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Subramanian B, Thanka Rajan S, P J Martin, Vijay Vaithilingam, Penelope A Bean, Margaret D M Evans, A Bendavid
Diamond like carbon (DLC) films were deposited onto Ti6Al4V and Si wafer substrates by RF plasma enhanced chemical vapor deposition. The influence of dopants such as fluorine (F), silicon (Si), and nitrogen (N) on composition, structure, and biocompatibility was investigated. Ion scattering spectroscopy analysis revealed the presence of dopant atoms in the outer-most layers of the films. Raman studies showed that the position of the G-band shifts to higher frequencies with the fluorine and nitrogen content in the DLC film, whereas the incorporation of Si into DLC induces a decrease of the position of the G peak...
May 22, 2018: Biointerphases
Ulla König, Evmorfia Psarra, Olga Guskova, Eva Bittrich, Klaus-Jochen Eichhorn, Martin Müller, Petra B Welzel, Manfred Stamm, Petra Uhlmann
The development of bioengineered surface coatings with stimuli-responsive properties is beneficial for a number of biomedical applications. Environmentally responsive and switchable polymer brush systems have a great potential to create such smart biointerfaces. This study focuses on the bioconjugation of cell-instructive peptides, containing the arginine-glycine-aspartic acid tripeptide sequence (RGD motif), onto well-defined polymer brush films. Herein, the highly tailored end-grafted homo polymer brushes are either composed of the polyelectrolyte poly(acrylic) acid (PAA), providing the reactive carboxyl functionalities, or of the temperature-responsive poly(N-isopropylacrylamide) (PNIPAAm)...
May 18, 2018: Biointerphases
Mengli Zhao, Ye Cao, Huanhuan Gong, Yanqiu Sun, Jianhua Deng, Dejun Li, Rongxin Wan, Hanqing Gu
One of the key challenges in engineering tissues for cell-based therapies is developing biocompatible scaffold materials to direct cell behavior. In this paper, the cytocompatibilities of a flexible three-dimensional graphene scaffold (3D-G) and the same scaffold implanted with nitrogen ions (N+ /3D-G) are compared using an in vitro assay based on 3(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide. The N+ /3D-G samples were prepared from low-temperature hydrothermally synthesized flexible 3D-G by ion implantation and were found to display improved adhesion and proliferation of rat osteoblast and mouse fibroblast cells...
May 16, 2018: Biointerphases
Jonas K Hannestad, Fredrik Höök, Peter Sjövall
No abstract text is available yet for this article.
May 8, 2018: Biointerphases
Siyu He, Hongyuan Li, Carmen L Gomes, Dmitri V Voronine
Optical detection and conformational mapping of aptamers are important for improving medical and biosensing technologies and for better understanding of biological processes at the molecular level. The authors investigate the vibrational signals of deoxyribonucleic acid aptamers specific to Listeria monocytogenes immobilized on gold substrates using tip-enhanced Raman scattering (TERS) spectroscopy and nanoscale imaging. The authors compare topographic and nano-optical signals and investigate the fluctuations of the position-dependent TERS spectra...
May 3, 2018: Biointerphases
Lorena M Cucci, Alessia Munzone, Irina Naletova, Antonio Magrì, Diego La Mendola, Cristina Satriano
Angiogenin is a protein crucial in angiogenesis, and it is overexpressed in many cancers and downregulated in neurodegenerative diseases, respectively. The protein interaction with actin, through the loop encompassing the 60-68 residues, is an essential step in the cellular cytoskeleton reorganization. This, in turn, influences the cell proliferation and migration processes. In this work, hybrid nanoassemblies of gold nanoparticles with angiogenin fragments containing the 60-68 sequence were prepared and characterized in their interaction with both model membranes of supported lipid bilayers (SLBs) and cellular membranes of cancer (neuroblastoma) and normal (fibroblasts) cell lines...
April 16, 2018: Biointerphases
Laetitia Bernard, Patrick Rupper, Greta Faccio, Dirk Hegemann, Olivier Scholder, Manfred Heuberger, Katharina Maniura-Weber, Marianne Vandenbossche
Time-of-flight secondary ion mass spectrometry (ToF-SIMS) is increasingly used for the detailed chemical characterization of complex organic materials. Of particular interest in biointerface materials, it provides the accurate molecular information on their surface, a prerequisite for the understanding of subsequent interaction with biomaterials. Plasma polymer films are promising biointerface materials, as tuning the deposition parameters allows the control over film stability and density of surface functional groups...
