微流控芯片上的肿瘤组织微阵列构建

研发了一种多层复合微流控芯片,包含64细胞培养微孔阵列,该微阵列集成了细胞进样、水凝胶三维支架形成和持续灌流培养的过程.以MCF-7乳腺癌细胞为模型,连续培养中监测细胞存活率、细胞密度、增殖率和细胞内pH值,并同时进行冰冻切片后免疫组化染色.实验结果显示,乳腺癌细胞在水凝胶微球中增殖形成了类组织结构.E-cadherin及Vinculin在细胞内、细胞间隙均出现较强表达,提示水凝胶微球中细胞建立了细胞-细胞、细胞-间质连接.芯片上连续培养15天内细胞存活率保持在85％以上,细胞增殖率随时间延长而递减.细胞内pH值检测显示芯片3D培养细胞内部呈现明显的酸化,其程度随着细胞密度增大而增加.这种芯片肿瘤组织微阵列构建方法简单高效,有望发展成为肿瘤研究的有力工具.     

基于双向浓度梯度的微流控芯片系统对 肿瘤细胞侵袭能力的多重分析

利用微流控芯片易于模拟体内生理环境、 流体控制精确及易于集成等优势, 将基于扩散原理的浓度梯度形成结构与经典的圣诞树形浓度梯度发生器相集成, 建立了在垂直和水平方向上形成连续、 双向浓度梯度的微流控芯片系统, 采用该系统对不同类型细胞(HEK-293, MCF-7, SGC-7901)的侵袭力进行了定量分析; 通过在垂直方向上施加血清浓度梯度, 在水平方向上施加抗肿瘤药物十字孢碱浓度梯度, 分析了在连续药物浓度作用下的人胃癌SGC-7901细胞侵袭能力被抑制的情况, 同时观察并定量评价了伴随细胞侵袭力变化过程中细胞增殖能力受抑制的情况. 研究结果表明, 该系统可形成稳定的双向物质浓度梯度; 在血清浓度梯度存在情况下, 伴随十字孢碱浓度梯度的升高, 肿瘤细胞侵袭(P<0.0001)和增殖能力(P<0.001)均呈现浓度依赖性的连续降低. 建立的双向浓度梯度微流控芯片系统可用于评价复杂环境对细胞的多重影响, 也为研究细胞间相互作用、 多种药物联用及药物筛选等提供了良好的研究平台.     

基于微流控芯片的乳腺癌细胞微环境酸化检测

建立了基于微流控芯片的乳腺癌微环境酸化模型和动态检测微环境酸化情况的分析方法。设计了一种多层复合式微流控芯片,将乳腺癌细胞悬液引入含有水凝胶前体的芯片培养室后,在硝酸纤维素薄膜上固化形成3D培养支架。芯片通道连续灌流模拟血流供应,并将非电化学的pH检测器引入芯片,通过图像分析得到实时的pH变化。通过观察癌细胞的存活率、增殖率、乳酸水平及pH值,分析微环境的酸化情况,同时与正常细胞进行比较。结果表明,连续灌流培养7 d,乳腺癌细胞的存活率保持在90%以上;随着培养天数的增加,芯片上癌细胞微环境的pH值逐渐降低,且灌流速度越低,pH值下降越明显,而正常细胞微环境的pH值无明显变化。基于微流控芯片的微环境酸化检测平台可实时动态检测微环境的pH值,有望成为相关肿瘤研究的有力工具。     

浓度梯度微流控芯片在药物筛选中的应用

微流控芯片技术作为21世纪极具代表性的微型分析平台技术之一,以其试剂消耗低、分析微型化、可集成化、易于控制、自动化和良好的生物相容性等优点而成为研究热点,在生物、医学、食品和环境等多个领域都有杰出表现,尤其是药物筛选领域。其中备受关注的浓度梯度微流控芯片更是取得了显著成果。本文综述了近年来用于药物筛选的浓度梯度纸基芯片、浓度梯度水凝胶芯片、浓度梯度液滴芯片、浓度梯度聚二甲基硅氧烷(PDMS)芯片的研究进展;同时对浓度梯度微流控芯片在单细胞分析、组合药物筛选、三维(3D)细胞培养和细胞微环境模拟等方面的应用及优缺点进行了阐述,并在此基础上对其发展前景进行了展望。     

多层纸芯片乳腺癌组织微阵列用于抗肿瘤药物测试

开发了一种多层纸芯片细胞培养平台,将乳腺癌细胞分别接种于多层的图形化纸芯片的亲水区,折叠后构建了仿真实体肿瘤.多层纸芯片覆以微孔薄膜,用以仿真血管内皮层.培养不同时间后,拆解多层纸芯片检测乳腺癌组织内各层面的细胞形态、存活率、细胞周期分布以及细胞内乳酸含量.实验结果显示,各层纸芯片培养的乳腺癌细胞存活率均高于80％,并形成了类组织结构.芯片乳腺癌组织内部呈酸化倾向,且酸化程度随着培养时间的延长而升高.与二维(2D)培养细胞相比较,纸芯片乳腺癌组织内细胞增殖比例显著降低(15％ vs 60％).多层纸芯片乳腺癌组织显示了更接近体内情况的药物反应机制,细胞存活率随阿霉素浓度升高呈现缓慢下降趋势,IC50值显著高于2D培养细胞组(5.0 μmol/L vsl.144 μmol/L).这种多层纸芯片乳腺癌组织微阵列构建简便、仿真度高,有望成为抗肿瘤药物反应测试的有力工具.     

