Biomedical Photonics

Journal Name	Impact Factor	CiteScore	Launched Year	First Decision (median)	APC
Applied Sciences applsci	2.5	5.3	2011	17.8 Days	CHF 2400
Biomedicines biomedicines	3.9	5.2	2013	15.3 Days	CHF 2600
Cancers cancers	4.5	8.0	2009	16.3 Days	CHF 2900
Diagnostics diagnostics	3.0	4.7	2011	20.5 Days	CHF 2600
Photonics photonics	2.1	2.6	2014	14.8 Days	CHF 2400

15 pages, 2688 KiB

Open AccessArticle

Hyperspectral Imaging Combined with Deep Learning to Detect Ischemic Necrosis in Small Intestinal Tissue

by Lechao Zhang, Yao Zhou, Danfei Huang, Libin Zhu, Xiaoqing Chen, Zhonghao Xie, Guihua Cui, Guangzao Huang, Shujat Ali and Xiaojing Chen

Photonics 2023, 10(7), 708; https://doi.org/10.3390/photonics10070708 - 21 Jun 2023

Cited by 2 | Viewed by 1154

Abstract

Obtaining adequate resection margins in small intestinal necrotic tissue remains challenging due to the lack of intraoperative feedback. Here, we used hyperspectral imaging (HSI), an imaging technique for objective identification, combined with deep learning methods for automated small intestine tissue classification. As part [...] Read more.

Obtaining adequate resection margins in small intestinal necrotic tissue remains challenging due to the lack of intraoperative feedback. Here, we used hyperspectral imaging (HSI), an imaging technique for objective identification, combined with deep learning methods for automated small intestine tissue classification. As part of a prospective experimental study, we recorded hyperspectral datasets of small intestine biopsies from seven white rabbits. Based on the differences in the spectral characteristics of normal and ischemic necrotic small intestinal tissues in the wavelength range of 400–1000 nm, we applied deep learning techniques to objectively distinguish between these two types of tissues. The results showed that three-dimensional convolutional neural networks were more effective in extracting both spectral and spatial features of small intestine tissue hyperspectral data for classification. The combination of a deep learning model and HSI provided a new idea for the objective identification of ischemic necrotic tissue in the small intestine. Full article

(This article belongs to the Topic Biomedical Photonics)

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10 pages, 3542 KiB

Open AccessArticle

Confocal Single-Pixel Imaging

by Cheolwoo Ahn and Jung-Hoon Park

Photonics 2023, 10(6), 687; https://doi.org/10.3390/photonics10060687 - 14 Jun 2023

Viewed by 1762

Abstract

Obtaining depth-selective images requires gating procedures such as spatial, nonlinear, or coherence gating to differentiate light originating from different depths of the volume of interest. Nonlinear gating requires pulsed excitation sources and excitation probes, limiting easy usage. Coherence gating also requires broadband sources [...] Read more.

Obtaining depth-selective images requires gating procedures such as spatial, nonlinear, or coherence gating to differentiate light originating from different depths of the volume of interest. Nonlinear gating requires pulsed excitation sources and excitation probes, limiting easy usage. Coherence gating also requires broadband sources and interferometry requiring specialized stable setups. Spatial gating can be used both for fluorescence and reflection geometry and various light sources and thus has the least requirements on hardware, but still requires the use of a pinhole which makes it difficult to use for photography or widefield imaging schemes. Here, we demonstrate that we can utilize a single digital micromirror device (DMD) to simultaneously function as a dynamic illumination modulator and automatically synchronized dynamic pinhole array to obtain depth-sectioned widefield images. Utilizing the multiplexed measurement advantage of single-pixel imaging, we show that the depth and ballistic light gating of the confocal single pixel imaging scheme can be utilized to obtain images through glare and multiple scattering where conventional widefield imaging fails to recover clear images due to saturation or random scattered noise. Full article

(This article belongs to the Topic Biomedical Photonics)

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11 pages, 1367 KiB

Open AccessCommunication

Background Rejection in Two-Photon Fluorescence Image Scanning Microscopy

by Colin J. R. Sheppard, Marco Castello, Giorgio Tortarolo, Alessandro Zunino, Eli Slenders, Paolo Bianchini, Giuseppe Vicidomini and Alberto Diaspro

Photonics 2023, 10(5), 601; https://doi.org/10.3390/photonics10050601 - 22 May 2023

Cited by 1 | Viewed by 1947

Abstract

We discuss the properties of signal strength and integrated intensity in two-photon excitation confocal microscopy and image scanning microscopy. The resolution, optical sectioning and background rejection are all improved over nonconfocal two-photon microscopy. Replacing the pinhole of confocal two-photon microscopy with a detector [...] Read more.

We discuss the properties of signal strength and integrated intensity in two-photon excitation confocal microscopy and image scanning microscopy. The resolution, optical sectioning and background rejection are all improved over nonconfocal two-photon microscopy. Replacing the pinhole of confocal two-photon microscopy with a detector array increases the peak intensity of the point spread function. The outer pixels of a detector array give signals from defocused regions, and thus the processing of these, such as through subtraction, can further improve optical sectioning and background rejection. Full article

(This article belongs to the Topic Biomedical Photonics)

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11 pages, 2620 KiB

Open AccessCommunication

Restricted Feeding Resets the Peripheral Clocks of the Digestive System

by Kazuo Nakazawa, Minako Matsuo, Naobumi Kimura and Rika Numano

Biomedicines 2023, 11(5), 1463; https://doi.org/10.3390/biomedicines11051463 - 17 May 2023

Viewed by 1636

Abstract

All organisms maintain an internal clock that matches the Earth’s rotation over a period of 24 h, known as the circadian rhythm. Previously, we established Period1 luciferase (Per1::luc) transgenic (Tg) mice in order to monitor the expression rhythms of the Per1 clock [...] Read more.

