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Biomedical optics

Cheyann Lee Wetteland, Huinan Liu
This article reports a new process for creating polymer-based nanocomposites with enhanced dispersion of ceramic nanoparticles without using any surfactants, and the resulted changes in their optical and biological properties. Specifically, dispersion of two different ceramic nanoparticles, i.e, hydroxyapatite (nHA) and magnesium oxide (nMgO) nanoparticles, in a model biodegradable polymer, namely poly (lactic-co-glycolic acid) (PLGA), was studied. High-power sonication was integrated with dual asymmetric centrifugal (DAC) mixing to improve dispersion of nanoparticles during solvent casting...
June 14, 2018: Journal of Biomedical Materials Research. Part A
Giacomo Dacarro, Angelo Taglietti, Piersandro Pallavicini
Prussian blue (PB) is a coordination polymer studied since the early 18th century, historically known as a pigment. PB can be prepared in colloidal form with a straightforward synthesis. It has a strong charge-transfer absorption centered at ~700 nm, with a large tail in the Near-IR range. Irradiation of this band results in thermal relaxation and can be exploited to generate a local hyperthermia by irradiating in the so-called bio-transparent Near-IR window. PB nanoparticles are fully biocompatible (PB has already been approved by FDA) and biodegradable, this making them ideal candidates for in vivo use...
June 11, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Jermana L Moraes, Matheus X Rocha, Glauber G Vasconcelos, José E Vasconcelos Filho, Victor Hugo C de Albuquerque, Auzuir R Alexandria
Heart Rate Variability (HRV) is an important tool for the analysis of a patient’s physiological conditions, as well a method aiding the diagnosis of cardiopathies. Photoplethysmography (PPG) is an optical technique applied in the monitoring of the HRV and its adoption has been growing significantly, compared to the most commonly used method in medicine, Electrocardiography (ECG). In this survey, definitions of these technique are presented, the different types of sensors used are explained, and the methods for the study and analysis of the PPG signal (linear and nonlinear methods) are described...
June 9, 2018: Sensors
V Pereno, M Aron, O Vince, C Mannaris, A Seth, M de Saint Victor, G Lajoinie, M Versluis, C Coussios, D Carugo, E Stride
The study of the effects of ultrasound-induced acoustic cavitation on biological structures is an active field in biomedical research. Of particular interest for therapeutic applications is the ability of oscillating microbubbles to promote both cellular and tissue membrane permeabilisation and to improve the distribution of therapeutic agents in tissue through extravasation and convective transport. The mechanisms that underpin the interaction between cavitating agents and tissues are, however, still poorly understood...
May 2018: Biomicrofluidics
Ya-Hui Han, Ranjith Kumar Kankala, Shi-Bin Wang, Ai-Zheng Chen
In recent times, photo-induced therapeutics have attracted enormous interest from researchers due to such attractive properties as preferential localization, excellent tissue penetration, high therapeutic efficacy, and minimal invasiveness, among others. Numerous photosensitizers have been considered in combination with light to realize significant progress in therapeutics. Along this line, indocyanine green (ICG), a Food and Drug Administration (FDA)-approved near-infrared (NIR, >750 nm) fluorescent dye, has been utilized in various biomedical applications such as drug delivery, imaging, and diagnosis, due to its attractive physicochemical properties, high sensitivity, and better imaging view field...
May 24, 2018: Nanomaterials
Meng Qiu, Wen Xiu Ren, Taeho Jeong, Miae Won, Geun Young Park, David Kipkemoi Sang, Li-Ping Liu, Han Zhang, Jong Seung Kim
Phosphorene, also known as single- or few-layer black phosphorus (FLBP), is a new member of the two-dimensional (2D) material family and has attracted significant attention in recent years for applications in optoelectronics, energy storage and biomedicine due to its unique physicochemical properties and excellent biocompatibility. FLBP is regarded as a potential biological imaging agent for cancer diagnosis due to its intrinsic fluorescence (FL) and photoacoustic (PA) properties and negligible cytotoxicity...
June 8, 2018: Chemical Society Reviews
Kai Xing, Ruiqing Fan, Fengyou Wang, Huan Nie, Xi Du, Shuang Gai, Ping Wang, Yulin Yang
Metal-organic frameworks (MOFs), as drug delivery carriers, with high loading capacity and controllable release behavior can provide a more efficacious therapy in cancer treatments. In our work, a novel biocompatible zinc metal-organic frameworks Zn-cpon-1 with (3,6)-connected rtl 3D topological network was designed and synthesized through the template supporting induced approach by the ClO4- anion. The optically and chemically stable Zn-cpon-1 could be verified as a pH-responsive dual-emission platform and excellent drug delivery carrier with higher 5-Fluorouracil (5-FU) (44...
