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Kim DK, Park JY, Kang YJ, Khang D. Drug Repositioning of Metformin Encapsulated in PLGA Combined with Photothermal Therapy Ameliorates Rheumatoid Arthritis. Int J Nanomedicine 2023; 18:7267-7285. [PMID: 38090362 PMCID: PMC10711299 DOI: 10.2147/ijn.s438388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 11/30/2023] [Indexed: 12/18/2023] Open
Abstract
Purpose Rheumatoid arthritis (RA) is a highly prevalent form of autoimmune disease that affects nearly 1% of the global population by causing severe cartilage damage and inflammation. Despite its prevalence, previous efforts to prevent the perpetuation of RA have been hampered by therapeutics' cytotoxicity and poor delivery to target cells. The present study exploited drug repositioning and nanotechnology to convert metformin, a widely used antidiabetic agent, into an anti-rheumatoid arthritis drug by designing poly(lactic-co-glycolic acid) (PLGA)-based spheres. Moreover, this study also explored the thermal responsiveness of the IL-22 receptor, a key regulator of Th-17, to incorporate photothermal therapy (PTT) into the nanodrug treatment. Materials and Methods PLGA nanoparticles were synthesized using the solvent evaporation method, and metformin and indocyanine green (ICG) were encapsulated in PLGA in a dropwise manner. The nanodrug's in vitro anti-inflammatory properties were examined in J744 and FLS via real-time PCR. PTT was induced by an 808 nm near-infrared (NIR) laser, and the anti-RA effects of the nanodrug with PTT were evaluated in DBA/1 collagen-induced arthritis (CIA) mice models. Further evaluation of anti-RA properties was carried out using flow cytometry, immunofluorescence analysis, and immunohistochemical analysis. Results The encapsulation of metformin into PLGA allowed the nanodrug to enter the target cells via macropinocytosis and clathrin-mediated endocytosis. Metformin-encapsulated PLGA (PLGA-MET) demonstrated promising anti-inflammatory effects by decreasing the expression of pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α), increasing the expression of anti-inflammatory cytokines (IL-10 and IL-4), and promoting the polarization of M1 to M2 macrophages in J774 cells. The treatment of the nanodrug with PTT exhibited more potent anti-inflammatory effects than free metformin or PLGA-MET in CIA mice models. Conclusion These results demonstrated that PLGA-encapsulated metformin treatment with PTT can effectively ameliorate inflammation in a spatiotemporal manner.
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Affiliation(s)
- Dae Kyu Kim
- Deparment of Biochemistry, Bowdoin College, Brunswick, ME, 04011, USA
- Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon, 21999, South Korea
| | - Jun Young Park
- Department of Health Sciences and Technology, GAIHST, Gachon University, Incheon, 21999, South Korea
| | - Youn Joo Kang
- Department of Rehabilitation Medicine, Nowon Eulji Medical Center, Eulji University School of Medicine, Seoul, 01830, South Korea
| | - Dongwoo Khang
- Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon, 21999, South Korea
- Department of Health Sciences and Technology, GAIHST, Gachon University, Incheon, 21999, South Korea
- Department of Physiology, School of Medicine, Gachon University, Incheon, 21999, South Korea
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2
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McCann PC, Hiramatsu K, Goda K. Highly Sensitive Low-Frequency Time-Domain Raman Spectroscopy via Fluorescence Encoding. J Phys Chem Lett 2021; 12:7859-7865. [PMID: 34382803 DOI: 10.1021/acs.jpclett.1c01741] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Fluorescence-encoded vibrational spectroscopy has become increasingly more popular by virtue of its high chemical specificity and sensitivity. However, current fluorescence-encoded vibrational spectroscopy methods lack sensitivity in the low-frequency region, which if addressed could further enhance their capabilities. Here, we present a method for highly sensitive low-frequency fluorescence-encoded vibrational spectroscopy, termed fluorescence-encoded time-domain coherent Raman spectroscopy (FLETCHERS). By first exciting molecules into vibrationally excited states and then promoting the vibrating molecules to electronic states at varying times, the molecular vibrations can be encoded onto the emitted time-domain fluorescence intensity. We demonstrate the sensitive low-frequency detection capability of FLETCHERS by measuring vibrational spectra in the lower fingerprint region of rhodamine 800 solutions as dilute as 250 nM, which is ∼1000 times more sensitive than conventional vibrational spectroscopy. These results, along with further improvement of the method, open up the prospect of performing single-molecule vibrational spectroscopy in the low-frequency region.
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Affiliation(s)
- Phillip C McCann
- Department of Chemistry, The University of Tokyo, Tokyo 113-0033, Japan
| | - Kotaro Hiramatsu
- Department of Chemistry, The University of Tokyo, Tokyo 113-0033, Japan
- Research Center for Spectrochemistry, The University of Tokyo, Tokyo 113-0033, Japan
- PRESTO, Japan Science and Technology Agency, Saitama 332-0012, Japan
| | - Keisuke Goda
- Department of Chemistry, The University of Tokyo, Tokyo 113-0033, Japan
- Department of Bioengineering, University of California, Los Angeles, California 90095, United States
- Institute of Technological Sciences, Wuhan University, Wuhan, Hubei 430072, China
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3
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Junker J, Wilken D, Huntington E, Heurs M. High-precision cavity spectroscopy using high-frequency squeezed light. OPTICS EXPRESS 2021; 29:6053-6068. [PMID: 33726135 DOI: 10.1364/oe.416713] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 01/15/2021] [Indexed: 06/12/2023]
Abstract
In this article, we present a novel spectroscopy technique that improves the signal-to-shot-noise ratio without the need to increase the laser power. Detrimental effects by technical noise sources are avoided by frequency-modulation techniques (frequency up-shifting). Superimposing the signal on non-classical states of light leads to a reduced quantum noise floor. Our method reveals in a proof-of-concept experiment small signals at Hz to kHz frequencies even below the shot noise limit. Our theoretical calculations fully support our experimental findings. The proposed technique is interesting for applications such as high-precision cavity spectroscopy, e.g., for explosive trace gas detection where the specific gas might set an upper limit for the laser power employed.