开放式微流控芯片上的肿瘤组织微阵列构建

构建了一种具有自动形成细胞培养阵列和多步骤灵活操作特点的开放式微流控芯片。此芯片具有3层复合式结构:底层为微通道贯穿的细胞培养池阵列,顶层是开放式培养池,二者之间为一层纳米孔薄膜。纳米孔薄膜具有"透气阻水"的特性,既起到止流阀作用实现液体自动分配,又允许跨膜扩散,模拟血管内皮层扩散屏障结构。结合移液工作站,开放式微流控芯片可以完成细胞换液、药物处理和细胞活力测试等一系列分析步骤。本研究以乳腺癌细胞为模型,在芯片上90 s内可构建包含三维细胞培养和仿真血管内皮的10×10肿瘤组织微阵列。形态学和免疫组织化学检测证实了芯片肿瘤组织的仿真效果。抗肿瘤药物测试结果表明,这种开放式微流控组织阵列芯片允许在仿真条件下进行包含复杂操作步骤的细胞实验,是细胞研究的有利工具。     

微流控芯片单细胞进样,溶膜及分离检测胞内谷胱甘肽

单细胞分析对重大疾病的早期诊断等方面有重要意义[1].微流控分析芯片的网络结构和微米级的通道尺寸适合于单细胞进样、溶膜和分离分析.但目前的报道主要集中在细胞培养、计数和筛选[2].我们在十字通道微流控芯片上,通过调节储液池的液面高度和细胞悬液密度,使单细胞逐个通过芯片进样通道和分离通道之间的区域,再结合控制电渗流方向,使单细胞固定在分离通指定位置,然后用电泳缓冲液结合高电场实现细胞快速溶膜,接着进行电泳分离和LIF检测.实现了单个血红细胞内谷胱甘肽(GSH)的高效分离及定量分析.     

基于微流控芯片的肿瘤细胞体外药敏试验研究进展

在抗癌药物研发及疾病治疗过程中,药物溶液实现梯度浓度及混合配置,对确定最佳浓度和联合治疗方案至关重要。微流控技术通过设定微通道网络实现复杂的溶液处理,可进行药理学分析。微流控技术是构建体外微环境、开展细胞培养和药敏研究的重要手段。本文针对肿瘤细胞体外药敏试验研究,在微流控技术原理、制造材料、结构设计和制造特点等方面,对近10年来微流控芯片功能结构、在细胞体外培养和药物筛选应用中的研究进展做了概括和综述,对未来用于癌症个性化治疗的微流控芯片结构和功能进行了展望。     

水凝胶微流控芯片的快速加工及在细胞培养检测中的应用

采用具有紫外光聚合性能的聚乙二醇(PEG)基水凝胶材料, 通过紫外光聚合作用快速加工双层水凝胶微流控芯片, 并验证了其对肿瘤细胞代谢液进行检测的可行性. 与传统微流控芯片材料相比, 该水凝胶芯片材料具有更好的生物相容性及可操控性, 可直接加工成形, 在生物学领域特别是细胞培养过程控制方面具有良好的应用前景. 实验结果表明, 该水凝胶微流控芯片可在微尺度空间有效模拟细胞生长环境, 并实现对细胞连续捕获后的原位培养. 将该芯片与卟啉可视阵列传感器系统结合, 经代谢特征分析可有效区分不同种类肿瘤细胞, 实现芯片细胞培养平台上的细胞代谢指纹快速可视化传感检测.     

微流控芯片药物诱导细胞凋亡

发展了一种以微流控芯片为平台的药物诱导细胞凋亡的新方法.选择HeLa细胞为对象,通过浓度梯度芯片形成稳定的药物浓度梯度,诱导HeLa细胞凋亡,利用荧光能量共振转移（fluorescence resonance energy transfer,FRET）成像系统进行实时监测,分析细胞对不同浓度化合物的毒性反应.结果表明,细胞在顺铂诱导下发生明显的起泡和皱缩,FRET比率值逐渐降低,在药物浓度梯度作用下,芯片每个通道内细胞呈现不同程度的凋亡.该方法实现了药物浓度梯度诱导细胞凋亡的实时监测和定量分析,为抗肿瘤药物评价和高通量药物筛选提供了新的手段.     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.