Therapeutic Intervention with Dietary Chitosan Nanoparticles Alleviates Fish Pathological and Molecular Systemic Inflammatory Responses against Infections

Marine bio-sourced chitosan nanoparticles (CSNP) are antimicrobial and immunomodulatory agents beneficial for fish medicine. Herein, dietary CSNP was investigated for the amelioration of the systemic inflammatory responses of an induced fish model. One hundred and forty-four rainbow trout were assigned to one pathogen-free and non-supplemented group (negative control), and three challenged groups: non-supplemented (positive control), CSNP-preventive, and CSNP-therapeutic. After a feeding experiment extended for 21 days, the organosomatic indices (OSI) and molecular aspects were assessed. After a challenge experiment extended for further 28 days, CSNP-therapeutic intervention was assessed on fish survival and systemic inflammatory responses on pathology, histo-morphology, and molecular aspects. With CSNP administration, OSI nonsignificantly decreased and the relative expression of targeted inflammatory-mediator genes was significantly increased. The CSNP-therapeutic fish showed an RPS of 80% as compared to the positive control group, and CSNP-therapeutic administration retained the highest gene expression augmentation up to 28 days after the challenge. Notably, the splenic reticulin fibers framework of the CSNP-therapeutic group retained the highest integrity among the groups during the infection. After recovery, reticulin fibers density in the CSNP-therapeutic samples was significantly higher than in the negative control group, which indicates high innate immunity. Thus, CSNP showed promising biotherapeutic features enhancing fish resistance against infections.     

Alginate Microsphere Encapsulation of Drug-Loaded Nanoparticles: A Novel Strategy for Intraperitoneal Drug Delivery

Alginate hydrogels have been broadly investigated for use in medical applications due to their biocompatibility and the possibility to encapsulate cells, proteins, and drugs. In the treatment of peritoneal metastasis, rapid drug clearance from the peritoneal cavity is a major challenge. Aiming to delay drug absorption and reduce toxic side effects, cabazitaxel (CAB)-loaded poly(alkyl cyanoacrylate) (PACA) nanoparticles were encapsulated in alginate microspheres. The PACAlg alginate microspheres were synthesized by electrostatic droplet generation and the physicochemical properties, stability, drug release kinetics, and mesothelial cytotoxicity were analyzed before biodistribution and therapeutic efficacy were studied in mice. The 450 µm microspheres were stable at in vivo conditions for at least 21 days after intraperitoneal implantation in mice, and distributed evenly throughout the peritoneal cavity without aggregation or adhesion. The nanoparticles were stably retained in the alginate microspheres, and nanoparticle toxicity to mesothelial cells was reduced, while the therapeutic efficacy of free CAB was maintained or improved in vivo. Altogether, this work presents the alginate encapsulation of drug-loaded nanoparticles as a promising novel strategy for the treatment of peritoneal metastasis that can improve the therapeutic ratio between toxicity and therapeutic efficacy.     

金免疫层析法检测囊虫循环抗原试验研究

应用胶体金和免疫层析技术进行了检测金免疫层析法(GICA)囊虫循环抗原(CA)试验研究。5株抗囊虫McAb和一株多抗用于最佳配对的筛选,一株用于标记胶体金,另一株包被NC膜。以双抗体夹心ELISA为对照,GICA用于CA检测,观察其敏感性、特异性和稳定性。结果显示,以McAb 1A5和1B6配对的结果最佳,1A5最适标记量为10μg／mL,186最佳包被浓度为1 g／L;用GICA和ELISA两种方法检测囊虫CA,痈猪血清和囊液的符合率达100％,病人血清和脑脊液的符合率达80％;CA最低检测量为10 ng,检测正常猪、人及其他疾病血清,均呈阴性;检测时间5-15 min,整个实验仅一步操作;GICA试纸条分别在4℃和室温下保存105 d以及在37℃保存45 d,检测结果均未发现改变。以上结果表明,快速检测囊虫循环抗原的金免疫层析法具有简便、快速、敏感、特异和稳定的特点,适合基层使用。     

纳米载铜蒙脱石对生长肥育猪生产性能

摘要：试验旨在研究日粮中添加纳米载铜蒙脱石对生长育肥猪生产性能及血液生化指标的影响。选取72头健康“杜×大×长”三元杂交断奶仔猪,随机分为3组,每组3个重复,每个重复8头(公母各半)。分别饲喂基础日粮（对照组）、基础日粮+20 mg/kg泰乐菌素+100 mg/kg磺胺二甲基嘧啶(SM2)（试验Ⅰ组）和基础日粮+1500 mg/kg纳米载铜蒙脱石（MMT-Cu）（试验Ⅱ组）。比较研究MMT-Cu和泰乐菌素＋磺胺二甲基嘧啶对生长肥育猪生产性能及血液生化指标的影响。结果表明,与对照组和试验Ⅰ组相比,试验Ⅱ组料重比、血清ALB、SUN、Ch、TP含量极显著下降(P<0.01);血钙含量、GTP活性极显著提高（P<0.01）;TP和GLU含量显著下降 (P<0.05)。因此,纳米载铜蒙脱石提高了生长肥育猪的料重比,并对血清中ALB 、Ca、GPT、SUN、TG、Ch、TP、GLU均产生不同程度的影响。     

