optical sensors
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The clinical assessment of microvascular pathologies (in diabetes and in inflammatory skin diseases, for example) requires the visualization of superficial vascular anatomy. Photoacoustic tomography (PAT) scanners based on an all-optical Fabry-Perot ultrasound sensor can provide highly detailed 3D microvascular images, but minutes-long acquisition times have precluded their clinical use. Here we show that scan times can be reduced to a few seconds and even hundreds of milliseconds by parallelizing the optical architecture of the sensor readout, by using excitation lasers with high pulse-repetition frequencies and by exploiting compressed sensing. A PAT scanner with such fast acquisition minimizes motion-related artefacts and allows for the volumetric visualization of individual arterioles, venules, venous valves and millimetre-scale arteries and veins to depths approaching 15 mm, as well as for dynamic 3D images of time-varying tissue perfusion and other haemodynamic events. In exploratory case studies, we used the scanner to visualize and quantify microvascular changes associated with peripheral vascular disease, skin inflammation and rheumatoid arthritis. Fast all-optical PAT may prove useful in cardiovascular medicine, oncology, dermatology and rheumatology.
- MeSH
- kůže krevní zásobení MeSH
- lidé MeSH
- mikrocévy diagnostické zobrazování MeSH
- optoakustické techniky * metody přístrojové vybavení MeSH
- revmatoidní artritida diagnostické zobrazování MeSH
- zobrazování trojrozměrné * metody přístrojové vybavení MeSH
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- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Recent advances in optical sensing technologies underpin the development of high-performance, surface-sensitive analytical tools capable of reliable and precise detection of molecular targets in complex biological media in non-laboratory settings. Optical fibre sensors guide light to and from a region of interest, enabling sensitive measurements of localized environments. This positions optical fibre sensors as a highly promising technology for a wide range of biochemical and healthcare applications. However, their performance in real-world biological media is often limited by the absence of robust post-modification strategies that provide both high biorecognition and antifouling capabilities. In this study, we present the proof-of-concept antifouling and biorecognition performance of a polymer brush nano-coating synthesized at the sensing region of optical fibre long-period grating (LPG) sensors. Using a newly developed antifouling terpolymer brush (ATB) composed of carboxybetaine methacrylamide, sulfobetaine methacrylamide, and N-(2-hydroxypropyl)methacrylamide, we achieve state-of-the-art antifouling properties. The successful on-fibre ATB synthesis is confirmed through scanning electron microscopy (SEM), fluorescence microscopy, and label-free bio-detection experiments based on antibody-functionalized ATB-coated LPG optical fibres. Despite the challenges in handling optical fibres during polymerization, the resulting nano-coating retains its remarkable antifouling properties upon exposure to blood plasma and enables biorecognition element functionalization. These capabilities are demonstrated through the detection of IgG in buffer and diluted blood plasma using anti-IgG-functionalized ATB-coated sensing regions of LPG fibres in both label-based (fluorescence) and label-free real-time detection experiments. The results show the potential of ATB-coated LPG fibres for use in analytical biosensing applications.
Measuring the transduction of electrical signals within neurons is a key capability in neuroscience. Fluorescent voltage sensitive dyes (VSDs) were early tools that complemented classical electrophysiology by enabling the optical recording of membrane potential changes from many cells simultaneously. Recent advances in the VSD field have led to bright and highly sensitive sensors that can be targeted to the desired cell populations in live brain tissue. Despite this progress, recently, protein-based genetically encoded voltage indicators (GEVIs) have become the go-to tools for targeted voltage imaging in complex environments. In this Perspective, we summarize progress in developing targetable VSDs, discuss areas where these synthetic sensors are or could become relevant, and outline hurdles that need to be overcome to promote the routine use of targetable VSDs in neuroscience research.
- MeSH
- akční potenciály fyziologie účinky léků MeSH
- fluorescenční barviva MeSH
- lidé MeSH
- membránové potenciály fyziologie MeSH
- neurony * fyziologie MeSH
- zobrazování pomocí barviva citlivého na potenciál metody trendy MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
- Research Support, N.I.H., Extramural MeSH
MicroRNAs (miRNAs) are small non-coding RNAs (18-22 nucleotides) that regulate gene expression and are associated with various diseases, including Laryngeal Cancer (LCa), which has a high mortality rate due to late diagnosis. Traditional methods for miRNA detection present several drawbacks (time-consuming steps, high cost and high false positive rate). Early-stage diagnosis and selective detection of miRNAs remain challenging. This study proposes a 3D flexible biosensor that combines nanofibers (NFs), gold nanoparticles (AuNPs), and an inverse molecular sentinel (iMS) for enzyme-free, SERS-based detection of miRNA-223-3p, evaluated as a potential LCa biomarker. The electrospun flexible nanofibers decorated with AuNPs enhance Raman signal. Selective detection of miRNA-223-3p is achieved by immobilizing an iMS-DNA probe labeled with a Raman reporter (Cyanine 3) on the AuNPs. The iMS distinctive stem-and-loop structure undergoes a conformational change upon interaction with the miRNA-223-3p, producing an "on to off" SERS signal. The proposed sensor demonstrated a linear detection range from 10 to 250 fM, with a limit of detection (LOD) of 19.50 ± 0.05 fM. The sensor selectivity was confirmed by analyzing the SERS signal behaviour in the presence of both Non-complementary miRNA and miRNA with three mismatched base pairs. This easily fabricable sensor requires no amplification and offers key advantages, including sensitivity, flexibility, and cost-effectiveness.
