scholarly journals Focusing light inside live tissue using reversibly switchable bacterial phytochrome as a genetically encoded photochromic guide star

2019 ◽  
Vol 5 (12) ◽  
pp. eaay1211 ◽  
Author(s):  
Jiamiao Yang ◽  
Lei Li ◽  
Anton A. Shemetov ◽  
Sangjun Lee ◽  
Yuan Zhao ◽  
...  
Keyword(s):  
Biomedical Applications ◽  
Near Infrared ◽  
Scattering Media ◽  
Light Delivery ◽  
Mouse Tumors ◽  
Wavefront Shaping ◽  
Guide Star ◽  
Absorption Contrast ◽  
Delivery Efficiency

Focusing light deep by engineering wavefronts toward guide stars inside scattering media has potential biomedical applications in imaging, manipulation, stimulation, and therapy. However, the lack of endogenous guide stars in biological tissue hinders its translations to in vivo applications. Here, we use a reversibly switchable bacterial phytochrome protein as a genetically encoded photochromic guide star (GePGS) in living tissue to tag photons at targeted locations, achieving light focusing inside the tissue by wavefront shaping. As bacterial phytochrome-based GePGS absorbs light differently upon far-red and near-infrared illumination, a large dynamic absorption contrast can be created to tag photons inside tissue. By modulating the GePGS at a distinctive frequency, we suppressed the competition between GePGS and tissue motions and formed tight foci inside mouse tumors in vivo and acute mouse brain tissue, thus improving light delivery efficiency and specificity. Spectral multiplexing of GePGS proteins with different colors is an attractive possibility.

scholarly journals Chemistry Routes for Copolymer Synthesis Containing PEG for Targeting, Imaging, and Drug Delivery Purposes

Pharmaceutics ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 327 ◽  
Author(s):  
Kamil Rahme ◽  
Nazih Dagher
Keyword(s):  
Biomedical Applications ◽  
Near Infrared ◽  
Blood Stream ◽  
Biocompatible Polymers ◽  
Low Molecular Weight ◽  
Blood Components ◽  
Vast Number ◽  
Macrophage Phagocytosis ◽  
Sterical Hindrance

Polyethylene glycol (PEG) is one of the most frequently used polymers for coating nanocarriers to enhance their biocompatibility, hydrophilicity, stability, and biodegradability. PEG is now considered to be among the best biocompatible polymers. It offers sterical hindrance against other nanoparticles and blood components such as opsonin, preventing their macrophage phagocytosis and resulting in a prolonged circulation time in blood stream, consequently a ‘stealth character’ in vivo. Therefore, PEG has a very promising future for the development of current therapeutics and biomedical applications. Moreover, the vast number of molecules that PEG can conjugate with might enhance its ability to have an optimistic perspective for the future. This review will present an update on the chemistry used in the modern conjugation methods for a variety of PEG conjugates, such methods include, but are not limited to, the synthesis of targeting PEG conjugates (i.e., Peptides, Folate, Biotin, Mannose etc.), imaging PEG conjugates (i.e., Coumarin, Near Infrared dyes etc.) and delivery PEG conjugates (i.e., doxorubicin, paclitaxel, and other hydrophobic low molecular weight drugs). Furthermore, the type of nanoparticles carrying those conjugates, along with their biomedical uses, will be briefly discussed.

scholarly journals Listening to laser light interactions with objects of art: a novel photoacoustic approach for diagnosis and monitoring of laser cleaning interventions

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
George J. Tserevelakis ◽  
Paraskevi Pouli ◽  
Giannis Zacharakis
Keyword(s):  
Near Infrared ◽  
Structural Information ◽  
Low Cost ◽  
Diagnostic Technique ◽  
Laser Cleaning ◽  
Detection Sensitivity ◽  
Scattering Media ◽  
Reliable Monitoring ◽  
The Rich ◽  
Absorption Contrast

Abstract Photoacoustic (PA) imaging is a novel, rapidly expanding diagnostic technique, which has been predominately developed in the context of contemporary biomedical research studies. In this review, we demonstrate how PA technologies can break through the barriers of biomedicine to find innovative applications in cultural heritage (CH) diagnostics and laser cleaning monitoring. Having over three orders of magnitude higher transmission through strongly scattering media, compared to light in the visible and near infrared, PA signals offer substantially improved detection sensitivity, providing optical absorption contrast at high spatial resolution. This unique combination of features is employed for establishing novel diagnostic methodologies aiming to uncover well-hidden features and provide structural information in multi-layered CH objects such as paintings and documents. Finally, we demonstrate that the PA effect can be successfully utilized for the reliable monitoring of laser cleaning interventions on stonework, allowing for a safe and well-controlled cleaning procedure which will safeguard CH objects’ original surfaces. Simplicity of implementation, effectiveness and low-cost features provided by the developed diagnostic and monitoring systems, highlight the rich potential of emerging PA technologies in CH studies and offer exciting possibilities for future implementations.

scholarly journals Hyaluronate modified upconversion nanoparticles for near infrared light-triggered on–off tattoo systems

