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raman imaging

Jihwan Son, Gawon Yi, Jihye Yoo, Changhee Park, Heebeom Koo, Hak Soo Choi
Nanoparticles (NPs) play a key role in nanomedicine in multimodal imaging, drug delivery and targeted therapy of human diseases. Consequently, due to the attractive properties of NPs including high stability, high payload, multifunctionality, design flexibility, and efficient delivery to target tissues, nanomedicine employs various types of NPs to enhance targeting and treatment efficacy. In this review, we primarily focus on light-responsive materials, such as fluorophores, photosensitizers, semiconducting polymers, carbon structures, gold particles, quantum dots, and upconversion crystals, for their biomedical applications...
October 12, 2018: Advanced Drug Delivery Reviews
Adam M Hanninen, Richard C Prince, Raul Ramos, Maksim V Plikus, Eric O Potma
We studied the use of vibrationally resonant, third-order sum-frequency generation (TSFG) for imaging of biological samples. We found that laser-scanning TSFG provides vibrationally sensitive imaging capabilities of lipid droplets and structures in sectioned tissue samples. Although the contrast is based on the infrared-activity of molecular modes, TSFG images exhibit a high lateral resolution of 0.5 µ m or better. We observed that the imaging properties of TSFG resemble the imaging properties of coherent anti-Stokes Raman scattering (CARS) microscopy, offering a nonlinear infrared alternative to coherent Raman methods...
October 1, 2018: Biomedical Optics Express
Chi Shu, Keren Chen, Maria Lynch, Jason R Maher, Hani A Awad, Andrew J Berger
Bone strength is a worldwide health concern. Although multiple techniques have been developed to evaluate bone quality, there are still gaps to be filled. Here we report a non-invasive approach for the prediction of bone strength in vivo using spatially offset Raman spectroscopy. Raman spectra were acquired transcutaneously from the tibiae of mice from 4 to 23 weeks old and subsequently on the exposed bones. Partial least squares regression was applied to generate predictions of the areal bone mineral density (aBMD), volumetric bone mineralization density (vBMD), and maximum torque (MT) of each tibia as quantified by dual-energy X-ray absorptiometry, microCT imaging, and biomechanical tests, respectively...
October 1, 2018: Biomedical Optics Express
Lenita Marangoni-Lopes, Gabriela Rovai-Pavan, Carolina Steiner-Oliveira, Marinês Nobre-Dos-Santos
OBJECTIVE: We aimed to evaluate whether radiotherapy causes changes in the mineral composition, hardness, and morphology of enamel and dentin of primary teeth. MATERIALS AND METHODS: Thirty specimens of primary teeth were subjected to radiotherapy. At baseline and after 1,080, 2,160, and 3,060 cGy, the specimens were subjected to microhardness, FT-Raman spectroscopy, and scanning electron microscopy (SEM) analysis. The pH of artificial saliva was determined, as were the calcium and phosphate concentrations...
October 12, 2018: Caries Research
Yanxiao Li, Congjie Wei, Chenglin Wu
Silver nanowire graphene (AgNW-GN) composite, as an alternative transparent conductive film (TCF) to conventional indium tin oxide (ITO), has much improved mechanical and electrical properties. These advantages make AgNW-GN an ideal TCF for planar devices. The adhesion of AgNW-GN composite film plays a critical role in these applications. However, the effect of silver nanowire on the adhesion between AgNW-GN and copper substrate remains unexplored. In the present work, AgNW-GN composite films with different AgNW concentrations were prepared and their adhesion with copper substrates was characterized using the double cantilever beam (DCB) experiment and the digital image correlation (DIC)...
October 6, 2018: Journal of Colloid and Interface Science
Xiaoxia Wu, Yan Peng, Xiaomei Duan, Lingyan Yang, Jinze Lan, Fu Wang
A large number of deaths from cancer can be attributed to the lack of effective early-stage diagnostic techniques. Thus, accurate and effective early diagnosis is a major research goal worldwide. With the unique phenomenon of localized surface plasmon resonance (LSPR), plasmonic nanomaterials have attracted considerable attention for applications in surface-enhanced Raman scattering (SERS) and metal-enhanced fluorescence (MEF). Both SERS and MEF are ultra-sensitive methods for the detection and identification of early tumor at molecular level...
October 11, 2018: Nanomaterials
Aparna Dravid U, Nirmal Mazumder
A cancerous cell is characterized by morphological and metabolic changes which are the key features of carcinogenesis. Adenosine triphosphate (ATP) in cancer cells is primarily produced by aerobic glycolysis rather than oxidative phosphorylation. In normal cellular metabolism, nicotinamide adenine dinucleotide (NADH) is considered as a principle electron donor and flavin adenine dinucleotide (FAD) as an electron acceptor. During metabolism in a cancerous cell, a net increase in NADH is found as the pathway switched from oxidative phosphorylation to aerobic glycolysis...