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4
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Pope NJ, Powell SM, Wigle JC, Denton ML. Wavelength- and irradiance-dependent changes in intracellular nitric oxide level. JOURNAL OF BIOMEDICAL OPTICS 2020; 25:1-20. [PMID: 32790251 PMCID: PMC7423318 DOI: 10.1117/1.jbo.25.8.085001] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 07/23/2020] [Indexed: 06/11/2023]
Abstract
SIGNIFICANCE Photobiomodulation (PBM) refers to the beneficial effects of low-energy light absorption. Although there is a large body of literature describing downstream physiological benefits of PBM, there is a limited understanding of the molecular mechanisms underlying these effects. At present, the most popular hypothesis is that light absorption induces release of nitric oxide (NO) from the active site of cytochrome c oxidase (COX), allowing it to bind O2 instead. This is believed to increase mitochondrial respiration, and result in greater overall health of the cell due to increased adenosine triphosphate production. AIM Although NO itself is a powerful signaling molecule involved in a host of biological responses, less attention has been devoted to NO mechanisms in the context of PBM. The purpose of our work is to investigate wavelength-specific effects on intracellular NO release in living cells. APPROACH We have conducted in-depth dosimetry analyses of NO production and function in an in vitro retinal model in response to low-energy exposure to one or more wavelengths of laser light. RESULTS We found statistically significant wavelength-dependent elevations (10% to 30%) in intracellular NO levels following laser exposures at 447, 532, 635, or 808 nm. Sequential or simultaneous exposures to light at two different wavelengths enhanced the NO modulation up to 50% of unexposed controls. Additionally, the immediate increases in cellular NO levels were independent of the function of NO synthase, depended greatly on the substrate source of electrons entering the electron transport chain, and did not result in increased levels of cyclic guanosine monophosphate. CONCLUSIONS Our study concludes the simple model of light-mediated release of NO from COX is unlikely to explain the wide variety of PBM effects reported in the literature. Our multiwavelength method provides a novel tool for studying immediate and early mechanisms of PBM as well as exploring intracellular NO signaling networks.
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Affiliation(s)
- Nathaniel J. Pope
- Oak Ridge Institute of Science and Education, Air Force Research Laboratory, Joint Base San Antonio Fort Sam Houston, Texas, United States
| | - Samantha M. Powell
- National Research Council, Air Force Research Laboratory, Joint Base San Antonio Fort Sam Houston, Texas, United States
| | - Jeffrey C. Wigle
- Air Force Research Laboratory, Joint Base San Antonio Fort Sam Houston, Texas, United States
| | - Michael L. Denton
- Air Force Research Laboratory, Joint Base San Antonio Fort Sam Houston, Texas, United States
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5
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Lunova M, Smolková B, Uzhytchak M, Janoušková KŽ, Jirsa M, Egorova D, Kulikov A, Kubinová Š, Dejneka A, Lunov O. Light-induced modulation of the mitochondrial respiratory chain activity: possibilities and limitations. Cell Mol Life Sci 2020; 77:2815-2838. [PMID: 31583425 PMCID: PMC11104903 DOI: 10.1007/s00018-019-03321-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 09/11/2019] [Accepted: 09/23/2019] [Indexed: 12/17/2022]
Abstract
Biological effects of high fluence low-power (HFLP) lasers have been reported for some time, yet the molecular mechanisms procuring cellular responses remain obscure. A better understanding of the effects of HFLP lasers on living cells will be instrumental for the development of new experimental and therapeutic strategies. Therefore, we investigated sub-cellular mechanisms involved in the laser interaction with human hepatic cell lines. We show that mitochondria serve as sub-cellular "sensor" and "effector" of laser light non-specific interactions with cells. We demonstrated that despite blue and red laser irradiation results in similar apoptotic death, cellular signaling and kinetic of biochemical responses are distinct. Based on our data, we concluded that blue laser irradiation inhibited cytochrome c oxidase activity in electron transport chain of mitochondria. Contrary, red laser triggered cytochrome c oxidase excessive activation. Moreover, we showed that Bcl-2 protein inhibited laser-induced toxicity by stabilizing mitochondria membrane potential. Thus, cells that either overexpress or have elevated levels of Bcl-2 are protected from laser-induced cytotoxicity. Our findings reveal the mechanism how HFLP laser irradiation interfere with cell homeostasis and underscore that such laser irradiation permits remote control of mitochondrial function in the absence of chemical or biological agents.
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Affiliation(s)
- Mariia Lunova
- Institute of Physics, Czech Academy of Sciences, 18221, Prague, Czech Republic
- Institute for Clinical and Experimental Medicine (IKEM), 14021, Prague, Czech Republic
| | - Barbora Smolková
- Institute of Physics, Czech Academy of Sciences, 18221, Prague, Czech Republic
| | - Mariia Uzhytchak
- Institute of Physics, Czech Academy of Sciences, 18221, Prague, Czech Republic
| | - Klára Žofie Janoušková
- Institute for Clinical and Experimental Medicine (IKEM), 14021, Prague, Czech Republic
- First Faculty of Medicine, Charles University, 12108, Prague, Czech Republic
| | - Milan Jirsa
- Institute for Clinical and Experimental Medicine (IKEM), 14021, Prague, Czech Republic
| | | | | | - Šárka Kubinová
- Institute of Physics, Czech Academy of Sciences, 18221, Prague, Czech Republic
- Institute of Experimental Medicine, Czech Academy of Sciences, 14220, Prague, Czech Republic
| | - Alexandr Dejneka
- Institute of Physics, Czech Academy of Sciences, 18221, Prague, Czech Republic
| | - Oleg Lunov
- Institute of Physics, Czech Academy of Sciences, 18221, Prague, Czech Republic.
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6
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Manifold B, Thomas E, Francis AT, Hill AH, Fu D. Denoising of stimulated Raman scattering microscopy images via deep learning. BIOMEDICAL OPTICS EXPRESS 2019; 10:3860-3874. [PMID: 31452980 PMCID: PMC6701518 DOI: 10.1364/boe.10.003860] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 06/18/2019] [Accepted: 07/04/2019] [Indexed: 05/06/2023]
Abstract
Stimulated Raman scattering (SRS) microscopy is a label-free quantitative chemical imaging technique that has demonstrated great utility in biomedical imaging applications ranging from real-time stain-free histopathology to live animal imaging. However, similar to many other nonlinear optical imaging techniques, SRS images often suffer from low signal to noise ratio (SNR) due to absorption and scattering of light in tissue as well as the limitation in applicable power to minimize photodamage. We present the use of a deep learning algorithm to significantly improve the SNR of SRS images. Our algorithm is based on a U-Net convolutional neural network (CNN) and significantly outperforms existing denoising algorithms. More importantly, we demonstrate that the trained denoising algorithm is applicable to images acquired at different zoom, imaging power, imaging depth, and imaging geometries that are not included in the training. Our results identify deep learning as a powerful denoising tool for biomedical imaging at large, with potential towards in vivo applications, where imaging parameters are often variable and ground-truth images are not available to create a fully supervised learning training set.