All organisms maintain an internal clock that matches the Earth’s rotation over a period of 24 h, known as the circadian rhythm. Previously, we established Period1 luciferase (Per1::luc) transgenic (Tg) mice in order to monitor the expression rhythms of the Per1 clock gene in each tissue in real time using a bioluminescent reporter. The Per1 gene is a known key molecular regulator of the mammalian clock system in the autonomous central clock in the suprachiasmatic nucleus (SCN), and the peripheral tissues. Per1::luc Tg mice were used as a biosensing system of circadian rhythms. They were maintained by being fed ad lib (FF) and subsequently subjected to 4 hour (4 h) restricted feeding (RF) during the rest period under light conditions in order to examine whether the peripheral clocks of different parts in the digestive tract could be entrained. The peak points of the bioluminescent rhythms in the Per1::luc Tg mouse tissue samples were analyzed via cosine fitting. The bioluminescent rhythms of the cultured peripheral tissues of the esophagus and the jejunum exhibited phase shift from 5 to 11 h during RF, whereas those of the SCN tissue remained unchanged for 7 days during RF. We examined whether RF for 4 h during the rest period in light conditions could reset the activity rhythms, the central clock in the SCN, and the peripheral clock in the different points in the gastrointestinal tract. The fasting signals during RF did not entrain the SCN, but they did entrain each peripheral clock of the digestive system, the esophagus, and the jejunum. During RF for 7 days, the peak time of the esophagus tended to return to that of the FF control, unlike that of the jejunum; hence, the esophagus was regulated more strongly under the control of the cultured SCN compared to the jejunum. Thus, the peripheral clocks of the digestive system can entrain their molecular clock rhythms via RF-induced fasting signals in each degree, independently from the SCN. Full article

(This article belongs to the Topic Biomedical Photonics)

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15 pages, 7673 KiB

Open AccessArticle

Head Phantom for the Acquisition of Pulsatile Optical Signals for Traumatic Brain Injury Monitoring

by Maria Roldan and Panicos A. Kyriacou

Photonics 2023, 10(5), 504; https://doi.org/10.3390/photonics10050504 - 26 Apr 2023

Cited by 3 | Viewed by 1952

Abstract

(1) Background: Tissue phantoms can provide a rigorous, reproducible and convenient approach to evaluating an optical sensor’s performance. The development, characterisation and evaluation of a vascular head/brain phantom is described in this study. (2) Methods: The methodology includes the development of mould-cast and [...] Read more.

(1) Background: Tissue phantoms can provide a rigorous, reproducible and convenient approach to evaluating an optical sensor’s performance. The development, characterisation and evaluation of a vascular head/brain phantom is described in this study. (2) Methods: The methodology includes the development of mould-cast and 3D-printed anatomical models of the brain and the skull and a custom-made in vitro blood circulatory system used to emulate haemodynamic changes in the brain. The optical properties of the developed phantom were compared to literature values. Artificial cerebrospinal fluid was also incorporated to induce changes in intracranial pressure. (3) Results: A novel head model was successfully developed to mimic the brain and skull anatomies and their optical properties within the near-infrared range (660–900 nm). The circulatory system developed mimicked normal arterial blood pressure values, with a mean systole of 118 ± 8.5 mmHg and diastole of 70 ± 8.5 mmHg. Similarly, the cerebrospinal fluid circulation allowed controlled intracranial pressure changes from 5 to 30 mmHg. Multiwavelength pulsatile optical signals (photoplethysmograms (PPGs)) from the phantom’s cerebral arteries were successfully acquired. Conclusions: This unique head phantom technology forms the basis of a novel research tool for investigating the relationship between cerebral pulsatile optical signals and changes in intracranial pressure and brain haemodynamics. Full article

(This article belongs to the Topic Biomedical Photonics)

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12 pages, 1677 KiB

Open AccessArticle

Quantitative Endogenous Fluorescence Analysis Discriminates Glioblastoma Tumor through Visible and NIR Excitation

by Hussein Mehidine, Emile Kaadou Mouawad, Pascale Varlet, Bertrand Devaux and Darine Abi Haidar

Photonics 2023, 10(4), 434; https://doi.org/10.3390/photonics10040434 - 12 Apr 2023

Cited by 1 | Viewed by 1634

Abstract

Nowadays, the ability to diagnose brain tumors intraoperatively and delineate their margins, as accurately as possible, is of primordial importance during surgery. However, the exact tumor boundaries and targets are difficult to find due to the similar visual appearances especially at the margins, [...] Read more.

