不同超声辐照时间和微泡剂量介导HepG2细胞基因转染的实验研究

Objective To investigate the relationship of gene transfection efficiency with different ultrasound exposure time and different dose of microhuhble,and to find the appropriate ultrasound parameters for gene transfection. Methods Plasmid encoding enhanced green fluorescent protein(pEGFP) was chosen as a report gene and HepG2 cells were chosen as research object. The HepG2 cells plus pEGFP and different dose of microbubble were exposed to ultrasound(1 MHz,0.5 W/cm2) with varying time. Twenty-four hours later, the expression of EGFP in the cells was observed by fluorescence microscope,the transfection efficiency was assessed by FACS and the cell viability was observed by trypan blue exclusion. Results The expression of EGFP in all experimental groups was different,and the approving transfection efficiency was got by ultrasound exposed for 20 s when the dose of microbubble was 60 μl. Conclusions With fixed ultrasound frequency and power, different transfection efficiency was got when the exposure time and dose of microbubble were different. The appropriate parameter was 20 s,60 μl, which can supply information for further study.     

超声微泡介导GFP转染C57810及mdx小鼠骨骼肌细胞的实验研究

目的 探讨细胞膜孔开放及含氟烷气体白蛋白外膜在超声微泡介导GFP转染C57810及mdx小鼠骨骼肌细胞中的机制.方法 以肌细胞膜缺损为主要病理改变的mdx小鼠与正常C57810小鼠为研究对象,目的基因GFP与Optison或SonoVue混合注入小鼠胫前肌,一侧胫前肌经超声辐照,另一侧胫前肌不经超声辐照.C57810小鼠作为正常对照,实验分组如下:①C57810小鼠生理盐水组(4条左胫前肌);②C57810小鼠生理盐水+超声组(4条右胫前肌);③C57810小鼠Optison组(4条左胫前肌);④C57810小鼠Oprison+超声组(4条右胫前肌);⑤C57810小鼠SonoVue组(4条左胫前肌);⑥C57810小鼠SonoVue+超声组(4条右胫前肌).mdx肌营养不良小鼠实验分组如下:①mdx小鼠生理盐水组(4条左胫前肌);②mdx小鼠生理盐水+超声组(4条右胫前肌);③mdx小鼠+Optison组(4条左胫前肌);④mdx小鼠Optison+超声组(4条右胫前肌);⑤mdx小鼠SonoVue组(4条左胫前肌);⑥mdx小鼠SonoVue+超声组(4条右胫前肌).1周后处死小鼠,荧光显微镜观察发出绿色荧光者为GFP阳性肌纤维细胞,计数最大GFP阳性肌纤维细胞数,作为GFP基因转染效率指标.结果 正常C57810小鼠:①无超声作用时,与阴性对照组比较,Optison微泡显著提高GFP基因转染水平(P<0.01),SonoVue微泡不提高GFP基因转染水平;②有超声作用时,与阴性对照组比较,Optison微泡显著提高GFP基因转染水平(P<0.01);③有超声作用时,与阴性对照组比较,SonoVue微泡显著提高GFP基因转染水平(P<0.01).mdx小鼠:①与正常C57810小鼠比较,GFP单独(生理盐水组)显著提高GFP基因转染水平(P<0.01),Optison微泡显著提高GFP基因转染水平(P<0.01),SonoVue微泡显著提高GFP基因转染水平(P<0.01);②与阴性对照组比较,Optison微泡显著提高GFP基因转染水平(P<0.01),SonoVue微泡显著提高GFP基因转染水平(P<0.01).结论 细胞膜孔开放是微泡提高基因转染水平的重要因素,含氟烷气体白蛋白外膜是Optison微泡提高GFP转染水平的主要成分.

