一种基于萘酰亚胺的检测细胞内pH值的荧光探针及其生物成像应用

细胞内溶酶体的pH值对细胞自噬、吞噬、酶加工等各项生命活动有着重要影响.细胞核是真核细胞中最大的细胞器,控制着生物体内的遗传和代谢过程,参与代谢过程的酶对pH值的变化很敏感.因此,研究细胞体内的pH值变化至关重要.我们设计并以简单的两步反应合成了一种新型荧光探针NpH-1.该探针以萘酰亚胺作为荧光团,以吗啉基团作为对p...     

成骨肿瘤细胞在纳米氧化钛陶瓷表面的生物活性研究

以羟基磷灰石和氧化镁为晶粒生长抑制剂制备的纳米氧化钛陶瓷为研究对象, 采用体外成骨细胞Ros17/28与材料复合培养的方法, 通过MTT法、荧光染色法和SEM细胞形貌观察等手段综合判断细胞在材料表面的活性, 以此评价纳米氧化钛陶瓷的生物活性. 结果表明, 以羟基磷灰石为晶粒生长抑制剂的氧化钛陶瓷晶体颗粒尺寸达到纳米级, 其生物活性超出了以氧化镁为晶粒生长抑制剂的氧化钛陶瓷和纯羟基磷灰石陶瓷, 具有优异的生物相容性, 是生物活性陶瓷.     

X射线照射Hep-2细胞对其培养基吸收光谱的影响

采用分光光度计分别测量了受不同剂量X射线照射后继续培养48h时的人上皮样喉癌细胞株Hep-2的培养基RPMI1640的紫外吸收光谱,分析了该培养基中蛋白质的紫外吸收特性.结果发现:各组培养基的吸收光谱存在明显的差别,新鲜培养基RPMI1640(10%胎牛血清)233nm处的吸收峰在细胞生长过程中位移至235nm,275nm处的吸收峰位移至278nm.反映出各组培养基中芳香族氨基酸中各种氨基酸如色氨酸、酪氨酸、苯丙氨酸的含量的变化,说明癌细胞在生长过程中对这几种氨基酸的改变不是按等量比的.实验还发现细胞培养基的吸收光谱强度与各剂量组细胞数基本成正相关,进而与细胞所受X射线照射的剂量有内在的联系.这些结果将为利用光谱技术研究人喉癌最佳X射线放射剂量奠定基础.     

Organic Nanocrystals Based on a Solid-emission-tunable AIEgen for Cell Imaging

The development of fluorescent nanocrystals based on organic small molecules is of great importance in bioimaging due to the merits of easy modification,high brightness and excellent photostability,however suffering from the emission-detrimental aggregation-caused quenching(ACQ)effect.Herein,we successfully designed and synthesized an AIE-active di(N,N-dimethylaniline)-dibenzofulvene(named as NFTPE),which exhibits the crystallization-induced emission enhancement(CIEE)effect.Interestingly,two types of yellow-and orange-emissive crystals for NFTPE were obtained,exhibiting aggregation microenvironment-dependent emission tuning in the solid state.Single-crystal analysis and density functional theory(DFT)calculations reveal that different aggregation microenvironments result in the distinct molecular conformation for various emission.Excitingly,the crystallization of NFTPE in an aqueous solution under the assistance of amphiphilic PEG polymer matrices could be monitored in situ by the fluorescence changes,facilitating the preparation of NFTPE nanocrystals(NFTPE-NCs)by adjusting the aggregation microenvironment.The obtained NFTPE-NCs exhibit the superior performance in cell imaging in respect to high brightness,photostability,and biocompatibility,thus demonstrating the potential in bioimaging applications.     