October 11, 2018: Lasers in Medical Science
Binge Deng, Xia Luo, Meng Zhang, Liming Ye, Yu Chen
Acyclovir (ACV) is a synthetic antiviral agent with serious side effect, particularly its nephrotoxicity, so this study was to explore the ultrasensitive detection of ACV by surface-enhanced Raman scattering (SERS). The enhancement capability of nanoparticles prepared by different chemical reduction were compared, and Ag nanoparticles reduced by citrate are the most propriate enhanced substrate for acyclovir. In addition, comparison between prominent SERS-enhanced bands and the precise mode descriptions predicted through density functional theory (DFT) simulations is used to understand the mechanisms between ACV and metallic surface...
September 24, 2018: Colloids and Surfaces. B, Biointerfaces
Feng Shao, Renato Zenobi
Two-dimensional (2D) materials have been one of the most extensively studied classes of modern materials, due to their astonishing chemical, optical, electronic, and mechanical properties, which are different from their bulk counterparts. The edges, grain boundaries, local strain, chemical bonding, molecular orientation, and the presence of nanodefects in these 2D monolayers (MLs) will strongly affect their properties. Currently, it is still challenging to investigate such atomically thin 2D monolayers with nanoscale spatial resolution, especially in a label-free and non-destructive way...
October 10, 2018: Analytical and Bioanalytical Chemistry
Yong Cheol Shin, Su-Jin Song, Yu Bin Lee, Moon Sung Kang, Hyun Uk Lee, Jin-Woo Oh, Dong-Wook Han
Background: Black phosphorus (BP) has emerged as a novel class of nanomaterials owing to its unique optical and electronic properties. BP, a two-dimensional (2D) nanomaterial, is a structure where phosphorenes are stacked together in layers by van der Waals interactions. However, although BP nanodots have many advantages, their biosafety and biological effect have not yet been elucidated as compared to the other nanomaterials. Therefore, it is particularly important to assess the cytotoxicity of BP nanodots for exploring their potentials as novel biomaterials...
2018: Biomaterials Research
Vanessa Cavalli, Denise Aparecida da Rosa, Daylana Pacheco da Silva, Matheus Kury, Priscila C S Liporoni, Luis Eduardo S Soares, Airton Abraão Martins
OBJECTIVE: High concentrations of hydrogen peroxide can cause adverse effects on composition and structure of teeth. However, the addition of calcium and fluoride in bleaching agents may reduce enamel demineralization. To evaluate chemical changes of sound and demineralized enamels submitted to high concentrations of hydrogen peroxide containing fluoride (F) or calcium (Ca). MATERIAL AND METHODS: Enamel blocks of bovine incisors with standard dimensions were obtained and half of them were submitted to pH-cycling to promote initial enamel caries lesions...
October 4, 2018: Journal of Applied Oral Science: Revista FOB
Jonathan R Young, Heidi Coy, Hyun J Kim, Michael Douek, Anthony Sisk, Allan J Pantuck, Steven S Raman
OBJECTIVE: The purpose of this study was to determine whether qualitative MDCT features are associated with the carbonic anhydrase IX (CAIX) score of clear cell renal cell carcinoma (RCC). The CAIX score has been previously found to have prognostic significance for disease-free survival, overall survival, and lymph node involvement. MATERIALS AND METHODS: A cohort of 105 histologically proven clear cell RCCs in patients who underwent preoperative four-phase renal mass MDCT was derived from 2001 to 2013...
October 9, 2018: AJR. American Journal of Roentgenology
Krzysztof Czamara, Elzbieta Karnas, Zuzanna Majka, Tomasz Wojcik, Ewa K Zuba-Surma, Malgorzata Baranska, Agnieszka Kaczor
Confocal Raman imaging combined with fluorescence-activated cell sorting was used for in vitro studies of cell cultures to look at biochemical differences between the cells in different cell phases. To answer the question what is the impact of the cell cycle phase on discrimination of pathological cells, the combination of several factors was checked: a confluency of cell culture, the cell cycle dynamics and development of pathology. Confluency of 70% and 100% results in significant phenotypic cell changes that can be also diverse for different batches...
