壳聚糖纳米粒子基因载体的研究现状

背景:壳聚糖纳米粒子因其独有特性作为基因载体的研究日益增多.目的:综述了壳聚糖纳米粒子作为基因载体的研究进展,进一步促进基因治疗的效果.方法:应用计算机检索web of science 数据库和中国学术期刊数据库中2000-01/2011-04 关于壳聚糖及其衍生物作为基因载体研究的文章,在标题和摘要中以"chitosan,gene"或 "壳聚糖;基因"为检索词进行检索.选择内容与基因载体和壳聚糖相关的文章,初检得到120 篇文献,根据纳入标准选择31 篇文章进行综述.结果与结论:壳聚糖基因纳米粒子作为非病毒基因述文章的数量、主要结载体将在基因治疗领域中发挥举足轻重的作用,今后壳聚糖转基因体系的研究将更为深入.如何标记、可视跟踪壳聚糖DNA 复合物进入不同细胞的过程,明确其基因转染机制,进一步提高基因转染效率,使其尽快进入基因治疗临床应用是今后研究的主要方向.     

壳聚糖纳米粒子基因载体的研究现状

背景：壳聚糖纳米粒子因其独有特性作为基因载体的研究日益增多。目的：综述了壳聚糖纳米粒子作为基因载体的研究进展,进一步促进基因治疗的效果。方法：应用计算机检索web of science数据库和中国学术期刊数据库中2000-01/2011-04关于壳聚糖及其衍生物作为基因载体研究的文章,在标题和摘要中以＂chitosan,gene＂或＂壳聚糖;基因＂为检索词进行检索。选择内容与基因载体和壳聚糖相关的文章,初检得到120篇文献,根据纳入标准选择31篇文章进行综述。结果与结论：壳聚糖基因纳米粒子作为非病毒基因述文章的数量、主要结载体将在基因治疗领域中发挥举足轻重的作用,今后壳聚糖转基因体系的研究将更为深入。如何标记、可视跟踪壳聚糖DNA复合物进入不同细胞的过程,明确其基因转染机制,进一步提高基因转染效率,使其尽快进入基因治疗临床应用是今后研究的主要方向。     

壳聚糖季铵盐作为基因递送载体的初步研究

背景:非病毒载体因其安全性好而在基因治疗领域赢得了广泛的关注,各种各样的非病毒载体处在不断的研究中,壳聚糖季铵盐作为一种新的生物材料,同样也具有作为基因递送载体的潜质.目的:考察壳聚糖季铵盐体外基因转染活性,寻求一种新的非病毒基因载体递送系统.设计、时间及单位:对比观察实验,于2008-04/12在浙江省医学科学院生物工程所完成.材料:质粒pcDNA3.1-EGFP为浙江省医学科学院生物工程实验室保存.以3-氯-2-羟丙基三甲基氯化铵作为改性剂制备壳聚糖季铵盐,用复凝聚法制备载基因纳米粒.方法:凝胶阻滞实验分析壳聚糖季铵盐包裹质粒的能力,DNase Ⅰ的保护实验分析载基因纳米粒的抵抗核酸酶降解的能力,体外基因转染实验评价纳米粒的体外转染活性,用倒置荧光显微镜观察和流式细胞仪测定转染结果.通过考察转染液中有无牛血清和递送不同剂量的基因对转染效率的影响,寻求本递送系统较好的转染条件.另外,用MTT法测定壳聚糖季铵盐的细胞毒性.主要观察指标:壳聚糖季铵盐和pcDNA 3.1-EGFP以何种比例结合形成的纳米粒、转染液中有无牛血清,质粒的量为多少时对人胚肾T细胞的转染效率足最高的;不同浓度的壳聚糖季铵盐对细胞生长的影响.结果:壳聚糖季钱盐纳米粒能转入人胚肾T细胞,虽然转染效率略逊丁聚乙烯亚胺,但是细胞毒性明显小于聚乙烯亚胺.壳聚糖季铵盐纳米粒转染细胞72 h后效率较高,经综合分析,当pcDNA质量为2 μg,壳聚糖季铵盐和pcDNA以质量比为5结合形成的纳米粒,在无血清条件下对人胚肾T细胞进行转染,转染效率足最高的.结论:壳聚糖季铵盐纳米粒能将基因递送到细胞内,并且报告基因能在细胞内表达.因此,壳聚糖季铵盐用做基因递送的载体系统值得进一步的研究.     