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7
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Denton ML, Ahmed EM, Noojin GD, Tijerina AJ, Gamboa G, Gonzalez CC, Rockwell BA. Effect of ambient temperature and intracellular pigmentation on photothermal damage rate kinetics. JOURNAL OF BIOMEDICAL OPTICS 2019; 24:1-15. [PMID: 31230427 PMCID: PMC6977020 DOI: 10.1117/1.jbo.24.6.065002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Accepted: 05/30/2019] [Indexed: 06/09/2023]
Abstract
Computational models predicting cell damage responses to transient temperature rises generated by exposure to lasers have implemented the damage integral (Ω), which time integrates the chemical reaction rate constant described by Arrhenius. However, few published reports of empirical temperature histories (thermal profiles) correlated with damage outcomes at the cellular level are available to validate the breadth of applicability of the damage integral. In our study, an analysis of photothermal damage rate processes in cultured retinal pigment epithelium cells indicated good agreement between temperature rise, exposure duration (τ), and threshold cellular damage. Full-frame thermograms recorded at high magnification during laser exposures were overlaid with fluorescence damage images taken 1 h postexposure. From the image overlays, pixels of the thermogram correlated with the boundary of cell death were used to extract threshold thermal profiles. Assessing photothermal responses at these boundaries standardized all data points, irrespective of laser irradiance, damage size, or optical and thermal properties of the cells. These results support the hypothesis that data from boundaries of cell death were equivalent to a minimum visible lesion, where the damage integral approached unity (Ω = 1) at the end of the exposure duration. Empirically resolved Arrhenius coefficients for use in the damage integral determined from exposures at wavelengths of 2 μm and 532 nm and durations of 0.05-20 s were consistent with literature values. Varying ambient temperature (Tamb) between 20°C and 40°C during laser exposure did not change the τ-dependent threshold peak temperature (Tp). We also show that, although threshold laser irradiance varied due to pigmentation differences, threshold temperatures were irradiance independent.
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Affiliation(s)
- Michael L. Denton
- 711th Human Performance Wing, Airman Systems Directorate, Bioeffects Division, Optical Radiation Bioeffects Branch, JBSA Fort Sam Houston, Texas, United States
| | | | | | | | | | - Cherry C. Gonzalez
- 711th Human Performance Wing, Airman Systems Directorate, Bioeffects Division, Optical Radiation Bioeffects Branch, JBSA Fort Sam Houston, Texas, United States
| | - Benjamin A. Rockwell
- 711th Human Performance Wing, Airman Systems Directorate, Bioeffects Division, Optical Radiation Bioeffects Branch, JBSA Fort Sam Houston, Texas, United States
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8
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Commiskey PW, Heisel CJ, Paulus YM. Non-Therapeutic Laser Retinal Injury. INTERNATIONAL JOURNAL OF OPHTHALMIC RESEARCH 2019; 5:321-335. [PMID: 32923732 PMCID: PMC7486027 DOI: 10.17554/j.issn.2409-5680.2019.05.90] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
BACKGROUND: As lasers have become an increasingly important component of commercial, industrial, military, and medical applications, reported incidents of non-therapeutic laser eye injuries have increased. The retina is particularly vulnerable due to the focusing power and optical transparency of the eye. Continued innovations in laser technology will likely mean that lasers will play an increasingly important and ubiquitous role throughout the world. Critical evaluation should thus be paid to ensure that non-therapeutic injuries are minimized, recognized, and treated appropriately. METHODS: A comprehensive literature review on the PubMed database was conducted to present case reports and case series representative of the variety of laser eye injuries in different injury circumstances, tissue types, and biological damage mechanisms. RESULTS: A general summary of non-therapeutic laser retina injuries is presented, including information about growth of the industry, increasingly accessible online markets, inconsistent international regulation, laser classifications, laser wavelengths, and laser power, mechanisms of tissue injury, and a demonstration of the variety of settings in which injury may occur. Finally, 68 cases found in the literature are summarized to illustrate the presentations and outcomes of these patients. CONCLUSIONS: As non-therapeutic laser eye injuries increase in frequency, there is a greater need for public health, policy, diagnosis, and treatment of these types of injuries.
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Affiliation(s)
- Patrick W Commiskey
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI, the United State
| | - Curtis J Heisel
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI, the United State
| | - Yannis M Paulus
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI, the United State.,Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, the United State
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9
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Kwok SJJ, Jo Y, Lin HH, Choi M, Yun SH. Millisecond cellular labelling in situ with two-photon photoconversion. BIOMEDICAL OPTICS EXPRESS 2018; 9:3067-3077. [PMID: 29984083 PMCID: PMC6033565 DOI: 10.1364/boe.9.003067] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 05/23/2018] [Accepted: 06/06/2018] [Indexed: 06/08/2023]
Abstract
In situ labeling of cells within living biological tissues using photoconversion has provided valuable information on cellular physiology in their natural environments. However, current photoconvertible probes typically require seconds to minutes of light exposure, limiting their uses in rapid biological processes such as intracellular diffusion and circulating cells. Here, we report that two-photon photoconversion of cyanine-based dyes offers unprecedentedly rapid photoconversion down to millisecond timescales per cell. We demonstrate potential biological applications including measuring intracellular diffusion kinetics in a spinal nerve, labeling of rapidly flowing cells in a microfluidic channel, and photoconversion of a circulating cell in vivo.
