癌细胞细胞周期自体荧光谱特征

为了研究癌细胞自体荧光光谱在细胞周期变化过程中是否发生变化,对同步化培养的宫颈癌细胞(HeLa)在细胞周期各时相(G1期,S期,G2期和M期)样品的自体荧光谱进行了测最.测量结果表明,HeLa细胞在细胞周期变化过程中有自体荧光现象存在,其特征荧光峰位于360 nm和680 nm处,且各时相样品的荧光光谱强度各不相同.这些差异说明HeLa细胞在细胞周期变化过程中细胞内荧光物质(含芳香族氨基酸和卟啉)产生了相应的变化从而导致了不同时相的荧光光谱强度的差异.细胞周期各时相的荧光光谱能够反映细胞生长变化过程中芳香族氨基酸和卟啉的变化,可为采用光谱技术对痛细胞生长周期进行研究提供依据.     

基于超短脉冲的癌细胞荧光光谱

研究用于癌症诊断与治疗的光敏剂血卟啉(hematoporphyrin derivative,HPD)的超快光动力学过程。采用超短脉冲激光光谱技术和皮秒时间相关单光子计数系统,测量经血卟啉培养的活体癌细胞与正常细胞的荧光光谱、荧光寿命特性及荧光峰值强度随时间的变化,观测到:癌细胞样品在645nm处具有特征发射光谱峰;癌细胞与正常细胞样品荧光寿命的快成分分别为150,300ps;癌细胞与正常细胞的荧光峰值强度经12h分别衰减10%和55%。对测量所得的荧光光谱曲线及时间分辨荧光衰减曲线分析,计算出:在癌细胞内部血卟啉浓度增大了约2个数量级;癌细胞与正常细胞的荧光寿命分别为824,1798ps;血卟啉在癌细胞与正常细胞样品中滞留时间分别为17,6d。测量结果确认了荧光光谱技术诊断与治疗癌症的可行性,并对发展超短脉冲激光光谱技术早期诊断与治疗癌症具有重要的指导意义和临床应用价值。     

胃癌细胞显微后向散射光谱分析

为了实验分析单个人正常胃上皮细胞与癌变细胞显微后向散射光谱的区别,结合光纤共聚焦显微成像技术和细胞散射理论,建立了一套基于光纤共聚焦的细胞检测显微光谱分析装置。该装置能够同时获取细胞显微图像和显微光谱医学信息。利用该装置测量了贴壁正常胃上皮细胞GES-1和癌变胃上皮细胞NCI-N87,得到了这两种细胞株细胞水平的显微光谱特性,其光谱具有明显的区别,说明该装置能够在细胞水平上辨别正常和癌变细胞的显微光谱。所得到的正常和癌变胃上皮细胞的显微后向散射光谱曲线与现有单核细胞散射分析结果一致,为以后的细胞水平检测癌变研究提供了必要的基础。     

单个鼻咽癌细胞的拉曼光谱分析的研究

利用激光镊子拉曼光谱系统研究了鼻咽癌细胞株和正常人鼻咽部气道上皮细胞株的单个细胞的拉曼光谱,对于每个细胞在不同部位测3个点。结果显示：正常细胞和癌细胞的平均拉曼光谱有显著差异：正常的细胞光谱强度比癌细胞的明显要高;正常细胞的1304和1336 cm-1处峰的强度比值为1.05,癌细胞的为1.22。用PCA主成分分析和DFA判别分析分别对单个细胞的平均光谱和不同位置所取得的单独光谱进行分析,结果发现：PCA和DFA均可以把癌细胞和正常细胞正确区分,对于单独光谱,DFA的效果更好一些。同时还发现同一个细胞中不同的光谱位置对PCA和DFA的区分度影响不是很大;PCA和DFA的图中还表明癌细胞的均匀度要比正常细胞的差。以上的研究均表明：激光镊子拉曼光谱可以成为区别正常鼻咽细胞和鼻咽癌细胞的有效手段。     

用激光拉曼光谱区分胃癌变细胞与正常细胞

利用激光拉曼光谱对胃癌细胞及正常胃细胞进行了对比检测,对胃癌细胞特征拉曼峰作了初步探讨,发现胃癌患者标本的特征拉曼峰与非胃癌患者标本的光谱有明显的不同。实验发现,浓度为每mL 1.25×105个胃癌细胞的样品在经过若干天培养后均能够被检测出胃癌细胞的特征拉曼峰,分别位于特定波长583,633,656 nm处。这是几个很少见诸报道的新拉曼光谱峰。不论是特征拉 曼峰,还是在胃癌细胞及正常胃细胞的几个共有的拉曼峰674, 707, 773, 799 nm处,拉曼光谱强度都是随血清中癌细胞浓度的增加而增加。激光拉曼光谱分析有可能发展成为一种快速有效的癌细胞检测方 法。     