April 5, 2018: Biointerphases
Marco Werner, Thorsten Auth, Paul A Beales, Jean Baptiste Fleury, Fredrik Höök, Holger Kress, Reid C Van Lehn, Marcus Müller, Eugene P Petrov, Lev Sarkisov, Jens-Uwe Sommer, Vladimir A Baulin
Synthetic polymers, nanoparticles, and carbon-based materials have great potential in applications including drug delivery, gene transfection, in vitro and in vivo imaging, and the alteration of biological function. Nature and humans use different design strategies to create nanomaterials: biological objects have emerged from billions of years of evolution and from adaptation to their environment resulting in high levels of structural complexity; in contrast, synthetic nanomaterials result from minimalistic but controlled design options limited by the authors' current understanding of the biological world...
April 3, 2018: Biointerphases
Amy V Walker, Lev D Gelb, Grant E Barry, Polatip Subanajouy, Ananta Poudel, Manami Hara, Igor V Veryovkin, Graeme I Bell, Luke Hanley
Femtosecond laser desorption ionization mass spectrometry was used to obtain mass spectrometric (MS) images of lipids in human pancreatic tissue. The resulting MS images were analyzed using multivariate analysis, specifically principal component analysis and maximum a posteriori (MAP) reconstruction. Both analysis methods showed that the MS images can be separated into lipid and non-lipid areas. MAP analysis further indicated that the lipid areas are composed of phosphatidylcholines and fatty acids. However, definitive identification of the lipids cannot be made because none of the intact parent ions of phosphatidylcholine, sphingomyelins, and/or other lipids were observed...
April 2, 2018: Biointerphases
Minh Uyen Thi Le, Jin Gyeong Son, Hyun Kyoung Shon, Jeong Hyang Park, Sung Bae Lee, Tae Geol Lee
Time-of-flight secondary ion mass spectrometry (ToF-SIMS) imaging elucidates molecular distributions in tissue sections, providing useful information about the metabolic pathways linked to diseases. However, delocalization of the analytes and inadequate tissue adherence during sample preparation are among some of the unfortunate phenomena associated with this technique due to their role in the reduction of the quality, reliability, and spatial resolution of the ToF-SIMS images. For these reasons, ToF-SIMS imaging requires a more rigorous sample preparation method in order to preserve the natural state of the tissues...
March 30, 2018: Biointerphases
Michael J Taylor, Hannah Aitchison, Morgan J Hawker, Michelle N Mann, Ellen R Fisher, Daniel J Graham, Lara J Gamble
Biopolymers are used extensively in the manufacture of porous scaffolds for a variety of biological applications. The surfaces of these scaffolds are often modified to encourage specific interactions such as surface modification of scaffolds to prevent fouling or to promote a cell supportive environment for tissue engineering implants. However, few techniques can effectively characterize the uniformity of surface modifications in a porous scaffold. By filling the scaffold pores through polymer embedding, followed by analysis with imaging time-of-flight secondary ion mass spectrometry (ToF-SIMS), the distribution and composition of surface chemical species though complex porous scaffolds can be characterized...
March 30, 2018: Biointerphases
Hatice Ceren Ates, Ebru Ozgur, Haluk Kulah
Methods for isolation and quantification of circulating tumor cells (CTCs) are attracting more attention every day, as the data for their unprecedented clinical utility continue to grow. However, the challenge is that CTCs are extremely rare (as low as 1 in a billion of blood cells) and a highly sensitive and specific technology is required to isolate CTCs from blood cells. Methods utilizing microfluidic systems for immunoaffinity-based CTC capture are preferred, especially when purity is the prime requirement...
March 23, 2018: Biointerphases
Louise Wogelred, Fredrik Höök, Björn Agnarsson, Peter Sjövall
Accurate detection and quantification of individual molecules is important for the development of improved diagnostic methods as well as biochemical characterization of disease progression and treatments. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) is a surface analysis technique capable of imaging the distribution of specific molecules on surfaces with a high spatial resolution (<1 μm) and high sensitivity. ToF-SIMS is particularly suitable for detection of molecules up to ∼2 kDa, including lipids, whereas larger molecules, such as peptides and proteins, are fragmented during analysis, which makes them difficult to identify...