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- biosenzitivní techniky * metody MeSH
- časná detekce nádoru metody MeSH
- kovové nanočástice * chemie MeSH
- lidé MeSH
- limita detekce MeSH
- mikro RNA * analýza genetika MeSH
- nádory hrtanu * diagnóza genetika MeSH
- nanovlákna * chemie MeSH
- Ramanova spektroskopie * metody MeSH
- zlato * chemie MeSH
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- lidé MeSH
- Publikační typ
- časopisecké články MeSH
The analysis of biomedical signals is a very challenging task. This review paper is focused on the presentation of various methods where biomedical data, in particular vital signs, could be monitored using sensors mounted to beds. The presented methods to monitor vital signs include those combined with optical fibers, camera systems, pressure sensors, or other sensors, which may provide more efficient patient bed monitoring results. This work also covers the aspects of interference occurrence in the above-mentioned signals and sleep quality monitoring, which play a very important role in the analysis of biomedical signals and the choice of appropriate signal-processing methods. The provided information will help various researchers to understand the importance of vital sign monitoring and will be a thorough and up-to-date summary of these methods. It will also be a foundation for further enhancement of these methods.
Hepatic in vitro models that accurately replicate phenotypes and functionality of the human liver are needed for applications in toxicology, pharmacology and biomedicine. Notably, it has become clear that liver function can only be sustained in 3D culture systems at physiologically relevant cell densities. Additionally, drug metabolism and drug-induced cellular toxicity often follow distinct spatial micropatterns of the metabolic zones in the liver acinus, calling for models that capture this zonation. We demonstrate the manufacture of accurate liver microphysiological systems (MPS) via engineering of 3D stereolithography printed hydrogel chips with arrays of diffusion open synthetic vasculature channels at spacings approaching in vivo capillary distances. Chip designs are compatible with seeding of cell suspensions or preformed liver cell spheroids. Importantly, primary human hepatocytes (PHH) and hiPSC-derived hepatocyte-like cells remain viable, exhibit improved molecular phenotypes compared to isogenic monolayer and static spheroid cultures and form interconnected tissue structures over the course of multiple weeks in perfused culture. 3D optical oxygen mapping of embedded sensor beads shows that the liver MPS recapitulates oxygen gradients found in the acini, which translates into zone-specific acet-ami-no-phen toxicity patterns. Zonation, here naturally generated by high cell densities and associated oxygen and nutrient utilization along the flow path, is also documented by spatial proteomics showing increased concentration of periportal- versus perivenous-associated proteins at the inlet region and vice versa at the outlet region. The presented microperfused liver MPS provides a promising platform for the mesoscale culture of human liver cells at phenotypically relevant densities and oxygen exposures. STATEMENT OF SIGNIFICANCE: A full 3D tissue culture platform is presented, enabled by massively parallel arrays of high-resolution 3D printed microperfusion hydrogel channels that functionally mimics tissue vasculature. The platform supports long-term culture of liver models with dimensions of several millimeters at physiologically relevant cell densities, which is difficult to achieve with other methods. Human liver models are generated from seeded primary human hepatocytes (PHHs) cultured for two weeks, and from seeded spheroids of hiPSC-derived human liver-like cells cultured for two months. Both model types show improved functionality over state-of-the-art 3D spheroid suspensions cultured in parallel. The platform can generate physiologically relevant oxygen gradients driven by consumption rather than supply, which was validated by visualization of embedded oxygen-sensitive microbeads, which is exploited to demonstrate zonation-specific toxicity in PHH liver models.
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- hepatocyty * metabolismus MeSH
- hydrogely metabolismus MeSH
- játra * MeSH
- kyslík metabolismus MeSH
- lidé MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Otto Wolfbeis, Professor emeritus of Analytical Chemistry at the University of Regensburg, passed away on June 1, 2023. Along with his seminal work on optical sensors and fluorescent (nano)materials, he will be remembered as an outstanding researcher who inspired many talents around the world.