Abstract：

Objective To investigate the role of sonoporation and the deblic of microbubbles with perfluoropropane gas and albumin in the mechanisms of microbubble-mediated gene enhancement by experimenting in skeletal muscle in C57B10/mdx mice. Methods Plasmid DNA (10 μg) encoding green fluorescent protein (GFP) was mixed with Optison or SonoVue dissolved in saline and injected into the tibialis anterior (TA) muscle of /C57B10/mdx mice with and without adjunct ultrasound. The efficiencies of GFP transgene expression were determined under different experimental conditions. C57B10 mice as normal control:①C57B10 mice + saline (4 left TAs);②C57B10 mice + saline + ultrasound (4 right TAs) ;③C57B10 mice + Optison(4 left TAs);④C57B10 mice+ Optison + ultrasound(4 right TAs);⑤ C57B10 mice + SonoVue(4 left TAs) ;⑥C57B10 mice + SonoVue + ultrasound(4 right TAs). Mdx mice groups:① mdx mice + saline(4 left TAs) ;② mdx mice + saline + ultrasound(4 right TAs);③ mdx mice + Optison (4 left TAs) ; ④ mdx mice + Optison + ultrasound (4 right TAs); ⑤mdx mice + SonoVue(4 left TAs) ;⑥mdx mice + SonoVue + ultrasound(4 right TAs). Mice were sacrificed 1 week after plasmid DNA injection. Fibres with fluorescence green signals were determined as GFP-positive fibres by fluorescence microscopy. Readout was performed on the section with the maximum number of transfected fibers. Results C57B10 mice: ?Optison without ultrasound had significantly increased gene expression compared with negative control ( P <0. 01). SonoVue without ultrasound did not enhance gene expression. ?Optison with ultrasound had significantly increased gene expression compared with negative control (P < 0.01). ?SonoVue with ultrasound had significantly increased gene expression compared with negative control ( P<0. 01).Mdx mice:? Compared with C57B10 mice, GFP alone demonstrated significant GFP expression in mdx mice ( P <0. 01) , Optison demonstrated significant GFP expression in mdx mice ( P <0.01), and SonoVue demonstrated significant GFP expression in mdx mice ( P <0. 01). ?Microbubble groups (Optison and SonoVue) had significantly increased gene expression compared with negative control (P <0. 01). Conclusions In the mechanisms of microbubble-mediated gene enhancement, sonoporation is the key step. The deblic of microbubbles with perfluoropropane gas and albumin is the main constituent in the mechanisms of Optison-mediated gene enhancement. fibers.Results C5781 0 mice:①Optison without ultrasound had significantly increased gene expressioncompared with negative control(P<0.01).SonoVue without ultrasound did not enhance gene expression.②Optison with ultrasound had significantly increased gene expression compared with negative control(P<0.01).③SonoVue with ultrasound had significantly increased gene expression compared with negativecontr01(P相似文献   

载Fe3O4全氟溴辛烷纳米粒增强超声显像的实验研究

目的 探讨载磁性纳米材料Fe3O4颗粒的全氟溴辛烷纳米粒(Fe3O4-PFOB)增强超声显像的效果.方法 将Fe3O4-PFOB纳米粒与RAW264.7 巨噬细胞孵育30 min、1 h后,分别进行光镜及体外超声检查.12只健康SD大鼠随机分为2组,分别于注射Fe3O4-PFOB及空白PFOB纳米粒前后进行大鼠肝脏超声显像,并用DFY超声图像定量分析诊断仪评价显像效果.结果 Fe3O4-PFOB纳米粒与巨噬细胞孵育1 h后可见大量Fe3O4-PFOB纳米粒被巨噬细胞吞噬,巨噬细胞吞噬纳米粒后能够增强超声回声信号.体内显像中,与空白PFOB纳米粒相比,Fe3O4-PFOB能够更好地增强大鼠肝实质超声显像效果,而且其增强显影时间延长.结论 膜壳装载Fe3O4颗粒的Fe3O4-PFOB纳米粒能够有效增强超声显像效果,有望实现一种造影剂多种模态显像.

Abstract：

Objective To study the feasibility of the Fe3O4-loaded lipid perfluorooctylbromide nanoparticles (Fe3O4-PFOB) for enhanced ultrasound imaging.Methods The Fe3O4-PFOB nanoparticles,incubated with RAW264.7 macrophage cells,were monitored by microscope and ultrasound.Twelve SD rats were randomized into two groups,Fe3O4-PFOB group and PFOB group.Ultrasound imaging of rats' liver was performed before and after intravenous injection of the contrast agents.The liver echogenic intensity was quantified by DFY ultrasound quantified system analysis.Results Incubation of the Fe3O4-PFOB nanoparticles with macrophages resulted in the uptake of Fe3O4-PFOB by macrophages.Macrophages loaded with Fe3O4-PFOB exhibited enhanced echogenicity in vitro.In in vivo imaging,Fe3O4-PFOB produced better and prolonged ultrasound enhancement of rats' liver compared to PFOB nanoparticles.Conclusions Fe3O4-PFOB nanoparticles could enhance ultrasound imaging and may potentially serve as a multimodal probe for ultrasound,CT and MR imaging.     