基于皮秒时间分辨的癌细胞荧光寿命研究

研究了用于癌症诊断与治疗的光敏剂血卟啉(hematoporphyrin derivative,HPD)的超快光动力学过程,采用超短脉冲激光光谱技术和皮秒时间相关单光子计数系统,测量了经血卟啉培养的活体癌细胞与正常细胞的皮秒时间分辨荧光光谱及荧光峰值强度随时间衰变曲线,观测到：癌细胞与正常细胞样品荧光寿命的快成分分别为150和300 ps;癌细胞与正常细胞的荧光峰值强度经12 h分别衰减10%和55%。经对测量所得的荧光衰减曲线进行分析,计算出癌细胞与正常细胞的荧光寿命分别为824和1798 ps;血卟啉在癌细胞与正常细胞样品中滞留时间分别为17天和6天。结果表明癌细胞与正常细胞对血卟啉亲和性及对血卟啉滞留的稳定性有显著差异,测量结果确认了荧光光谱技术诊断与治疗癌症的可行性,并对实时监测生物样品微弱超快荧光具有重要的指导意义和临床应用价值。     

染色体的显微光谱

利用显微光谱技术在可见光范围内测定了蚕豆根尖染色体，小白鼠髓细胞染色体和小白鼠骨髓细胞微核的光谱，其光谱形状各具有特征，峰值亦有差异。     

肝癌细胞和正常肝细胞的自体荧光光谱研究

利用荧光光纤传感器来检测癌症必须弄清楚肝癌细胞与正常肝细胞是否具有不同的荧光特征.在体外培养了SMMC-7721肝癌细胞和HL-7702正常肝细胞,然后用荧光光谱仪对它们的自体荧光进行检测.结果表明,两种细胞的自体荧光发射光谱在550～720 nm范围内发射峰的数目和峰位均相间(602 nm和691 nm),只是主峰的波形略有差异.在720～800 nm范围内,肝癌细胞有一特征荧光峰,峰位置在734 nm附近,而正常肝细胞则无此峰.通过对多代培养的细胞进行荧光光谱测试,发现两种细胞的荧光光谱特征在细胞传代的过程中保持不变,说明细胞中的荧光特征在传代过程中保持稳定.这两方面的实验为利用荧光光纤传感器来检测癌症提供了一定的参考.     

用于胃癌早期检测的可见光显微光谱研究

反射光谱技术在早期癌症检测中具有非常好的应用前景。对比常见的漫反射可见光谱技术,可见光显微光谱技术能够获取细胞大小范围内的信息,而且不受探头结构差异导致的传输光程长短,以及测量时探头施加压力导致的血红蛋白浓度异常变化的影响。基于光纤共聚焦显微系统,建立了可见光显微光谱实验装置,测量了离体正常和癌变胃组织的显微光谱,给出了样品在600-700nm波长范围内的显微光谱分布情况,实验结果表明可见光显微光谱技术简单、有效,可用于胃癌的早期检测。     

基于拉曼光谱的微重力三维培养条件下的人HepG2细胞的研究

采用一个波长为785 nm的半导体激光束来囚禁人的肝癌细胞并激发人的肝癌细胞的拉曼光谱,分析模拟微重力三维培养条件下的人肝癌细胞的DNA、蛋白和脂类的生物学物质的变化和表达情况。结果显示,微重力三维培养条件下和平面培养下的人的肝癌细胞的拉曼光谱在527,1 367,1 438,1 659 cm-1处有明显的差异。     

Determining the effective density of airborne nanoparticles using multiple charging correction in a tandem DMA/ELPI setup

The cysteamine-modified hyaluronic acid (HA) polymer was employed to coat quantum dots (QDs) through a convenient one-step reverse micelle method, with the final QDs hydrodynamic size of around 22.6 nm. The HA coating renders the QDs with very good stability in PBS for more than 140 days and resistant to large pH range of 2–12. Besides, the HA-coated QDs also show excellent fluorescence stability in BSA-containing cell culture medium. In addition, the cell culture assay indicates no significant cytotoxicity for MD-MB-231 breast cancer cells, and its targeting ability to cancer receptor CD44 has been demonstrated on two breast cancer cell lines. The targeting mechanism was further proved by the HA competition experiment. This work has established a new approach to help solve the stability and toxicity problems of QDs, and moreover render the QDs cancer targeting property. The current results indicate that the HA polymer-coated QDs hold the potential application for both in vitro and in vivo cancer imaging researches.     

