Effects of graphene on the proliferation, migration and morphology of dental pulp stem cells / 口腔疾病防治

Objective@# To investigate the effects of graphene on the proliferation, migration and cell morphology of dental pulp stem cells (DPSCs).@*Methods@#Graphene powder was prepared by the oxidation-reduction method, and a 0.5 mg/mL graphene dispersion was prepared. Raman spectroscopy and atomic force microscopy were used to characterize the structure and surface morphology of graphene. DPSCs were isolated and cultured in vitro. MTT assay was used to detect the effects of different concentrations of graphene dispersions (0, 1, 5, 10, 20, 50, 100 μg/mL) on the proliferation and wound healing assay was used to detected the migration abilities of DPSCs. The effects of graphene on the morphology of DPSCs were observed by immunofluorescence staining. @*Results @# In the present study, compared with the control group (0 μg/mL), the proliferation of DPSCs in the 100 μg/mL group was inhibited at 72 h (P < 0.05), and the proliferation of DPSCs in the other groups was not significantly affected (P > 0.05). Graphene dispersions at 10 and 20 μg/mL promoted the migration of DPSCs (P < 0.05). After being cultured in 20 μg/mL graphene dispersions for 3 days, the DPSCs showed a large and orderly cytoskeletal structure, and the spread area of cells was not significantly different from that of the control group (0 μg/mL) (P > 0.05), while some cells had the morphological characteristics of nerve cells.@* Conclusion @# Graphene has good biocompatibility and is expected to be a suitable material for tissue engineering within fitting concentration.

Application of Raman Spectroscopy in the Diagnosis of Oral Cancer / 中国医学科学院学报

Oral cancer is a common and deadly malignancy.While multidisciplinary treatment(mainly surgery)has been applied in the treatment of cancer treatment,early diagnosis and complete removal of the primary lesion are essential for a better prognosis.Raman spectroscopy is an optical technique that detects inelastic scattered light generated by the interaction of light and matter.It can detect the vibrational spectra of biochemical and biomolecular structures and tissue conformations,and can provide the "molecular fingerprint" for cells,tissues,and biological fluids.With the development of related technologies and optical instruments,Raman spectroscopy has been widely applied in medical fields.This article reviews the research advances and application of Raman spectroscopy in the diagnosis of oral cancer.

Study of the chemical interaction between a high-viscosity glass ionomer cement and dentin

Abstract Objective To investigate the chemical interactions between a high-viscosity glass ionomer cement (GIC) (KetacTM Molar Easymix, 3M ESPE, Seefeld, Bavaria, Germany) and human dentin. It was also analyzed the dynamics of GIC setting mechanism based on the time intervals required for the GIC and the GIC mixed with dentin to achieve stability. Material and Methods Each constituent of GIC - powder (P) and liquid (L) - and powdered dentin (D), as well as the associations P+L, D+L, and P+L+D in the concentrations of 29%, 50%, 65%, 78%, 82%, and 92% of GIC were analyzed with Fourier transform infrared (FTIR) and Raman spectroscopy. Results New optical absorption bands and/or Raman bands, which were not present in P, L, or D, were observed in the associations. The concentrations of 29% and 50% of GIC showed higher interaction, revealing that the amount of dentin influences the formation of new optical absorption or scattering bands. FTIR bands showed that the setting time to achieve bond stability was longer for the high-viscosity GIC (38±7 min) than for the sample with 29% of GIC (28±4 min). Conclusions The analysis revealed the formation of new compounds or molecular rearrangements resulting from the chemical interactions between GIC and dentin. Moreover, this study provides an effective method to evaluate the dynamics of the setting mechanism of GICs.

Effect of the Bis-Dimethylamino Benzydrol Coinitiator on the Mechanical and Biological Properties of a Composite

Abstract To examine the effect of the alternative coinitiator 4,4'bis dimethylamino benzydrol (BZN) in degree of conversion (DC), mechanical and biological properties of experimental composites. The coinitiator BZN was used in three concentrations (0.2, 0.5 and 1.2%), and the coinitiator DMAEMA was used as control at the same concentrations as above. The molar concentration of camphorquinone (CQ) and coinitiators was kept constant (1:1). The composites were manipulated and submitted to microhardness test (VHN), flexural and compressive strength (in MPa), elastic modulus (GPa), DC (FT-IR) and in vitro cytotoxicity (against 3T3 fibroblastic cells) of the experimental resins. Data were subjected to two-way ANOVA and Tukey post-test (α=0.05). The experimental composite resin with BZN showed higher DC values compared to control DMAEMA groups. For the mechanical properties, microhardness values were higher in BZN groups; flexural strength and elastic modulus were similar between all the groups. Compressive strength for groups BZN0.5 and DMAEMA0.5 were not statistically different, being the lowest values attributed to group BZN0.2. The experimental resins with BZN and DMAEMA were considered nontoxic against 3T3 fibroblasts. The inclusion of the coinitiator BZN in experimental composites was considered nontoxic against 3T3 fibroblast cells, without compromising DC and mechanical properties.