叶酸-壳聚糖介导survivin shRNA基因纳米载体的制备

背景:叶酸-壳聚糖纳米粒是一种新犁的高靶向纳米载体,可进一步提高药物的靶向性,并进一步实现缓释和控释给药.目的:探讨叶酸-壳聚糖纳米粒作为survivin shRNA重组质粒载体传递系统的可行性以及对大肠癌细胞(SW480)的转染效率.设计、时间及地点:对比观察实验,于2008-06/2009-01在中南大学卫生部纳米生物技术重点实验室完成.材料:壳聚糖(脱乙酰度>90%)由上海伯奥生物科技有限公司提供,叶酸由国药集团化学试剂有限公司提供,survivin shRNA重组质粒由上海吉凯基因化学技术有限公司提供.方法:首先制备粒径均匀的叶酸偶联壳聚糖纳米粒,然后将20 mg/L survivin shRNA重组质粒和10 mg/L叶酸-壳聚糖混合制各基因纳米复合物,同时以阳离子脂质体基因复合物作为对照,将上述两者转染大肠癌细胞.主要观察指标:基因纳米复合物的理化性质及转染效率;Western blotting检测转染后肿瘤细胞中survivin蛋白的表达.结果:成功制备叶酸-壳聚糖介导的survivin shRNA重组质粒基因纳米复合物.该基因纳米复合物转染大肠癌细胞的效果强于阳离子脂质体基因复合物.且转染后大肠癌细胞中survivin蛋白的表达显著低于阳离子脂质体基因复合物.结论:叶酸-壳聚糖纳米粒作为载体系统能将survivin shRNA重组质粒商效递送到大肠癌细胞,从而诱导人大肠癌细胞的凋亡.     

壳聚糖基因转移载体在关节软骨细胞中表达的定量分析

目的:壳聚糖作为基因转移的载体存在着转染效率的问题。实验对壳聚糖介导的报告基因增强型绿色荧光蛋白在关节软骨细胞中的基因表达效率进行定量分析。方法:实验于2005-09/2006-06在健康科学研究所骨科细胞与分子生物学实验室完成。①实验材料:壳聚糖购自Sigma公司;荧光质粒pEGFP-C3为Clontech公司产品;成年新西兰白兔2只。②实验分组:实验分为空白对照组(软骨细胞不转染)、裸质粒pEGFP-C3对照组和壳聚糖-pEGFP转染组。③实验过程:软骨细胞取自新西兰白兔的关节软骨。以多聚糖壳聚糖为载体,荧光质粒pEGFP-C3作为报告基因,利用高速震荡法制备壳聚糖-pEGFP超微颗粒,用制备的携带不同量(1,2,3,4,5μg)DNA的壳聚糖-pEGFP超微颗粒对软骨细胞进行体外转染。裸质粒pEGFP-C3对照组加入等量的DNA。④实验评估:光镜观察软骨细胞及壳聚糖-DNA超微颗粒的形态;荧光显微镜观察不同条件下绿色荧光蛋白的表达并进行定量分析。结果:①光镜下观察空白对照组,裸质粒pEGFP-C3对照组及壳聚糖-pEGFP转染组,软骨细胞形态均呈多角形,贴壁生长,增长活跃,转染组软骨细胞周围黏附有大量的球形小颗粒;制备的壳聚糖-DNA超微颗粒大小均匀,直径大约在150～300nm。②在壳聚糖-pEGFP超微颗粒转染的软骨细胞中观察到有绿色荧光蛋白的表达,且DNA含量在1～5μg范围内,细胞的转染效率和表达效率随颗粒包被的DNA量的增加而增加。结论:壳聚糖在关节基因转移中具有一定的体外DNA导入的功能,且随壳聚糖-pEGFP超微颗粒所携带的DNA量的增加转染效率和表达效率增加,经进一步研究它有望成为一种关节体内基因导入的有效工具。     