超声爆破微泡介导内皮抑素基因抑制兔颈动脉粥样硬化的实验研究

目的 探讨利用超声爆破微泡介导内皮抑素(endostatin,ES)基因转染对兔颈动脉粥样硬化斑块内新生血管及斑块生长的抑制作用.方法 20只颈动脉粥样硬化模型兔随机分为三组:A组,微泡+超声;B组,对照质粒+微泡+超声;C组,ES质粒+微泡+超声.建模2周行超声爆破微泡介导基因转染,间隔3周时重复转染1次.建模14周时行超声及数字减影血管造影(DSA)检查,病理检测病变血管新生内膜、斑块内新生血管及ES表达情况.结果 超声显示A组和B组内膜明显增厚,斑块较大,管腔明显狭窄,收缩期峰值流速(PSV)增加,C组上述指标明显较A组和B组低(P＜0.05).病理检测C组内中膜厚度(IMT)、内膜厚度(IT)、内中膜厚度比(IT/MT)、内膜面积(IA)、内中膜面积比(IA/MA)及新生内膜狭窄率与A组和B组比较差异均有统计学意义(P＜0.05).C组颈动脉新生血管及血管内皮生长因子(VEGF)表达均较A组和B组低,内膜及胫前肌可见较多ES表达,而A组和B组无明显ES表达.结论 一定超声辐照条件下,超声爆破微泡介导ES基因转染可抑制兔颈动脉粥样硬化病变的发展,有可能为动脉粥样硬化性疾病的基因治疗提供一种安全有效的方法 .

Abstract：

Objective To explore the inhibition effect on angiogenesis and plaque growth of carotid atherosclerosis by transfection of endostatin gene using microbubbles combined with ultrasound exposure.Methods Twenty rabbit models of carotid atherosclerosis were randomly divided into 3 groups:group A,microbubble+ ultrasound; group B, control plasmid + microbubble + ultrsound; group C, ES plasmid +microbubble+ ultrasound. Two weeks after surgery, ultrasound/microbubble mediated gene transfer was performed,and it was performed once again three weeks after the first transfection. Ultrasonography and digital subtraction angiography(DSA) were performed at the time of 14 weeks. The carotid arteries were taken to detect the neointima and angiogenesis, and the expression of endostatin was detected using pathological means. Results The imagings of ultrasound showed that the intima in group A and B were thick significantly with larger plaques, and the lumen became stenosis with the peak systolic velocity increasing,however,in group C,the parameters mentioned above were significantly less than those of group A and B ( P＜0.05). Pathological results displayed that intima-media thickness (IMT), intima thickness (IT), intima thickness/media thickness (IT/MT), intima area (IA), intima area/media area (IA/MA) and neointimal stenosis rates were greater in group A and B, however, they were less in group C ( P＜0.05).The number of neovascularization and vascular endothelial growth factor(VEGF) expression in group A and B were more than those of group C. There was more endostatin positive expression in carotid arteries and anterior tibial muscles of group C, while there was nearly no expression in group A and B. Conclusions Under the conditioned ultrasonic irradiation, ultrasound/microbubble mediated endostatin gene transfection can inhibit the development of carotid atherosclerosis in rabbits, which might provide a safe and effective strategy for gene therapy of atherosclerotic disease in future.     

超声辐照纳米聚合物体外控释 DNA 效果的研究

目的 利用自制携抗体结合前列腺癌细胞,探讨超声辐照PLGA纳米粒(PLGA-NPs)体外控释脱氧核糖核酸(DNA),靶向抑癌作用.方法 通过溶剂蒸干法制备携有前列腺癌雄激素受体抗体的PLGA纳米粒(NPs-PLGA-GFP-AR),包裹有绿色荧光蛋白(GFP)作为标志;加入前列腺癌PC4 2细胞培养2h后,以脉冲波(pulsed wave,PW)、连续波(continuous wave,CW)超声条件进行体外辐照对比,共聚焦荧光显微镜下观测细胞转染效果.结果 NPs摄入未增加,声辐照后绿色荧光蛋白表达急剧明显增加;无超声辐照的癌细胞中5d后始见绿色荧光,超声辐照3d即可见绿色荧光;196 h后肿瘤细胞凋亡.PW1、2、3(Duty Factor,DF为10％、20％、30％,0.05～0.15 W/cm2))组与无超声比较转染率差异显著(P＜0.05),10％、20％、30％组间转染率无显著差异(P＞0.05);连续波超声辐照CW1、2、3(DF为10、20、30％,声强为0.1～0.25 W/cm2)与无超声组对照组差异显著(P＜0.05),但癌细胞脱壁、死亡率高.结论 超声辐照对NPs有体外促降解及靶向控释DNA作用.     