RSC Advances ◽  
2017 ◽  
Vol 7 (24) ◽  
pp. 14805-14808 ◽  
Author(s):  
Seulgi Han ◽  
Songeun Beack ◽  
Sanghwa Jeong ◽  
Byung Woo Hwang ◽  
Myeong Hwan Shin ◽  
...  
Keyword(s):  
Biomedical Applications ◽  
Near Infrared ◽  
Infrared Light ◽  
Upconversion Nanoparticles ◽  
Near Infrared Light ◽  
Nir Light

We successfully developed an NIR light-triggered in vivo on–off tattoo system using hyaluronate modified upconversion nanoparticles for various biomedical applications.

scholarly journals Counterion-insulated near-infrared dyes in biodegradable polymer nanoparticles for in vivo imaging

2021 ◽  
Author(s):  
Joanna Sobska ◽  
Bohdan Andreiuk ◽  
Ilya O. Aparin ◽  
Andreas Reisch ◽  
Wojciech Krezel ◽  
...  
Keyword(s):  
Contrast Agents ◽  
Biodegradable Polymer ◽  
In Vivo Imaging ◽  
Biomedical Applications ◽  
Near Infrared ◽  
Polymeric Nanoparticles ◽  
Polymer Nanoparticles ◽  
Potential Biodegradability

Abstract Polymeric nanoparticles (NPs) are highly attractive for biomedical applications due to their potential biodegradability and capacity to encapsulate different loads, notably drugs and contrast agents. For in vivo optical...

scholarly journals A microrobotic system guided by photoacoustic computed tomography for targeted navigation in intestines in vivo

2019 ◽  
Vol 4 (32) ◽  
pp. eaax0613 ◽  
Author(s):  
Zhiguang Wu ◽  
Lei Li ◽  
Yiran Yang ◽  
Peng Hu ◽  
Yang Li ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Biomedical Applications ◽  
Near Infrared ◽  
Tissue Imaging ◽  
Infrared Light ◽  
Precise Control ◽  
Deep Imaging ◽  
Diverse Environment ◽  
Deep Tissue Imaging

Recently, tremendous progress in synthetic micro/nanomotors in diverse environment has been made for potential biomedical applications. However, existing micro/nanomotor platforms are inefficient for deep tissue imaging and motion control in vivo. Here, we present a photoacoustic computed tomography (PACT)–guided investigation of micromotors in intestines in vivo. The micromotors enveloped in microcapsules are stable in the stomach and exhibit efficient propulsion in various biofluids once released. The migration of micromotor capsules toward the targeted regions in intestines has been visualized by PACT in real time in vivo. Near-infrared light irradiation induces disintegration of the capsules to release the cargo-loaded micromotors. The intensive propulsion of the micromotors effectively prolongs the retention in intestines. The integration of the newly developed microrobotic system and PACT enables deep imaging and precise control of the micromotors in vivo and promises practical biomedical applications, such as drug delivery.

scholarly journals Comparison of Dual Beam Dispersive and FTNIR Spectroscopy for Lactate Detection

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1891
Author(s):  
Nystha Baishya ◽  
Mohammad Mamouei ◽  
Karthik Budidha ◽  
Meha Qassem ◽  
Pankaj Vadgama ◽  
...  
Keyword(s):  
Biomedical Applications ◽  
Near Infrared ◽  
Prediction Models ◽  
Full Range ◽  
Multivariate Techniques ◽  
Analyte Concentration ◽  
Predictive Capability ◽  
Advantages And Disadvantages ◽  
Dual Beam

Near Infrared (800–2500 nm) spectroscopy has been extensively used in biomedical applications, as it offers rapid, in vivo, bed-side monitoring of important haemodynamic parameters, which is especially important in critical care settings. However, the choice of NIR spectrometer needs to be investigated for biomedical applications, as both the dual beam dispersive spectrophotomer and the FTNIR spectrometer have their own advantages and disadvantages. In this study, predictive analysis of lactate concentrations in whole blood were undertaken using multivariate techniques on spectra obtained from the two spectrometer types simultaneously and results were compared. Results showed significant improvement in predicting analyte concentration when analysis was performed on full range spectral data. This is in comparison to analysis of limited spectral regions or lactate signature peaks, which yielded poorer prediction models. Furthermore, for the same region, FTNIR showed 10% better predictive capability than the dual beam dispersive NIR spectrometer.

Probing Near-Infrared Quantum Dots for Imaging and Biomedical Applications

2011 ◽  
Vol 345 ◽  
pp. 3-11 ◽  
Author(s):  
Zi Hao Wang ◽  
Xue Feng Wang ◽  
Han Jiang ◽  
Jing Ding ◽  
Jian Dong Wang ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Biomedical Applications ◽  
Near Infrared ◽  
Light Emission ◽  
Chemical Properties ◽  
Fluorescent Imaging ◽  
Light Emitting ◽  
Photo Stability

As light-emitting nanocrystals, quantum dots (QDs) have created a new realm of bioscience by combining nanomaterials with biology. They also have been a major focus of research and development during the past decade, which will profoundly influence future biological as well as biomedical research. In recent years, near-infrared (NIR) quantum dots have emerged in analytical applications, especially for in vitro and in vivo imaging. The impetus behind such endeavors can be attributed to their unique optical and chemical properties, with size-tunable light emission, high photo stability, and manifold fluorescence colors. In this review, we focus on fluorescent imaging with near-infrared (NIR) quantum dots (QDs) both in vitro and in vivo, and the advantages of QDs and potential problems to their use in practical biomedical applications. The ultimate targets aim at decreasing the cytotoxicity of QDs and the future outlook of QD applications in biomedical fields.

