Liquid crystallinity in collagen systems in vitro and in vivo

Collagens are unique triple helical proteins present in large quantities in a fibrillar form in tissues like tendon, bone, skin, cornea, where type I collagen predominates. The passage from triple helical molecules to fibrils obeys to controlled assembly properties, both in vitro by pH raise and in vivo through enzymatic control. The passage from individual fibrils to ordered fibrillar arrays could rely on self-assembly processes as suggested by the liquid crystalline properties of collagen. The present review considers this question recalling the liquid crystalline ordering properties of collagen or procollagen at high concentrations and the question of molecular packing within fibrils. The presence of alignments, undulations and twist at a suprafibrillar level will be described both from basic data in living tissues and recent experiments in self assembled materials. The possible link between laboratory experiences and biological processes will be discussed.     

新型四氢萘类化合物合成及体外抗真菌活性研究

根据真菌羊毛甾醇14α-去甲基化酶的三维结构模型设计、合成了48个新型四氢萘类化合物, 所有化合物的结构经过IR, ¹H NMR和MS确证. 体外抗真菌活性研究表明所有化合物对7种临床致病真菌都有抗真菌活性, 特别是化合物18, 21, 22, 24的抗真菌活性最强. 对接研究显示设计的先导化合物与靶酶活性腔中氨基酸功能残基结合, 作用模式不同于氮唑类化合物. 结果表明新型四氢萘类化合物是一类全新结构类型的抗真菌化合物.     

Impact and mechanism of TiO2 nanoparticles on DNA synthesis in vitro

The impact of TiO₂ nanoparticles on DNA synthesis in vitro in the dark and the molecular mechanism of such impact were studied. The impact of TiO₂ nanoparticles on DNA synthesis was investigated by adding TiO₂ nanoparticles in different sizes and at various concentrations into the polymerase chain reaction (PCR) system. TiO₂ nanoparticles were premixed with the DNA polymerase, the primer or the template, respectively and then the supernatant and the precipitation of each mixture were added into the PCR system separately to observe the impact on DNA synthesis. Sequentially the interaction between TiO₂ nanoparticles and the DNA polymerase, the primer or the template was further analyzed by using UV-visible spectroscopy and polyacrylamide gel electrophoresis (PAGE). The results suggest that TiO₂ nanoparticles inhibit DNA synthesis in the PCR system in the dark more severely than microscale TiO₂ particles at the equivalent concentration and the inhibition effect of TiO₂ nanoparticles is concentration dependent. The molecular mechanism of such inhibition is that in the dark, TiO₂ nanoparticles interact with the DNA polymerase through physical adsorption while TiO₂ nanoparticles do with the primer or the template in a chemical adsorption manner. The disfunction levels of the bio-molecules under the impact of TiO₂ nanoparticles are in the following order: the primer > the template > the DNA polymerase. Supported by the National Natural Science Foundation of China (Grant Nos. 50572074 & 50673078), the Shanghai Key Fundamental Project (Grant No. 06JC14068) and the Innovation Program of Shanghai Municipal Education Commission (Grant No. 08ZZ21)     

20 （S） -20-O- Camptothecin β-Aminopropionate： Novel Synthesis and Antitumor Activity in vitro

IntroductionCamptothecin(CPT,1, Scheme 1), a pentacyclicalkaloid isolated from theCamptotheca acuminatebyWallet al. in 1966, shows a broad-spectrum antitumoractivity[1]. However, because of its lowwater solubilityand high toxicity, its clinical applicatio…     

Impact of Arsenic Trioxide on LS-174T Cell Growth and the Activity of Telomerase

The therapeutic action of arsenic trioxide（ As203 ） on solid tumors has aroused widespread interest among scholars. To study the impact of As2O3 on human colorectal carcinoma cells（ LS-174T cell） and the activity of telomerase, the methods of PCR-ELISA, flow cytometry （FCM） and MTT assay in vitro were utilized. The results show that （1） with an increase in the concentration of As2O3, the ratio of living the cells to dead cells decreases significantly, and the IC50 value is 5.23 μg/mL; （2） the cells of the experimental groups can endure a series of morphological changes similar to the features of apoptosis ; （3） the apoptotic curves of FCM pictures appear after 24 h, and the cells show the apoptosis in a time-dependent manner; （4） As2O3 can inhibit the activity of telomerase of the cell extraction obviously in a concentration-dependent and time-dependent manner after 24 h. It can be concluded from the experiment results in vitro that As2O3 can induce the apoptosis of LS-174T cells and inhibit the telomerase activity. Therefore, it has been proposed, for the first time, that these two factors （the apoptosis of LS-174T cells and the inhibition to the telomerase activity） are important causes of the LS-174T cell death caused by As2O3.     