Optison增强质粒GFP转染小鼠骨骼肌机制的研究

Objective To investigate the possible mechanisms of Optison-mediated gene enhancement by experimenting with different constituents,both with and without ultrasound. Methods Plasmid DNA（10 μg） encoding green fluorescent protein（GFP） was mixed with Optison or its constituents dissolved in saline （in equivalent concentration as that in Optison） and injected into the tibialis anterior （TA） muscle of mice with and without adjunct ultrasound. The efficiencies of GFP transgene expression were determined under different experimental conditions, ①plasmid ＋ saline as negative control; ②plasmid ＋ Optison as positive control; ③plasmid ＋ heat-treated Optison; ④plasmid ＋ albumin; ⑤plasmid ＋ N-acetyltryptophan; ⑥ plasmid ＋ caprylic acid. Transfection efficiency was assessed by counting the number of GFP-positive fibres. Tissue damage was assessed by measuring the maximal damage area on serial sections. Results Heat- treated Optison and albumim potentiated gene transfection without significant increased tissue damage when ultrasound was applied. Heat-treated Optison was effective even without ultrasound. No significant potentiation was demonstrated with N-acetyltryptophan and caprylic acid with or without ultrasound. Conclusions Ultrasound,deblic of microbubbles with perfluoropropane gas and albumin may be potentiate transfection in this model.     

Enhanced effects of IL-6/IL-2 fusion gene trans-duction in inhibition of B16 cell turnorigenicity and metastatic potential

In order to investigate the effects of cytokine fusedgene transfection on tumor cell modification, threeretroviral vectors for human interleukin 6 (IL-6),interleukin 2 (IL-2) and, IL-6/IL-2 fusion gene wereconstructed. The retroviral vectors were introduced intomurine B16 melanoma cell line respectively and theeffects of single or fused cytokine gene on tumor cellbiology in vitro and in vivo were examined. In vivo, thethree cytokine gene-modified B16 cells all showeddecreased tumorigenicity and metastatic potentials,however, the reduction in tumorigenicity and metastasis     

去唾液酸糖蛋白受体介导的肝靶向纳米脂质超声造影剂的制备及体外实验

目的 以肝细胞膜特异性受体去唾液酸糖蛋白受体为靶向受体,利用共价结合的原理,制备出肝靶向性液态氟碳纳米超声造影剂,观察该造影剂的一般特性、与人肝细胞L02的靶向结合及体外聚集显像效果.方法 利用还原胺法制备去唾液酸糖蛋白特异性配体半乳糖化多聚赖氨酸(Gal-PLL);利用旋转蒸发及声振法制备液态氟碳纳米脂质超声造影剂;培养人肝细胞L02,于不同时间点观察与L02细胞的靶向结合;Philips iU 22超声诊断仪L12-5探头对比观察靶向液态氟碳纳米脂质超声造影剂的体外显像效果.结果 靶向液态氟碳纳米脂质超声造影剂粒径极小,分布均匀,形态呈圆球形,且能与L02有效结合;体外乳胶囊显示:脱气水侧呈现无回声,靶向液态氟碳纳米脂质超声造影剂侧呈现高回声.结论 以去唾液酸糖蛋白受体为靶向受体,自制的携半乳糖化多聚赖氨酸的靶向液态氟碳纳米脂质超声造影剂能有效与人肝细胞LO2靶向结合,该靶向超声造影剂能在体外聚集显影.该靶向超声造影剂粒径极小,是细胞水平上肝靶向性超声分子显像的一种理想的超声分子探针.