March 15, 2018: Biointerphases
Marcel Heeger, Bonnie J Tyler, Martin Körsgen, Heinrich F Arlinghaus
In this study, the influence of two different cluster primary ions in laser secondary neutral mass spectrometry (Laser-SNMS) has been investigated. Despite the many advantages of Laser-SNMS, fragmentation of neutral organic molecules during both sputtering and photoionization has limited its efficiency for the study of large organic and biological molecules. Cluster ion sputtering, and in particular large argon gas cluster sputtering, has been proposed as a means of reducing this fragmentation. Molecules of 9-fluorenylmethoxycarbonyl-pentafluoro-l-phenylalanine were sputtered using Bi3 + and Ar2000 + cluster primary ions, and the desorbed neutral species ("secondary neutrals") were postionized using a 7...
March 2, 2018: Biointerphases
Hyun Kyong Shon, Shin Hye Kim, Sohee Yoon, Chan Young Shin, Tae Geol Lee
Brain imaging using time-of-flight secondary ion mass spectrometry (ToF-SIMS) has been reported to produce the distorted biomolecular distributions due to the cholesterol-induced matrix effect when cholesterol migrates to the surface, particularly in white matter, which contains a high level of cholesterol. Frozen-hydrated analysis has been used to inhibit the movement of cholesterol in the brain. In this paper, the authors propose new sample preparation and drying methods that can be used to obtain accurate biomolecular images at room temperature, instead of frozen-hydrated analysis using liquid-nitrogen, which must be continuously supplied to maintain the sample at -160 °C during the experiment...
March 1, 2018: Biointerphases
Anja Henss, Svenja-K Otto, Kaija Schaepe, Linda Pauksch, Katrin S Lips, Marcus Rohnke
Within this study, the authors use human mesenchymal stem cells incubated with silver nanoparticles (AgNPs) as a model system to systematically investigate the advantages and drawbacks of the fast imaging delayed extraction mode for two-dimensional and three-dimensional (3D) analyses at the cellular level. The authors compare the delayed extraction mode with commonly employed measurement modes in terms of mass and lateral resolution, intensity, and dose density. Using the delayed extraction mode for single cell analysis, a high mass resolution up to 4000 at m/z = 184...
February 28, 2018: Biointerphases
Corryn E Chini, Gregory L Fisher, Ben Johnson, Michael M Tamkun, Mary L Kraft
Advances in three-dimensional secondary ion mass spectrometry (SIMS) imaging have enabled visualizing the subcellular distributions of various lipid species within individual cells. However, the difficulty of locating organelles using SIMS limits efforts to study their lipid compositions. Here, the authors have assessed whether endoplasmic reticulum (ER)-Tracker Blue White DPX® , which is a commercially available stain for visualizing the endoplasmic reticulum using fluorescence microscopy, produces distinctive ions that can be used to locate the endoplasmic reticulum using SIMS...
February 26, 2018: Biointerphases
Katherine E Marusak, Julia R Krug, Yaying Feng, Yangxiaolu Cao, Lingchong You, Stefan Zauscher
The emerging field of biofabrication capitalizes on nature's ability to create materials with a wide range of well-defined physical and electronic properties. Particularly, there is a current push to utilize programmed, self-organization of living cells for material fabrication. However, much research is still necessary at the interface of synthetic biology and materials engineering to make biofabrication a viable technique to develop functional devices. Here, the authors exploit the ability of Escherichia coli to contribute to material fabrication by designing and optimizing growth platforms to direct inorganic nanoparticle (NP) synthesis, specifically cadmium sulfide (CdS) NPs, onto porous polycarbonate membranes...
February 9, 2018: Biointerphases
Jonas K Hannestad, Fredrik Höök, Peter Sjövall
The organization of lipid membranes plays an important role in a wide range of biological processes at different length scales. Herein, the authors present a procedure based on time-of-flight secondary ion mass spectrometry (ToF-SIMS) to characterize the nanometer-scale ordering of lipids in lipid membrane structures on surfaces. While ToF-SIMS is a powerful tool for label-free analysis of lipid-containing samples, its limited spatial resolution prevents in-depth knowledge of how lipid properties affect the molecular assembly of the membrane...
February 8, 2018: Biointerphases
Martin Körsgen, Bonnie J Tyler, Marcel Heeger, Moritz Buhl, Heinrich F Arlinghaus
The use of time-of-flight secondary ion mass spectrometry (SIMS) is of increasing interest for biological and medical applications due to its ability to provide chemical information on a submicrometer scale. However, the detection of larger biomolecules such as phospholipids and peptides is often inhibited by high fragmentation rates and low ionization efficiencies. One way to increase the secondary ion molecular yield is to chemically modify the surface using the matrix-enhanced SIMS approach, where an organic matrix is placed upon the surface...
February 8, 2018: Biointerphases
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