A ratiometric near-infrared naphthalimide-based fluorescent probe with high sensitivity for detecting Fe2+ in vivo

Iron is one of the essential trace elements in the human body. It plays an important role in human biology and pathology. Deregulation of iron levels in cells is associated with disease development. In this work, we synthesized a novel near-infrared intramolecular charge transfer (ICT) based ratiometric fluorescent probe to detect Fe²⁺, by using naphthalimide and indole moieties as building blocks. Our work showed that the radiometric probe has excellent selectivity, sensitivity and rapid response. Moreover, we could successfully perform real-time monitoring of Fe²⁺ in HeLa cells and C. elegans.     

伐地那非衍生物的合成和体内活性评价

首次完成了伐地那非衍生物—2-[2-乙氧基-5-(4-乙基-哌嗪-1-磺酰基)-吡啶]-5-甲基-7-丙基-3H-咪唑[5,1-f]-三 嗪-4-酮(1)的合成, 并且对其进行了家兔阴茎勃起的体内实验, 结果表明该化合物无壮阳作用.     

In vitro macrophage uptake and in vivo biodistribution of long-circulation nanoparticles with poly(ethylene-glycol)-modified PLA (BAB type) triblock copolymer

The effect of the PEG-grafted degree in the range of 0–30% on the in vitro macrophage uptake and in vivo biodistribution of poly(ethylene glycol)–poly(lactic acid)–poly(ethylene glycol) (PELE) nanoparticles (NPs) were investigated in this paper. The prepared NPs were characterized in terms of size, zeta potential, hydrophilicity, poly(vinyl alcohol) (PVA) residual on nanoparticles surfaces as well as drug loading. The macrophage uptake and biodistribution including plasma clearance kinetics following intravenous administration in mice of the NPs labeled by 6-coumarin were evaluated. The results showed that, except for the particles size, the hydrophilicity, superficial charges and in vitro phagocytosis amount of NPs are dependent on the PEG content in the copolymers greatly. The higher of the PEG content, the more hydrophilicity and the nearer to neutral surface charge was observed. And the prolonged circulation half-life (t_1/2) of the PELE NPs in plasma was also strongly depended on the PEG content with the similar trend. In particular for PELE30 (containing 30% of PEG content) NPs, with the lowest phagocytosis uptake accompanied the highest hydrophilicity and approximately neutral charge, it had the longest half-life in vivo with almost 12-fold longer and accumulation in the reticuloendothelial system organs close to 1/2-fold lower than those of reference PLA. These results demonstrated that the PELE30 NPs with neutral charge and suitable size has a promising potential as a long-circulating oxygen carrier system with desirable biocompatibility and biofunctionality.     

高通量虚拟筛选CDK2/Cyclin A2靶点抑制剂

CDK2/Cyclin A2复合蛋白的异常表达与乳腺癌、 口腔癌、 食管鳞状细胞癌的发生密切相关. CDK2/ Cyclin A2复合蛋白的活性位点不同于CDK2单体. 至今临床上尚无靶向此复合蛋白的药物分子. 针对CDK2/Cyclin A2复合蛋白, 以实验报道的10个抑制剂分子构建药效团模型, 通过药物体外药代动力学（ADME）、 Docking、 聚类分析、 毒性预测, 从DrugBank, ChEMBL和TCM@Taiwan 3个数据库约90万组数据中进行高通量虚拟筛选, 进一步进行MD模拟、 MM/PBSA结合自由能计算、 能量分解和平均非共价作用(aNCI)分析, 筛选出3个抑制效果优于阳性实验药Roscovitine的先导分子: DrugBank-2004, DrugBank-583和ChEMBL-7122. 与CDK2蛋白相比, CDK2/Cyclin A2复合蛋白结合位点空间变大, 先导分子与Lys33, Asp86, Lys129和Asp145残基之间的排斥作用有所降低, 导致结合自由能更大.     