Abstract：

Objective To prepare the liver targeting nano-liquid perfluorocarbon ultrasound contrast agent and observe its general characteristics;to observe the targeting combined effects of the human liver cells L02 and the targeted ultrasound contrast agent ;to evaluate the gathering imaging effects of the targeted ultrasound contrast agent. Methods Amine method was used to prepared asialoglycoprotein Gal specific ligand polylysine (Gal-PLL), rotary evaporator and sonicated liquid fluorocarbon were used to prepare nano lipid ultrasound contrast agent. Human liver cell L02 were cultured, the combined effects were observed according to the reacting time of the cells and the targeted nano-lipid ultrasound contrast agent. The nanolipid ultrasound contrast agent and the degassed_ water_ were loaded into cysts and their ultrasound imaging effects were observed by ultrasound diagnostic apparatus Philips iU22. Results The particle size of the liquid fluorocarbon nano-targeted lipid ultrasound contrast agent was extremely small, uniform, cylindrical and spherical. The cysts in vitro showed that the side of the targeted liquid perfluorocarbon nano-lipid ultrasound contrast agent showed high echo. Conclusions The targeted liquid perfluorocarbon nano-lipid ultrasound contrast agent can be effectively targeted to the human liver cells L02 due to carrying home-made Gal-PLL. The targeted ultrasound contrast agents can be imaging by ultrasound and be confirmed in vitro.The size of the contrast agent was small, therefore, it can be considered an ideal ultrasonic molecular probe and achieve the ultrasound molecular imaging in cell level.     

X-连锁迟发性脊髓骨骺发育不良家系的基因诊断

ObjectiveTo investigate the molecular pathogenesis of a pedigree of X-linked spondyloepiphyseal dysplasia atarda (SEDL) and to establish methods of gene diagnosis. Methods Clinical diagnosis was made based on height measurement, radiological examination and pedigree analysis. Peripheral blood samples of relevant family members were collected. After genomic DNA extraction, single strand conformation polymorphism (SSCP) followed with DNA sequencing was used to detect SEDL gene exons 36. Microsatellite marker DXS16 was selected for linkage analysis. Results The abnormal electrophoretic bands were detected in exon 4 of probands by PCR-SSCP. A c. 218C ＞ T mutation in exon 4 of SEDL gene was found in three probands, which resulted in a change in amino acid sequence S37L. The heterozygous exon 4 mutation was identified in three carriers, but not in healthy individuals, and no mutations were detect in exon 3, 5 and 6 of probands. Three unmarried young females (Ⅲ10, Ⅳ6 and Ⅳ7) were found to harbor the mutation by DNA sequencing analysis. ConclusionsA c. 218C ＞ T missense mutation in exon 4 of SEDL gene is the cause of molecular pathogenesis of the pedigree. SSCP and DNA sequencing can be used for prenatal gene diagnosis.     

X-连锁迟发性脊髓骨骺发育不良家系的基因诊断

ObjectiveTo investigate the molecular pathogenesis of a pedigree of X-linked spondyloepiphyseal dysplasia atarda (SEDL) and to establish methods of gene diagnosis. Methods Clinical diagnosis was made based on height measurement, radiological examination and pedigree analysis. Peripheral blood samples of relevant family members were collected. After genomic DNA extraction, single strand conformation polymorphism (SSCP) followed with DNA sequencing was used to detect SEDL gene exons 36. Microsatellite marker DXS16 was selected for linkage analysis. Results The abnormal electrophoretic bands were detected in exon 4 of probands by PCR-SSCP. A c. 218C ＞ T mutation in exon 4 of SEDL gene was found in three probands, which resulted in a change in amino acid sequence S37L. The heterozygous exon 4 mutation was identified in three carriers, but not in healthy individuals, and no mutations were detect in exon 3, 5 and 6 of probands. Three unmarried young females (Ⅲ10, Ⅳ6 and Ⅳ7) were found to harbor the mutation by DNA sequencing analysis. ConclusionsA c. 218C ＞ T missense mutation in exon 4 of SEDL gene is the cause of molecular pathogenesis of the pedigree. SSCP and DNA sequencing can be used for prenatal gene diagnosis.     

