A novel gene carrier based on amino-modified silica nanoparticles

Uniform-sized amino-modified silica nanoparticles have been prepared by the controlled synchronous hydrolysis of tetraethoxysilane and N-(β-amimoethyl)-γ-aminopropyltriethoxysilane in water nanodroplet of the water-in-oil microemulsion.These nanoparticles display positive charge potential at definited pH,This is due to the presence of amino groups on the surface of the nanoparticles,Nanoparticles-plasmid DNA complexes can easily form through electrostatical binding between the positive charges of the amino-modified silica nanoparticles and the negative charges of the plasmid DNA,The complexes can be also dissociated under alkaline pH or high ionic strength conditions.And enzymatic digestion of the plasmid DNA is almost inhibited by these nanoparticles complexes.A novel non-viral gene carrier based on the amino-modified silica nanoparticles is proposed under the combination of nanotechnology,biotechnology and gene engineering technology.The plasmid DNA can successfully cross various systemic barriers to COS-7 cells as well as mediate high expression of Green Fluorescence Protein(GFP)gene in cells by use of this novel gene carrier.     

A novel nonviral nanoparticle gene vector: Poly-L-lysine-silica nanoparticles

DNA delivery is a core technology for gene structure and function research as well as clinical settings. The ability to safely and efficiently targeted transfer foreign DNA into cells is a fundamental goal in biotechnology. With the development of nanobiotechnology, nanoparticle gene vectors brought about new hope to reach the goal. In our research, silica nanoparticles (SiNP) were synthesized first in a microemulsion system polyoxyethylene nonylphenyl ether (OP-10)/cyclohexane/ammonium hydroxide, at the same time the effects of SiNP size and its distribution were elucidated by orthogonal analysis; then poly-L-lysine (PLL) was linked on the surface of SiNP by nanoparticle surface energy and electrostatically binding; lastly a novel complex nanomateial—poly-L-lysine-silica nanoparticles (PLL-SiNP) was prepared. The analysis of plasmid DNA binding and DNase I enzymatic degradation discovered that PLL-SiNP could bind DNA, and protect it against enzymatic degradation. Cell transfection showed that PLL-SiNP could efficiently transfer PEGFPC-2 plasmid DNA into HNE1 cell line. These results indicated that PLL-SiNP was a novel nonviral nanoparticle gene vector, and would probably play an important role in gene structure and function research as well as gene therapy.     

Research advances in gene therapy for Parkinson's disease

During the long period of time when people have been seeking for an effective therapeutic method for PD, the gene therapy has shown greater and greater advantages over other methods. It can be performed mainly in two ways: ex vivo and in vivo. With the former, TH gene as well as some neurotrophic factor genes (such as GDNF, BNDF genes) can be invited to some cell lines or primary cells thus forming engineered cells and then implanting them into brain. While with the latter, viral vectors including HSV-1, Ad, AAV that can be utilized to construct recombinant viruses, or non-virus vectors can be used to delived DNA into brain directly. The present review summarizes the recent research advances in the gene therapy for PD, and it is reasonable for us to predict a notable progress in prevention and treatment for PD in the next decade.     

Water-soluble chitosan nanoparticles as a novel carrier system for protein delivery

High MW chitosan (CS) solutions have already been proposed as vehicles for protein delivery. The aim of the present work is to investigate the potential utility of water-soluble chitosan (WSC) as vehicles to load and deliver proteins. WSC nanoparticles (WSC NP) with various formations were prepared based on ionic gelation of WSC with pentasodium tripolyphosphate (TPP) anions. Bovine serum albumin (BSA) was used as a model protein drug incorporated into the WSC nanoparticles. Blank and BSA-loaded WSC nanoparticles were examined and determined to have a spherical shape with diameters between 35―190 nm, and zeta potential between 35―42 mV. FTIR confirmed that the tripolyphosphoric groups of TPP linked to the ammonium groups of WSC in the nanoparticles. Some factors affecting delivery properties of BSA have been investigated. Altering the concentration of BSA from 0.05 to 1 mg/mL enhanced the loading capacity of BSA but decreased loading efficiency simultaneously. Also, with the introduction of poly ethylene glycol (PEG), BSA release accelerated. Nanoparticle preparation from WSC with various deacetylation degrees (DDs) from 72.6% to 90% and MWs ranging from 3.5 to 15.8 kDa promoted loading efficiency and decreased the release rate. These results indicate that WSC nanoparticles are promising carriers for protein delivery.     