壳聚糖溶液pH对载细胞海藻酸钠-壳聚糖微胶囊性能的影响

以激光共聚焦扫描显微镜为研究手段, 原位直观地考察了在不同pH条件下聚电解质膜的络合程度和蛋白扩散情况. 通过分析pH值对微胶囊膜性能的影响规律, 并结合不同种类细胞对环境pH的敏感特性, 确定了制备细胞培养用海藻酸钠-壳聚糖微胶囊的最佳pH值. 结果表明, 当壳聚糖溶液的pH值由3.50增加到6.50, 微胶囊膜的络合深度呈现高-低-高的趋势, 而微胶囊膜的膨胀性能呈现低-高-低的趋势, 模型蛋白通过微囊膜的扩散呈现低-高-低的趋势, 拐点均出现在pH=4.00和5.50处. 结合动物细胞及微生物细胞对环境pH耐受能力的考察, 确定制备微囊化动物细胞时, 微胶囊成膜反应溶液的最佳pH值为5.50; 制备微囊化大肠杆菌时, 反应溶液的最佳pH值为5.00; 制备微囊化酵母菌时, 反应溶液的最佳pH值为4.50.     

Co@SiO2核壳式纳米粒子的合成、性质表征及在细胞分离和细胞芯片上的应用

合成了Co@SiO2核壳式纳米粒子, 并采用透射电镜(TEM)、 X射线衍射(XRD)、扫描电镜(SEM)和振动样品磁强计(VSM)对其形状、尺寸、荧光及磁特性进行了表征, 探讨了其在细胞分离和细胞芯片上的应用和原理.     

Effects of ultrasound on Microcystis aeruginosa cell destruction and release of intracellular organic matter

Harmful algal blooms negatively impact ecosystems and threaten drinking water sources. One potential method to effectively counteract algal blooms is ultrasonication. However, ultrasonication can easily lead to the release of intracellular organic matter (IOM). The purpose of this study was to investigate the relationship between the destruction of algal cells and IOM release at different ultrasound frequencies. Microcystis aeruginosa cells were ultrasonicated at 20 kHz with an intensity of 0.038 W/mL, 740 kHz with an intensity of 0.113 W/mL, and 1120 kHz with an intensity of 0.108 W/mL. The IOM release was detected by fluorescence spectroscopy in addition to the more commonly used haemocytometry and optical density. After ultrasonication for 15 min, the removal rate of algal cells reached 10.5% at 20 kHz, 9.46% at 740 kHz, and 35.4% at 1120 kHz. The 20 kHz and 740 kHz ultrasound caused local damage to algal cells and then disrupted them, whereas the 1120 kHz ultrasound directly disrupted most algal cells. The extracellular organic matter (EOM), which was increased by ultrasonication, mainly consisted of protein-like compounds, chlorophyll, and a small amount of humic-like substances. Gas vacuoles had been destructed before the cells were broken, as indicated by the decrease of cell size and the wrinkles on the cell surface. Moreover, the removal of algae cells while upholding integrity is more conducive to the safety of the water environment.     

Molecular engineering and biomedical applications of ultra-sensitive fluorescent probe for Ag+

A series of probes KJ-x (x = 1−3) with carbon chains of different lengths based on the matrix of rhodamine B were engineered to detect Ag⁺ in aqueous solution in this work. Among them, KJ-1 is selected as the best option after in vitro investigation in view of its most sensitive and rapid response to Ag⁺, whose possible sensing mechanism is studied by experimental investigation and theoretical calculation. To identify the practical application of the probe, the detection of Ag⁺ in nonantibiotic fungicide Silver&Health and differentiation between normal hepatocytes and hepatoma cells using confocal imaging was conducted.     

Design,synthesis and docking studies of new hydrazinyl-thiazole derivatives as anticancer and antimicrobial agents