超声造影剂SonoVue介导质粒绿色荧光蛋白转染小鼠骨骼肌细胞的实验研究

目的 探讨微泡造影剂SonoVue介导基因转染小鼠骨骼肌细胞的作用。方法 采用质粒绿色荧光蛋白（GFP）作为目的基因，超声结合SonoVue作用于小鼠H2K成肌细胞，照射时间分别为10s、20s、30s、40s、50s、60s，流式细胞仪测定GFP阳性细胞率，台盼蓝染色测定细胞生存率。SonoVue结合或不结合超声作用于小鼠胫前肌，1周后处死小鼠，荧光显微镜测定GFP阳性肌纤维数，HE染色估计肌肉破坏面积。结果 加入SonoVue后，GFP阳性细胞率与细胞生存率总体显著低于阳性对照组；动物实验显示，SonoVue结合或不结合超声均显著增强GFP基因表达水平作用。结论 体外细胞培养SonoVue无增强GFP基因转染的作用，却增加细胞损伤；活体小鼠实验显示SonoVue具有良好的增强骨骼肌细胞基因表达作用。     

超声造影剂Levovist介导质粒GFP转染小鼠骨骼肌细胞的实验研究

目的探讨空气型微泡造影剂Levovist介导基因转染小鼠骨骼肌细胞的作用。方法采用质粒GFP作为目的基因，超声(1MHz脉冲波，20％工作周期，空间时间峰值强度1W／cm^2)结合Levovist作用于小鼠H2K成肌细胞，照射时间分别为10s、20s、30s、40s、50S、60s，流式细胞仪测定GFP阳性细胞率，台盼蓝染色测定细胞生存率。超声结合Levovist作用于小鼠胫前肌，1周后处死小鼠，荧光显微镜测定GFP阳性肌纤维数，HE染色估计肌肉破坏面积。结果超声单独作用于H2K细胞显示出较佳的增强GFP基因表达的作用，加入微泡造影剂Levovist后，细胞死亡率显著增加，GFP基因表达水平降低；动物实验显示，Levovist结合或不结合超声均无增强GFP基因表达水平作用，但会增加肌肉损伤面积。结论本实验条件下，Levovist无增强骨骼肌细胞基因表达作用，却加重细胞损伤。     

超声靶向微泡破坏联合聚乙烯亚胺增强裸鼠移植瘤基因输送的初步研究

目的 探讨超声靶向微泡破坏(UTMD)联合聚乙烯亚胺(PEI)增强裸鼠Hela细胞(人宫颈癌)移植瘤基因输送的可行性和应用价值.方法 分别将2种质粒DNA[红色荧光蛋白质粒(RFP)和荧光素酶质粒(pCMV-LUC)]与PEI以不同氮/磷酸盐比(N/P比)混合,利用凝胶阻滞实验对PEI/DNA复合物进行分析.经荷瘤裸鼠尾静脉分别注入PBS、质粒、质粒+Sono Vue微泡、PEI/DNA复合物+Sono Vue微泡,仅对一侧肿瘤行超声辐照(3 MHz、2 W/cm2、2 min、20%占空比),另一侧肿瘤作为对照,并对该转染方法 的靶向性进行分析.超声辐照3 d后处死动物,行RFP表达观察、荧光素酶活性检测和组织学检查.结果 琼脂糖凝胶电泳显示PEI可有效地缩合质粒DNA.与裸质粒组比较,UTMD(超声辐照+Sono Vue微泡)能明显提高RFP转染率.与非辐照对照侧比较,UTMD的运用使RFP表达明显增强,荧光素酶活性增加了14倍(P＜0.01).UTMD联合PEI可显著增强基因转染,受辐照移植瘤的荧光素酶活性增加了10倍(P＜0.01);与非联合PEI时比较,荧光素酶表达增加了111倍(P＜0.01).无论有否超声照射,裸鼠其他器官组织中均无明显的基因表达(P＞0.05),且未观察到明显的组织损伤.结论 UTMD联合PEI可显著增强报告基因在肿瘤组织的靶向传输和转染,是一种很有前景、新型而安全的体内基因输送方法.     