Resumo Analisar o efeito do co-iniciador alternativo 4,4'bisdimetilaminobenzidrol (BZN) no grau de conversão (GC) e nas propriedades mecânicas e biológicas de resinas compostas experimentais. O co-iniciador BZN foi utilizado em três concentrações (0,2, 0,5 e 1,2), e o co-iniciador DMAEMA como controle, nas mesmas concentrações acima. A concentração molar entre canforoquinona (CQ) e os co-iniciadores foi mantida constante (1:1). As resinas compostas foram manipuladas e submetidas aos testes de microdureza (VHN), resistência à compressão e flexural (em MPa), módulo de elasticidade (em GPa), GC (em %, por meio de espectroscopia micro-Raman e FTIR com KBr), citotoxicidade in vitro (frente às células fibroblásticas 3T3) das resinas experimentais. Os resultados foram submetidos ao teste ANOVA 1 fator e pós-teste de Tukey (α=0,05). As resinas compostas experimentais com o BZN apresentaram GC e propriedades mecânicas satisfatórias, além de serem consideradas atóxicas a fibroblastos 3T3. A inclusão do co-iniciador BZN à resina composta foi considerada não tóxica frente a células fibroblásticas 3T3 e sem comprometer o grau de conversão e as propriedades mecânicas da mesma.

Glycerol Salicylate-based Pulp-Capping Material Containing Portland Cement

The purpose of this study was to evaluate the water sorption, solubility, pH and ability to diffuse into dentin of a glycerol salicylate-based, pulp-capping cement in comparison to a conventional calcium hydroxide-based pulp capping material (Hydcal). An experimental cement was developed containing 60% glycerol salicylate resin, 10% methyl salicylate, 25% calcium hydroxide and 5% Portland cement. Water sorption and solubility were determined based on mass changes in the samples before and after the immersion in distilled water for 7 days. Material discs were stored in distilled water for 24 h, 7 days and 28 days, and a digital pHmeter was used to measure the pH of water. The cement's ability to diffuse into bovine dentin was assessed by Raman spectroscopy. The glycerol salicylate-based cement presented higher water sorption and lower solubility than Hydcal. The pH of water used to store the samples increased for both cements, reaching 12.59±0.06 and 12.54±0.05 after 7 days, for Hydcal and glycerol salicylate-based cements, respectively. Both cements were able to turn alkaline the medium at 24 h and sustain its alkalinity after 28 days. Hydcal exhibited an intense diffusion into dentin up to 40 µm deep, and the glycerol salicylate-based cement penetrated 20 µm. The experimental glycerol salicylate-based cement presents good sorption, solubility, ability to alkalize the surrounding tissues and diffusion into dentin to be used as pulp capping material.

O objetivo deste estudo foi avaliar a sorção e solubilidade em água, pH e habilidade de difusão na dentina de um cimento para capeamento pulpar à base de glicerol salicilato e compará-lo a um cimento comercial para capeamento pulpar à base de hidróxido de cálcio (Hydcal). Um cimento experimental contendo 60% de resina de glicerol salicilato, 10% de salicilato de metila, 25% de hidróxido de cálcio e 5% de cimento Portland foi formulado. Sorção e solubilidade em água foram determinadas a partir da alteração na massa de espécimes antes e após a imersão em água destilada por 7 dias. Discos dos cimentos foram armazenados em água destilada por 24h, 7 dias e 28 dias e o pH da água foi aferido após cada período. A habilidade de difundir-se no interior de dentina bovina foi avaliada por espectroscopia Raman. O cimento à base de glicerol salicilato apresentou maior sorção e menor solubilidade em comparação com o Hydcal. O pH da água de armazenamento dos espécimes aumentou para ambos os cimentos, chegando a 12,59±0,06 e 12,54±0,05 após 7 dias, para o Hydcal e o cimento à base de glicerol salicilato, respectivamente. Os cimentos foram capazes de promover a alcalinização do meio após 24h e sustentaram a alcalinidade após 28 dias. Hydcal exibiu intensa difusão na dentina até 40 μm de profundidade e o cimento à base de glicerol salicilato penetrou 20 μm. O cimento experimental à base de glicerol salicilato apresentou adequada sorção, solubilidade, habilidade de alcalinizar o meio e difundir-se no interior da dentina para uso como um material para capeamento pulpar.