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Affiliation(s)
- Sheldon J J Kwok
- Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, 50 Blossom Street, Boston, MA 02114, USA
- Harvard-MIT Health Sciences and Technology, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
| | - Yongjae Jo
- Department of Biomedical Engineering, Sungkyunkwan University, Suwon 16419, South Korea
- Center for Neuroscience Imaging Research, Institute for Basic Science, Suwon 16419, South Korea
| | - Harvey H Lin
- Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, 50 Blossom Street, Boston, MA 02114, USA
| | - Myunghwan Choi
- Department of Biomedical Engineering, Sungkyunkwan University, Suwon 16419, South Korea
- Center for Neuroscience Imaging Research, Institute for Basic Science, Suwon 16419, South Korea
| | - Seok-Hyun Yun
- Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, 50 Blossom Street, Boston, MA 02114, USA
- Harvard-MIT Health Sciences and Technology, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
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10
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Lynnyk A, Lunova M, Jirsa M, Egorova D, Kulikov A, Kubinová Š, Lunov O, Dejneka A. Manipulating the mitochondria activity in human hepatic cell line Huh7 by low-power laser irradiation. BIOMEDICAL OPTICS EXPRESS 2018; 9. [PMID: 29541521 PMCID: PMC5846531 DOI: 10.1364/boe.9.001283] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Low-power laser irradiation of red light has been recognized as a promising tool across a vast variety of biomedical applications. However, deep understanding of the molecular mechanisms behind laser-induced cellular effects remains a significant challenge. Here, we investigated mechanisms involved in the death process in human hepatic cell line Huh7 at a laser irradiation. We decoupled distinct cell death pathways targeted by laser irradiations of different powers. Our data demonstrate that high dose laser irradiation exhibited the highest levels of total reactive oxygen species production, leading to cyclophilin D-related necrosis via the mitochondrial permeability transition. On the contrary, low dose laser irradiation resulted in the nuclear accumulation of superoxide and apoptosis execution. Our findings offer a novel insight into laser-induced cellular responses, and reveal distinct cell death pathways triggered by laser irradiation. The observed link between mitochondria depolarization and triggering ROS could be a fundamental phenomenon in laser-induced cellular responses.
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Affiliation(s)
- Anna Lynnyk
- Institute of Physics of the Czech Academy of Sciences, Prague, 18221, Czech Republic
| | - Mariia Lunova
- Institute of Physics of the Czech Academy of Sciences, Prague, 18221, Czech Republic
- Institute for Clinical & Experimental Medicine (IKEM), Prague, 14021, Czech Republic
| | - Milan Jirsa
- Institute for Clinical & Experimental Medicine (IKEM), Prague, 14021, Czech Republic
| | | | | | - Šárka Kubinová
- Institute of Physics of the Czech Academy of Sciences, Prague, 18221, Czech Republic
- Institute of Experimental Medicine of the Czech Academy of Sciences, Prague, 14220, Czech Republic
| | - Oleg Lunov
- Institute of Physics of the Czech Academy of Sciences, Prague, 18221, Czech Republic
| | - Alexandr Dejneka
- Institute of Physics of the Czech Academy of Sciences, Prague, 18221, Czech Republic
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11
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Yong D, Ding D. Lasing with cell-endogenous fluorophores: parameters and conditions. Sci Rep 2017; 7:13569. [PMID: 29051508 PMCID: PMC5648766 DOI: 10.1038/s41598-017-12711-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Accepted: 09/18/2017] [Indexed: 01/05/2023] Open
Abstract
The notion of lasing with biologics has recently been realized and has rapidly developed with the collective objective of creating lasers in vivo. One major limitation of achieving this is the requirement of exogenous dyes and fluorescent materials. We thus investigate for the first time the possibility of lasing unlabelled cells, using just cell-endogenous fluorophores - the source of cell autofluorescence. In this work, we theoretically studied the lasing potential and efficiency of flavins and reduced nicotinamide adenine dinucleotide (phosphate) (NAD(P)H) using a dye lasing model based on coupled rate equations. Analytical solutions for one- and two-photon pumped system were used in multi-parameter studies. We found that at physiological conditions, the more abundant NAD(P)H can be lased with a cavity quality factor of 105. We then recommended the tuning of intersystem crossing to make the lasing of flavins feasible even at their low physiological concentrations. Under conditions of reduced intersystem crossing, we concluded that it is more practical to lase unlabelled cells using flavins, because lasing thresholds and cavity quality factors were both at least an order lower. We also note the higher threshold requirements and lower efficiencies of two-photon pumping, but recognize its potential for realizing lasing in vivo.
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Affiliation(s)
- Derrick Yong
- Precision Measurements Group, Singapore Institute of Manufacturing Technology, 2 Fusionopolis Way, Innovis #08-04, 138634, Singapore, Singapore.
| | - Ding Ding
- Precision Measurements Group, Singapore Institute of Manufacturing Technology, 2 Fusionopolis Way, Innovis #08-04, 138634, Singapore, Singapore
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12
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Miura Y, Pruessner J, Mertineit CL, Kern K, Muenter M, Moltmann M, Danicke V, Brinkmann R. Continuous-wave Thulium Laser for Heating Cultured Cells to Investigate Cellular Thermal Effects. J Vis Exp 2017. [PMID: 28715366 DOI: 10.3791/54326] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
An original method to heat cultured cells using a 1.94 µm continuous-wave thulium laser for biological assessment is introduced here. Thulium laser radiation is strongly absorbed by water, and the cells at the bottom of the culture dish are heated through thermal diffusion. A laser fiber with a diameter of 365 µm is set about 12 cm above the culture dish, without any optics, such that the laser beam diameter is almost equivalent to the inner diameter of the culture dish (30 mm). By keeping a consistent amount of culture medium in each experiment, it is possible to irradiate the cells with a highly reproducible temperature increase. To calibrate the temperature increase and its distribution in one cell culture dish for each power setting, the temperature was measured during 10 s of irradiation at different positions and at the cellular level. The temperature distribution was represented using a mathematical graphics software program, and its pattern across the culture dish was in Gaussian form. After laser irradiation, different biological experiments could be performed to assess temperature-dependent cell responses. In this manuscript, viability staining (i.e., distinguishing live, apoptotic, and dead cells) is introduced to help determine the threshold temperatures for cell apoptosis and death after different points in time. The advantages of this method are the preciseness of the temperature and the time of heating, as well as its high efficiency in heating cells in a whole cell culture dish. Furthermore, it allows for study with a wide variety of temperatures and time durations, which can be well-controlled by a computerized operating system.
