Different types of degradable vectors from low-molecular-weight polycation-functionalized poly(aspartic acid) for efficient gene delivery

Poly(aspartic acid) (PAsp) has been employed as the potential backbone for the preparation of efficient gene carriers, due to its low cytotoxicity, good biodegradability and excellent biocompatibility. In this work, the degradable linear or star-shaped PBLA was first prepared via ring-opining polymerization of β-benzyl-l-aspartate N-carboxy anhydride (BLA-NCA) initiated by ethylenediamine (ED) or ED-functionalized cyclodextrin cores. Then, PBLA was functionalized via aminolysis reaction with low-molecular-weight poly(2-(dimethylamino)ethyl methacrylate) with one terminal primary amine group (PDMAEMA-NH₂), followed by addition of excess ED or ethanolamine (EA) to complete the aminolysis process. The obtained different types of cationic PAsp-based vectors including linear or star PAsp-PDM-NH₂ and PAsp-PDM-OH exhibited good condensation capability and degradability, benefiting gene delivery process. In comparison with gold standard polyethylenimine (PEI, ∼25 kDa), the cationic PAsp-based vectors, particularly star-shaped ones, exhibited much better transfection performances.     

Preparation of 111In-DTPA morpholino oligomer for low abdominal accumulation

An ability to quantitate the beta cell mass by noninvasive nuclear imaging will be very useful in the prevention, diagnosis, and treatment of diabetes. However, to be successful, radioactivity from the pancreas must not be obscured by the background radioactivity in the abdomen. Pretargeting offers the promise of achieving high target organ to normal tissue ratios. In preparation for pancreas imaging studies by pretargeting using morpholino oligomers (MORF/cMORF), it was necessary to develop a simple and efficient method to radiolabel the cMORF effector. Because we have shown that labeling the cMORF with ¹¹¹In via DTPA reduces excretion into the intestines compared to labeling with ^99mTc via MAG₃, the conjugation of DTPA to cMORF was investigated for ¹¹¹In labeling. The amine-derivatized cMORF was conjugated with DTPA using 1-ethyl-3(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC) as an alternative to the conventional cyclic anhydride. The conjugation efficiency (represented by the number of DTPA groups attached per cMORF) was investigated by changing the EDC, DTPA, and cMORF molar ratios. Different open columns were considered for the purification of DTPA–cMORF. Before conjugation, each cMORF molecule was confirmed to have an amine by trinitrobenzene sulfonic acid (TNBS) assay using the ω-amino butyric acid as positive standard and the non-amine derivatized cMORF as negative standard. The average number of DTPA groups per cMORF was 0.15–0.20 following the conjugation over a cMORF/DTPA molar ratio of 0.5–5 and over a cMORF/EDC molar ratio of 20–60. The conjugation efficiency was lower than expected probably due to steric hindrance. A 1×50 cm P-4 column using ammonium acetate as eluting buffer provided an adequate separation of DTPA–cMORF from free DTPA. The ¹¹¹In labeling efficiency by transchelation from acetate exceeded 95%, thus avoiding the need for postlabeling purification. Despite the lower than expected conjugation efficiency in which no more than one-fifth of the cMORF were DTPA-derivatized, a specific radioactivity of at least 300 μCi/μg or 1.90 Ci/μmol of cMORF was achieved. In conclusion, a protocol is described for ¹¹¹In-DTPA–cMORF that provides the high specific activity favorable to beta cell imaging because of the low mass fraction of beta cells in pancreas (1–2%) and obviates the need for postlabeling purification.     

创伤应激与肝细胞凋亡

创伤会使机体产生应激,在多种因素作用下,可能促使细胞凋亡导致病理损伤,创伤应激致细胞凋亡的机制复杂,仍有很多存在争议的问题,尤其是对那些非神经系统器官而言.临床上很多肝脏疾病均受应激因素的影响,导致肝细胞凋亡而产生肝损伤.目前应激损害研究主要集中在应激对心理造成的损害,而对肝、脑、肺、肾等实质脏器的损害研究不多,机制尚不明确.肝脏是人体新陈代谢的总枢纽,是严重应激损伤的核心靶器官,受创伤应激后的应激性高血糖、钙超载、氧化应激、缺血再灌注、炎性损伤和免疫抑制等因素影响,可发生肝细胞凋亡等病理性损害,故研究创伤应激与肝细胞凋亡的内在联系具有重要意义.     

Using a multiplex polymerase chain reaction for the identification of Beijing strains of <Emphasis Type="Italic">Mycobacterium tuberculosis</Emphasis>

The genotype of a Beijing strain of Mycobacterium tuberculosis (MTB) is usually determined by spoligotyping. However, this technique requires special equipment and is time-consuming. In this study, we developed a new multiplex polymerase chain reaction (PCR) to differentiate between Beijing and non-Beijing strains of MTB. A total of 323 MTB isolates were genotyped by both spoligotyping and the novel multiplex PCR. By spoligotyping, 169 (52.3%) isolates were determined to be Beijing strains and the remaining 154 (47.7%) isolates were non-Beijing strains. The multiplex PCR method produced results identical to those of spoligotyping in the identification of Beijing strains of MTB. This method is highly sensitive, specific, and fast. It is also cost-effective and suitable for screening large numbers of samples.     