Investigation of Protective Effect of Phenethyl Alcohol Glycosides Extracted from Herba Cistanchis on Human Sperm DNA with Oxidative Damage by Raman Spectroscopy / 广州中医药大学学报

Objective To study the protective effect of phenethyl alcohol glycosides extracted from Herba Cistan-chis on human sperm DNA with oxidative damage by Raman spectroscopy. Methods The human sperm model of oxidative damage was induced with Fenton’s reagent in vitro. After co-cultured with the phenethyl alcohol gly-cosides extracted from Herba Cistanchis ( in the dosage of 0.1, 0.01 and 0.001 μg/mL) , the changes of the sperm nuclear DNA were observed by using confocal micro-Raman spectroscopy. Results The intensity and peaks of the Raman spectra of the human sperm nuclei treated by Fenton’s reagent were changed significantly, and then the changes of intensity and peaks were inhibited after treatment with phenethyl alcohol glycosides of Herba Cistanchis, the inhibition being dose-dependent. Conclusion The phenylethyl alcohol glycosides ex-tracted from Herba Cistanchis have protective effect on human sperm DNA with oxidative damage.

Identification of Norvasc and counterfeit drugs based on Raman spectra of phar-maceutical excipients / 药学实践杂志

Objective To build an identification method for Norvascand its counterfeit drugs based on the differences of their pharmaceutical excipients with the original and generic Amlodipine besylatetablets as tools .Methods Raman spectra of pharmaceutical excipients which were usually used in tablets were collected .Similarity algorithm and characteristic Raman bands were used to search the excipients contained in the tablets .If the excipients was not the same as excipients contained in Nor-vasc ,the tablet was judged as counterfeit drugs .Otherwise ,principal component analysis was used to identify counterfeit and generic .Results and conclusion The method based on Raman spectra of pharmaceutical excipients could identify Norvasc and counterfeit drugs efficiently and accurately .

Surface Enhanced Raman Scattering Spectrum Recognition for Trace Detection of Common Drugs in Urine / 分析化学

Assembling an adapted smoothing method and a classifier of wavelet transform combined support vector machine ( SVM) , a Raman spectrum recognition approach was built for low signal noise ratio situation. Firstly, spectra data were denoised by the adapted smoothing method. The smoothing window was adapted to the signal noise ratio, which would effectively remove noise with the intensity of the signal well remained. Secondly, the wavelet transform was used for dimension reduction of the data. The decomposition level of wavelet transform was optimized according to the best classification result of the training set. Lastly, SVM was used for classification. Cross Validation ( CV ) was applied to obtain the optimized parameters of SVM. Conditions for the effective parameters were searched considering the relation between the cross_validation result and the classification accuracy. Combined with the surface enhanced Raman scattering ( SERS ) technology , the developed spectrum recognition approach was used for qualitative analysis of methamphetamine ( MAMP ) and 3, 4_methylenedioxymethamphetamine ( MDMA ) in peopleˊs urine, where the detecting accuracy is above 95. 0%. The uniform Au nanorods (NRs) SERS substrate synthetized by the Hefei Institute of Intelligent Machines of Chinese Academy of Sciences was used for the experiment. Raman spectra were acquired using an Inspector Raman ( DeltaNu) spectrometer, with the excitation wavelength of 785 nm and the integrate time of 5 seconds.

Comparison of Surface Enhanced Raman Spectrum for Three Cephalosporins under Different pH Condi-tions / 中国药师

Objective:To study the Raman spectrum and the surface enhanced Raman spectrum ( SERS) of cefalexin, cefadroxil and cephradine, and analyze the surface enhanced Raman spectrum of the three compounds under different pH conditions. Methods:The Raman spectrum and the surface enhanced Raman spectrum of the three compounds under different pH conditions were detected and measured by a portable Raman spectroscopy. Results: The results showed that the three compounds could exhibit characteristic peak information in the surface enhanced Raman spectroscopy corresponding to that in the normal Raman spectrum, and the pH values had certain impact on the surface enhanced Raman spectrum of the three substances. Conclusion: Both the Raman spectrum and the surface enhanced Raman spectrum of cefalexin, cefadroxil and cephradine reflect certain fingerprint characteristics, and it is feasible to use Raman scattering method to identify the three cephalosporins.

