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Biomedical optics

S Rajaboopathi, S Thambidurai
In the present study, green synthesis of silver nanoparticles (AgNPs) functionalized with seaweed (Padina gymnospora) extract was investigated. Thus synthesized AgNPs were coated on cotton fabric by pad try-cure method using citric acid as a cross linking agent. The chemical linkage of colloidal AgNPs onto the cellulosic structure are characterized and confirmed by FTIR, SEM, EDX and AFM analysis. The optical, crystalline and morphological features of the functionalized AgNPs were confirmed by UV-Visible, X-ray diffraction and TEM analysis...
April 18, 2018: Journal of Photochemistry and Photobiology. B, Biology
Zhenluan Xue, Songjun Zeng, Jianhua Hao
Optical bioimaging by using the new short-wavelength infrared window (SWIR, also named as NIR-II, 1000-1700 nm) is emerged as a next generation imaging technique for disease diagnosis owing to the unprecedented improvements in imaging sensitivity and spatial resolution. However, it is challenging to search new imaging agents with highly biocompatible and bright narrow-band emission located in the 1500-1700 nm (referred as NIR-IIb) region. Here we developed high quality polyacrylic acid (PAA) modified NaYF4 :Gd/Yb/Er nanorods (PAA-NRs) with remarkably enhanced NIR-IIb emission and decent bio-compatibility for in vivo cerebral vascular bioimaging and small tumor visualization...
April 17, 2018: Biomaterials
Bader AlQattan, Ali K Yetisen, Haider Butt
Contact lenses are ubiquitous biomedical devices used for vision correction and cosmetic purposes. Their application as quantitative analytical devices is highly promising for point-of-care diagnostics. However, it is a challenge to integrate nanoscale features into commercial contact lenses for application in low-cost biosensors. A neodymium-doped yttrium aluminum garnet (Nd:YAG) laser (1064 nm, 3 ns pulse, 240 mJ) in holographic interference patterning mode was utilized to produce optical nanostructures over the surface of a hydrogel contact lens...
April 24, 2018: ACS Nano
Thomas R Carey, Kristen L Cotner, Brian Li, Lydia L Sohn
Advancements in microfluidic technologies have led to the development of many new tools for both the characterization and sorting of single cells without the need for exogenous labels. Label-free microfluidics reduce the preparation time, reagents needed, and cost of conventional methods based on fluorescent or magnetic labels. Furthermore, these devices enable analysis of cell properties such as mechanical phenotype and dielectric parameters that cannot be characterized with traditional labels. Some of the most promising technologies for current and future development toward label-free, single-cell analysis and sorting include electronic sensors such as Coulter counters and electrical impedance cytometry; deformation analysis using optical traps and deformation cytometry; hydrodynamic sorting such as deterministic lateral displacement, inertial focusing, and microvortex trapping; and acoustic sorting using traveling or standing surface acoustic waves...
April 24, 2018: Wiley Interdisciplinary Reviews. Nanomedicine and Nanobiotechnology
Stephanie M Shrader, William F Greentree
Since their development in the 1960s, Göttingen minipigs have become a popular nonrodent animal model in biomedical research, especially for ocular studies, because of their ease of handling, size, well-monitored genetics, and ocular anatomy that is similar to humans. The purpose of this mini-review is to introduce the reader to the various ways in which this animal model is currently being utilized in ocular research and to provide an overview of the diagnostic modalities that aid in this research. To date, the Göttingen minipig has been used for a variety of ocular research endeavors, including studies evaluating the safety and efficacy of ocular therapeutics, glaucoma etiopathogenesis and treatment, novel biomaterials, surgical procedures, and implantable materials/devices...
January 1, 2018: Toxicologic Pathology
Marc de Wergifosse, Edith Botek, Evelien De Meulenaere, Koen Clays, Benoît Champagne
The first hyperpolarizability ( ) of six fluorescent proteins (FPs), namely eGFP, eYFP, SHardonnay, ZsYellow, DsRed, and mCherry, has been calculated to unravel structure-property relationships on their second-order nonlinear optical properties, owing to their potential for multidimensional biomedical imaging. The ONIOM scheme has been employed and several of its refinements have been addressed to incorporate efficiently the effects of the microenvironment on the nonlinear optical responses of the FP chromophore that is embedded in a protective -barrel protein cage...
April 20, 2018: Journal of Physical Chemistry. B
Jernej Laloš, Peter Gregorčič, Matija Jezeršek
We present an optical study of elastic wave propagation inside skin phantoms consisting of agar gel as induced by an Er:YAG (wavelength of 2.94 μm) laser pulse. A laser-beam-deflection probe is used to measure ultrasonic propagation and a high-speed camera is used to record displacements in ablation-induced elastic transients. These measurements are further analyzed with a custom developed image recognition algorithm utilizing the methods of particle image velocimetry and spline interpolation to determine point trajectories, material displacement and strain during the passing of the transients...