June 7, 2018: ACS Applied Materials & Interfaces
O V Angelsky, A Ya Bekshaev, P P Maksimyak, A P Maksimyak, S G Hanson
A method is described for the generation of micrometer-sized vapor-gas bubbles in a water suspension containing absorptive pigment nanoparticles. The diluted suspension (mean interparticle distance 20 μm) absorbs the continuous laser radiation (wavelength 808 nm), and each particle in the best illuminated volume (~10 × 10 × 200 μm3 ) serves as a bubble-nucleation center. The suspension heating is inessential (several degrees above the room temperature) and the bubbles are formed mainly of the air gases dissolved in water...
May 28, 2018: Optics Express
Yunyao Zhang, Liqing Huang, Ning Zhang, Heng Tian, Jingping Zhu
In the recent past, optical spectroscopy and imaging methods for biomedical diagnosis and target enhancing have been widely researched. The challenge to improve the performance of these methods is to know the sensitive depth of the backwards detected light well. Former research mainly employed a Monte Carlo method to run simulations to statistically describe the light sensitive depth. An experimental method for investigating the sensitive depth was developed and is presented here. An absorption plate was employed to remove all the light that may have travelled deeper than the plate, leaving only the light which cannot reach the plate...
May 28, 2018: Optics Express
Leli Zeng, Gongcheng Ma, Jing Lin, Peng Huang
Photoacoustic (PA) imaging (PAI) is a noninvasive and nonionizing biomedical imaging modality that combines the advantages of optical imaging and ultrasound imaging. Based on PAI, photoacoustic detection (PAD) is an emerging approach that is involved with the interaction between PA probes and analytes resulting in the changes of photoacoustic signals for molecular detection with rich contrast, high resolution, and deep tissue penetration. This Review focuses on the recent development of PA probes in PAD. The following contents will be discussed in detail: 1) the construction of PA probes; 2) the applications and mechanisms of PAD to different types of analytes, including microenvironments, small biomolecules, or metal ions; 3) the challenges and perspectives of PA probes in PAD...
June 5, 2018: Small
Zheng Luo, Yang Xu, Enyi Ye, Zibiao Li, Yun-Long Wu
Gold nanoparticles (AuNPs), with elegant thermal, optical, or chemical properties due to quantum size effects, may serve as unique species for therapeutic or diagnostic applications. It is worth mentioning that their small size also results in high surface activity, leading to significantly impaired stability, which greatly hinders their biomedical utilizations. To overcome this problem, various types of macromolecular materials are utilized to anchor AuNPs so as to achieve advanced synergistic effect by dispersing, protecting, and stabilizing the AuNPs in polymeric-Au hybrid self-assemblies...
June 4, 2018: Macromolecular Rapid Communications
Sourabh Shukla, Christina Dickmeis, Rainer Fischer, Ulrich Commandeur, Nicole F Steinmetz
Viral nanoparticles are attractive platforms for biomedical applications and are frequently employed for optical imaging in tissue culture and preclinical animal models as fluorescent probes. Chemical modification with organic dyes remains the most common strategy to develop such fluorescent probes. Here we report a genetic engineering approach to incorporate fluorescent proteins in viral nanoparticles, which can be propagated in their plant host. The fluorescent viral nanoparticles so obtained obviate post-harvest modifications and thereby maximize yields...
2018: Methods in Molecular Biology
Yu-Chun Hsiao, Chih-Hung Wang, Wen-Bin Lee, Gwo-Bin Lee
Cell fusion technology has been exploited in a wide variety of biomedical applications, and physical, chemical, and biological approaches can all be used to fuse two different types of cells; however, no current technique is adept at inducing both cell pairing and fusion at high efficiencies and yields. Hence, we developed a new method featuring the use of optically induced dielectrophoresis (ODEP) in conjunction with an optically induced, locally enhanced electric field for accurate and automatic cell pairing and fusion on a microfluidic device...
