超声联合微泡辅助卡铂抑制A549细胞活性的适宜剂量研究

目的 探讨超声辅助卡铂抑制体外A549细胞活性的适宜卡铂剂量及超声能量参数。方法 96孔板接种A549细胞,加入浓度梯度0-400>μg/ml的卡铂培养24小时后,每孔加入 10μlCCK8 溶液,孵育 1.5 小时,酶标仪测定在450nm处的吸光度值,计算细胞抑制率,应用Graphpad Prism 5软件的“药物剂量-效应模型”计算卡铂24小时IC50。设置空白组、US组、USMB组、CBP组、CBP+US组、CBP+USMB组,卡铂浓度为50 μg/ml,声强梯度范围为0.2-2.2W/cm2,频率1MHz,占空比10%,辐照时间1分钟,培养24小时,CCK8法测细胞存活率,应用SPSS24.0分析存活率差异,筛选有效剂量。光学倒置显微镜观察各组细胞形态学变化。结果 卡铂24小时IC50为65.72μg/ml。抑制A549细胞活性的强弱排序为CBP+USMB组>CBP+US组>CBP组>USMB组>US组,CBP+USMB组与其余4组之间差异有统计学意义(P<0.001),CBP(50μg/ml)+USMB(0.2-1.0W/cm2)5组之间差异无统计学意义(P>0.05)。处理组均可见细胞形态不规则、贴壁性降低,以CBP+USMB组为著。结论 卡铂50μg/ml、声强0.6W/cm2为24小时联合疗法适宜剂量。超声联合微泡可以与卡铂协同抑制A549细胞活性,成为肿瘤联合疗法的新策略。     

耐药基因反义寡脱氧核苷酸经声学微泡及超声介导转染对QGY/CDDP细胞多药耐药的影响

肿瘤细胞多药耐药(MDR)是影响肝癌治疗效果的重要因素,因此逆转MDR成为研究肝癌治疗方法的热点之一.目前没有一个有效、靶向的肿瘤MDR逆转方法[1].本研究以声学微泡+超声+mdrl或mrp反义寡脱氧核菅酸(ASODN)逆转QGY/CDDP细胞多药耐药,探讨MDR的逆转方法及其机制.     

The Acoustic Scatter from Single biSphere Microbubbles

Single microbubble acoustic acquisitions provide information on the behaviour of microbubble populations by enabling the generation of large amounts of data. Acoustic signals from single polylactide-shelled and albumin coated biSphere™ microbubbles have been acquired. The responses observed from a range of incident frequencies and acoustic pressures varied in duration. Partial echoes shorter than the incident pulse duration have been observed for low frequency pulses of sufficient amplitude, suggesting release of gas from bubbles. The results presented suggest that the mechanism of scatter from hard shelled agents may be shell disruption and gas release, or partly from gas leaking from defected shell sites, which has previously not been observed optically. These results can provide the basis for improved imaging through optimization of incident pulse parameters, with potential benefits to both diagnostic and therapeutic techniques. (E-mail: d.h.thomas@ed.ac.uk)     

携P-选择素抗体靶向微泡评价大白兔睾丸缺血/再灌注损伤的实验研究

目的:探讨携P-选择素抗体靶向脂质微泡评价睾丸完全缺血/再灌注损伤的可行性。方法:制备普通脂质微泡(MB)和携P-选择素抗体靶向微泡(MBp)。30只大白兔随机分成对照组、缺血/再灌注损伤(IRI)0.5 h组、1 h组、2 h组、4 h组,每组6只,在缺血/再灌注术后行MB和MBp的双侧睾丸造影(间隔20 min),经过4～5 min待健侧睾丸实质中MB或MBp完全消失,测量术侧睾丸第一帧超声造影的声强度(F-P,10-5AU)。随后将术侧睾丸取下行免疫组化分析。结果:MBp造影图像显示各IRI组术侧睾丸F-P值分别大于各组的MB(P均0.05),并在2 h[MBp(8.34±1.20)10-5AU,MB(1.87±0.25)10-5AU]最高。对照组术侧睾丸MB、MBp声强度未见明显差异(均为0 AU)(P0.05)。免疫组化示对照组睾丸血管内皮无明显P-选择素表达,而IRI组P-选择素表达增加,并随时间延长而增多。结论:携P-选择素抗体靶向微泡超声造影能够评价睾丸IRI的炎症反应。     