Increase in the number of infections caused by pathogenic microbes in cancer patients has prompted the searcher to invest in the development of agents having dual anticancer and antimicrobial properties. The present study is concerned with synthesis and screening for anticancer and antimicrobial activity of a series of 5-hydrazinyl-2-(2-(1-(thien-2-yl)ethylidene)hydrazinyl)thiazole derivatives. The structure elucidation of the synthesized hydrazinyl thiazole derivatives was illustrated by spectroscopic and elemental analysis. All the newly synthesized compounds 5a-p were evaluated for in-vitro cytotoxic activity against breast carcinoma (MCF-7 cell line), hepatocellular carcinoma (HePG-2) and colorectal cancer (HCT-116) cell lines using MTT assay method. Compounds 5 g, 5h showed broad spectrum activity against three cancer cell lines with IC₅₀ ranged from 3.81 to 11.34 µM in compared to the reference drug Roscovitine (IC₅₀ = 9.32 to 13.82 µM), while compounds 5 l and 5 m were found to be more selective against HePG-2 and HCT-116 cell line (IC₅₀ = 9.29 and 8.93 µM respectively) and compound 5j was more selective against HePG-2 and MCF-7 cell lines (IC₅₀ = 6.73 and 10.87 µM respectively). The inhibitory activity of the most promising compounds was tested against the EGFR and ARO enzymes and were further tested for apoptosis and Annexin V/PI staining. The results of enzyme-based tests revealed that the tested compound 5j has a dual inhibitory effect on the EGFR and ARO enzymes with IC₅₀ = 82.8 and 98.6 nM respectively in compared to the reference drugs Erlotinib and Letrozole (IC₅₀ = 62.4 and 79 nM respectively). Furthermore, the majority of the tested hydrazinyl thiazole derivatives exhibited significant antimicrobial activity against the used pathogenic microbes species. Compounds 4b, 5h, 5j and 5 m exerted a good antibacterial and antifungal activity against all tested pathogenic microbes. Therefore, it was concluded that compounds 5 h, 5j and 5 m proved to possess dual anticancer and antimicrobial agent and may serves as a useful lead compounds in search for further modification or derivatization to give more potent and selective agents.     

黏惰化及酸敏感修饰对纳米粒子黏膜穿透的影响

使用纳米粒子进行疾病的诊断和治疗是当前研究的一个热点. 由于受到黏液层的阻碍, 纳米粒子对于黏膜上皮细胞的进入效果不佳, 从而限制了其对黏膜相关疾病的诊断和治疗. 本文设计合成了一种具有黏惰性的酸敏感纳米粒子(MSNs-pCBMA-DMMA), 可有效穿透黏液层进入黏膜上皮细胞. 首先采用溶胶-凝胶法合成了表面氨基化的介孔二氧化硅纳米粒子(MSNs-NH₂), 然后通过原子转移自由基聚合法(ATRP)使两性离子羧基甜菜碱甲基丙烯酸酯(CBMA)在MSNs-NH₂表面上聚合形成聚羧基甜菜碱甲基丙烯酸酯(pCBMA), 获得惰性化的粒子(MSNs-pCBMA), 最后将酸响应性分子2,3-二甲基马来酸酐(DMMA)修饰于MSNs-pCBMA表面, 制备了MSNs-pCBMA-DMMA. 场发射透射电子显微镜(TEM)、 傅里叶变换红外光谱(FTIR)、 氢核磁共振波谱(¹H NMR)和纳米粒度Zeta电位测定仪等分析结果表明, 本文合成了MSNs-pCBMA-DMMA, 且粒子表面电位随pH值降低显著增加, 在pH=7.4~5.7范围内具有酸敏感能力. Transwell^?小室实验表明, pCBMA的接枝提高了粒子在模拟黏液中的渗透速率, 而DMMA的修饰则进一步增强了粒子的扩散能力, 4 h内MSNs-pCBMA-DMMA的模拟黏液渗透率达到16.3%, 为MSNs-pCBMA的1.9倍, MSNs-NH₂的3倍, 而以MSNs-NH₂的表观渗透系数（P_app）为标准计算得到的MSNs-pCBMA-DMMA的相对表观渗透系数达到了2.96. 细胞毒性试验验证MSNs-pCBMA-DMMA粒子的生物安全性良好. 细胞摄取试验表明, 相比于其它粒子MSNs-pCBMA-DMMA能够更快的被黏膜上皮细胞摄取. 本文所构建的纳米粒子能够快速渗透黏液且易于被黏膜上皮细胞摄取, 为其应用于黏膜相关疾病的活体诊断和治疗提供了基础.