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Biomedical optics

Ilya Krasnikov, Alexey Seteikin, Ann-Kathrin Kniggendorf, Merve Meinhardt-Wollweber, Bernhard Roth
Raman spectroscopy can be employed to measure the chemical composition of a sample, which can in turn be used to extract biological information. The aim of this paper is to introduce an efficient simulation technique for Raman spectroscopy in turbid (scattering) media taking into account relevant detector parameters and the sampling volume. We simulate the process of photon motion in turbid media by means of the Monte Carlo (MC) method. The numerical simulation of Raman scattering consists of two stages: calculation of the photon fluence at each point of the medium and subsequent generation of the corresponding amount of Raman photons at each point...
December 1, 2017: Journal of the Optical Society of America. A, Optics, Image Science, and Vision
Ye Wang, Michal E Pawlowski, Tomasz S Tkaczyk
A prototype fiber-based imaging spectrometer was developed to provide snapshot hyperspectral imaging tuned for biomedical applications. The system is designed for imaging in the visible spectral range from 400 to 700 nm for compatibility with molecular imaging applications as well as satellite and remote sensing. An 81 × 96 pixel spatial sampling density is achieved by using a custom-made fiber-optic bundle. The design considerations and fabrication aspects of the fiber bundle and imaging spectrometer are described in detail...
2017: Optical Engineering: the Journal of the Society of Photo-optical Instrumentation Engineers
Xingshu Li, Sungsook Yu, Dayoung Lee, Gyoungmi Kim, Buhyun Lee, Yejin Cho, Bi-Yuan Zheng, Mei-Rong Ke, Jian-Dong Huang, Ki Taek Nam, Xiaoyuan Chen, Juyoung Yoon
Supramolecular chemistry provides a "bottom-up" method to fabricate nanostructures for biomedical applications. Herein, we report a facile strategy to directly assemble a phthalocyanine photosensitizer (PcS) with an anticancer drug mitoxantrone (MA) to form uniform nanostructures (PcS-MA), which not only display nanoscale optical properties but also have the capability of undergoing nucleic acid-responsive disassembly. These supramolecular assemblies possess activatable fluorescence emission and singlet oxygen generation associated with the formation of free PcS, mild photothermal heating, and a concomitant chemotherapeutic effect associated with the formation of free MA...
December 12, 2017: ACS Nano
Jie Shi, Ya Li, Qianqian Li, Zhen Li
Enzymes play an indispensable role in maintaining the normal life activities. The abnormalities of content and activity in specific enzymes are usually associated with the occurrence and closely related the development of major diseases. Correspondingly, fluorescent bioprobes with distinctive sensing mechanisms and different functionalities have attracted growing attention, as convenient tools for optical probing and monitoring the activity of enzyme. Ideally and excitedly, the recently emerged luminogens with an aggregation-induced emission (AIE) feature could perfectly overcome the aggregation-caused quenching (ACQ) effect of conventional bioprobes...
December 12, 2017: ACS Applied Materials & Interfaces
Bing Xu, Yang Shi, Zhaoxin Lao, Jincheng Ni, Guoqiang Li, Yanlei Hu, Jiawen Li, Jiaru Chu, Dong Wu, Koji Sugioka
Microarray technology provides an excellent platform for biomedical and biochemical research including basic scientific studies, drug discovery, and diagnostics. Here, we develop a novel method referred to as real-time two-photon lithography in a controlled flow in which femtosecond laser two-photon lithography is performed in situ in the sequential mode stopping and flowing the flow of liquid resin containing microparticles to achieve 100% trapping on a one-bead-to-one-trap basis. Polydisperse particles can be all trapped to form a desired array by freely designing trap structures, resulting in an unprecedentedly high capture efficiency of ∼100%...
December 12, 2017: Lab on a Chip
Amir Handelman, Nadezda Lapshina, Boris Apter, Gil Rosenman
Bio-nanophotonics is a wide field in which advanced optical materials, biomedicine, fundamental optics, and nanotechnology are combined and result in the development of biomedical optical chips. Silk fibers or synthetic bioabsorbable polymers are the main light-guiding components. In this work, an advanced concept of integrated bio-optics is proposed, which is based on bioinspired peptide optical materials exhibiting wide optical transparency, nonlinear and electrooptical properties, and effective passive and active waveguiding...