CaF2对硅酸三钙的制备及其生物活性的影响

采用固相反应制备不同CaF掺量的生物活性硅酸三钙(3CaO·SiO22,C3S),并研究CaF2对C3S的制备及生物活性的影响.化学滴定、TGA/DTA、XRD、SEM和FTIR的分析结果表明,在煅烧过程中,CaF2有效的促进CaCO3的分解,并能形成低共熔化合物,促进C3S的形成;存急冷过程中,CaF2抑制CS晶型转变和分解,CaF2有效提高固相反应制备C§的纯度;模拟体液(SBD浸泡实验结果表明掺与小掺CaF2的C3s表面分别在1 d和3 d内诱导形成诱导磷厌石,这表明掺CaF2可以提高C3S的生物活性.     

Recent advances in the development of activatable multifunctional probes for in vivo imaging of caspase-3

Caspases are a family of proteases that play critical roles in controlling inflammation and cell death.Apoptosis is a caspase-3 mainly controlled behavior to avoid inflammation and damage to surrounding cells,whereas anomalistic cell apoptosis may be associated with many diseases.The detection and imaging of caspase-3 will be of great significance in evaluating the early therapeutic effect of tumors.Developing smart fluorescent probes may be helpful for the visualization of the rapeutic effect compared with "always on" probes.Thus,more and more works toward activatable fluorescent probes for caspase-3 imaging have been reported.In addition,multifunctional probes have also been designed to further improve the imaging of caspase-3.Herein,this review systematically summarized the representative wo rk of caspase-3 from the perspective of molecular design that it will play a guiding role in the design of probes that respond to caspase-3.Also,challenges and perspectives toward the field for imaging of cell apoptosis(caspase-3) are also discussed.     

α-Tocopherol-loaded Ca-pectinate microcapsules: Optimization, in vitro release, and bioavailability

We used response surface methodology to optimize microcapsule preparation conditions, including the ratio of pectin:α-tocopherol (TP) (X₁), emulsifier concentration (X₂), and CaCl₂ concentration (X₃) for maximal entrapment efficiency (EE) of TP-loaded Ca-pectinate microcapsules. The values of X₁, X₂, and X₃, optimized for maximal EE were a ratio of 9.7:6.3, and 1.33% and 5.09%, respectively. The experimental results obtained from the optimum formulation agreed with the predicted results, indicating the usefulness of models for EE. TP release from the Ca-pectinate microcapsules prepared according to the optimized conditions was slow and incomplete in simulated gastric fluid, whereas it was relatively rapid and considerably sustained in simulated intestinal fluid. An in vivo release study revealed that physical entrapment of TP within Ca-pectinate microcapsules can be a good technique to demonstrate the sustained release pattern of TP and to improve the bioavailability for TP following oral administration.     

三有机锡(4R)-3-[[(2S)-5-氧-2-吡咯烷基]羰基]-4-噻唑烷甲酸酯的合成、结构和体外抗癌活性

利用三有机锡氢氧化物和手性配体(4R)-3-[[(2S)-5-氧-2-吡咯烷基]羰基]-4-噻唑烷甲酸(HL)反应合成了3个三有机锡(4R)-3-[[(2S)-5-氧-2-吡咯烷基]羰基]-4-噻唑烷甲酸酯R3SnL[1,R=c-C6H11(a),C6H5(b),C6H5C(CH3)2CH2(c)],通过元素分析、IR、1H NMR和X-射线单晶衍射表征了其结构。化合物1a属正交晶系,P212121空间群;化合物1b属单斜晶系,P21空间群。二者均为由羧基氧和内酰胺羰基氧桥联配位形成的右螺旋链状有机锡配位聚合物,锡原子具有五配位[SnC3O2]畸变三角双锥构型。化合物1a和1b对体外2种人癌细胞Colo205和Bcap37增殖均有强的抑制作用,其活性为1b1a。     