Nowadays, the ability to diagnose brain tumors intraoperatively and delineate their margins, as accurately as possible, is of primordial importance during surgery. However, the exact tumor boundaries and targets are difficult to find due to the similar visual appearances especially at the margins, leading in many cases to poor surgical outcomes and a high risk of recurrences. To solve this dogma, our group tried to determine different tissue optical signatures such as optical parameters and endogenous fluorescence. For that, we conducted a comparative study to differentiate between healthy and tumorous tissues under one- and two-photon excitations on optical properties to explore several optical parameters. In addition, the study of endogenous fluorescence can successfully help with the discrimination between tissue types using one- and two-photon excitations. This works suggests that the multimodal analysis of optical signatures of tissues could be a reliable technique that can be used to differentiate between healthy and tumorous tissues. This can help in the future with the implementation of such techniques in vivo during surgery to help the surgeon with the decision that needs to be taken as for tissue resection. Full article

(This article belongs to the Topic Biomedical Photonics)

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15 pages, 5518 KiB

Open AccessArticle

FACAM: A Fast and Accurate Clustering Analysis Method for Protein Complex Quantification in Single Molecule Localization Microscopy

by Cheng Wu, Weibing Kuang, Zhiwei Zhou, Yingjun Zhang and Zhen-Li Huang

Photonics 2023, 10(4), 427; https://doi.org/10.3390/photonics10040427 - 10 Apr 2023

Cited by 1 | Viewed by 2331

Abstract

Single molecule localization microscopy (SMLM) enables the analysis and quantification of protein complexes at the nanoscale. Using clustering analysis methods, quantitative information about protein complexes (for example, the size, density, number, and the distribution of nearest neighbors) can be extracted from coordinate-based SMLM [...] Read more.

Single molecule localization microscopy (SMLM) enables the analysis and quantification of protein complexes at the nanoscale. Using clustering analysis methods, quantitative information about protein complexes (for example, the size, density, number, and the distribution of nearest neighbors) can be extracted from coordinate-based SMLM data. However, since a final super-resolution image in SMLM is usually reconstructed from point clouds that contain millions of localizations, current popular clustering methods are not fast enough to enable daily quantification on such a big dataset. Here, we provide a fast and accurate clustering analysis method called FACAM, which is modified from the Alpha Shape method (a point dataset analysis method used in many fields). By taking advantage of parallel computation, FACAM is able to process millions of localizations in less than an hour, which is at least 10 times faster than the popular DBSCAN method. Furthermore, FACAM adaptively determines the segmentation threshold, and thus overcomes the problem of user-defined parameters. Using simulation and experimental datasets, we verified the advantages of FACAM over other reported clustering methods (including Ripley’s H, DBSCAN, and ClusterViSu). Full article

(This article belongs to the Topic Biomedical Photonics)

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12 pages, 6904 KiB

Open AccessArticle

Lensed Fiber-Optic Two-Photon Endomicroscopy for Field-of-View Enhancement

by Conghao Wang, Huilan Liu, Jianrui Ma, Qiang Fu, Yijun Li, Yanchuan Chen, Yuqian Gao, Jingquan Tian, Xinlei Luo, Fei Yu, Chunzhu Zhao, Runlong Wu, Aimin Wang and Lishuang Feng

Photonics 2023, 10(3), 342; https://doi.org/10.3390/photonics10030342 - 22 Mar 2023

Cited by 2 | Viewed by 2163

Abstract

Two-photon endomicroscopy is a promising technique with the ability to achieve in situ imaging and diagnosis at subcellular resolution. The large field-of-view capability is essential and useful to locate and image suspicious areas of biological tissue. In this work, we report objective-lens-free, lensed [...] Read more.

Two-photon endomicroscopy is a promising technique with the ability to achieve in situ imaging and diagnosis at subcellular resolution. The large field-of-view capability is essential and useful to locate and image suspicious areas of biological tissue. In this work, we report objective-lens-free, lensed fiber-optic two-photon endomicroscopy for field-of-view enhancement. The field of view of this two-photon endomicroscopic probe is 750 μm with a resolution of 3.03 μm. This 1.6 g miniature probe has an integrated outer diameter of 5.8 mm and a rigid length of 33.5 mm. The imaging performance of the lensed-fiber-optic two-photon endomicroscopy was validated by examining an ex vivo mouse heart, kidney, brain, stomach wall tissues, and in vivo brain tissue. Full article

(This article belongs to the Topic Biomedical Photonics)

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11 pages, 2393 KiB

Open AccessCommunication

Enhancement of the Efficacy of Photodynamic Therapy against Uropathogenic Gram-Negative Bacteria Species

by Vadim Elagin, Ivan Budruev, Artem Antonyan, Pavel Bureev, Nadezhda Ignatova, Olga Streltsova and Vladislav Kamensky

Photonics 2023, 10(3), 310; https://doi.org/10.3390/photonics10030310 - 14 Mar 2023

Cited by 7 | Viewed by 1889

Abstract

Antimicrobial photodynamic therapy (aPDT) was demonstrated to be effective against various species of Gram-positive bacteria. However, the complex structure of a Gram-negative bacteria envelope limits the application of aPDT. Thus, the goal of this study was to improve the efficiency of antimicrobial photodynamic [...] Read more.

Antimicrobial photodynamic therapy (aPDT) was demonstrated to be effective against various species of Gram-positive bacteria. However, the complex structure of a Gram-negative bacteria envelope limits the application of aPDT. Thus, the goal of this study was to improve the efficiency of antimicrobial photodynamic therapy with Fotoditazin against uropathogenic Gram-negative bacteria. The non-ionic detergent Triton X-100 and emulsifier Tween 80 were tested. The effect of extracellular photosensitizer on aPDT efficacy was analyzed. Moreover, the irradiation regime was optimized in terms of the output power and emitting mode. It was found that Triton X-100 at 10% vol enhanced the efficacy of aPDT of E. coli up to 52%. The subsequent observation demonstrated that, when the photosensitizer was removed from the extracellular space, the efficacy of aPDT on various Gram-negative species decreased dramatically. As for the irradiation mode, an increase in the laser output power led to an increase in the aPDT efficacy. The pulsed irradiation mode did not affect the aPDT efficacy. Thus, in order to achieve optimal aPDT efficacy, bacteria should be irradiated at 450-mW output power in the presence of Triton X-100 and a photosensitizer in the extracellular environment. However, it should be noted that the efficacy of aPDT of K. pneumoniae was significantly lower than for other species. The developed aPDT technique may be effective in a native environment of uropathogenic microorganisms. Full article