自制功能锻炼器对膝关节骨性关节炎患者疼痛、关节功能的疗效观察

目的 观察自制功能锻炼器对膝关节骨性关节炎(KOA)患者的临床治疗效果.方法 选取2019年5月-2020年4月我科住院的K O A患者100例为实验对象,随机分为干预组和对照组,各50例.对照组在常规治疗和护理干预基础上配合传统功能锻炼,干预组在常规治疗和护理干预基础上使用自制功能锻炼器进行功能锻炼.两组分别治疗2周...     

阿尔治用于膝关节腔内注射的观察与护理

目的探讨阿尔治膝关节腔内注射治疗骨性关节炎的临床效果及护理方法。方法对我科61例骨性关节炎患者进行膝关节腔内注射430次进行疗效观察及护理，重点对患者进行有针对性的心理护理，预防注射部位的感染及功能锻炼的护理。结果本组61例心理状态稳定，关节腔注射后均未发生感染，治疗效果满意，有效率达80．3％。结论阿尔治膝关节腔内注射是目前治疗骨性关节炎的有效方法，加强患者心理护理，注射后预防关节腔感染及功能锻炼是提高治疗效果的保证。     

膝关节关节腔内药物注射治疗KOA的进展

正膝关节骨性关节炎(Knee Osteoarthritis,KOA)是一种退行性关节疾病~([1]),病程进展缓慢,严重者甚至会导致残疾~([2]),是中老年群体的常见病~([3]),我国约有8.1%的人群患有不同程度的KOA~([4])。该病以关节疼痛、畸形、活动受限为主要临床表现,病情逐渐加重,缠绵难愈。膝关节人工关节置换术被认为是治疗晚期KOA的金标准~([5]),但是由于关节假体寿命的限制,小于55岁的患者较老年患者有高达5倍的翻     

玻璃酸钠关节内注射联合隐神经阻滞治疗膝关节骨性关节炎

目的:观察玻璃酸钠关节内注射联合隐神经阻滞治疗膝关节骨性关节炎(osteoarthritis,OA)的有效性。方法:膝关节OA患者84例,随机分为联合治疗组(C组,n=42)和单纯注射组(H组,n=42)。C组行玻璃酸钠关节内注射联合隐神经阻滞,H组单纯玻璃酸钠关节内注射。评价治疗前、治疗后4周和12周时的西安大略和麦克马斯特大学关节炎指数(Western Ontario and Mc Master Universities Arthritis Index,WOMAC)评分和SF-36生活质量评分,记录治疗中和治疗后的并发症。结果:两组患者阻滞前WOMAC和SF-36评分无显著差异,治疗后4周和12周时的WOMAC评分明显低于、SF-36评分明显高于治疗前基础值(P<0.05),但C组更为显著(P<0.05)。结论:玻璃酸钠关节内注射联合隐神经阻滞可改善膝关节OA的疼痛和功能障碍,是治疗膝关节OA的有效方法。     