December 11, 2017: Advanced Materials
Haowen Ruan, Joshua Brake, J Elliott Robinson, Yan Liu, Mooseok Jang, Cheng Xiao, Chunyi Zhou, Viviana Gradinaru, Changhuei Yang
Noninvasive light focusing deep inside living biological tissue has long been a goal in biomedical optics. However, the optical scattering of biological tissue prevents conventional optical systems from tightly focusing visible light beyond several hundred micrometers. The recently developed wavefront shaping technique time-reversed ultrasonically encoded (TRUE) focusing enables noninvasive light delivery to targeted locations beyond the optical diffusion limit. However, until now, TRUE focusing has only been demonstrated inside nonliving tissue samples...
December 2017: Science Advances
Laimonas Kelbauskas, Rishabh Shetty, Bin Cao, Kuo-Chen Wang, Dean Smith, Hong Wang, Shi-Hui Chao, Sandhya Gangaraju, Brian Ashcroft, Margaret Kritzer, Honor Glenn, Roger H Johnson, Deirdre R Meldrum
Quantitative three-dimensional (3D) computed tomography (CT) imaging of living single cells enables orientation-independent morphometric analysis of the intricacies of cellular physiology. Since its invention, x-ray CT has become indispensable in the clinic for diagnostic and prognostic purposes due to its quantitative absorption-based imaging in true 3D that allows objects of interest to be viewed and measured from any orientation. However, x-ray CT has not been useful at the level of single cells because there is insufficient contrast to form an image...
December 2017: Science Advances
Hyuntai Kim, Jinseob Kim, Haechan An, Yohan Lee, Gun-Yeal Lee, Jeongkyun Na, Kyoungyoon Park, Seungjong Lee, Seung-Yeol Lee, Byoungho Lee, Yoonchan Jeong
We propose and investigate a metallic Fresnel zone plate (FZP/MFZP) implemented on a silver-coated optical fiber facet for super-variable focusing of light, the focal point of which can be drastically relocated by varying the wavelength of the incident light. We numerically show that when its nominal focal length is set to 20 μm at 550 nm, its effective focal length can be tuned by ~13.7 μm for 300-nm change in the visible wavelength range. This tuning sensitivity is over 20 times higher than that of a conventional silica-based spherical lens...
November 27, 2017: Optics Express
Huaiyu Wang, Xue-Feng Yu
As a new kind of 2D material, black phosphorus has gained increased attention in the past three years. Although few-layered black phosphorus nanosheets (BPs) degrade quickly under ambient conditions to phosphate anions, which greatly hampers their optical and electronic applications, this property also makes BPs highly biocompatible and biodegradable, and is regarded as an advantage for various biomedical applications. This Concept summarizes the state-of-art progresses of BPs, from fabrication and surface modification to biomedical applications...
December 8, 2017: Small
Aaron Alford, Veronika Kozlovskaya, Eugenia Kharlampieva
The sub-nanometer scale provided by small angle neutron and X-ray scattering is of special importance to pharmaceutical and biomedical investigators. As drug delivery devices become more functionalized and continue decreasing in size, the ability to elucidate details on size scales smaller than those available from optical techniques becomes extremely pertinent. Information gathered from small angle scattering therefore aids the endeavor of optimizing pharmaceutical efficacy at its most fundamental level. This chapter will provide some relevant examples of drug carrier technology and how small angle scattering (SAS) can be used to solve their mysteries...
2017: Advances in Experimental Medicine and Biology
Mobin Ibne Mokbul
Optical coherence tomography is a micrometer-scale imaging modality that permits label-free, cross-sectional imaging of biological tissue microstructure using tissue backscattering properties. After its invention in the 1990s, OCT is now being widely used in several branches of neuroscience as well as other fields of biomedical science. This review study reports an overview of OCT's applications in several branches or subbranches of neuroscience such as neuroimaging, neurology, neurosurgery, neuropathology, and neuroembryology...
2017: Journal of Medical Engineering
Qiang Li, Rabin Dhakal, Jaeyoun Kim
High aspect-ratio elastomeric micropillars play important roles as the platform for microscale sensing and actuation. Many soft-lithographic techniques have been developed for their facile realization but most of the techniques are limited to build the micropillars only on totally flat, widely accessible substrate areas with the micropillar's structural characteristics completely predetermined, leaving little room for in situ control. Here we demonstrate a new technique which overcomes these limitations by directly drawing micropillars from pipette-dispensed PDMS microdroplets using vacuum-chucked microspheres...