Non-viral gene carrier mediated short hairpin RNA interference for inhibition of tumor cells growth

A tumor-targeting gene vector G250mAb-PEI-PEG has been prepared by modification of polyethylenimine （PEI） with polyethyleneglycol （PEG） and G250, a monoclonal antibody against the G250 antigen on tumor cell surface. The transfection efficiency was as high as 70% in G250 positive HeLa cells, whereas the transfection efficiency was relatively low （30%） in normal NIH3T3 cells. A plasmid encoding the short hairpin RNA （shRNA） specific for nucleostemin gene （NS） was efficiently transfected into the HeLa cells with this nonviral gene vector. RNA interference down-regulated the expression of NS gene in HeLa cells, inhibited cells proliferation and induced apoptosis. However, the growth and activity of the NIH3T3 cells were not affected under the same treatment. These results indicate that the reported nonviral gene vector, G250mAb-PEI-PEG, can target and efficiently deliver genes into HeLa cells, and has the potential for the cervical cancer treatment.     

TNF基因治疗肿瘤的研究进展

肿瘤坏死因子 (TNF)是一种既能直接杀死肿瘤细胞 ,又能通过激活免疫系统发挥抗肿瘤作用的细胞因子 .其基因工程药品临床应用后 ,具有严重的毒副作用 ,因此 ,人们开始了TNF基因冶疗的研究 .TNF基因治疗为TNF在肿瘤治疗中的应用开拓了新的途径     

MOSFET器件热载流子效应SPICE模型

为了预测MOSFET器件在热载流子效应影响下的退化情况,建立了一套描述MOSFET器件热载流子效应的可靠性SPICE模型.首先,改进了BSIM3v3模型中的衬底电流模型,将拟合的精确度提高到95%以上.然后,以Hu模型为主要理论依据,结合BSIM3v3模型中各参数的物理意义及其受热载流子效应影响的物理机理,建立了器件各电学参数在直流应力下的退化模型.最后,依据准静态方法将该模型应用于热载流子交流退化模型中.实验数据显示,直流和交流退化模型的仿真结果与实测结果的均方根误差分别为3.8%和4.5%.该模型能准确反映MOSFET器件应力下电学参数的退化情况,且为包含MOSFET器件的电路的性能退化研究提供了模拟依据.     

Investigation of hrDNA targeting vector-mediated tumor-specific suicide gene therapy for hepatocellular carcinoma

Vectors pose most pivotal problem of gene therapy[1]. Because of the high transfection efficiency both in vitro and in vivo, the viral vector has been employed in 70% clinical trials of gene therapy (http://www.wiley.co.uk/ genmed/clinical). However, thei…     

反相微乳液制备pH响应型纳米水凝胶及其作为药物载体的研究

利用反相微乳液聚合,通过改变交联剂含量制备不同粒径的纳米水凝胶聚(甲基丙烯酸二甲氨基乙酯-co-甲基丙烯酸羟乙酯)(P(DMAEMA-co-HEMA)).纳米水凝胶的结构和形貌通过FT-IR、1H-NMR和TEM等进行了表征.利用紫外-可见分光光度计(UV)检测溶液在不同pH下的透光率,结果显示纳米水凝胶在酸性条件下有明显的溶胀现象.选取阿霉素(DOX)为模型药物研究了该纳米水凝胶作为药物载体的可行性,结果发现该纳米水凝胶能很好地负载药物,载药率达45.7%.利用紫外光谱法测定载药纳米水凝胶分别在pH 5.0和7.4的溶液中的药物释放行为,结果表明该纳米水凝胶具有较好的pH响应性,在酸性条件下纳米水凝胶的溶胀现象使得药物释放速率比在中性环境下快.     