细胞因子对逆转录病毒载体介导的小鼠骨髓造血干细胞基因转移效率的影响

本实验探讨细胞因子SCF,IL-3和IL-6对基因转移效率的影响,为临床基因治疗提供可靠依据。以小鼠造血干细胞为靶细胞,应用包装细胞株PA317-GCGPXSN制备病毒上清,实施基因转移,采用FACS,GM-CFU,PCR和Southern blot方法测定基因转移效率。实验结果为:SCF,IL-3,IL-6单用或联合应用后,FACS测定的基因转移效率为0.07％-0.20％,GM-CFU测定的结果为20.4％-46.40％,阳性对照组测定的结果则分别为0.06％和10.92％。结论提示SCF/IL-3,SCF/IL-3/IL-6联合应用能显著提高基因转移效率。     

Adeno-associated virus vector mediated gene transfer to pancreatic beta cells

Insulin-dependent diabetes mellitus (IDDM) or type 1 diabetes is an autoimmune disease that results in destruction of the insulin-producing pancreatic islet beta cells. Several factors induce the invasion of immune cells into islets and trigger inflammation. Gene therapy approaches targeting the islet cells could be an effective treatment to prevent the onset or reverse type 1 diabetes. Allogeneic islet transplantation provides short-term treatment. However, genetically modified islets, which resist the host immune response, could provide long-term solutions. Adeno-associated virus (AAV) is emerging as a prominent vector system for delivering therapeutic genes for human gene therapy. AAV vector can transduce nondividing cells and provide long-term gene expression by integrating into host chromosome. Therefore, it is an appropriate vector system for islet cell gene therapy. To test the efficacy of AAV vector to transduce pancreatic endocrine cells, we constructed AAV vectors using plasmid pSub201. Wild-type AAV DNA analogue from plasmid psub201 was subcloned into a cloning plasmid pSP72 and AAV vectors were constructed by inserting the transgenes with heterologous promoter in place of AAV open reading frames (rep and cap). In this report we demonstrate the transduction of pancreatic islet cells with AAV vectors encoding bacterial -galactosidase enzyme or enhanced green fluorescent protein (EGFP) as reporter gene. Dispersed porcine and rat islet cells can be transduced by AAV vector, with an efficiency of 47% and 38%, respectively. In particular porcine islet insulin producing beta cells were transduced with an efficiency of 39%. Intact rat islet cells were transduced with an efficiency of 26% as estimated by FACS analysis following transduction with an AAV vector encoding EGFP. Transduction of intact rat islets with an AAV vector did not alter glucose-induced insulin secretion. AAV vector transduction was higher in transformed islet cell lines INS-1 and RIN m5F with an efficiency of 65% and 57%, respectively. These new results suggest that AAV vectors will provide an improved method of gene delivery to pancreatic islets and isolated pancreatic beta cells.     

新合成壳聚糖季铵盐/DNA复合物在Hela细胞中的转染效率

背景:壳聚糖季铵盐衍生物可以提高载体的转染效率,同时解决了壳聚糖溶解性差的问题,扩展了其pH值适用范围.目的:合成一种新型壳聚糖季铵盐载体,研究其与质粒结合的条件及转染效率,并与壳聚糖进行对比.设计、时间及单位:分子生物学,对比观察实验,于2008-08/10在浙江大学医学院附属第二医院完成.材料:壳聚糖季铵盐-N-2-羟丙基三甲基氯化铵壳聚糖为北京理工大学高分子材料实验室合成.质粒pEGFP-C1为浙江大学医学院郑一春惠赠.Hela细胞为浙江大学医学院程静提供.方法:将N-2-羟丙基三甲基氯化铵壳聚糖配制成质量浓度为0.2 g/L、pH值为5.5(或6.9、7.6)、乙酸钠终浓度为50 mmol/L的乙酸溶液,迅速与质粒pEGFP-C1混合,并在旋转混合器上涡流15～30 S,室温静置30 min以上,促进复合物的形成.主要观察指标:通过凝胶阻滞实验研究了pH值及时间对壳聚糖季铵盐与质粒结合能力的影响.通过荧光倒置显微镜观察壳聚糖季铵盐作为载体转染Hela细胞的效率,并与壳聚糖进行对比.结果:N-2-羟丙基三甲基氯化铵壳聚糖能够在酸性、中性及碱性条件下溶解,并能够与质粒DNA很好的结合形成复合物,拓展了其使用范围.在酸性条件下,N-2-羟丙基三甲基氯化铵壳聚糖与质粒的结合作用强于壳聚糖.壳聚糖及N-2-羟丙基三甲基氯化铵壳聚糖在酸性条件下,30 min即可与质粒形成稳定的复合物,并在12 h内保持良好的稳定性.Hela细胞的体外转染结果表明,N-2-羟丙基三甲基氯化铵壳聚糖的转染效率大于壳聚糖.结论:N-2-羟丙基三甲基氯化铵壳聚糖所适用的pH值范围较壳聚糖更加广泛,其稳定性与壳聚糖无明显差别,并且对Hela细胞的体外转染效率略高于壳聚糖,值得对其进行更深入的研究.     