氨基糖衍生物二丁基锡配合物的合成、结构表征和生物活性

分别由2-[(2Z)-3-羧基-1-氧代-2-丙烯基]氨基-2-脱氧-1,3,4,6-四-O-乙酰基-β-D-吡喃葡萄糖(1a), 2-[(2-羧基苯甲酰基)氨基]-2-脱氧-1,3,4,6-四-O-乙酰基-β-D-吡喃葡萄糖(2a)和氧化二正丁基锡反应合成了两个新化合物双-{2-[(2Z)-3-羧基-1-氧代-2-丙烯基]氨基-2-脱氧-1,3,4,6-四-O-乙酰基-β-D-吡喃葡萄糖}-二正丁基锡酯(1)和双-{2-[(2-羧基苯甲酰基)氨基]-2-脱氧-1,3,4,6-四-O-乙酰基-β-D-吡喃葡萄糖}-二正丁基锡酯(2), 并经红外光谱、核磁共振(¹H, ¹³C NMR)、质谱初步确定了其结构. 体外抗肿瘤活性结果表明, 化合物1对人肺癌细胞株A-549和人肝癌细胞株BEL-7402的细胞毒活性显示为强效; 而对小鼠白血病细胞株P388和人白血病细胞株HL-60的细胞毒活性为弱效. 化合物2对肿瘤细胞株HL-60, A-549和BEL-7402具有强效的细胞毒活性; 而对肿瘤细胞株P388的作用则为弱效. 克隆基因分析表明化合物1和2在3.82×10^－6 和 3.02×10^－6 mol/L均具有造血细胞毒性.     

二[三(2-甲基-2-苯基)丙基锡]二元酸酯(CH2)n[CO2Sn(CH2CMe2Ph)3]2(n=2,3,4)的合成、结构及体外抗癌活性

丁二酸、戊二酸和己二酸分别与μ-氧-双[三(2-甲基-2-苯基)丙基]锡反应,合成了3个二[三(2-甲基-2-苯基)丙基锡]二元酸酯(CH₂)_n[CO₂Sn(CH₂CMe₂Ph)₃]₂(n=2(1),3(2),4(3))。对化合物1~3进行了元素分析、红外光谱及核磁共振(¹H,¹³C)表征,并通过X-射线晶体衍射分析测定晶体结构。化合物中锡与配基原子构成畸型四面体构型。试验表明,化合物2和3均对人癌细胞Colo205、HepG2、MCF-7、Hela、NCI-H460的增殖具有较强的抑制作用。     

二[三(2-甲基-2-苯基)丙基锡]二元酸酯(CH2)n[CO2Sn(CH2CMe2Ph)3]2(n=2, 3, 4)的合成、结构及体外抗癌活性

丁二酸、戊二酸和己二酸分别与μ-氧-双[三(2-甲基-2-苯基)丙基]锡反应, 合成了3个二[三(2-甲基-2-苯基)丙基锡]二元酸酯(CH₂)_n[CO₂Sn(CH₂CMe₂Ph)₃]₂(n=2 (1), 3 (2), 4 (3))。对化合物1~3进行了元素分析、红外光谱及核磁共振(¹H, ¹³C)表征, 并通过X-射线晶体衍射分析测定晶体结构。化合物中锡与配基原子构成畸型四面体构型。试验表明, 化合物2和3均对人癌细胞Colo205、HepG2、MCF-7、Hela、NCI-H460的增殖具有较强的抑制作用。     

DyCl_3对原代培养的成骨细胞增殖、分化和矿化功能表达的影响(英文)