April 1, 2018: Biomedical Optics Express
Yide Zhang, Prakash D Nallathamby, Genevieve D Vigil, Aamir A Khan, Devon E Mason, Joel D Boerckel, Ryan K Roeder, Scott S Howard
Super-resolution fluorescence microscopy is an important tool in biomedical research for its ability to discern features smaller than the diffraction limit. However, due to its difficult implementation and high cost, the super-resolution microscopy is not feasible in many applications. In this paper, we propose and demonstrate a saturation-based super-resolution fluorescence microscopy technique that can be easily implemented and requires neither additional hardware nor complex post-processing. The method is based on the principle of stepwise optical saturation (SOS), where M steps of raw fluorescence images are linearly combined to generate an image with a [Formula: see text]-fold increase in resolution compared with conventional diffraction-limited images...
April 1, 2018: Biomedical Optics Express
Narges Elahi, Mehdi Kamali, Mohammad Hadi Baghersad
Recent advances in nanotechnology are as a result of the development of engineered nanoparticles. Efficiently, metallic nanoparticles have been widely exploited for biomedical application and among them, gold nanoparticles (AuNPs) are highly remarkable. Consequent upon their significant nature, spherical and gold nanorods (Au NRs) nanoparticles attract extreme attention. Their intrinsic features such as optical, electronic, physicochemical and, surface plasmon resonance (SPR); which can be altered by changing the characterizations of particles such as shape, size, aspect ratio, or environment; ease of synthesis and functionalization properties have resulted to various applications in different fields of biomedicine such as sensing, targeted drug delivery, imaging, photothermal and photodynamic therapy as well as the modulation of two or three applications...
July 1, 2018: Talanta
Hongling Deng, Sa Huang, Chen Xu
Nowadays, in order to improve the diagnostic accuracy of the disease, more and more contrast agents have been applied in the clinical imaging modalities. A combination of nanotechnology with optical, computed X-ray tomography (CT), and magnetic resonance imaging (MRI) has great potential to improve disease diagnosis and therapy. Herein, we developed a novel multimodal contrast agent for deep-tissue bioimaging based on PEGylated Mn2+ doped NaLuF4 :Yb/Er nanoparticles (PEG-UCNPs). The multimodal nanoprobes have revealed the intensely red upconversion luminescence emission for deep-tissue upconversion luminescence (UCL) imaging...
July 1, 2018: Talanta
Irene Villa, Chiara Villa, Angelo Monguzzi, Vladimir Babin, Elena Tervoort, Martin Nikl, Markus Niederberger, Yvan Torrente, Anna Vedda, Alessandro Lauria
Luminescent nanoparticles are researched for their potential impact in medical science, but no materials approved for parenteral use have been available so far. To overcome this issue, we demonstrate that Eu3+-doped hafnium dioxide nanocrystals can be used as non-toxic, highly stable probes for cellular optical imaging and as radiosensitive materials for clinical treatment. Furthermore, viability and biocompatibility tests on artificially stressed cell cultures reveal their ability to buffer reactive oxygen species, proposing an anti-cytotoxic feature interesting for biomedical applications...
April 19, 2018: Nanoscale
Xuechao Yu, Peng Yu, Di Wu, Bahadur Singh, Qingsheng Zeng, Hsin Lin, Wu Zhou, Junhao Lin, Kazu Suenaga, Zheng Liu, Qi Jie Wang
The interest in mid-infrared technologies surrounds plenty of important optoelectronic applications ranging from optical communications, biomedical imaging to night vision cameras, and so on. Although narrow bandgap semiconductors, such as Mercury Cadmium Telluride and Indium Antimonide, and quantum superlattices based on inter-subband transitions in wide bandgap semiconductors, have been employed for mid-infrared applications, it remains a daunting challenge to search for other materials that possess suitable bandgaps in this wavelength range...
April 18, 2018: Nature Communications
Aizhan Tastanova, Marc Folcher, Marius Müller, Gieri Camenisch, Aaron Ponti, Thomas Horn, Maria S Tikhomirova, Martin Fussenegger
Diagnosis marks the beginning of any successful therapy. Because many medical conditions progress asymptomatically over extended periods of time, their timely diagnosis remains difficult, and this adversely affects patient prognosis. Focusing on hypercalcemia associated with cancer, we aimed to develop a synthetic biology-inspired biomedical tattoo using engineered cells that would (i) monitor long-term blood calcium concentration, (ii) detect onset of mild hypercalcemia, and (iii) respond via subcutaneous accumulation of the black pigment melanin to form a visible tattoo...