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Affiliation(s)
- Yoko Miura
- Institute of Biomedical Optics, University of Luebeck; Medical Laser Center Luebeck GmbH, University of Leubeck; Department of Ophthalmology, University of Luebeck;
| | | | | | | | | | | | - Veit Danicke
- Medical Laser Center Luebeck GmbH, University of Leubeck
| | - Ralf Brinkmann
- Institute of Biomedical Optics, University of Luebeck; Medical Laser Center Luebeck GmbH, University of Leubeck
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13
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Carling CJ, Viger ML, Nguyen Huu VA, Garcia AV, Almutairi A. In Vivo Visible Light-Triggered Drug Release From an Implanted Depot. Chem Sci 2015; 6:335-341. [PMID: 25598962 PMCID: PMC4295782 DOI: 10.1039/c4sc02651a] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Accepted: 10/04/2014] [Indexed: 01/03/2023] Open
Abstract
Controlling chemistry in space and time has offered scientists and engineers powerful tools for research and technology. For example, on-demand photo-triggered activation of neurotransmitters has revolutionized neuroscience. Non-invasive control of the availability of bioactive molecules in living organisms will undoubtedly lead to major advances; however, this requires the development of photosystems that efficiently respond to regions of the electromagnetic spectrum that innocuously penetrate tissue. To this end, we have developed a polymer that photochemically degrades upon absorption of one photon of visible light and demonstrated its potential for medical applications. Particles formulated from this polymer release molecular cargo in vitro and in vivo upon irradiation with blue visible light through a photoexpansile swelling mechanism.
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Affiliation(s)
- Carl-Johan Carling
- Skaggs School of Pharmacy and Pharmaceutical Sciences , University of California, San Diego , 9500 Gilman Dr. , La Jolla , California 92093 , USA . ; Tel: +1-858-246-0871
- KACST-UCSD Center for Excellence in Nanomedicine , University of California, San Diego , 9500 Gilman Dr. , La Jolla , California 92093 , USA
| | - Mathieu L. Viger
- Skaggs School of Pharmacy and Pharmaceutical Sciences , University of California, San Diego , 9500 Gilman Dr. , La Jolla , California 92093 , USA . ; Tel: +1-858-246-0871
- KACST-UCSD Center for Excellence in Nanomedicine , University of California, San Diego , 9500 Gilman Dr. , La Jolla , California 92093 , USA
| | - Viet Anh Nguyen Huu
- KACST-UCSD Center for Excellence in Nanomedicine , University of California, San Diego , 9500 Gilman Dr. , La Jolla , California 92093 , USA
- Department of NanoEngineering , University of California, San Diego , 9500 Gilman Dr. , La Jolla , California 92093 , USA
| | - Arnold V. Garcia
- Skaggs School of Pharmacy and Pharmaceutical Sciences , University of California, San Diego , 9500 Gilman Dr. , La Jolla , California 92093 , USA . ; Tel: +1-858-246-0871
- KACST-UCSD Center for Excellence in Nanomedicine , University of California, San Diego , 9500 Gilman Dr. , La Jolla , California 92093 , USA
| | - Adah Almutairi
- Skaggs School of Pharmacy and Pharmaceutical Sciences , University of California, San Diego , 9500 Gilman Dr. , La Jolla , California 92093 , USA . ; Tel: +1-858-246-0871
- KACST-UCSD Center for Excellence in Nanomedicine , University of California, San Diego , 9500 Gilman Dr. , La Jolla , California 92093 , USA
- Department of NanoEngineering , University of California, San Diego , 9500 Gilman Dr. , La Jolla , California 92093 , USA
- Department of Materials Science and Engineering , University of California, San Diego , 9500 Gilman Dr. , La Jolla , California 92093 , USA
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Dhakal KR, Gu L, Shivalingaiah S, Dennis TS, Morris-Bobzean SA, Li T, Perrotti LI, Mohanty SK. Non-scanning fiber-optic near-infrared beam led to two-photon optogenetic stimulation in-vivo. PLoS One 2014; 9:e111488. [PMID: 25383687 PMCID: PMC4226470 DOI: 10.1371/journal.pone.0111488] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Accepted: 09/24/2014] [Indexed: 11/18/2022] Open
Abstract
Stimulation of specific neurons expressing opsins in a targeted region to manipulate brain function has proved to be a powerful tool in neuroscience. However, the use of visible light for optogenetic stimulation is invasive due to low penetration depth and tissue damage owing to larger absorption and scattering. Here, we report, for the first time, in-depth non-scanning fiber-optic two-photon optogenetic stimulation (FO-TPOS) of neurons in-vivo in transgenic mouse models. In order to optimize the deep-brain stimulation strategy, we characterized two-photon activation efficacy at different near-infrared laser parameters. The significantly-enhanced in-depth stimulation efficiency of FO-TPOS as compared to conventional single-photon beam was demonstrated both by experiments and Monte Carlo simulation. The non-scanning FO-TPOS technology will lead to better understanding of the in-vivo neural circuitry because this technology permits more precise and less invasive anatomical delivery of stimulation.
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Affiliation(s)
- Kamal R. Dhakal
- Biophysics and Physiology Lab, Department of Physics, The University of Texas at Arlington, Arlington, Texas, United States of America
| | - Ling Gu
- Biophysics and Physiology Lab, Department of Physics, The University of Texas at Arlington, Arlington, Texas, United States of America
| | - Shivaranjani Shivalingaiah
- Biophysics and Physiology Lab, Department of Physics, The University of Texas at Arlington, Arlington, Texas, United States of America
| | - Torry S. Dennis
- Department of Psychology, The University of Texas at Arlington, Arlington, Texas, United States of America
| | - Samara A. Morris-Bobzean
- Department of Psychology, The University of Texas at Arlington, Arlington, Texas, United States of America
| | - Ting Li
- Key lab for Neuroinformatics of Ministry of Education, University of Electronic Science & Technology of China, Chengdu, Sichuan, China
| | - Linda I. Perrotti
- Department of Psychology, The University of Texas at Arlington, Arlington, Texas, United States of America
| | - Samarendra K. Mohanty
- Biophysics and Physiology Lab, Department of Physics, The University of Texas at Arlington, Arlington, Texas, United States of America
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15
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Choi TY, Denton ML, Noojin GD, Estlack LE, Shrestha R, Rockwell BA, Thomas R, Kim D. Thermal evaluation of laser exposures in an in vitro retinal model by microthermal sensing. JOURNAL OF BIOMEDICAL OPTICS 2014; 19:97003. [PMID: 25222532 DOI: 10.1117/1.jbo.19.9.097003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Accepted: 08/25/2014] [Indexed: 06/03/2023]
Abstract
A temperature detection system using a micropipette thermocouple sensor was developed for use within mammalian cells during laser exposure with an 8.6-μm beam at 532 nm. We have demonstrated the capability of measuring temperatures at a single-cell level in the microscale range by inserting micropipettebased thermal sensors of size ranging from 2 to 4 μm into the membrane of a live retinal pigment epithelium (RPE) cell subjected to a laser beam. We setup the treatment groups of 532-nm laser-irradiated single RPE cell and in situ temperature recordings were made over time. Thermal profiles are given for representative cells experiencing damage resulting from exposures of 0.2 to 2 s. The measured maximum temperature rise for each cell ranges from 39 to 73°C; the RPE cells showed a signature of death for all the cases reported herein. In order to check the cell viability, real-time fluorescence microscopy was used to identify the transition of pigmented RPE cells between viable and damaged states due to laser exposure.