(This article belongs to the Topic Biomedical Photonics)

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13 pages, 2351 KiB

Open AccessArticle

Rapid On-Site Microscopy and Mapping of Diagnostic Biopsies for See-And-Treat Guidance of Localized Prostate Cancer Therapy

by Madeline R. Behr, Shams K. Halat, Andrew B. Sholl, Louis Spencer Krane and Jonathan Quincy Brown

Cancers 2023, 15(3), 792; https://doi.org/10.3390/cancers15030792 - 27 Jan 2023

Cited by 3 | Viewed by 1851

Abstract

Prostate cancer continues to be the most diagnosed non-skin malignancy in men. While up to one in eight men will be diagnosed in their lifetimes, most diagnoses are not fatal. Better lesion location accuracy combined with emerging localized treatment methods are increasingly being [...] Read more.

Prostate cancer continues to be the most diagnosed non-skin malignancy in men. While up to one in eight men will be diagnosed in their lifetimes, most diagnoses are not fatal. Better lesion location accuracy combined with emerging localized treatment methods are increasingly being utilized as a treatment option to preserve healthy function in eligible patients. In locating lesions which are generally <2cc within a prostate (average size 45cc), small variance in MRI-determined boundaries, tumoral heterogeneity, patient characteristics including location of lesion and prostatic calcifications, and patient motion during the procedure can inhibit accurate sampling for diagnosis. The locations of biopsies are recorded and are then fully processed by histology and diagnosed via pathology, often days to weeks later. Utilization of real-time feedback could improve accuracy, potentially prevent repeat procedures, and allow patients to undergo treatment of clinically localized disease at earlier stages. Unfortunately, there is currently no reliable real-time feedback process for confirming diagnosis of biopsy samples. We examined the feasibility of implementing structured illumination microscopy (SIM) as a method for on-site diagnostic biopsy imaging to potentially combine the diagnostic and treatment appointments for prostate cancer patients, or to confirm tumoral margins for localized ablation procedures. We imaged biopsies from 39 patients undergoing image-guided diagnostic biopsy using a customized SIM system and a dual-color fluorescent hematoxylin & eosin (H&E) analog. The biopsy images had an average size of 342 megapixels (minimum 78.1, maximum 842) and an average imaging duration of 145 s (minimum 56, maximum 322). Comparison of urologist’s suspicion of malignancy based on MRI, to pathologist diagnosis of biopsy images obtained in real time, reveals that real-time biopsy imaging could significantly improve confirmation of malignancy or tumoral margins over medical imaging alone. Full article

(This article belongs to the Topic Biomedical Photonics)

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17 pages, 6334 KiB

Open AccessArticle

Detection of Changes in Macrophage Polarization as a Result of 5-Aminolevulinic Acid Photodynamic Therapy Using Fluorescence-Lifetime Imaging Microscopy

by Anastasia Ryabova, Igor Romanishkin, Alexey Skobeltsin, Inessa Markova, Daria Pominova, Kirill Linkov and Victor Loschenov

Photonics 2022, 9(12), 961; https://doi.org/10.3390/photonics9120961 - 10 Dec 2022

Cited by 5 | Viewed by 2203

Abstract

Non-invasive detection of polarized macrophages in tumors is an urgent task in terms of combined antitumor therapy. By analyzing the fluorescence lifetime of the metabolic cofactors—the reduced form of nicotinamide adenine dinucleotide (NADH) and flavins—differences in cellular metabolism of normal tissue, tumor, inflammatory [...] Read more.

Non-invasive detection of polarized macrophages in tumors is an urgent task in terms of combined antitumor therapy. By analyzing the fluorescence lifetime of the metabolic cofactors—the reduced form of nicotinamide adenine dinucleotide (NADH) and flavins—differences in cellular metabolism of normal tissue, tumor, inflammatory and anti-inflammatory macrophages were demonstrated. In this work we studied changes in the polarization of macrophages obtained from THP-1 monocytes in response to photodynamic therapy with 5-aminolevulinic acid (ALA–PDT). Moderate ALA–PDT in vitro led to changes in M0 macrophages metabolism towards M1 polarization, wherein M1 and M2 macrophages died and were replaced by non-polarized cells. The interstitial distribution of polarized macrophages after ALA–PDT was studied in a mouse tumor model of grafted Lewis lung carcinoma. In response to ALA–PDT, there was an increase in the inflammatory macrophages fraction in the tumor node. Metabolic fluorescence-lifetime imaging microscopy (FLIM) was performed for macrophages in vitro and for tumor cryosections. It was shown that analysis of phasor diagrams for the NADH, flavins, and 5-ALA-induced protoporphyrin IX (PpIX) fluorescence lifetime helps to determine the change in metabolism in response to different modes of PDT at the cellular and tissue levels. These data can be used for post-surgery tissue inspection. Full article

(This article belongs to the Topic Biomedical Photonics)

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7 pages, 1026 KiB

Open AccessCommunication

High-Throughput DNA Analysis Platform Based on an Optofluidic Ring Resonator Laser

by Chan Seok Jun and Wonsuk Lee

Appl. Sci. 2022, 12(23), 12143; https://doi.org/10.3390/app122312143 - 28 Nov 2022

Cited by 1 | Viewed by 1722

Abstract

We demonstrate an optofluidic laser using DNA microdroplets, an intercalating dye, and a glass capillary ring resonator. Only the target DNA emits the laser signal, while the non-target DNA, including those with single-base mismatches, exhibits zero optical signals. Subsequently, a single laser emission [...] Read more.