A delay-constrained energy-efficient component carrier adjusting scheme for LTE-Advanced systems

The energy efficiency and packet delay tradeoffs in long term evolution-advanced （LTE-A） systems are investigated.Analytical expressions are derived to explain the relation of energy efficiency to mean packet delay,arrival rate and component carrier （CC） configurations,from the theoretical respective which reveals that the energy efficiency of multiple CC systems is closely related to the frequency of CCs and the number of active CCs.Based on the theoretical analysis,a CC adjusting scheme for LTE-A systems is proposed to maximize energy efficiency subject to delay constraint by dynamically altering the on/off state of CCs according to traffic variations.Numerical and simulation results show that for CCs in different frequency bands with equal transmit power,the proposed scheme could significantly improve the energy efficiency of users in all aggregation levels within the constraint of mean packet delay.     

PLA-PAMAM纳米粒作为非病毒基因载体的研究

采用乳化-分散-蒸发方法制备了表面含有聚酰胺-胺树状大分子的聚乳酸纳米粒,并将DNA与该阳离子纳米粒复合,研究了复合物的理化性质、细胞毒性和转染效率.结果表明在氮/磷比为2以上时,DNA与阳离子纳米粒形成了稳定且带正电的复合物,能保护DNA抵御核酸酶的降解,且复合物的细胞毒性较小.在无血清介质中,阳离子纳米粒可以将DNA有效地转移到细胞内得到表达,转染效率与未纳米化的PAMAM相比有明显的提高,且转染的最佳氮/磷比为2～5.     

Bioeffects of different functionalized silica nanoparticles on HaCaT cell line

With the fast development of nanotechnology, all kinds of nanomaterials came forth and got to be widelyapplied because of their unique properties[1―3]. At the same time, the bioeffects from nanomaterials were universally paid attention to because people …     

新型硅质吸附剂的合成及对黄酮的选择分离

利用分子印迹技术，以水溶性黄酮芦丁为模板剂与具有专一识别官能团的氯丙基三乙氧基硅烷反应制备出前驱物，然后将前驱物与正硅酸乙酯进行协同水解、凝胶老化和模板剂的洗脱，从而制备出对芦丁具有高效选择性的内置型硅质吸附剂．实验结果表明：该吸附剂具有较高的吸附容量，即使在有与芦丁结构相似的黄酮存在下，对芦丁依然有较高的选择性吸附能力；TEM照片表明该吸附剂具有与印迹分子相匹配的纳米孔洞，而对FTIR光谱分析表明该吸附剂在印迹识别过程有新的化学键生成．     

使用病毒载体的罕见病基因疗法临床进展

 很大一部分的罕见病由遗传因素决定,难以用普通的小分子或大分子药物治愈,而基因治疗有望从根本上修正人体功能的缺失或异常,给罕见病患者带来改善生活质量的希望。目前许多基因疗法的临床试验正在开展,病毒载体是常用的基因递送方法,本文讨论了用于临床基因递送的多种病毒载体,包括腺相关病毒、逆转录病毒和慢病毒,重点列举了这些病毒在罕见病临床试验中的研究、应用和进展,评价了这些病毒的优缺点,并简述了基因疗法的研究方向及应用前景。     

HSVTK gene therapy for carcinoembryonic antigen-producing human lung cancer cells

The long-term success of gene therapy for cancer relies heavily on the development of effective targeting systems. We investigate the possibility of targeted gene therapy using promoter of carcinoembryonic antigen (CEA) gene. By using luciferase reporter gene, we found that CEA promoter exhibit 16 times high activity in CEA-producing lung cancer cells, A549 than in nonproducing cells, Hela. We also constructed a recombinant expression plasmid pCEATK, in which CEA promoter drives the effector gene, thymidine kinase gene of Herpes Simplex Virus (HSVTK). A549 cells transfected with pCEATK became 865 times more sensitive to ganciclovir (GCV) than the control cells. However, Hela cells transfected with this plasmid remained resistant to GCV. These data indicate the potential for targeted gene therapy using the CEA promoter against CEA-producing tumor cells, such as lung cancer cells. Foundation item: Supported by the National Natural Science Foundation of China Natural Science Foundation of Hubei Province Biography: XIAO Geng-fu(1966-), male, phD graduate candidate, Lecturer.     