Effect of small peptide(P-15) on HJMSCs adhesion to hydroxyap-atite

P-15, a synthetic peptide of 15-amino acids, has been tested in clinical trials to enhance cell adhesion and promote osseointe-gration. This feature of P-15 has also inspired the development of designing new bone substitute materials. Despite the increasing applications of P-15 in bone graft alternatives, few studies focus on the mechanism of cell adhesion promoted by P-15 and the mechanical property changes of the cells interacting with P-15. In this article, we used atomic force microscope(AFM) based single cell indentation force spectroscopy to study the impact of P-15 on the stiffness and the adhesion ability of human jaw bone mesenchymal stem cells(HJMSCs) to hydroxyapatite(HA). We found that the stiffness of HJMSCs increases as the concentration of P-15 grows in short culture intervals and that the adhesion forces between HJMSCs and HA particles in both the presence and absence of P-15 are all around 30 p N. Moreover, by calculating the binding energy of HJMSCs to HA particles mixed with and without P-15, we proved that P-15 could increase the adhesion energy by nearly four times. Scanning electron microscope(SEM) was also exploited to study the morphology of HJMSCs cultured in the presence and absence of P-15 on HA disc surface for a short term. Apparent morphological differences were observed between the cells cultured with and without P-15. These results explain the probable underlying adhesion mechanism of HJMSC promoted by P-15 and can serve as the bases for the design of bone graft substitute materials.     

“组合—矩阵法”推算j—j耦合谱项

首次应用组合一矩阵法推引ｊ－ｊ耦合谱项。     

Hyaluronan in the epidermal and the dermal extracellular matrix: its role in cutaneous hydric balance and integrity of anuran integument

New researches have revealed that hyaluronan (HA) is not a passive molecule. HA has being pointed out to participate in many processes, such as cell interactions, proliferating and migrating cell events and function as hydrate agent. The present study was undertaken to localize HA in Bufo ictericus integument providing a better understating for the role of cutaneous HA. Paraffinized sections were stained with haematoxylin-eosin and with 1% Alcian blue 8GX at pH 1.0 and 2.5. Alcianophilic reaction was visualized in both spongious dermis and Eberth-Katschenko layer. The mucus cells of mucus glands were also stained with AB methods. Besides these histological techniques, the localization of HA was performed using the FITC-labeled HA probe labeled with fluorescein isothiocyanate. In the extracellular matrix of spongious dermis, the reaction for HA was evident, being less intense in hypodermis and in pericellular keratinocyte matrix of the cornified tubercles regions. Thus, since HA was localized in the pericellular epidermal matrix and in the spongious dermis of anuran integument, it plays an important role in hydric balance, and is essential for integument integrity and functionality.     

人体血液白细胞的显微光谱

采用显微光谱技术，得到了正常人及白血病患者的白细胞在可见光范围的光谱。结果显示，淋巴细胞和粒细胞的显微光谱各具特征，不同类型的白血病患者的淋巴细胞和粒细胞的显微光谱与正常人的相比也不同。结果不仅实现了白细胞的显微光谱学分类，而且可能为临床医学提供参考。     

一种数字化高灵敏度荧光显微镜及其在竹红菌甲素研究中的应用

研制了一种可探测细胞微弱光图像的数字化高灵敏度荧光显微镜，采用视频数字化增强型ＣＣＤ系统作为高灵敏度的接收系统，像增强器亮度增益为４１，０００，因而这种荧光显微镜可探测到普通荧光显微镜不能观察的微弱光图像，并可减少荧光物质的浓度和激发光的强度，减少对细胞自然生理环境的影响，数字化高灵敏度荧光显微镜在给出细胞微弱荧光图像的同时，并可给出图像上每一像元的发光强度和细胞平均发光强度，使用此仪器已首次直接     

Degradable Nanomotors Using Platinum Deposited Complex of Calcium Carbonate and Hyaluronate Nanogels for Targeted Drug Delivery