December 5, 2017: Scientific Reports
Guangjian Zeng, Meiying Liu, Ruming Jiang, Qiang Huang, Long Huang, Qing Wan, Yanfeng Dai, Yuanqing Wen, Xiaoyong Zhang, Yen Wei
In recent years, the fluorescent polymeric nanoparticles (FPNs) with aggregation-induced emission (AIE) feature have been extensively exploited in various biomedical fields owing to their advantages, such as low toxicity, biodegradation, excellent biocompatibility, good designability and optical properties. Therefore, development of a facile, efficient and well designable strategy should be of great importance for the biomedical applications of these AIE-active FPNs. In this work, a novel method for the fabrication of AIE-active FPNs has been developed through the self-catalyzed photo-initiated reversible addition fragmentation chain transfer (RAFT) polymerization using an AIE dye containing chain transfer agent (CTA), which could initiate the RAFT polymerization under light irradiation...
February 1, 2018: Materials Science & Engineering. C, Materials for Biological Applications
Danielle Nascimento Silva, Arianne Pontes Oriá, Nayone Lantyer Araujo, Emanoel Martins-Filho, Caterina Muramoto, Fernanda de Azevedo Libório, Alessandra Estrela-Lima
The objective of this study was to describe the anatomic and histologic features of the Sapajus sp. eye, comparing similarities and differences of humans and other species of non-human primates for biomedical research purposes. Computed tomography (CT) of adnexa, eye and orbit live animal, as well as formolized pieces of the same structures of Sapajus sp. for anatomical and histological study were also performed. The anatomical description of the eye and adnexa was performed using the techniques of topographic dissection and exenteration...
2017: PloS One
Hua Shi, Qingming Luo
Biophotonics is a highly interdisciplinary field where physicists, chemists, biologists, physicians and engineers work together to solve the problems appearing in biology and medicine. In China, the Biophotonics discipline is often referred to as Biomedical Photonics, under the first-level disciplines Biomedical Engineering or Optical Engineering, and was initiated in the late 1990s. Over the past 20 years, biophotonics research in China expanded extraordinarily and has reached the frontiers of the world-level sciences...
December 2017: Journal of Biophotonics
Linnea Gustafsson, Ronnie Jansson, My Hedhammar, Wouter van der Wijngaart
Spider silk has recently become a material of high interest for a large number of biomedical applications. Previous work on structuring of silk has resulted in particles (0D), fibers (1D), films (2D), and foams, gels, capsules, or microspheres (3D). However, the manufacturing process of these structures is complex and involves posttreatment of chemicals unsuitable for biological applications. In this work, the self-assembly of recombinant spider silk on micropatterned superhydrophobic surfaces is studied. For the first time, structuring of recombinant spider silk is achieved using superhydrophobic surfaces under conditions that retain the bioactivity of the functionalized silk...
December 4, 2017: Advanced Materials
Hyemin Kim, Yoonsang Park, Songeun Beack, Seulgi Han, Dooyup Jung, Hyung Joon Cha, Woosung Kwon, Sei Kwang Hahn
The development of intrinsically multicolor-emitting carbon nanodots (CNDs) has been one of the great challenges for their various fields of applications. Here, the controlled electronic structure engineering of CNDs is performed to emit two distinct colors via the facile surface modification with 4-octyloxyaniline. The so-called dual-color-emitting CNDs (DC-CNDs) can be stably encapsulated within poly(styrene-co-maleic anhydride) (PSMA). The prepared water-soluble DC-CNDs@PSMA can be successfully applied to in vitro and in vivo dual-color bioimaging and optogenetics...
November 2017: Advanced Science (Weinheim, Baden-Wurttemberg, Germany)
Pranjal Nautiyal, Fahad Alam, Kantesh Balani, Arvind Agarwal
Nanomechanics has played a vital role in pushing our capability to detect, probe, and manipulate the biological species, such as proteins, cells, and tissues, paving way to a deeper knowledge and superior strategies for healthcare. Nanomechanical characterization techniques, such as atomic force microscopy, nanoindentation, nanotribology, optical tweezers, and other hybrid techniques have been utilized to understand the mechanics and kinetics of biospecies. Investigation of the mechanics of cells and tissues has provided critical information about mechanical characteristics of host body environments...
November 29, 2017: Advanced Healthcare Materials
Kehao Wang, Demetrios T Venetsanos, Jian Wang, Andy T Augousti, Barbara K Pierscionek
The lens provides refractive power to the eye and is capable of altering ocular focus in response to visual demand. This capacity diminishes with age. Current biomedical technologies, which seek to design an implant lens capable of replicating the function of the biological lens, are unable as yet to provide such an implant with the requisite optical quality or ability to change the focussing power of the eye. This is because the mechanism of altering focus, termed accommodation, is not fully understood and seemingly conflicting theories require experimental support which is difficult to obtain from the living eye...
November 30, 2017: Scientific Reports
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