采用MTT法、碱性磷酸酶活性测定、油红O的染色和定量测定、矿化功能的测定以及qRT-PCR等手段在细胞和分子水平上研究了DyCl3对原代培养的成骨细胞增殖、分化和矿化功能的影响。研究结果表明,在测试浓度范围内,DyCl3均抑制成骨细胞增殖。浓度为1×10-8,1×10-6和1×10-5mol·L-1的DyCl3促进成骨细胞分化。在测试浓度范围内,DyCl3均抑制成骨细胞横向分化为脂肪细胞。浓度为1×10-5mol·L-1的DyCl3促进成骨细胞矿化结节的形成,而浓度为1×10-7mol·L-1和1×10-6mol·L-1的DyCl3抑制成骨细胞矿化结节的形成,进一步降低浓度为1×10-8mol·L-1,它则对成骨细胞矿化功能没有影响。浓度1×10-6mol·L-1的DyCl3显著降低PPAR-γmRNA表达水平,但相同浓度DyCl3则显著上调RUNX-2mRNA表达水平。实验结果提示,DyCl3对体外培养的成骨细胞增殖、分化及矿化功能的影响与浓度和作用时间有关,而且,它们是影响其生物效应从毒性到活性,从损伤到保护,从上调到下调转变的关键因素。这些结果对深入理解稀土离子对骨代谢的影响具有重要的价值。     

Discovery of novel inhibitors of anti-apoptotic Bcl-2 proteins derived from Bim BH3 domain

The BH3 mimetics targeting the interaction between the BH3-only proteins and their prosurvival Bcl-2 family proteins have shown enormous potential as cancer therapeutics. Herein, seven analogues targeting anti-apoptotic Bcl-2 proteins derived from the Bim BH3 domain via sequence simplification and/or modification are described. The in vitro binding affinity on anti-apoptotic Bcl-2 proteins and cell killing activity were evaluated. The results showed that analogues could significantly bind to target proteins and exhibited anti-cancer effect against three cancer cell lines. Of particular interest were the analogue SM-5 (K_D=9.48 nmol/L for Bcl-2) and SM-6 (K_D=0.08 nmol/L for Bcl-x_L), which exhibited improved binding affinity compared with the lead Bim (K_D=16.90 nmol/L for Bcl-2 and 22.2 nmol/L for Bcl-x_L, respectively). These results indicated that the peptide sequence containing the four hydrophobic side chains occupying pockets within the BH3-recognition cleft of anti-apoptotic Bcl-2 proteins might be the minimum sequence required for the bioactivity and the active core region of Bim. Promising inhibitors of anti-apoptotic Bcl-2 proteins with high bioactivity might be designed based on the active core.     

FTIR and NMR study of poly(lactide-co-glycolide) and hydroxyapatite implant degradation under in vivo conditions

The influence of hydroxyapatite (HAP) addition on the rate and mechanism of lactide-co-glycolide copolymer (PGLA) degradation after implantation (in vivo study) was analyzed and compared with the process taking place during in vitro studies. Structural and phase changes of poly(lactide-co-glycolide) and its composite with hydroxyapatite were determined using IR and NMR spectroscopy.Degradation of PGLA and PGLA + HAP composite in biological environment proceeds faster than under in vitro condition. Concentration of glycolidyl units in the copolymer chain decreases and that of lactidyl units increases during in vivo degradation both, in PGLA and in PGLA + HAP composite. However, in the case of the composite the decrease of glycolidyl units concentration is slower and after 6 weeks of degradation the contents of lactidyl and glycolidyl units remain stable. On the other hand, PGLA + HAP composite degrades faster than pure PGLA. The addition of HAP nanoparticles distinctly accelerates degradation of PGLA copolymer which is probably connected with the increase of hydrophilicity of the composite and inhibition of semi-crystalline lactidyl domains formation during the degradation process. Observation of the bone tissue after implantation of PGLA + HAP allows to conclude that the degradation of the composite occurs simultaneously with the implant replacement by the bone cells.     

氯化镨对原代培养的小鼠成骨细胞增殖、分化和矿化功能的影响

采用噻唑蓝(MTT)法、碱性磷酸酶(ALP)比活性测定、油红O染色、I型胶原测定以及矿化结节染色及定量分析等方法 ,研究了不同浓度的氯化镨对原代培养的成骨细胞增殖、分化、矿化功能以及横向分化为脂肪细胞的影响。结果表明:氯化镨对成骨细胞增殖、分化、矿化功能以及横向分化为脂肪细胞的影响与作用浓度和时间密切相关,但没有呈现出时间和剂量依赖性。结果提示,氯化镨对骨代谢的影响是复杂的,其具有保护还是损害作用取决于作用浓度和时间。作用浓度和时间是影响氯化镨生物效应转变的关键因素。