Transgene expression in the guinea pig cochlea mediated by a lentivirus-derived gene transfer vector.

The utility of lentivirus as a gene delivery vector in the cochlea was evaluated in vitro and in vivo. Lentivirus transduction was assessed through expression analysis of a reporter gene, green fluorescent protein (GFP), integrated within the viral genome. In vitro characterization of lentivirus-GFP was assessed by infection of explants from cochleas of neonatal rat. The lentiviral vector transduced both spiral ganglion neurons (SGNs) and glial cells. In vivo characterization of lentivirus-GFP was assessed by directly infusing the vector into the guinea pig cochlea via an osmotic minipump. Sections of lentivirus-infused cochlea revealed a highly restricted fluorescence pattern limited to the periphery of the perilymphatic space. Transduction of SGNs and glial cells by lentivirus in vitro but not in vivo suggests limited dissemination of the viral vector from the perilymphatic space. The cellular and tissue architecture of the lentivirus-infused cochlea was intact and free of inflammation. Restricted transduction of cell types confined to the periphery of the perilymphatic space by the lentivirus is ideal for stable production of gene products secreted into the perilymph.     

Transfection efficiency of chitosan vectors: effect of polymer molecular weight and degree of deacetylation.

Chitosans of defined molecular weight (Mw 10-213 kDa) and degree of deacetylation (DD 46-88%) were synthesized, complexed with pEGFP-C2 plasmid into nanoparticles (NP) and evaluated for cellular uptake and transfection efficiency in the A549 cell model. DNA condensation of >90% was achieved at the N/P ratio of 6, independent of the chitosan Mw and DD. However, chitosan vectors of lower Mw or DD were less efficient at retaining the DNA upon dilution, and consequentially, less capable of protecting the condensed DNA from degradation by DNase and serum components. A549 cellular uptake of the NP was also significantly reduced by decreasing the Mw or DD of the chitosan vector. These factors contributed to the low transfection efficiencies for chitosan vectors of low Mw or DD. There was good correlation between transfection efficiency, cellular uptake and zeta potential of the NP, suggesting that cellular uptake mediated by electrostatic interactions with the cell membrane preceded efficient transfection. NP produced with chitosan of Mw 213 kDa and DD of 88% showed the highest zeta potential (+23 mV), cellular uptake (4.1 microg/mg protein) and transfection efficiency (12.1%), while chitosan vector with Mw of 213 kDa and DD of 46% showed the lowest cellular uptake (0.4 microg/mg protein) and transfection efficiency (0.05%). Confocal microscopy images suggested that the chitosan-complexed DNA successfully escaped from the endo-lysosomal compartment for nuclear translocation and expression. Intracellular DNA disassembly appeared to occur at different locations depending on the retentive capacity of the chitosan vector.     