超声造影剂Optison介导质粒GFP转染小鼠骨骼肌细胞的实验研究

目的 探讨微泡造影剂Optison介导基因转染小鼠骨骼肌细胞的作用.方法 采用质粒GFP作为目的基因,超声(1 MHz脉冲波,20%工作周期,空间时间峰值强度1 W/cm2)结合Optison作用于小鼠体外H2K成肌细胞,照射时间分别为10、20、30、40、50及60 s,流式细胞仪测定GFP阳性细胞率,台盼蓝染色测定细胞生存率.超声结合Optison作用于小鼠胫前肌,1周后处死小鼠,荧光显微镜检测GFP阳性肌纤维数,HE染色后计算肌肉损伤面积.结果 活体外细胞实验结果显示,与阳性对照组相比,Optison结合超声作用于H2K细胞10、20及30 s时,显著增强GFP基因表达水平(P＜0.01),但于40、50及60 s时基因表达水平显著降低(P＜0.01),细胞死亡率总体显著增加(P＜0.01).动物实验结果显示,Optison单独或结合超声均显著增强GFP基因表达水平,且Optison单独作用显著减少肌肉损伤面积.结论 Optison可显著增强活体小鼠骨骼肌细胞基因表达水平,同时具有肌肉保护作用.     

超声介导白蛋白微泡破裂对外源性基因在ECV304细胞和BALB/c鼠心肌中的表达

目的 探讨经超声介导白蛋白微泡破裂对外源性基因在体外ECV304细胞的转染效率及表达情况和在BALB／c鼠心肌中的表达及显像效果。方法 18只BALB／c小鼠分为裸质粒组（P组）、质粒＋超声介导转化组（P＋U组）、质粒＋白蛋白微泡＋超声介导转化组（P＋M＋U组），每组6只。选择携带增强绿色荧光蛋白基因（EGFP）的质粒DNA并与自制的白蛋白微泡相混，以超声介导白蛋白微泡破裂方法分别在体外对ECV304细胞及体内对BALB／c鼠心肌细胞进行基因转染，并测定基因转染和表达效率。结果 体内和体外研究表明，超声介导的白蛋白微泡破裂组（P＋M＋U组）与P和P＋U组相比可明显提高外源性基因转染及表达效率（P〈0．01）。体外采用频率0．8MHz、声强1．0W／cm^2、10％占空比，并30s两次的超声介导白蛋白微泡破裂可有效稳定地转染EGFP基因在ECV304细胞中的表达，并对细胞无毒副作用；体内超声介导白蛋白微泡破裂后具有良好的心肌灌注显像效果。结论 超声介导的白蛋白微泡破裂是一种安全且有效的基因转染方法，在一定的超声条件下可明显提高外源性基因在体内和体外的转染和表达。     

Formulation and characterization of poly (D,L-lactide-co-glycolide) nanoparticle containing vascular endothelial growth factor for gene delivery

OBJECTIVE: The stability, in vitro release, in vitro cell transfection efficiency and in vivo gene transfer of vascular endothelial growth factor (VEGF(165)) plasmid DNA-loaded poly(d,l-lactide-co-glycolide) (PLGA) nanoparticles were investigated. METHODS: DNA-loaded nanoparticles were prepared with PLGA bearing VEGF(165) plasmid DNA and characterized with respect to morphology, size and encapsulation efficiency. The gene transfer efficiency of nanoparticles was tested in vitro on the cultured myocardial cells. And then the suspension of VEGF-loaded nanoparticles (VEGF-NPs) was injected into myocardial tissues in vivo to observe the process of nanoparticles as vectors for gene transfer to cardiac myocytes and to detect its biological effect and evaluate angiogenesis. RESULTS: The encapsulation efficiency of the VEGF-NPs was 58.06 +/- 2.8% and their diameter ranged 100-300 nm. VEGF gene could be successfully transfected into myocardial cells by nanoparticles, which significantly enhanced gene transfection efficiency. A great number of nanoparticles were seen in the myocardial cytoplasm and nucleus. Furthermore, the nanoparticles began to dissolve and degrade. There was a significant increase in the number of capillaries in the VEGF-NPs group when compared with the plasmid DNA group. CONCLUSION: The PLGA nanoparticles are capable of DNA delivery to cardiac myocytes for treating ischaemic myocardium. The direct gene transfer of VEGF-NPs into ischaemic rabbit myocardium can improve cardiac function and increase the number of capillaries.     