Recently, micro/nanomotor systems have been widely investigated for biomedical applications especially for the active transport and delivery of specific drugs. However, there are few stimuli-responsive micro/nanomotor systems to enhance the drug delivery efficiency and reduce side effects by the spatiotemporal controllability. Here, a degradable nanomotor is first fabricated for targeted drug delivery using a platinum (Pt)-deposited complex of calcium carbonate and cuccurbit[6]uril-conjugated hyaluronate (Pt/CaCO₃@HA-CB[6]). The nanomotors could efficiently deliver model drugs to the cells in reactive oxygen species (ROS) abundant environments such as the tumor site. After reaching the tumor site around pH 6.5, Pt/CaCO₃@HA-CB[6] nanomotors (≈1 µm) are pH-responsively disintegrated by the dissociation of CaCO₃ and the encapsulated HA-CB[6] (≈300 nm) are released for cancer cell uptake. The released HA conjugate are finally uptaken into cancer cells via HA receptor-mediated endocytosis. Moreover, model drugs are modularly loaded into the nanomotors via the host–guest chemistry of CB[6] for stable delivery to cancer cells. Taken together, Pt/CaCO₃@HA-CB[6] nanomotors systems could be successfully harnessed for active drug delivery to cancer cells.     

Review of ferroelectric hydroxyapatite and its application to biomedicine*

ABSTRACT

Hydroxyapatite (HA) is a major component of bone in humans and animals. Until about 10 years ago, it was considered to have a centrosymmetric crystal structure and could not contribute to the well-known piezoelectric effect in bone. This review describes the theoretical and experimental studies that showed that HA does have a non-centrosymmetric structure. Recent experiments have shown that HA exhibits piezoelectricity, pyroelectricity, and ferroelectricity. It has been made in the form of thick films and as space-charge electrets. It has an important biomedical application as an implant for bone cell attachment and growth.     

Effects of hydroxyapatite nanoparticles on proliferation and apoptosis of human breast cancer cells (MCF-7)

The study aimed to correlate cell proliferation inhibition with oxidative stress and p53 protein expression in cancerous cells. Hydroxyapatite (HAP) (Ca₁₀(PO₄)₆(OH)₂) is the essential component of inorganic composition in human bone. It has been found to have obvious inhibitory function on growth of many kinds of tumor cells and its nanoparticle has stronger anti-cancerous effect than macromolecule microparticles. Human breast cancer cells (MCF-7) were cultured and treated with HAP nanoparticles at various concentrations. Cells viability was detected with MTT colorimetric assay. The morphology of the cancerous cells was performed by transmission electron microscopy and the expression of a cell apoptosis related gene (p53) was determined by ELISA assay and flow cytometry (FCM). The intracellular reactive oxygen species (ROS) level in HAP exposed cells was measured by H₂DCFDA staining. DNA damage was measured by single-cell gel electrophoresis assay. The statistical analysis was done by one way ANOVA. The cellular proliferation inhibition rate was significantly (p < 0.05) increasing in a dose-dependent manner of HAP nanoparticles. Cell apoptotic characters were observed after MCF-7 cells were treated by HAP nanoparticles for 48 h. Moreover, ELISA assay and FCM shows a dose-dependent activation of p53 in MCF-7 cells treated with nanoHAP. These causative factors of the above results may be justified by an overproduction of ROS. In this study, a significant (p < 0.05) increase in the level of intracellular ROS in HAP-treated cells was observed. This study shows that HAP inhibits the growth of human breast cancer MCF-7 cells as well as induces cell apoptosis. This study shows that HAP NPs Induce the production of intracellular reactive oxygen species and activate p53, which may be responsible for DNA damage and cell apoptosis.     

In situ Raman spectroscopic monitoring of hydroxyapatite as human mesenchymal stem cells differentiate into osteoblasts

The differentiation of stem cells into specific cell types is playing an essential role in the development of stem cell therapy, tissue engineering, and regenerative medicine. In this research, Raman microspectroscopy was applied to monitor the development of hydroxyapatite [HA, Ca₅ (PO₄)₃ (OH)], which is associated with the differentiation of the human mesenchymal stem cells (hMSCs) into osteoblasts. Raman spectra exhibited dramatic changes in the HA region, 950–970 cm⁻¹, over the period of 7–21 days after the start of differentiation. This work demonstrates the successful application of Raman spectroscopy for monitoring and quantitatively evaluating hMSC differentiation into osteoblasts. Copyright © 2008 John Wiley & Sons, Ltd.