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Affiliation(s)
- Tae Y Choi
- University of North Texas, Department of Mechanical and Energy Engineering, 3940 N. Elm Street Denton, Texas 76207, United States
| | - Michael L Denton
- TASC, Inc., Department of Biomedical Sciences and Technologies, 4141 Petroleum Road, JBSA Fort Sam Houston, Texas 78234, United States
| | - Gary D Noojin
- TASC, Inc., Department of Biomedical Sciences and Technologies, 4141 Petroleum Road, JBSA Fort Sam Houston, Texas 78234, United States
| | - Larry E Estlack
- Conceptual MindWorks, Inc., 4141 Petroleum Road, JBSA Fort Sam Houston, Texas 78234, United States
| | - Ramesh Shrestha
- University of North Texas, Department of Mechanical and Energy Engineering, 3940 N. Elm Street Denton, Texas 76207, United States
| | - Benjamin A Rockwell
- 711th Human Performance Wing, Bioeffects Division, Optical Radiation Bioeffects Branch, 4141 Petroleum Road, JBSA Fort Sam Houston, Texas 78234, United States
| | - Robert Thomas
- 711th Human Performance Wing, Bioeffects Division, Optical Radiation Bioeffects Branch, 4141 Petroleum Road, JBSA Fort Sam Houston, Texas 78234, United States
| | - Dongsik Kim
- POSTECH, Department of Mechanical Engineering, San 31 Hyoja-Dong, Nam-Gu, Pohang, Gyungbuk 790-784, Republic of Korea
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16
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High-resolution in vivo imaging of regimes of laser damage to the primate retina. J Ophthalmol 2014; 2014:516854. [PMID: 24891943 PMCID: PMC4033483 DOI: 10.1155/2014/516854] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Revised: 02/12/2014] [Accepted: 02/13/2014] [Indexed: 11/18/2022] Open
Abstract
Purpose. To investigate fundamental mechanisms of regimes of laser induced damage to the retina and the morphological changes associated with the damage response. Methods. Varying grades of photothermal, photochemical, and photomechanical retinal laser damage were produced in eyes of eight cynomolgus monkeys. An adaptive optics confocal scanning laser ophthalmoscope and spectral domain optical coherence tomographer were combined to simultaneously collect complementary in vivo images of retinal laser damage during and following exposure. Baseline color fundus photography was performed to complement high-resolution imaging. Monkeys were perfused with 10% buffered formalin and eyes were enucleated for histological analysis. Results. Laser energies for visible retinal damage in this study were consistent with previously reported damage thresholds. Lesions were identified in OCT images that were not visible in direct ophthalmoscopic examination or fundus photos. Unique diagnostic characteristics, specific to each damage regime, were identified and associated with shape and localization of lesions to specific retinal layers. Previously undocumented retinal healing response to blue continuous wave laser exposure was recorded through a novel experimental methodology. Conclusion. This study revealed increased sensitivity of lesion detection and improved specificity to the laser of origin utilizing high-resolution imaging when compared to traditional ophthalmic imaging techniques in the retina.
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17
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Protective effect of a laser-induced sub-lethal temperature rise on RPE cells from oxidative stress. Exp Eye Res 2014; 124:37-47. [PMID: 24800654 DOI: 10.1016/j.exer.2014.04.014] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2014] [Revised: 03/22/2014] [Accepted: 04/18/2014] [Indexed: 11/22/2022]
Abstract
Recently introduced new technologies that enable temperature-controlled laser irradiation on the RPE allowed us to investigate temperature-resolved RPE cell responses. In this study we aimed primarily to establish an experimental setup that can realize laser irradiation on RPE cell culture with the similar temperature distribution as in the clinical application, with a precise time/temperature history. With this setup, we conducted investigations to elucidate the temperature-dependent RPE cell biochemical responses and the effect of transient hyperthermia on the responses of RPE cells to the secondary-exposed oxidative stress. Porcine RPE cells cultivated in a culture dish (inner diameter = 30 mm) with culture medium were used, on which laser radiation (λ = 1940 nm, spot diameter = 30 mm) over 10 s was applied as a heat source. The irradiation provides a radially decreasing temperature profile which is close to a Gaussian shape with the highest temperature in the center. Power setting for irradiation was determined such that the peak temperature (Tmax) in the center of the laser spot at the cells reaches from 40 °C to 58 °C (40, 43, 46, 50, 58 °C). Cell viability was investigated with ethidium homodimer III staining at the time points of 3 and 24 h following laser irradiation. Twenty four hours after laser irradiation the cells were exposed to hydrogen peroxide (H2O2) for 5 h, followed by the measurement of intracellular glutathione, intracellular 4-hydroxynonenal (HNE) protein adducts, and secreted vascular endothelial growth factor (VEGF). The mean temperature threshold for RPE cell death after 3 h was found to be around 52 °C, and for 24 h around 50 °C with the current irradiation setting. A sub-lethal preconditioning on Tmax = 43 °C significantly induced the reduced glutathione (GSH)/oxidized glutathione (GSSG) ratio, and decreased H2O2-induced increase of intracellular 4-HNE protein adducts. Although sub-lethal hyperthermia (Tmax = 40 °C, 43 °C, and 46 °C) caused a slight increase of VEGF secretion in 6 h directly following irradiation, secondary exposed H2O2-induced VEGF secretion was significantly reduced in the sub-lethally preheated groups, where the largest effect was seen following the irradiation with Tmax = 43 °C. In summary, the current results suggest that sub-lethal thermal laser irradiation on the RPE at Tmax = 43 °C for 10 s enhances cell defense system against oxidative stress, with increasing the GSH/GSSG ratio. Together with the results that the decreased amount of H2O2-induced 4-HNE in sub-lethally preheated RPE cells was accompanied by the lower secretion of VEGF, it is also strongly suggested that the sub-lethal hyperthermia may modify RPE cell functionality to protect RPE cells from oxidative stress and associated functional decrease, which are considered to play a significant role in the pathogenesis of age-related macular degeneration and other chorioretinal degenerative diseases.