Development of an in-vivo sensor for monitoring of water content in skin

2015 ◽  
Vol 4 (2) ◽  
Author(s):  
Rijk Schütz ◽  
Ihar Shchatsinin ◽  
Uwe Bindig ◽  
Carina Reble ◽  
Jürgen Helfmann
Keyword(s):  
Water Content ◽  
Water Distribution ◽  
Near Infrared ◽  
Pathological Condition ◽  
Scattering Media ◽  
Infrared Wavelength ◽  
Light Emitting ◽  
Tissue Phantoms ◽  
Life Threatening

AbstractA change in the water distribution of the human body, such as water retention in the skin, can be a symptom of a pathological condition including heart failure. Therefore, a sensor for the non-invasive quantification of the water content of the skin could be useful where continuous monitoring of patients is required to detect and avoid life threatening conditions. As water is a major absorber of tissue in the near-infrared wavelength range, the water content can be determined based on reflectance measurements. Measuring the diffuse reflectance at multiple distances from the point of illumination allows the determination of absorption in scattering media such as skin. The aim of this project was to develop a small and portable sensor based on light emitting diodes and photodiodes. Evaluation of the first functional sensor design has showed that the water content of tissue phantoms can be predicted with a prediction error of 1%. Further developments towards a sensor that can be applied in a future field study are ongoing.

Biomedical applications: Pitfalls in the practice

1994 ◽  
Vol 52 ◽  
pp. 378-379
Author(s):  
J. D. Shelburne ◽  
Peter Ingram ◽  
Victor L. Roggli ◽  
Ann LeFurgey
Keyword(s):  
Operating Room ◽  
Liquid Nitrogen ◽  
Lung Tissue ◽  
Biomedical Applications ◽  
Microprobe Analysis ◽  
Tissue Sample ◽  
Cellular Level ◽  
Tissue Samples ◽  
Asbestos Fibers

At present most medical microprobe analysis is conducted on insoluble particulates such as asbestos fibers in lung tissue. Cryotechniques are not necessary for this type of specimen. Insoluble particulates can be processed conventionally. Nevertheless, it is important to emphasize that conventional processing is unacceptable for specimens in which electrolyte distributions in tissues are sought. It is necessary to flash-freeze in order to preserve the integrity of electrolyte distributions at the subcellular and cellular level. Ideally, biopsies should be flash-frozen in the operating room rather than being frozen several minutes later in a histology laboratory. Electrolytes will move during such a long delay. While flammable cryogens such as propane obviously cannot be used in an operating room, liquid nitrogen-cooled slam-freezing devices or guns may be permitted, and are the best way to achieve an artifact-free, accurate tissue sample which truly reflects the in vivo state. Unfortunately, the importance of cryofixation is often not understood. Investigators bring tissue samples fixed in glutaraldehyde to a microprobe laboratory with a request for microprobe analysis for electrolytes.

Biological and biomedical applications of collagenous biomaterials

1990 ◽  
Vol 48 (3) ◽  
pp. 856-857
Author(s):  
Yasushi P. Kato ◽  
Michael G. Dunn ◽  
Frederick H. Silver ◽  
Arthur J. Wasserman
Keyword(s):  
Biomedical Applications ◽  
Soft Tissues ◽  
Collagen Fibers ◽  
Bone Collagen ◽  
Cover Slip ◽  
Fibroblast Migration ◽  
Cellular Expression ◽  
Defect Repair

Collagenous biomaterials have been used for growing cells in vitro as well as for augmentation and replacement of hard and soft tissues. The substratum used for culturing cells is implicated in the modulation of phenotypic cellular expression, cellular orientation and adhesion. Collagen may have a strong influence on these cellular parameters when used as a substrate in vitro. Clinically, collagen has many applications to wound healing including, skin and bone substitution, tendon, ligament, and nerve replacement. In this report we demonstrate two uses of collagen. First as a fiber to support fibroblast growth in vitro, and second as a demineralized bone/collagen sponge for radial bone defect repair in vivo.For the in vitro study, collagen fibers were prepared as described previously. Primary rat tendon fibroblasts (1° RTF) were isolated and cultured for 5 days on 1 X 15 mm sterile cover slips. Six to seven collagen fibers, were glued parallel to each other onto a circular cover slip (D=18mm) and the 1 X 15mm cover slip populated with 1° RTF was placed at the center perpendicular to the collagen fibers. Fibroblast migration from the 1 x 15mm cover slip onto and along the collagen fibers was measured daily using a phase contrast microscope (Olympus CK-2) with a calibrated eyepiece. Migratory rates for fibroblasts were determined from 36 fibers over 4 days.

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