October 8, 2018: Journal of Biophotonics
Matthew J TerBush, Khurram Rasheed, Zane Z Young, Jennifer L Ellis, Roan J Glocker, Adam J Doyle, Kathleen G Raman, Michael C Stoner
BACKGROUND: An anatomic severity grade (ASG) score to categorize and to define anatomic factors for abdominal aortic aneurysm (AAA) repair was proposed. Other studies have previously reported that aortic anatomic complexity is a marker of survival and resource utilization after repair, although it remains unclear whether individual components of the ASG score independently contribute to survival. This study analyzed and validated an aortic and iliac artery calcium scoring system that can potentially predict survival after AAA repair...
October 3, 2018: Journal of Vascular Surgery
Anna Jablonska, Alekdandra Jaworska, Mateusz Kasztelan, Sylwia Berbec, Barbara Palys
Surface Enhanced Raman Spectroscopy (SERS) has long history as ultrasensitive platform for the detection of biological species from small aromatic molecules to complex biological systems as circulating tumor cells. Thanks to unique properties of graphene, the range of SERS applications has largely expanded. Graphene is efficient fluorescence quencher improving quality of Raman spectra. It contributes also to the SERS enhancement factor through the chemical mechanism. In turn, the chemical flexibility of reduced graphene oxide (RGO) enables tunable adsorption of molecules or cells on SERS active surfaces...
October 4, 2018: Current Medicinal Chemistry
Elmar Schmälzlin, Benito Moralejo, Ingo Gersonde, Johannes Schleusener, Maxim E Darvin, Gisela Thiede, Martin M Roth
Imaging Raman spectroscopy can be used to identify cancerous tissue. Traditionally, a step-by-step scanning of the sample is applied to generate a Raman image, which, however, is too slow for routine examination of patients. By transferring the technique of integral field spectroscopy (IFS) from astronomy to Raman imaging, it becomes possible to record entire Raman images quickly within a single exposure, without the need for a tedious scanning procedure. An IFS-based Raman imaging setup is presented, which is capable of measuring skin ex vivo or in vivo...
October 2018: Journal of Biomedical Optics
Marianna Pannico, Anna Calarco, Gianfranco Peluso, Pellegrino Musto
In the present contribution the fabrication and characterization of functionalized gold nanospheres of uniform shape and controlled size is reported. These nano-objects are intended to be used as Surface Enhanced Raman Spectroscopy (SERS) sensors for in-vitro cellular uptake and localization. Thiophenol was used as molecular reporter and was bound to the Au surface by a chemisorption process in aqueous solution. The obtained colloidal solution was highly stable and no aggregation of the single nanospheres into larger clusters was observed...
October 4, 2018: Biosensors
M S Swapna, S S Shinker, S Suresh, S Sankararaman
BACKGROUND: The limitations of the existing techniques for the early detection of dengue fever necessitate the development of a powerful optical technique. OBJECTIVE: The present work is a study of Raman spectral modifications of blood on dengue infection and thereby to develop a spectroscopic method for its early detection. The images of the samples are subjected to fractal analysis to find the variation of fractal dimensions on dengue infection. METHODS: Correlation of platelet counts of dengue infected blood with Raman spectrum modification and fractal dimension...
September 25, 2018: Bio-medical Materials and Engineering
Tsunehisa Yamamoto, Takeo Minamikawa, Yoshinori Harada, Yoshihisa Yamaoka, Hideo Tanaka, Hitoshi Yaku, Tetsuro Takamatsu
Understanding the viability of the ischemic myocardial tissue is a critical issue in determining the appropriate surgical procedure for patients with chronic heart failure after myocardial infarction (MI). Conventional MI evaluation methods are; however, preoperatively performed and/or give an indirect information of myocardial viability such as shape, color, and blood flow. In this study, we realize the evaluation of MI in patients undergoing cardiac surgery by Raman spectroscopy under label-free conditions, which is based on intrinsic molecular constituents related to myocardial viability...
October 2, 2018: Scientific Reports
Dan Li, Yadan Ma, Huazhen Duan, Fei Jiang, Wei Deng, Xingang Ren
A fluorescent and surface-enhanced Raman spectroscopy (SERS) dual-mode probe is developed for imaging of intracellular Zn2+ based on N-(2-(bis(pyridine-2-ylmethyl)amino)ethyl)-2-mercaptoacetamide (MDPA) modified gold nanoparticles (MDPA-GNPs). Benefiting from the chelation-enhanced fluorescence (CHEF) between MDPA-GNPs and Zn2+ , the fluorescent intensities of MDPA-GNPs are substantially enhanced with the increment of Zn2+ concentrations, which can be clearly observed by the naked eye. Under physiological conditions, the probe exhibits a stable response for Zn2+ from 1 μM to 120 μM, with a detection limit of 0...
December 14, 2018: Analytica Chimica Acta
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