We demonstrate an optofluidic laser using DNA microdroplets, an intercalating dye, and a glass capillary ring resonator. Only the target DNA emits the laser signal, while the non-target DNA, including those with single-base mismatches, exhibits zero optical signals. Subsequently, a single laser emission detected within a few milliseconds can distinguish the target DNA from others, allowing for truly digital DNA sequence analysis from an optical point of view. In addition, the microdroplets could be individually investigated using our optofluidic system. These advances in laser-based DNA analysis make our proposed scheme a promising, rapid, and high-throughput DNA sequence analysis platform. Full article

(This article belongs to the Topic Biomedical Photonics)

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13 pages, 4781 KiB

Open AccessCommunication

Analysis of In Vivo Radachlorin Accumulation through FLIM-Assisted Examination of Ex Vivo Histological Samples

by Andrey V. Belashov, Anna A. Zhikhoreva, Stepan S. Kruglov, Andrey V. Panchenko, Irina V. Semenova and Oleg S. Vasyutinskii

Photonics 2022, 9(10), 711; https://doi.org/10.3390/photonics9100711 - 29 Sep 2022

Cited by 3 | Viewed by 1620

Abstract

We report an investigation of the in vivo accumulation of Radachlorin photosensitizer in a murine model in several types of normal and tumor tissues based on an FLIM-assisted analysis of fluorescence intensity images, time-resolved fluorescence signals, and phasor plots. Experiments were performed on [...] Read more.

We report an investigation of the in vivo accumulation of Radachlorin photosensitizer in a murine model in several types of normal and tumor tissues based on an FLIM-assisted analysis of fluorescence intensity images, time-resolved fluorescence signals, and phasor plots. Experiments were performed on ex vivo histological samples of normal and tumor tissues. It was shown that the investigation of fluorescence intensity distributions combined with that of time-resolved fluorescence images can be used for qualitative and—under some limitations—quantitative analyses of the relative uptake of this photosensitizer in tissues. The phasor plot representations of time-resolved fluorescence signals were shown to be suitable for identification of the accumulation of predominant photosensitizers in tissues. Full article

(This article belongs to the Topic Biomedical Photonics)

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10 pages, 1395 KiB

Open AccessArticle

Biophotonic Effects of Low-Level Laser Therapy at Different Wavelengths for Potential Wound Healing

by Tzu-Sen Yang, Le-Thanh-Hang Nguyen, Yu-Cheng Hsiao, Li-Chern Pan and Cheng-Jen Chang

Photonics 2022, 9(8), 591; https://doi.org/10.3390/photonics9080591 - 19 Aug 2022

Cited by 7 | Viewed by 3730

Abstract

Our objective was to assess the effect of low-level laser therapy (LLLT) administered using a diode laser on the growth processes of human fibroblast cells involved in wound healing. Initially, studies were conducted using a diode laser at wavelengths of 633, 520, and [...] Read more.

Our objective was to assess the effect of low-level laser therapy (LLLT) administered using a diode laser on the growth processes of human fibroblast cells involved in wound healing. Initially, studies were conducted using a diode laser at wavelengths of 633, 520, and 450 nm with an irradiance of 3 mW/cm². The distance between the light source and culture plate was 3 cm. The mechanism(s) of action of the diode laser illumination on human fibroblast cells were studied by examining different wavelengths to determine the relevant light parameters for optimal treatment. In addition, the percentages of fibroblast-mediated procollagen and matrix metallopeptidase (MMP)-1, -2, and -9 production were compared. In the clinical study, the changes in basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF), and fibroblast collagen production were assessed in 60 patients with complicated wounds who received LLLT (633 nm). No statistically significant difference was observed between red light versus green and blue light in the viability analysis. In addition, the effects of LLLT on the cell cultures of fibroblast cells in vitro demonstrated a decrease in the relative expression of MMP-1, -2, and -9 while using light with a wavelength of 633 nm. In the clinical study, 633 nm diode laser LLLT at 2–8 J/cm² was administered to 60 patients with complicated wounds; all patients showed increased levels of bFGF and VEGF and the occurrence of collagen synthesis. Our studies demonstrated that LLLT might affect fibroblast cell growth processes involved in wound healing. Full article

(This article belongs to the Topic Biomedical Photonics)

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11 pages, 2903 KiB

Open AccessArticle

Photobiomodulation Using Different Infrared Light Sources Promotes Muscle Precursor Cells Migration and Proliferation

by Renan Lovisetto, Tainá Caroline dos Santos Malavazzi, Lucas Andreo, Maria Fernanda Setubal Destro Rodrigues, Sandra Kalil Bussadori, Kristianne Porta Santos Fernandes and Raquel Agnelli Mesquita-Ferrari

Photonics 2022, 9(7), 469; https://doi.org/10.3390/photonics9070469 - 5 Jul 2022

Cited by 3 | Viewed by 1777

Abstract

Photobiomodulation (PBM) has demonstrated positive effects on the muscle repair process. The aim of the study was to evaluate the effects of infrared PBM using different light sources—low-level laser (LLL) at 780 nm (40 or 70 mW, 10 J/cm², 0.4 J) [...] Read more.