Evaluation of the effect of vector architecture on DNA condensation and gene transfer efficiency

The objective of this study was to evaluate the effect of vector architecture on DNA condensation, particle stability, and gene transfer efficiency. Two recombinant non-viral vectors with the same amino acid compositions but different architectures, composed of lysine-histidine (KH) repeating units fused to fibroblast growth factor, were genetically engineered. In one vector lysine residues were dispersed (KHKHKHKHKK)₆-FGF2, whereas in the other they were in clusters (KKKHHHHKKK)₆-FGF2. Organization of lysine residues in this manner was inspired by the sequence of DNA condensing motifs that exist in nature (e.g., histones) where lysine residues are organized in clusters. These two constructs were compared in terms of DNA condensation and gene transfer efficiency. It was observed that the construct with KH units in clusters was able to condense pDNA into more stable particles with sizes < 150 nm making them suitable for cellular uptake via receptor mediated endocytosis. This in turn resulted in five times higher transfection efficiency for the cKH-FGF2. This study demonstrates that in targeted non-viral gene transfer, the vector architecture plays as significant a role as its amino acid sequence. Thus, in the design of the non-viral vectors (synthetic or recombinant) this factor should be considered of paramount importance.     

TNF-alpha secretion and apoptosis of lymphocytes mediated by gene transfer

Efficient gene transfer of lymphocytes is extremely difficult. Apoptosis may play a role in this gene transfer resistance of lymphocytes. Here we show that transfection of lymphocytes via non-viral vectors leads to induction of apoptosis in a significant proportion of cells. Since apoptosis may be mediated via tumor necrosis factor d (TNF-alpha) and the TNF-alpha receptor pathway, we studied the amount of TNF-alpha secreted by lymphocytes transfected without gene insert. TNF-alpha secretion was dependent on the gene transfer method used. High amounts were detected using receptor-mediated gene transfer and lipofection. In contrast, only low amounts of TNF-alpha were detected after electroporation and retroviral gene transfer. In receptor-mediated gene transfer, TNF-alpha secretion was due to the use of anti-CD3 antibody. Transfection of lymphocytes led to selective decrease in CD120b/TNF-alpha receptor II (TNFR-2)-positive cells. Induction of apoptosis and necrosis mediated by TNF-alpha via TNFR-2 (p80) was partially blocked using a neutralizing anti-TNF-alpha antibody. Blockage of apoptosis and necrosis could be further increased by adding anti-Fas-ligand (FasL) antibody, suggesting that induction of apoptosis via FasL and Fas receptor (Apo-1/CD95) may also play a role. This blockage led to a significant increase in the proliferation rate of lymphocytes transfected with cytokine genes. In conclusion, various gene transfer techniques led to TNF-alpha secretion, apoptosis and necrosis of lymphocytes. Apoptosis and necrosis could be partially blocked using a neutralizing anti-TNF-alpha antibody.     

Virus-like gene transfer into cells mediated by polyoma virus pseudocapsids

Mouse polyoma virus-like particles (or pseudocapsids) are composed solely of recombinant viral coat protein. They can interact with DNA and transport it to cells, resulting in gene expression both in tissue culture and in mice. We demonstrate that DNA transfer in vitro depends on partial packaging of DNA within the virus-like capsid. Cell surface sialic acid residues and an intact microtubule network, required for viral infectivity, are also necessary for pseudocapsid-mediated gene expression from heterologous DNA. Thus, gene delivery in this system requires pathways utilised by polyoma virions, rather than proceeding via the 'nonspecific' endosomal route typical of nonviral systems such as liposomes or calcium phosphate precipitates. Despite the fact that all cells appear to internalise pseudocapsid/DNA complexes, only a proportion show productive gene delivery. Bulk internalisation of complexes is dependent on actin fibres, but not cell surface sialic acid or microtubules, indicating that a second transport pathway exists for pseudocapsids which is nonproductive for gene transfer. The model suggested by these data demonstrates the virus-like properties of the pseudocapsid system, and provides a basis for further development to produce a highly effective gene delivery vehicle. Gene Therapy (2000) 7, 2122-2131.