共聚物P85和微泡造影剂对小鼠骨骼肌超声介导基因转染的影响

目的 探讨共聚物P85、微泡造影剂和超声在质粒DNA对小鼠骨骼肌基因转染中的影响.方法 应用共聚物P85、微泡造影剂Optison与DNA混合后直接小鼠胫前肌(TA)注射,并辐照超声.1周后取出胫前肌并快速冰冻切片,荧光显微镜计数表达GFP转染的肌纤维数,HE染色评价肌肉损伤情况.结果 共聚物P85和微泡造影剂Optison均可促进质粒DNA的基因转染(P<0.01,P<0.05).辐照超声可使P85介导的基因转染效率显著提高(P<0.01),但对微泡造影剂介导的基因转染却无显著提高(P>0.05),并且P85所介导的基因转染效率高于微泡造影剂介导的基因转染效率(P<0.01).微泡造影剂和P85耦合并辐照超声可使质粒的基因转染效率显著提高,与所有各组的差异有统计学意义(P<0.01).同时辐照超声显著增加含微泡造影剂组骨骼肌的损伤面积(P<0.01).结论 共聚物P85和微泡造影剂可介导质粒DNA的基因转染,辐照超声对其有促进作用,三者联合应用具有协同作用.     

超声微泡造影剂介导小鼠骨骼肌基因转染实验研究

目的探讨微泡造影剂在超声作用下是否可增加小鼠骨骼肌基因转染效率.方法 40只昆明小鼠随机分为4组,每组10只,第一组:在胫前肌注射造影剂与绿色荧光蛋白(GFP)质粒的混合溶液;第二组:注射与第一组相同的混合溶液后立即加超声辐照;第三组:注射GFP;第四组:在注射GFP后立即用超声辐照.7天后取小鼠胫前肌观察绿色荧光蛋白的表达情况.结果第一组与第二组有较多GFP表达,部分肌纤维绿色荧光较明亮,部分较暗淡;第三组和第四组GFP表达量较少.第一组与其余各组间的差异有显著性意义,P＜0.05;第二组与其余各组间的差异有显著性意义,P＜0.05;第三组与第四组间的差异无显著性意义,P＞0.05.结论超声微泡造影剂在超声作用下可明显增强小鼠骨骼肌的基因转染效率;未加超声波作用时,直接肌注携基因的超声微泡造影剂亦可增加小鼠骨骼肌的基因转染效率.     

超声介导质粒GFP转染小鼠H2K成肌细胞的实验研究

目的 探讨超声介导基因转染小鼠骨骼肌细胞的作用。方法 采用质粒GFP作为目的基因，超声(频率1MHz，脉冲波，工作周期20％)作用于H2K成肌细胞，分别使用两种空间时间峰值强度(0．5W／cm^2、1W／cm^2)，照射时间分别为10s、20s、30s、40s、50s、60s。流式细胞仪测定GFP阳性细胞率，台盼蓝染色测定细胞生存率。结果 较低能量超声(0．5W／cm^2)GFP阳性细胞率总体显著低于较高能量超声(1W／cm^2)，超声增强GFP转染H2K细胞的最佳条件为：空间时间峰值强度1W／cm^2，照射时间40～50s。超声作用并未明显增加细胞死亡率。结论 超声在增强骨骼肌细胞基因转染领域应用前景广阔。     

Ultrasonic enhancement of gene transfection in murine melanoma tumors

The enhancement of gene transfection by ultrasound (US) was evaluated in vitro and in vivo using the B16 mouse melanoma model. Cultured cells were either exposed in suspensions in vitro or implanted subcutaneously in female C57BL/6 mice for 10–14 days and, subsequently exposed, in vivo. For comparison to results with a luciferase plasmid, a reporter plasmid for green fluorescent protein (GFP) was used to evaluate transfection efficiency. US was supplied by a system, similar to a Dornier HM-3 lithotripter, that produced shock waves (SW) of 24.4 MPa peak positive and 5.2 MPa peak negative pressure amplitudes at the focus. The plasmids were mixed with the suspensions to achieve 20 μL mL⁻¹, or were injected intratumorally to provide 0.2 mg DNA per mL of tumor. Acoustic cavitation was promoted by retaining 0.2 mL of air in the 1.2-mL exposure chambers in vitro and by injecting air at 10% of tumor volume in vivo. In vitro, cell counts declined to 5.3% of shams after 800 SW exposure, with 1.4% of the cells expressing GFP after 2 days of culture. In vivo, 2 days after 400 SW exposure, viable-cell recovery from excised tumors was reduced to 4.2% of shams and cell transfection was enhanced by a factor of about 8, reaching 2.5% of cell counts (p < 0.005 in t-test). These results show that strong tumor ablation induced by US shock wave treatment can be coupled with simultaneous enhancement of gene transfection.