Photobiomodulation (PBM) has demonstrated positive effects on the muscle repair process. The aim of the study was to evaluate the effects of infrared PBM using different light sources—low-level laser (LLL) at 780 nm (40 or 70 mW, 10 J/cm², 0.4 J) or LED at 850 nm (40 or 70 mW, 0.13 J/cm², 0.4 J)—and dosimetric parameters on the proliferation and migration of muscle cells. The results showed that LLL 40 mW and 70 mW, with the same radiation exposure, led to an increase in proliferation after 24 h, but no differences at 48 and 72 h. Cells irradiated with LED 70 mW exhibited an increase in proliferation in comparison to the control group and 40mW after 24 and 48 h, but not at 72 h. Moreover, cell migration was greater in comparison to the control after 6 and 24 h, and no differences were found at 12 h when LLL was used with an output power of 70 mW. Furthermore, no differences were found at 6 and 12 h with the 70 mW output power-LED, but an increase was observed in the cell migration after 24 h. In conclusion, PBM using different light sources and dosimetric parameters was able to modulate the proliferation of C2C12 myoblasts, but only PBM at 70 mW was able to modulate the migration of these cells. Full article

(This article belongs to the Topic Biomedical Photonics)

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17 pages, 5419 KiB

Open AccessArticle

Drift Artifacts Correction for Laboratory Cone-Beam Nanoscale X-ray Computed Tomography by Fitting the Partial Trajectory of Projection Centroid

by Mengnan Liu, Yu Han, Xiaoqi Xi, Linlin Zhu, Chang Liu, Siyu Tan, Jian Chen, Lei Li and Bin Yan

Photonics 2022, 9(6), 405; https://doi.org/10.3390/photonics9060405 - 8 Jun 2022

Cited by 2 | Viewed by 2522

Abstract

A self-correction method for the drift artifacts of laboratory cone-beam nanoscale X-ray computed tomography (nano-CT) based on the trajectory of projection centroid (TPC) is proposed. This method does not require additional correction phantoms, simplifying the correction process. The whole TPC is estimated by [...] Read more.

A self-correction method for the drift artifacts of laboratory cone-beam nanoscale X-ray computed tomography (nano-CT) based on the trajectory of projection centroid (TPC) is proposed. This method does not require additional correction phantoms, simplifying the correction process. The whole TPC is estimated by the partial TPC in the optimal projection set. The projection drift is calculated by the measured TPC and the estimated TPC. The interval search method is used so that the proposed method can adapt to the case of a truncated projection due to drift. The fixed-angle scanning experiment of the Siemens star and the partial derivative analysis of the projection position show the necessity of correcting drift artifacts. Further, the Shepp–Logan phantoms with different drift levels are simulated. The results show that the proposed method can effectively estimate the horizontal and vertical drifts within the projection drift range of

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2 mm (27 pixels) with high accuracy. Experiments were conducted on tomato seed and bamboo stick to validate the feasibility of the proposed method for samples with different textures. The correction effect on different reconstructed slices indicates that the proposed method provides performance superior to the reference scanning method (RSM) and global fitting. In addition, the proposed method requires no extra scanning, which improves the acquisition efficiency, as well as radiation utilization. Full article

(This article belongs to the Topic Biomedical Photonics)

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15 pages, 4574 KiB

Open AccessArticle

Evaluation of Proton-Induced Biomolecular Changes in MCF-10A Breast Cells by Means of FT-IR Microspectroscopy

by Valerio Ricciardi, Marianna Portaccio, Maria Lasalvia, Francesco Paolo Cammarata, Pietro Pisciotta, Giuseppe Perna, Vito Capozzi, Giada Petringa, Lorenzo Manti and Maria Lepore

Appl. Sci. 2022, 12(10), 5074; https://doi.org/10.3390/app12105074 - 18 May 2022

Cited by 3 | Viewed by 1909

Abstract

Radiotherapy (RT) with accelerated beams of charged particles (protons and carbon ions), also known as hadrontherapy, is a treatment modality that is increasingly being adopted thanks to the several benefits that it grants compared to conventional radiotherapy (CRT) treatments performed by means of [...] Read more.

Radiotherapy (RT) with accelerated beams of charged particles (protons and carbon ions), also known as hadrontherapy, is a treatment modality that is increasingly being adopted thanks to the several benefits that it grants compared to conventional radiotherapy (CRT) treatments performed by means of high-energy photons/electrons. Hence, information about the biomolecular effects in exposed cells caused by such particles is needed to better realize the underlying radiobiological mechanisms and to improve this therapeutic strategy. To this end, Fourier transform infrared microspectroscopy (μ-FT-IR) can be usefully employed, in addition to long-established radiobiological techniques, since it is currently considered a helpful tool for examining radiation-induced cellular changes. In the present study, MCF-10A breast cells were chosen to evaluate the effects of proton exposure using μ-FT-IR. They were exposed to different proton doses and fixed at various times after exposure to evaluate direct effects due to proton exposure and the kinetics of DNA damage repair. Irradiated and control cells were examined in transflection mode using low-e substrates that have been recently demonstrated to offer a fast and direct way to examine proton-exposed cells. The acquired spectra were analyzed using a deconvolution procedure and a ratiometric approach, both of which showed the different contributions of DNA, protein, lipid, and carbohydrate cell components. These changes were particularly significant for cells fixed 48 and 72 h after exposure. Lipid changes were related to variations in membrane fluidity, and evidence of DNA damage was highlighted. The analysis of the Amide III band also indicated changes that could be related to different enzyme contributions in DNA repair. Full article

(This article belongs to the Topic Biomedical Photonics)

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9 pages, 2220 KiB

Open AccessArticle

Comparison between Cylindrical, Trigonal, and General Symmetry Models for the Analysis of Polarization-Dependent Second Harmonic Generation Measurements Acquired from Collagen-Rich Equine Pericardium Samples

by Meropi Mari, Vassilis Tsafas, Despina Staraki, Costas Fotakis and George Filippidis

Photonics 2022, 9(4), 254; https://doi.org/10.3390/photonics9040254 - 11 Apr 2022

Cited by 1 | Viewed by 1988

Abstract

Polarization-dependent second harmonic generation (PSHG) microscopy is used as an innovative, high-resolution, non-destructive, and label-free diagnostic imaging tool to elucidate biological issues with high significance. In the present study, information on the structure and directionality of collagen fibers in equine pericardium tissue was [...] Read more.