- Publikační typ
- časopisecké články MeSH
The ability to optically image cellular transmembrane voltages at millisecond-timescale resolutions can offer unprecedented insight into the function of living brains in behaving animals. Here, we present a point mutation that increases the sensitivity of Ace2 opsin-based voltage indicators. We use the mutation to develop Voltron2, an improved chemigeneic voltage indicator that has a 65% higher sensitivity to single APs and 3-fold higher sensitivity to subthreshold potentials than Voltron. Voltron2 retained the sub-millisecond kinetics and photostability of its predecessor, although with lower baseline fluorescence. In multiple in vitro and in vivo comparisons with its predecessor across multiple species, we found Voltron2 to be more sensitive to APs and subthreshold fluctuations. Finally, we used Voltron2 to study and evaluate the possible mechanisms of interneuron synchronization in the mouse hippocampus. Overall, we have discovered a generalizable mutation that significantly increases the sensitivity of Ace2 rhodopsin-based sensors, improving their voltage reporting capability.
- MeSH
- akční potenciály fyziologie MeSH
- angiotensin-konvertující enzym 2 * MeSH
- mutace genetika MeSH
- myši MeSH
- neurony fyziologie MeSH
- rodopsin * genetika MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
OBJECTIVES: The significant differences in the fingerprint pattern frequencies in type 2 diabetes mellitus (T2DM) patients and controls could be a possible way to identify patients with a risk of developing T2DM. The results could be used in the earlier diagnosis and treatment. The study was undertaken to find out the reliability of fingerprint patterns as a possible predictive tool for T2DM diagnosis. METHODS: A total of 1,260 fingerprints were acquired using the optical contact sensor DactyScan 26i. The results of the qualitative analysis of the fingerprint pattern frequencies have been compared between T2DM patients and controls and also between the fingers to each other. We have detected the frequency of patterns: plain arch (Ap) and tented arch (At), radial loop (Lr), ulnar loop (Lu), double loop (Ld), spiral whorl (W), and plain whorl (concentric) (Wp). Statistical analysis was performed using Pearson's chi-square by Statistica ver. 12. RESULTS: We found statistically significant differences (p < 0.05) in the frequency of individual dermatoglyphic patterns among patients with diabetes and healthy controls as follows: in the left thumb (L1) in a radial loop, double loop and spiral whorl pattern; in the left middle finger (L3) in a tented arch and radial loop; in the right ring finger (R4) in a tented arch, spiral and plain whorl; and in the right little finger (R5) in a tented arch and spiral whorl. CONCLUSION: Fingerprint pattern frequencies might be used as another screening tool and indicator in T2DM prevention. Qualitative analysis of fingerprint patterns could be useful regarding the additional prevention diagnostics of T2DM in the population.
- MeSH
- dermatoglyfika MeSH
- diabetes mellitus 2. typu * diagnóza MeSH
- lidé MeSH
- pilotní projekty MeSH
- reprodukovatelnost výsledků MeSH
- výzkumný projekt MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
MXenes and their related nanocomposites with superior physicochemical properties such as high surface area, ease of synthesis and functionalization, high drug loading capacity, collective therapy potentials, pH-triggered drug release behavior, high photothermal conversion, and excellent photodynamic efficiency have been explored as alluring materials in photomedicine; the application of photons in medicine is facilitated for imaging and various disease treatment methods such as photothermal cancer/tumor ablation. Non-invasive theranostic strategies with synergistic activities have been developed using photothermal, photodynamic, and magnetic therapies together with remotely controlled drug/gene delivery for the diagnosis and treatment of various malignant diseases. Photothermal/photodynamic therapy and photoacoustic imaging using MXene-based structures have shown great promise in cancer phototherapy. However, hybridization and surface functionalization should be further explored to obtain biocompatible MXene-based composites/platforms with unique properties, high stability, and improved functionality in photomedicine. Toxicological and long-term biosafety assessments as well as clinical translation evaluations ought to be given high priority in research. Although some limited studies have revealed the excellent potentials of MXenes and their derivatives in photomedicine, further steps should be taken towards extensive research and detailed analysis in the field of optimizing the properties and improving the performance of these materials with a clinical and industrial outlook. Optical biosensing platforms have been developed along with electrochemical sensors and wearable sensors constructed from MXenes and their derivatives; future studies warrant the comprehensive analysis of optical transduction aspects such as colorimetry, electrochemiluminescence, photoluminescence, surface-enhanced Raman scattering, and surface plasmon resonance. Herein, the potentials of MXenes in photomedicine are deliberated encompassing important challenges and future research directions.
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- fotochemoterapie * MeSH
- fototerapie metody MeSH
- indukovaná hypertermie * metody MeSH
- lidé MeSH
- nádory * diagnostické zobrazování farmakoterapie MeSH
- nanokompozity * chemie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