骨填充网袋与球囊椎体后凸成形修复骨质疏松性椎体压缩性骨折

BACKGROUND: It remains controversial about the clinical outcomes of bone filling mesh containers (BFMCs) and percutaneous kyphoplasty (PKP) in pain relief, kyphosis correction, vertebral height restoration and reduction of cement leakage. OBJECTIVE: To compare the clinical outcomes of BFMCs and PKP for osteoporotic vertebral compressive fracture. METHODS: A total of 90 patients with osteoporotic vertebral compressive fracture were equivalently randomized into two groups, followed by treated with BFMCs or PKP, respectively. During a more than 3-month follow-up, pain relief, kyphotic angle, the vertebral height and cement leakage were observed in the two groups to assess the therapeutic effects. RESULTS AND CONCLUSION:Pain in all patients was relieved at 24 hours after operation. There was no significant difference in pain relief between two groups (P > 0.05). PKP was more effective to restore the vertebral height (P < 0.05), while BMCFs significantly reduced the leakage rate of bone cement (P < 0.05). These results suggest that BFMCs and PKP have their own advantages in the treatment of osteoporotic vertebral compressive fracture, but both exert analgesic effects.     

HCV核心基因插入突变体编码蛋白对人肝癌细胞系(Huh-7)细胞基因表达的影响

目的用基因表达分析法鉴定丙型肝炎病毒(HCV)核心(Core，C)区基因插入突变体编码蛋白在人肝癌细胞系(Huh-7)表达，探讨该蛋白生物学功能及其基因表达改变与致病的关系。方法构建HCV-1bc基因插入突变体编码蛋白重组表达质粒，建立表达c基因插入突变体编码蛋白Huh-7细胞系，按Affymetrix公司实验程序制备探针、再与该公司H0u133A和Hg-u133b芯片杂交。对基因表达上调或下调≥3倍的基因，用NetAflk作进一步分析。并用半定量RT-PCR对其中3个上调基因进行鉴定。结果Microarray分析显示，HCV-1b C基因插入突变体编码蛋白比c蛋白引起更多的基因表达改变，主要集中在信号传导、蛋白酶活性、分子转运、免疫反应等，特别是免疫反应基因表达更加显著。C基因插入突变体编码蛋白表达可同时导致凋亡基因／抗凋亡基因表达上调或下调及致癌基因上调。半定量RT-PCR对有趣的致癌基因FHL2、抗凋亡基因PRKCZ和凋亡基因LGALSI的鉴定结果表明，FHL2、PRKCZ和LGALSI基因的表达比空载体转染对照组相同基因明显上调。结论Hcvc基因插入突变体编码蛋白在Huh-7细胞表达对其基因表达有很大影响，其中对免疫反应基因的影响更明显，这一结果对理解HCV C基因插入突变体编码蛋白在HCV致病过程中的作用及其研制抗HCV药物均有重大的参考价值。     

一次性注射器填充级HDPE专用料的研制

通过对母料载体树脂的筛选,无机填料的选择,添加性能优良的耐辐射助剂,制成了具有耐辐射性能、加工性能良好的母料,该母料的制备工艺简单。本文所述的填充级HDPE专用料是将HDPE与填充母料经过简单掺混制成的。经测试专用料满足国家医药标准YY 0114—93《医用输液、输血、注射器聚乙烯专用料》的要求。制品厂试验表明:该填充级的HDPE专用料加工性能良好,用该填充级HDPE专用料注射成型的注射器芯杆装配成一次性注射器满足国家专业标准ZBC 31009—87《一次性无菌注射器》的要求。该填充母料的加入可大大降低材料的成本,100份HDPE 7006A可添加67份填充母料,该填充级专用料的价格比HDPE树脂降低约1500元/吨,因此该填充级HDPE专用料的推广和使用具有良好的经济效益。     

富集自体骨髓干细胞移植与髓芯减压治疗缺血性股骨头坏死患者血清成纤维细胞生长因子2、缺氧诱导因子1α、血管内皮生长因子的变化

背景：缺血性股骨头坏死以股骨头血液供应不足为主要病因。髓芯减压术属于临床常用治疗手段,有研究发现采用自体骨髓干细胞移植能较好地改善髋关节功能,二者联合应用可促使患者尽早恢复。 目的：观察自体骨髓干细胞移植联合髓芯减压治疗早期缺血性股骨头坏死的疗效以及血清成纤维细胞生长因子2、缺氧诱导因子1α、血管内皮生长因子水平。 方法：选取2016年1月至2018年1月收治的62例早期缺血性股骨头坏死患者进行研究,参照随机数字表法分为研究组(n=31)和对照组(n=31),对照组给予细针多孔道髓芯减压术治疗,研究组在对照组基础上联合自体骨髓干细胞移植治疗,观察两组患者治疗前后Harris评分、目测类比评分、血清成纤维细胞生长因子2、缺氧诱导因子1α、血管内皮生长因子水平及不良反应发生情况。 结果与结论：①两组患者治疗后3,6,12个月Harris评分均高于治疗前(P < 0.05),研究组高于对照组(P < 0.05);②两组患者治疗后3,6,12个月目测类比评分均低于治疗前(P < 0.05),研究组治疗后3,6个月目测类比评分低于对照组(P < 0.05);③两组患者治疗后3,6,12个月血清成纤维细胞生长因子2水平高于治疗前(P < 0.05),研究组高于对照组(P < 0.05);缺氧诱导因子1α、血管内皮生长因子水平明显低于治疗前(P < 0.05),研究组低于对照组(P < 0.05);④两组患者治疗后不良反应发生率比较差异无显著性意义(P > 0.05);⑤结果表明自体骨髓干细胞移植联合髓芯减压治疗早期缺血性股骨头坏死,可有效改善髋关节功能,促进股骨头坏死区修复,减轻患者疼痛,提高成纤维细胞生长因子2水平,降低缺氧诱导因子1α、血管内皮生长因子水平。 ORCID: 0000-0001-9884-7530(张景义) 中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程