Polarization-dependent second harmonic generation (PSHG) microscopy is used as an innovative, high-resolution, non-destructive, and label-free diagnostic imaging tool to elucidate biological issues with high significance. In the present study, information on the structure and directionality of collagen fibers in equine pericardium tissue was collected using PSHG imaging measurements. In an effort to acquire precise results, three different mathematical models (cylindrical, trigonal, and general) were applied to the analysis of the recorded PSHG datasets. A factor called the “ratio parameter” was calculated to provide quantitative information. The implementation of the trigonal symmetry model to the recorded data led to the extraction of improved results compared with the application of the widely used cylindrical symmetry model. The best outcome was achieved through the application of the general model that does not include any kind of symmetry for the data processing. Our findings suggest that the trigonal symmetry model is preferable for the analysis of the PSHG datasets acquired from the collagenous tissues compared with the cylindrical model approach although an increased computational time is required. Full article

(This article belongs to the Topic Biomedical Photonics)

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12 pages, 1329 KiB

Open AccessArticle

Methylene Blue Near-Infrared Fluorescence Imaging in Breast Cancer Sentinel Node Biopsy

by Oliver Budner, Tomasz Cwalinski, Jarosław Skokowski, Luigi Marano, Luca Resca, Natalia Cwalina, Leszek Kalinowski, Richelle Hoveling, Franco Roviello and Karol Polom

Cancers 2022, 14(7), 1817; https://doi.org/10.3390/cancers14071817 - 3 Apr 2022

Cited by 7 | Viewed by 3379

Abstract

Introduction: Fluorescence-based navigation for breast cancer sentinel node biopsy is a novel method that uses indocyanine green as a fluorophore. However, methylene blue (MB) also has some fluorescent properties. This study is the first in a clinical series presenting the possible use of [...] Read more.

Introduction: Fluorescence-based navigation for breast cancer sentinel node biopsy is a novel method that uses indocyanine green as a fluorophore. However, methylene blue (MB) also has some fluorescent properties. This study is the first in a clinical series presenting the possible use of MB as a fluorescent dye for the identification of sentinel nodes in breast sentinel node biopsy. Material and methods: Forty-nine patients with breast cancer who underwent sentinel node biopsy procedures were enrolled in the study. All patients underwent standard simultaneous injection of nanocolloid and MB. We visualized and assessed the sentinel nodes and the lymphatic channels transcutaneously, with and without fluorescence, and calculated the signal-to-background ratio (SBR). We also analyzed the corresponding fluorescence intensity of various dilutions of MB. Results: In twenty-three patients (46.9%), the location of the sentinel node, or the end of the lymphatic path, was visible transcutaneously. The median SBR for transcutaneous sentinel node location was 1.69 (range 1.66–4.35). Lymphatic channels were visible under fluorescence in 14 patients (28.6%) prior to visualization by the naked eye, with an average SBR of 2.01 (range 1.14–5.6). The sentinel node was visible under fluorescence in 25 patients (51%). The median SBR for sentinel node visualization with MB fluorescence was 2.54 (range 1.34–6.86). Sentinel nodes were visualized faster under fluorescence during sentinel node preparation. Factors associated with the rate of visualization included diabetes (p = 0.001), neoadjuvant chemotherapy (p = 0.003), and multifocality (p = 0.004). The best fluorescence was obtained using 40 μM (0.0128 mg/mL) MB, but we also observed a clinically relevant dilution range between 20 μM (0.0064 mg/mL) and 100 μM (0.032 mg/mL). Conclusions: For the first time, we propose the clinical usage of MB as a fluorophore for fluorescence-guided sentinel node biopsy in breast cancer patients. The quenching effect of the dye may be the reason for its poor detection rate. Our analysis of different concentrations of MB suggests a need for a detailed clinical analysis to highlight the practical usefulness of the dye. Full article

(This article belongs to the Topic Biomedical Photonics)

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16 pages, 2986 KiB

Open AccessArticle

Pterygium and Ocular Surface Squamous Neoplasia: Optical Biopsy Using a Novel Autofluorescence Multispectral Imaging Technique

by Abbas Habibalahi, Alexandra Allende, Jesse Michael, Ayad G. Anwer, Jared Campbell, Saabah B. Mahbub, Chandra Bala, Minas T. Coroneo and Ewa M. Goldys

Cancers 2022, 14(6), 1591; https://doi.org/10.3390/cancers14061591 - 21 Mar 2022

Cited by 8 | Viewed by 6981

Abstract

In this study, differentiation of pterygium vs. ocular surface squamous neoplasia based on multispectral autofluorescence imaging technique was investigated. Fifty (N = 50) patients with histopathological diagnosis of pterygium (PTG) and/or ocular surface squamous neoplasia (OSSN) were recruited. Fixed unstained biopsy specimens were [...] Read more.

