due to a short lifespan (min) posttransfusion, their use will be limited to control of active bleeding, without a sustained increase in platelet count. Conclusions – Fresh PC remains the product of choice for control of bleeding due to severe thrombocytopenia or thrombopathia. While cryopreservation and lyophilization of canine platelets offer the benefits of immediate availability and long‐term storage, the compromise is decreased in vivo recovery and survival of platelets and some degree of impaired function, though such products could still be life saving.     

Evaluation of sample pre-treatment and potential contamination of soluble carbon in soil extracts during lyophilisation

Lyophilisation of K₂SO₄ soil extracts has been proposed as a sample preparation technique before elemental analysis of carbon or nitrogen. However, previous measurements, based on wet oxidation or catalytic combustion, indicated that C measurements in lyophilised samples not always proved to be accurate. To determine whether the C analysis was affected by the lyophilisation process, an exploratory study was conducted to investigate the potential effects of the sample pre-treatment and of the lyophilisation process itself. This paper puts forward that the use of soil extracts, previously stored at −20 °C, may affect the recovery of salt in the samples and that contamination of the soluble carbon with exogenous C during lyophilisation is feasible. Therefore we recommend to use freshly prepared soil extracts for lyophilisation and always to include an internal standard among the unknown samples to account for a possible contamination.     

A comparison of liquid and lyophilized egg yolk plasma to low density lipoproteins for freezing of canine spermatozoa

The current study aimed to explore the potential usefulness of liquid or lyophilized egg yolk plasma (EYP) as a substitute for low‐density lipoproteins (LDL) for cryopreservation of canine spermatozoa. In the first experiment, a total of 20 ejaculates harvested from six Beagles were frozen in extenders containing 6% LDL (control) or liquid or lyophilized EYP at one of three concentrations (20%, 40% or 60%). Motility parameters were assessed 10 min after thawing using computer‐assisted sperm analysis. For both liquid and lyophilized EYP, the 40% concentration yielded motility similar (p > 0.05) to that observed with the control extender. In the second experiment, 12 ejaculates collected from the same six dogs were frozen in 6% LDL (Control), 40% liquid EYP or 40% lyophilized EYP extenders. Spermatozoal membrane integrity (hypo‐osmotic swelling test [HOSt] and SYBR14/propidium iodide [PI] staining), acrosome integrity (FITC‐Pisum sativum agglutinin staining) and DNA integrity (acridine orange staining) characteristics were evaluated 10 min after thawing. Both liquid and lyophilized 40% EYP‐based extenders successfully preserved all assessed integrity parameters as efficiently as the control. Results of this study suggest that lyophilized EYP is a viable alternative to LDL in freezing extenders for dog semen.     

Processing and Digestion of Press Juices from Different Fish Muscles; Temperature and Lyophilization Effects on Their Anti-Oxidative Properties

Press juices (PJs) from seven, mostly underutilized, fish were tested for their anti-oxidative properties. The effects of thermal processing, freezing, and lyophilization of fresh PJs on these properties were investigated. Lyophilized samples were further subjected to in vitro digestion. It was concluded that thermal processing significantly affected only the ferric ions reducing ability, while freezing affected the anti-oxidative properties of only certain species. Lyophilized samples from Dactylopterus volitans and Trachinus draco were able to delay significantly the onset of hemoglobin-mediated oxidation. Finally, the exposure of the PJs to different pH values during in vitro digestion seemed to play an important role in their 1,1-diphenyl-2-picrylhydrazyl (DPPH)% inhibition ability.     

Lyophilization Serves as an Effective Strategy for Drug Development of the α9α10 Nicotinic Acetylcholine Receptor Antagonist α-Conotoxin GeXIVA[1,2]

α-Conotoxin GeXIVA[1,2] is a highly potent and selective antagonist of the α9α10 nicotinic acetylcholine receptor (nAChR) subtype. It has the advantages of strong efficacy, no tolerance, and no effect on motor function, which has been expected help patients with neuropathic pain. However, drug development for clinical use is severely limited owing to its instability. Lyophilization is applied as the most preferred method to solve this problem. The prepared lyophilized powder is characterized by differential scanning calorimetry (DSC), powder X-ray diffractometry (PXRD), and Fourier transform infrared spectroscopy (FTIR). Molecular simulation is also used to explore the internal distribution and forces formed in the system. The analgesic effect on paclitaxel-induced neuropathic pain following single and 14-day repeated administrations are evaluated by the von Frey test and the tail-flick test. Trehalose combined with mannitol in a ratio of 1:1 is employed as the excipients in the determined formulation, where trehalose acts as the stabilizer and mannitol acts as the bulking agent, according to the results of DSC, PXRD, and FTIR. Both GeXIVA[1,2] (API) and GeXIVA[1,2] lyophilized powder (formulation) could produce stable analgesic effect. These results indicated that GeXIVA[1,2] lyophilized powder could improve the stability and provide an effective strategy to push it into clinical use as a new analgesic drug.