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18
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Whitney J, Carswell W, Rylander N. Arrhenius parameter determination as a function of heating method and cellular microenvironment based on spatial cell viability analysis. Int J Hyperthermia 2013; 29:281-95. [DOI: 10.3109/02656736.2013.802375] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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19
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Lapchak PA. Transcranial near-infrared laser therapy applied to promote clinical recovery in acute and chronic neurodegenerative diseases. Expert Rev Med Devices 2012; 9:71-83. [PMID: 22145842 DOI: 10.1586/erd.11.64] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
One of the most promising methods to treat neurodegeneration is noninvasive transcranial near-infrared laser therapy (NILT), which appears to promote acute neuroprotection by stimulating mitochondrial function, thereby increasing cellular energy production. NILT may also promote chronic neuronal function restoration via trophic factor-mediated plasticity changes or possibly neurogenesis. Clearly, NILT is a treatment that confers neuroprotection or neurorestoration using pleiotropic mechanisms. The most advanced application of NILT is for acute ischemic stroke based upon extensive preclinical and clinical studies. In laboratory settings, NILT is also being developed to treat traumatic brain injury, Alzheimer's disease and Parkinson's disease. There is some intriguing data in the literature that suggests that NILT may be a method to promote clinical improvement in neurodegenerative diseases where there is a common mechanistic component, mitochondrial dysfunction and energy impairment. This article will analyze and review data supporting the continued development of NILT to treat neurodegenerative diseases.
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Affiliation(s)
- Paul A Lapchak
- Cedars-Sinai Medical Center, Department of Neurology, Los Angeles, CA 90048, USA.
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20
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Shrestha R, Choi TY, Chang W, Kim D. A high-precision micropipette sensor for cellular-level real-time thermal characterization. SENSORS 2011; 11:8826-35. [PMID: 22164108 PMCID: PMC3231465 DOI: 10.3390/s110908826] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/05/2011] [Revised: 09/07/2011] [Accepted: 09/07/2011] [Indexed: 11/16/2022]
Abstract
We report herein development of a novel glass micropipette thermal sensor fabricated in a cost-effective manner, which is capable of measuring steady thermal fluctuation at spatial resolution of ∼2 μm with an accuracy of ±0.01 °C. We produced and tested various micrometer-sized sensors, ranging from 2 μm to 30 μm. The sensor comprises unleaded low-melting-point solder alloy (Sn-based) as a core metal inside a pulled borosilicate glass pipette and a thin film of nickel coating outside, creating a thermocouple junction at the tip. The sensor was calibrated using a thermally insulated calibration chamber, the temperature of which can be controlled with an accuracy of ±0.01 °C, and the thermoelectric power (Seebeck coefficient) of the sensor was recorded from 8.46 to 8.86 μV/°C. We have demonstrated the capability of measuring temperatures at a cellular level by inserting our temperature sensor into the membrane of a live retinal pigment epithelium cell subjected to a laser beam with a focal spot of 6 μm. We measured transient temperature profiles and the maximum temperatures were in the range of 38-55 ± 0.5 °C.
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Affiliation(s)
- Ramesh Shrestha
- Department of Mechanical and Energy Engineering, University of North Texas, 3940 N. Elm St, Denton, TX 76207, USA; E-Mail: E-Mail:
| | - Tae-Youl Choi
- Department of Mechanical and Energy Engineering, University of North Texas, 3940 N. Elm St, Denton, TX 76207, USA; E-Mail: E-Mail:
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +1-940-565-2198; Fax: +1-940-369-8675
| | - Wonseok Chang
- Department of Nanomechanical Systems, Korea Institute of Machinery and Materials, 156 Gajungbukno, Yuseong-gu, Daejeon 305-343, Korea; E-Mail:
| | - Donsik Kim
- Department of Mechanical Engineering, POSTECH, San 31 Hyoja-Dong, Nam-Gu, Pohang, Gyungbuk 790-784, Korea; E-Mail:
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21
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Cui L, Huxlin KR, Xu L, MacRae S, Knox WH. High-resolution, noninvasive, two-photon fluorescence measurement of molecular concentrations in corneal tissue. Invest Ophthalmol Vis Sci 2011; 52:2556-64. [PMID: 21228379 DOI: 10.1167/iovs.10-6620] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To perform high-resolution, noninvasive, calibrated measurements of the concentrations and diffusion profiles of fluorescent molecules in the live cornea after topical application to the ocular surface. METHODS An 800-nm femtosecond laser was used to perform two-photon fluorescence (TPF) axial scanning measurements. Calibration solutions consisting of sodium fluorescein (Na-Fl; concentration range, 0.01%-2.5%) and riboflavin (concentration range, 0.0125%-0.1%) were tested in well slides, and TPF signals were assessed. Excised feline eyeballs preserved in corneal storage medium and with either intact or removed corneal epithelia were then treated with Na-Fl, riboflavin, or fluorescein dextran (Fl-d) of different molecular weight (MW) for 30 minutes. Calibrated TPF was then used immediately to measure the concentration of these molecules across the central corneal depth. RESULTS The axial resolution of our TPF system was 6 μm, and a linear relationship was observed between TPF signal and low concentrations of most fluorophores. Intact corneas treated with Na-Fl or riboflavin exhibited a detectable penetration depth of only approximately 20 μm, compared with approximately 400 to 600 μm when the epithelium was removed before fluorophore application. Peak concentrations for intact corneas were half those attained with epithelial removal. Debrided corneas treated with 2,000,000 MW Fl-d showed a half-maximum penetration depth of 156.7 μm compared with 384 μm for the 3,000 MW dextran. The peak concentration of the high MW dextran was one quarter that of the lower MW dextran. CONCLUSIONS TPF is an effective, high-resolution, noninvasive method of quantifying the diffusion and concentration of fluorescent molecules across the cornea.