特高多花黑麦草在贵州的适应性研究

通过对特高多花黑麦草在贵州不同生态条件下的试验研究,结果表明:特高多花黑麦草在三个不同地区均能完成正常的生育期,且生长良好、适应性强、产草量高、营养价值丰富,具有良好的推广应用前景。     

基因组单核苷酸多态性图谱构建方法研究进展

为了获得高质量的金标孕酮单抗,通过采用柠檬酸三钠还原法,制备出符合要求的30 nm胶体金溶液,在此基础上摸索胶体金标记孕酮单克隆抗体的最佳条件,并对其进行质量鉴定。结果发现,用柠檬酸三钠还原法制备的30 nm胶体金溶液呈深红色,透射电镜观察,胶体金颗粒大小基本一致;胶体金标记孕酮单克隆抗体的最低稳定浓度为16 μg/mL,最适稳定浓度为19.2 μg/ mL,最适标记pH为8.5。制备的金标抗体复合物经电镜观察,周围有一层明显的低电子密度晕圈,且其D_{520 nm}值在0.2~0.4之间。     

猪伪狂犬病病毒gE抗体胶体金免疫层析检测方法的建立及应用

以纯化的抗人红细胞单链抗体(ScFv)-猪伪狂犬病病毒(PRV)gE蛋白双功能融合蛋白为诊断抗原和胶体金标记物,以羊抗猪IgG包被硝酸纤维膜作为质控带,制作检测猪伪狂犬病毒gE抗体的双抗原胶体金试纸条。利用方阵滴定试验筛选出金标抗原最佳工作浓度为17.6μg,检测线诊断抗原最佳标记量为1.76μg,血清最佳稀释度为1∶10,作用时间15 min,与猪瘟病毒(CSFV)、猪细小病毒(PPV)、猪繁殖与呼吸综合征病毒(PRRSV)、猪乙型脑炎病毒(JEV)、猪布鲁菌(Brucella)阳性血清和PRVgE缺失疫苗接种的猪免疫血清检测线均不出现红色条带,与PRV标准阳性血清反应检测线出现红色条带。试纸条操作简单,肉眼于15 min内可判定结果;试纸条在室温保存6个月,其特异性和敏感性没有明显变化;与美国IDEXX和法国LSI gE-ELISA抗体检测诊断试剂盒检测结果比较,1 164份猪血清的符合率均为90.55%。制备的胶体金试纸条具有操作简便、敏感性和特异性较高的特点,可用于PRV野毒感染的快速筛查。     

猪繁殖与呼吸综合征病毒胶体金检测试纸卡的研制

为快速检测猪繁殖与呼吸综合征病毒,应用抗猪繁殖与呼吸综合征病毒单克隆抗体PRRSV-3D10株和4H11株分别作为胶体金标记物和诊断抗体,羊抗鼠IgG作为质控线,制备胶体金免疫层析抗原检测试纸。该试纸卡具有良好的特异性、敏感性、重复性和稳定性,与PCR方法对比总符合率为93．3％。研究显示,本试纸卡能够快速、准确检测猪繁殖与呼吸综合征病毒,可为临床诊断提供参考。     

Yak interferon-alpha loaded solid lipid nanoparticles for controlled release

To explore the potential of a novel animal interferon formulation for controlled release, the yak interferon-alpha (IFN-α) glutathione S-transferase (GST) fusion protein was expressed in Escherichia coli (E. coli) and the purified recombinant IFN-α was encapsulated into solid lipid nanoparticles (SLN) by double emulsion solvent evaporation (w/o/w) method. The particle size and zeta potential of IFN-α-loaded SLN were 124.2 ± 10.2 nm and −11.2 ± 0.6 mV. The encapsulation efficiency of IFN-α and loading capacity of the SLN were 83.7 ± 4.5% and 1.73 ± 0.15%, respectively. In vitro release study and antiviral assay demonstrated that the IFN-α released from the SLN in a 16-day period exhibited antiviral activity in Madin-Darby bovine kidney (MDBK) cells against vesicular stomatitis virus (VSV), and showed a release pattern of an initial burst release followed by a sustained and slow release. Cytotoxicity assay in cell culture demonstrated that the SLN were not toxic. The results of this exploratory study suggest that the IFN-α-loaded SLN could be a useful formulation for controlled release in veterinary therapeutics.