May 2018: Biomicrofluidics
Vladimir Ararat Hovhannisyan, Chen-Yuan Dong, Feng-Jie Lai, Nan-Shan Chang, Shean-Jen Chen
Using multiphoton microscopy (MPM), we demonstrated that effective inducing of two-photon excited luminescence and second-harmonic generation signals in nano/microparticles of clinoptilolite type of zeolite (CZ) by femtosecond near-infrared laser excitation can be successfully utilized in multiphoton imaging of the drug adsorption processes. Adsorption of photodynamic active dyes (hypericin, chlorin e6, methylene blue, and fluorescein) and their release from CZ pores in the presence of biomolecules, such as collagen from bovine Achilles tendon, albumin, and hemoglobin, were investigated by absorption and fluorescence spectrometry...
June 2018: Journal of Biomedical Optics
Ashish Tiwari, Navneet C Verma, Anup Singh, Chayan K Nandi, Jaspreet K Randhawa
Due to their unique magnetic properties, multiple surface functionality and biocompatibility, superparamagnetic iron oxide nanoparticles (SPIONs) show very promising characteristics as magnetic resonance (MR) contrast agents in biomedical applications. However, a lack of fluorescence makes SPIONs inappropriate for multimodal bioimaging. SPIONs surface functionalized by either organic fluorescent molecules or semiconductor quantum dots (QDs) have been reported as bioimaging probes but subsequent deterioration of the fluorescent dyes due to low photostability and quick photobleaching limits their long term practical application...
May 30, 2018: Nanoscale
Chengchen Guo, Jeffery L Yarger
Gold nanoparticles have attracted considerable attention in recent research because of their wide applications in various fields such as material science, electrical engineering, physical science, and biomedical engineering. Researchers have developed many methods for synthesizing different kinds of gold nanoparticles, where the sizes and surface chemistry of the nanoparticles are considered to be the two key factors. Traditionally, the sizes of nanoparticles are determined by electron microscopy while the surface chemistry is characterized by optical spectroscopies such as IR spectroscopy and Raman spectroscopy...
May 29, 2018: Magnetic Resonance in Chemistry: MRC
Fabio De Marco, Mathias Marschner, Lorenz Birnbacher, Peter Noël, Julia Herzen, Franz Pfeiffer
Grating-based X-ray phase-contrast (gbPC) is an X-ray phase-contrast imaging method involving optical gratings that typically employs the Talbot self-imaging effect. X-ray phase contrast is known to provide significant benefits for biomedical imaging. To investigate these benefits for gbPC, a high-sensitivity gbPC micro-CT setup for small biological samples has been constructed. A gbPC projection measurement simultaneously retrieves the transmittance, differential-phase and dark-field modalities of a sample...
May 14, 2018: Optics Express
Alex Savchenko, Volodymyr Cherkas, Chao Liu, Gary B Braun, Alexander Kleschevnikov, Yury I Miller, Elena Molokanova
Noninvasive stimulation of cells is crucial for the accurate examination and control of their function both at the cellular and the system levels. To address this need, we present a pioneering optical stimulation platform that does not require genetic modification of cells but instead capitalizes on unique optoelectronic properties of graphene, including its ability to efficiently convert light into electricity. We report the first studies of optical stimulation of cardiomyocytes via graphene-based biointerfaces (G-biointerfaces) in substrate-based and dispersible configurations...
May 2018: Science Advances
Ahmed Al-Kattan, Viraj P Nirwan, Anton Popov, Yury V Ryabchikov, Gleb Tselikov, Marc Sentis, Amir Fahmi, Andrei V Kabashin
Driven by surface cleanness and unique physical, optical and chemical properties, bare (ligand-free) laser-synthesized nanoparticles (NPs) are now in the focus of interest as promising materials for the development of advanced biomedical platforms related to biosensing, bioimaging and therapeutic drug delivery. We recently achieved significant progress in the synthesis of bare gold (Au) and silicon (Si) NPs and their testing in biomedical tasks, including cancer imaging and therapy, biofuel cells, etc. We also showed that these nanomaterials can be excellent candidates for tissue engineering applications...
May 24, 2018: International Journal of Molecular Sciences
Alireza Mowla, Benjamin Wensheng Du, Thomas Taimre, Karl Bertling, Stephen Wilson, Aleksandar D Rakić
Specular reflection from the surface of targets or prepared specimens represents a significant problem in optical microscopy and related optical imaging techniques as usually the surface reflection does not contribute to the desired signal. Solutions exist for many of these imaging techniques; however, remedial techniques for imaging based on laser feedback interferometry (LFI) are absent. We propose a reflection cancellation technique based on crossed-polarization filtering that is tailored for a typical LFI configuration...
May 20, 2018: Applied Optics
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