新型Bola两亲分子作为基因治疗药物输递载体的研究

为检测新型Bola两亲分子(Orn-C16-G)用作基因载体的性能,制备了Bola与siRNA的复合物(Bolaplexes),用原子力显微镜观察其在不同复合比下的形貌;并转染Hela细胞,用CCK-8检测Bolaplexes的细胞毒性,用荧光显微镜、流式细胞仪表征Bolaplexes的细胞内吞效果。实验结果显示,复合比1∶1条件下,Bola分子可以有效地压缩siRNA分子形成较小尺寸的复合物(100～200 nm)。Bolaplexes可高效地进入Hela细胞,并且毒性低于商售转染试剂,有较好的应用前景。本研究为下一步Bola两亲分子用于基因治疗的临床研究奠定了基础。     

Gene therapy for cancer by mutant HSV deleted apoptosis-inhibited gene

A mutant HSV (mtHSV) deleted icp34.5, an apoptosis-inhibiting gene was constructed. It is supposed that the mtHSV can replicate in p53-deficient cells selectively and lead to oncolysis targetedly. Mice tumor model harboring sarcoma cell line s-180 was developed and the mtHSV was injected into the tumors. We found that the mean volume and weight of tumors of early therapeutic group(ETG) were reduced 49.29% and 38.31% of that of control tumors. In the mid-term group (MTG), the redutcion rate were 26.9% and 24.52% respectively. Foundation item: Supported by Foundation of 863 New Hi-technique Research (39880031); Research Fund for the Doctoral Programm of Higher Education (RFDP98048615); Chen-guang Project of Wuhan City (20005004024). Biography: Lan Ping (1971-), female, Ph.D candidate, research direction: molecular virology.     

硅藻土改性载体加速移动床生物膜反应器启动研究

聚乙烯(polyethylene,简称PE)载体存在挂膜速度慢、附着生物膜活性低以及水处理效果差等缺点.通过添加硅藻土改善PE载体的亲水性,改性后载体的接触角由94.3°降低至77.8°.在移动床生物膜反应器(moving bed biofilm reactor,简称MBBR)工艺挂膜启动过程中,相同条件下,相比于PE载体,硅藻土改性载体表面附着的生物膜具有较高的蛋白质和多糖含量,表明附着在硅藻土改性载体上的生物膜生物活性较高.生物膜生长稳定后,反应器R1(填充硅藻土改性载体)内总生物量比反应器R2(填充PE载体)内总生物量高35.6%,硅藻土改性载体表面附着的生物膜量比PE载体的高62.3%.相应的,挂膜启动过程中,反应器R1的COD和氨氮去除率也高于反应器R2.上述硅藻土改性载体在挂膜性能和水处理性能方面的优势,缩短了反应器R1的启动时间.     

运营商级网络地址翻译的不敏感排队模型

基于传统网络地址翻译的地址复用技术并不能很好地适应运营商级网络地址翻译(carrier grade network address translation,CGN)体系结构,端口资源利用率和服务质量难以得到保证。为了更好研究和评价CGN在端口复用方面的性能,该文将网络地址翻译端口资源调度状态机分解成排队网络,并建立基于Erlang公式的不敏感排队模型,使用该模型分析了传统网络地址翻译和CGN的性能。实验结果表明:尽管CGN有性能方面的局限,然而该模型相比传统网络地址翻译,能在一定范围内提高IPv4地址利用率。