TATp和CXCR4修饰的载V P3基因超声微泡制备及体外寻靶实验

目的：制备一种载VP3基因、反式激活转录激活肽（TATp）与基质细胞衍生因子‐1（SDF‐1）同时修饰的新型载基因高分子靶向超声造影剂,表征其性质。方法采用W／O／W双乳化法制备载基因超声微泡。并通过硫醚键将SDF‐1与TATp共价连接到聚乳酸／羟基乙酸共聚物（PLGA）微泡的表面,制备成靶向载基因超声微泡。Malvern测量仪测定其粒径、分布及表面电位,流式细胞仪及共聚焦显微镜检测TATp、SDF‐1在高分子微泡表面的连接状况,酶切反应实验鉴定其对DNA的保护性,光镜观察及流式细胞仪初步评估其体外寻靶能力,超声考察体外成像。结果靶向载基因超声微泡呈规则球形。粒径为（536．00±16．55）nm ,分布集中,表面电位为（－0．08±0．08）mV。平均载药量为0．62％,平均包封率为36．13％。对DNA保护作用持续60 min ,未见损坏。TATp、SDF‐1同时加载于PLGA微泡表面的连接率为69．84％。体外寻靶实验显示,靶向微泡较多地稳定簇聚在舌癌SCC‐15细胞膜上,连接率为91．44％。而非靶向微泡较少结合,连接率为12．96％。体外超声显像呈细小点状、均匀高回声。结论成功制备出TATp‐SDF‐1‐VP3‐PEG‐PLGA微泡,其能在体外高效靶向结合舌鳞癌SCC‐15细胞,且短时间穿过细胞膜。体外成像效果较好。     

Current Smokers Develop More Posterior Myocardial Infarctions Probably Due to Increased Tendency to Thrombosis

This investigation was carried out to determine whether smokers developed smaller infarcts as assessed by peak enzyme levels and also to what extent smoking could modify infarct localization. The study included 753 patients, of whom 351 had no history of previous coronary heart disease (CHD) (angina pectoris and/or myocardial infarction (MI)). The investigation was designed as an exposed (smoking) versus non-exposed (non-smoking) cohort study. Outcome was infarct size, posterior versus non-posterior MI and non-Q-wave versus Q-wave infarcts. In the total cohort of patients, 312 (41%) were smokers, the corresponding number in the restricted cohort of patients without a previous CHD (CHD-0-pts) was 169 (48%). Smokers were younger than non-smokers, and more of them were males. It was found that infarct size was similar in smokers and in non-smokers (crude and adjusted effects). Crude effects showed that smokers developed significantly more posterior infarcts than non-smokers; odds ratio (OR) for developing a posterior MI was 1.95 (2p &lt; 0.001) (all patients) and 2.34 (2&lt; 0.001) (CHD-0-pts), respectively. After adjusting for confounders (logistic regression model), OR in the two groups was 1.24 (2p = 0.256) and 1.95 (2p = 0.01), respectively. The study shows that current smokers were younger, and indicates that in those without a previous CHD, significantly more of them developed a posterior MI.     

Ultrasound‐mediated gene transfer (sonoporation) in fibrin‐based matrices: potential for use in tissue regeneration

It has been suggested that gene transfer into donor cells is an efficient and practical means of locally supplying requisite growth factors for applications in tissue regeneration. Here we describe, for the first time, an ultrasound‐mediated system that can non‐invasively facilitate gene transfer into cells entrapped within fibrin‐based matrices. Since ultrasound‐mediated gene transfer is enhanced using microbubbles, we compared the efficacy of neutral and cationic forms of these reagents on the ultrasound‐stimulated gene transfer process in gel matrices. In doing so we demonstrated the beneficial effects associated with the use of cationic microbubble preparations that interact directly with cells and nucleic acid within matrices. In some cases, gene expression was increased two‐fold in gel matrices when cationic microbubbles were compared with neutral microbubbles. In addition, incorporating collagen into fibrin gels yielded a 25‐fold increase in gene expression after application of ultrasound to microbubble‐containing matrices. We suggest that this novel system may facilitate non‐invasive temporal and spatial control of gene transfer in gel‐based matrices for the purposes of tissue regeneration. Copyright © 2013 John Wiley & Sons, Ltd.