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Affiliation(s)
- Liping Cui
- Institute of Optics, University of Roichester, Rochester, NY, USA
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22
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Obana A, Brinkmann R, Gohto Y, Nishimura K. A case of retinal injury by a violet light-emitting diode. Retin Cases Brief Rep 2011; 5:223-226. [PMID: 25390169 DOI: 10.1097/icb.0b013e3181e180d5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
PURPOSE To describe the first case of retinal injury by a misuse of a toy using light-emitting diode. METHODS A 15-year-old male Japanese student received irradiation on his right eye by a 5 mW light-emitting diode of 410 nm wavelength for 20 seconds in 2 days. He noticed decreased vision and central scotoma approximately 2 weeks later from these events. The mechanism of injury was evaluated from the estimated irradiance on the retina by comparison with experimental threshold data published. RESULTS Chorioretinal atrophy with visual loss and central scotoma has remained on the fovea. The patient received an estimated dose of 1.58 J/cm 2 times, which was close to the experimentally determined radiant exposure for photochemical injury of rat retina. CONCLUSION The violet light from light-emitting diodes is a potential hazard for the retina, and thus, direct viewing into the beam should be avoided. Children, especially, should not be allowed to play with such toys without being carefully instructed about their proper use and fully supervised.
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Affiliation(s)
- Akira Obana
- From the *Department of Ophthalmology, Seirei Hamamatsu General Hospital, Hamamatsu, Japan; †Photochemical Medicine Department, Photon Medical Research Center, Hamamatsu University School of Medicine, Hamamatsu, Japan; and ‡Institute of Biomedical Optics, University of Lübeck, Lübeck, Germany
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23
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Liggett TE, Griffiths TD, Gaillard ER. Isolation and characterization of a spontaneously immortalized bovine retinal pigmented epithelial cell line. BMC Cell Biol 2009; 10:33. [PMID: 19413901 PMCID: PMC3152772 DOI: 10.1186/1471-2121-10-33] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2008] [Accepted: 05/04/2009] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND The Retinal Pigmented Epithelium (RPE) is juxtaposed with the photoreceptor outer segments of the eye. The proximity of the photoreceptor cells is a prerequisite for their survival, as they depend on the RPE to remove the outer segments and are also influenced by RPE cell paracrine factors. RPE cell death can cause a progressive loss of photoreceptor function, which can diminish vision and, over time, blindness ensues. Degeneration of the retina has been shown to induce a variety of retinopathies, such as Stargardt's disease, Cone-Rod Dystrophy (CRD), Retinitis Pigmentosa (RP), Fundus Flavimaculatus (FFM), Best's disease and Age-related Macular Degeneration (AMD). We have cultured primary bovine RPE cells to gain a further understanding of the mechanisms of RPE cell death. One of the cultures, named tRPE, surpassed senescence and was further characterized to determine its viability as a model for retinal diseases. RESULTS The tRPE cell line has been passaged up to 150 population doublings and was shown to be morphologically similar to primary cells. They have been characterized to be of RPE origin by reverse transcriptase PCR and immunocytochemistry using the RPE-specific genes RPE65 and CRALBP and RPE-specific proteins RPE65 and Bestrophin. The tRPE cells are also immunoreactive to vimentin, cytokeratin and zonula occludens-1 antibodies. Chromosome analysis indicates a normal diploid number. The tRPE cells do not grow in suspension or in soft agar. After 3H thymidine incorporation, the cells do not appear to divide appreciably after confluency. CONCLUSION The tRPE cells are immortal, but still exhibit contact inhibition, serum dependence, monolayer growth and secrete an extra-cellular matrix. They retain the in-vivo morphology, gene expression and cell polarity. Additionally, the cells endocytose exogenous melanin, A2E and purified lipofuscin granules. This cell line may be a useful in-vitro research model for retinal maculopathies.
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Affiliation(s)
- Thomas E Liggett
- Department of Biological Sciences, Northern Illinois University, DeKalb, IL, USA
- Current address: Department of Neurological Sciences, Rush University Medical Center, Chicago, IL, USA
| | - T Daniel Griffiths
- Department of Biological Sciences, Marquette University, Milwaukee, WI, USA
| | - Elizabeth R Gaillard
- Department of Biological Sciences, Northern Illinois University, DeKalb, IL, USA
- Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, IL, USA
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Denton ML, Foltz MS, Schuster KJ, Noojin GD, Estlack LE, Thomas RJ. In vitro model that approximates retinal damage threshold trends. JOURNAL OF BIOMEDICAL OPTICS 2008; 13:054014. [PMID: 19021394 DOI: 10.1117/1.2981831] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Without effective in vitro damage models, advances in our understanding of the physics and biology of laser-tissue interaction would be hampered due to cost and ethical limitations placed on the use of nonhuman primates. We extend our characterization of laser-induced cell death in an existing in vitro retinal model to include damage thresholds at 514 and 413 nm. The new data, when combined with data previously reported for 532 and 458 nm exposures, provide a sufficiently broad range of wavelengths and exposure durations (0.1 to 100 s) to make comparisons with minimum visible lesion (in vivo) data in the literature. Based on similarities between in vivo and in vitro action spectra and temporal action profiles, the cell culture model is found to respond to laser irradiation in a fundamentally similar fashion as the retina of the rhesus animal model. We further show that this response depends on the amount of intracellular melanin pigmentation.
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Affiliation(s)
- Michael L Denton
- Northrop Grumman, Warfighter Concepts and Applications Department, San Antonio, Texas, USA
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25
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Denton ML, Foltz MS, Schuster KJ, Estlack LE, Thomas RJ. Damage thresholds for cultured retinal pigment epithelial cells exposed to lasers at 532 nm and 458 nm. JOURNAL OF BIOMEDICAL OPTICS 2007; 12:034030. [PMID: 17614738 DOI: 10.1117/1.2737394] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
The determination of safe exposure levels for lasers has come from damage assessment experiments in live animals, which typically involve correlating visually identifiable damage with laser dosimetry. Studying basic mechanisms of laser damage in animal retinal systems often requires tissue sampling (animal sacrifice), making justification and animal availability problematic. We determined laser damage thresholds in cultured monolayers of a human retinal pigment epithelial (RPE) cell line. By varying exposure duration and laser wavelength, we identified conditions leading to damage by presumed photochemical or thermal mechanisms. A comparison with literature values for ocular damage thresholds validates the in vitro model. The in vitro system described will facilitate molecular and cellular approaches for understanding laser-tissue interaction.
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Affiliation(s)
- Michael L Denton
- Northrop Grumman, Warfighter Concepts and Applications Department, San Antonio, Texas 78228, USA
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26
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Laser literature watch. Photomed Laser Surg 2006; 24:661-76. [PMID: 17069502 DOI: 10.1089/pho.2006.24.661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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