Raman spectroscopy in determination of forsythin content / 第二军医大学学报

Objective: To compare the two parameters in Raman spectroscopy quantitative analysis, so as to confirm the optimal one. Methods: The ratios of peak intensity and peak area were taken as parameters in quantitative analysis. The contents of forsythin in forsythia suspense leaves gathered at different time points from different regions were analyzed with laser Raman spectroscopy. When the ratio of the peak intensity was taken as parameter, the Raman peak of forsythin (ρΛr-H [1 319.1 cm-1]) and the peak of methanol (νasCH3-O [2 974. 7 cm-1]) were selected as quantitative peak and internal standard reference peak in the confocal micro-Raman spectra of forsythin methanol solution. When the ratio of the peak area was taken as parameter, the Raman peak of forsythin ( ρΛr-H [1 319.1 cm-1]) and the peak of methanol (νsCH3-O[3 020. 9 cm-1]) were selected. The ratios of intensity and area were taken as ordinate, and the content of forsythin was taken as abscissa. The two standard curves were plotted and the linear and recoveries were compared. Results: Both parameters had good linear relationship with forsythin concentration, with the correlation coefficients being 0.998 0 and 0.997 6; the recoveries were 100.04%-101.30% and the recycling was complete. The linear fitting of the results with two parameters were measured, and the regression equation was C2=1.030 4C 1=0.033 1, r=0.999 6. The results obtained with the two parameters were accurate and were largely identical. Conclusion: Both the relative peak intensity and the ratio of the peak area can be used as parameters for forsythin quantitative analysis with Raman spectroscopy. And the two parameters can obtain largely identical results. Raman spectroscopy with internal standard is a simple and rapid method for quantitative analysis of forsythin, and it can be used for quantitative analysis for Chinese herbs.

Algorithms of Raman spectrium analysis in fast identification of counterfeit hypoglycemic agents / 第二军医大学学报

Objective: To investigate the applicability of portable Raman spectroscopy for fast identification of counterfeit hypoglycemic agents. Methods: The Raman spectra of 6 hypoglycemic agents, their corresponding reference standards and 12 common pharmaceutical excipients were detected by BW&-Tek i-Raman portable spectrometer. The spectra were analyzed by three algorithms, namely, the minimized summation of first derivative of subtraction spectra algorithm, local straight-line screening (LSLS) algorithm, and modified LSLS (MLSLS) algorithm. Results: Among the three algorithms, MLSLS algorithm showed the best performance, with the total sensitivity, specificity, accuracy and efficiency being 96.77% , 97.20% , 99.29%, and 96.02%, respectively. Conclusion: The MLSLS algorithm, which is based on infrared spectroscopy, can be adapted to identify suspected counterfeit drugs based on portable Raman spectroscopy.

Raman Tweezers Techniques in Different Cells Research / 中国医学物理学杂志

Objective: To introduce the Raman spectrum, the optical tweezers physical principle and its working characteristics, unify the detail medical research work, summarize specific application situation of the Raman tweezers technology in the different cells domain. Methods: Use the optical tweezers to fix the living cells, simultaneously carry out Raman spectrometry on the living cell or the cell organ by using the laser Raman technology. By applying this technology, the samples will be captured in the suspending liquid. In an approximate physiological state, the single living specimens, such as the cells, the cell organs or the biological macro-molecules, will be studied and the real-time track to the research object physiological biochemistry process will be carried on, then the Raman spectrometry will be implemented to the living cells. Results: From the single cell level, Raman tweezers technology analyzes the oxygen ability and the deformability of red blood cells of normal persons and the Mediterranean Sea anemia patients, and implements the appraisal of blood red cell and the blood platelet of different species. The Raman tweezers technology reveals the differences between the organizational structure of the cancer cells and that of normal cells in the molecular level, providing important information and data for the cancer diagnosis and the mechanism analysis. The Raman tweezers technology has implemented the torsion and knotting of DNA molecules, and realizes the control and differentiation of human being's chromosome. Conclusion: The Raman tweezers technology is the prompt and effective tool for the real-time research of cell physiology and biochemistry changes, hopefully in the molecular level. It will become one of the most advanced tools to carry out examination and diagnosis of different kind of living cell. Surely it has a very bright prospect.

Study on the changes of the protein conformation of gestational diabetes mellitus (GDM) placenta tissue by using Raman spectroanalysis / 中国糖尿病杂志

Objective To study the protein conformational change of placenta tissue by using Raman spectrum.Methods By using Raman spectroanalysis,we detected the placenta protein conformational change of GDM and control groups.Results(1)In the placenta of GDM,the absorption bands of tryptophan and phenylalanine were increased obviously.(2)In the placenta of GDM,the secondary structure of protein was composed of α-helix,random coil and β-sheet.Conclusions In the placenta of GDM,the orderly conformations of main chains in protein are decreased.Side chains of amino acids,especially tryptophan and phenyl-alanine,are changed greatly.The structure variation of protein may be correlated to the diabetic complications.