April 18, 2018: Science Translational Medicine
Ramya Parameswaran, Bozhi Tian
One of the fundamental questions guiding research in the biological sciences is how cellular systems process complex physical and environmental cues and communicate with each other across multiple length scales. Importantly, aberrant signal processing in these systems can lead to diseases that can have devastating impacts on human lives. Biophysical studies in the past several decades have demonstrated that cells can respond to not only biochemical cues but also mechanical and electrical ones. Thus, the development of new materials that can both sense and modulate all of these pathways is necessary...
April 18, 2018: Accounts of Chemical Research
Kai Huang, Zhongjun Li, Jing Lin, Gang Han, Peng Huang
Two-dimensional transition metal carbides and nitrides known as MXenes, with a general formula of Mn+1Xn (n = 1-3), integrate the advantages of metallic conductive transition metals with large groups of carbides, nitrides, or carbonitrides. They have led to a burgeoning research interest in biomedical applications due to their ultrathin structure and fascinating physiochemical (electronic, optical, magnetic, etc.) properties. In this review, we summarize recent advances in biomedical applications for MXenes...
April 18, 2018: Chemical Society Reviews
Hui Wang, Qianwang Chen, Shuiqin Zhou
Nanosized crosslinked polymer networks, named as nanogels, are playing an increasingly important role in a diverse range of applications by virtue of their porous structures, large surface area, good biocompatibility and responsiveness to internal and/or external chemico-physical stimuli. Recently, a variety of carbon nanomaterials, such as carbon quantum dots, graphene/graphene oxide nanosheets, fullerenes, carbon nanotubes, and nanodiamonds, have been embedded into responsive polymer nanogels, in order to integrate the unique electro-optical properties of carbon nanomaterials with the merits of nanogels into a single hybrid nanogel system for improvement of their applications in nanomedicine...
April 18, 2018: Chemical Society Reviews
Shao-Kai Sun, He-Fang Wang, Xiu-Ping Yan
Persistent luminescence nanoparticles (PLNPs) are unique optical materials emitting long-lasting luminescence after ceasing excitation. Such a unique optical feature allows luminescence detection without constant external illumination to avoid the interferences of autofluorescence and scattering light from biological fluids and tissues. Besides, near-infrared (NIR) PLNPs have advantages of deep penetration and the reactivation of the persistent luminescence (PL) by red or NIR light. These features make the application of NIR-emitting PLNPs in long-term bioimaging no longer limited by the lifetime of PL...
April 17, 2018: Accounts of Chemical Research
Priya Darshani, Manju Bhargavi Gumpu, Prasanth Thumpati, John Bosco Balaguru Rayappan, Velayutham Ravichandiran, Gururaja Perumal Pazhani, Murugan Veerapandian
Progress in the development of phytochemistry has delivered advancement in materials functionality for range of inter/trans-disciplinary application. Here, we investigated the structural functionality of chemically synthesized phytoconstitutent, chalcone (butein) and flavanone (butin). Photoactive and electroactive behavior of butein and butin were comprehensively studied using UV-vis absorbance, photoluminescence and cyclic voltammetric techniques. Surface morphology of the butein and butin powders was characterized from scanning electron microscope at an operating voltage of 10 kV...
April 6, 2018: Journal of Photochemistry and Photobiology. B, Biology
Hui-Juan Li, Peng-Yun Li, Li-Ying Li, Abdul Haleem, Wei-Dong He
Narrowly distributed poly(l-lysine- b - N -isopropylacrylamide) (PLL- b -PNIPAM) was prepared through ring-opening polymerization of ε-benzyloxycarbonyl-l-lysine N -carboxy-α-amino anhydride and atom transfer radical polymerization of NIPAM, followed with the removal of ε-benzyloxycarbonyl group. Then gold nanoparticles (AuNPs) grafted with PLL- b -PNIPAM (PNIPAM-PLL-AuNPs) were obtained by the reduction of chloroauric acid with sodium citrate in the presence of PLL- b -PNIPAM...
April 16, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Nir Waiskopf, Yuval Ben-Shahar, Uri Banin
Hybrid semiconductor-metal nanoparticles (HNPs) manifest unique combined and often synergetic properties stemming from the materials combination. These structures exhibit spatial charge separation across the semiconductor-metal junction upon light absorption, enabling their use as photocatalysts. So far, the main impetus of photocatalysis research in HNPs addresses their functionality in solar fuel generation. Recently, it was discovered that HNPs are functional in efficient photocatalytic generation of reactive oxygen species (ROS)...
April 14, 2018: Advanced Materials
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