In this study, differentiation of pterygium vs. ocular surface squamous neoplasia based on multispectral autofluorescence imaging technique was investigated. Fifty (N = 50) patients with histopathological diagnosis of pterygium (PTG) and/or ocular surface squamous neoplasia (OSSN) were recruited. Fixed unstained biopsy specimens were imaged by multispectral microscopy. Tissue autofluorescence images were obtained with a custom-built fluorescent microscope with 59 spectral channels, each with specific excitation and emission wavelength ranges, suitable for the most abundant tissue fluorophores such as elastin, flavins, porphyrin, and lipofuscin. Images were analyzed using a new classification framework called fused-classification, designed to minimize interpatient variability, as an established support vector machine learning method. Normal, PTG, and OSSN regions were automatically detected and delineated, with accuracy evaluated against expert assessment by a specialist in OSSN pathology. Signals from spectral channels yielding signals from elastin, flavins, porphyrin, and lipofuscin were significantly different between regions classified as normal, PTG, and OSSN (p < 0.01). Differential diagnosis of PTG/OSSN and normal tissue had accuracy, sensitivity, and specificity of 88 ± 6%, 84 ± 10% and 91 ± 6%, respectively. Our automated diagnostic method generated maps of the reasonably well circumscribed normal/PTG and OSSN interface. PTG and OSSN margins identified by our automated analysis were in close agreement with the margins found in the H&E sections. Such a map can be rapidly generated on a real time basis and potentially used for intraoperative assessment. Full article

(This article belongs to the Topic Biomedical Photonics)

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16 pages, 2263 KiB

Open AccessArticle

Optimizing the Minimum Detectable Difference of Gamma Camera SPECT Images via the Taguchi Analysis: A Feasibility Study with a V-Shaped Slit Gauge

by Ching-Hsiu Ke, Wan-Ju Liu, Bing-Ru Peng, Lung-Fa Pan and Lung-Kwang Pan

Appl. Sci. 2022, 12(5), 2708; https://doi.org/10.3390/app12052708 - 5 Mar 2022

Cited by 4 | Viewed by 1812

Abstract

This study tried to propose an innovated idea of solidifying the resolution of gamma camera in routine quality control and recommended a quantified index as minimum detectable difference (MDD) of gamma camera SPECT images using the Taguchi analysis and an indigenous V-shaped slit [...] Read more.

This study tried to propose an innovated idea of solidifying the resolution of gamma camera in routine quality control and recommended a quantified index as minimum detectable difference (MDD) of gamma camera SPECT images using the Taguchi analysis and an indigenous V-shaped slit gauge. The gauge was customized to fulfill the quantitative requirement of the Taguchi analysis. The MDD among slit gauge of derived SPECT image was calculated from two overlapped peak profiles collected from a tangent slice of the V-shaped slit gauge with two nearby peaks. In particular, MDD was evaluated as minimum distance between two peak centers through the Student’s t-test with a constant, 1.96, which indicates that two peak centers separated distant enough to create a 95% confidence level of separation. Eighteen combinations of six gamma camera scanned factors were organized according to Taguchi analysis. Accordingly, (A) collimator, (B) detector to targe distance, (C) total counts, (D) acquired energy width, (E) Matrix size, and (F) zoom of collected ROI with each of two or three levels were organized into 18 groups to collect the slit gauge images according to Taguchi L₁₈ orthogonal array. Then, three well-trained radiologists were ranked the scanned gauge images to derive the fish-bone-plot of signal-to-noise ratio (S/N, dB) and correlated ANOVA. Furthermore, the quantified MDD was proposed to verify the optimal suggestion of gamma camera scanned protocol, and obtained the MDD as 8.4, 7.9, and 7.1 mm for the second group of original L₁₈ preset, conventional, and the optimal preset, respectively. Thus, the optimal preset of gamma camera was achieved in this study. The MDD proved to be a successful index in quantifying the imaging resolution of a gamma camera. Full article

(This article belongs to the Topic Biomedical Photonics)

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13 pages, 1228 KiB

Open AccessArticle

Fluorescence Polarization Imaging of Methylene Blue Facilitates Quantitative Detection of Thyroid Cancer in Single Cells

by Peter R. Jermain, Andrew H. Fischer, Lija Joseph, Alona Muzikansky and Anna N. Yaroslavsky

Cancers 2022, 14(5), 1339; https://doi.org/10.3390/cancers14051339 - 5 Mar 2022

Cited by 9 | Viewed by 3121

Abstract

Background: Diagnostic accuracy of the standard of care fine-needle aspiration cytology (FNAC) remains a significant problem in thyroid oncology. Therefore, a robust and accurate method for reducing uncertainty of cytopathological evaluation would be invaluable. Methods: In this double-blind study, we employed fluorescence emission [...] Read more.

Background: Diagnostic accuracy of the standard of care fine-needle aspiration cytology (FNAC) remains a significant problem in thyroid oncology. Therefore, a robust and accurate method for reducing uncertainty of cytopathological evaluation would be invaluable. Methods: In this double-blind study, we employed fluorescence emission and quantitative fluorescence polarization (Fpol) confocal imaging for sorting thyroid cells into benign/malignant categories. Samples were collected from malignant tumors, benign nodules, and normal thyroid epithelial tissues. Results: A total of 32 samples, including 12 from cytologically indeterminate categories, were stained using aqueous methylene blue (MB) solution, imaged, and analyzed. Fluorescence emission images yielded diagnostically relevant information on cytomorphology. Significantly higher MB Fpol was measured in thyroid cancer as compared to benign and normal cells. The results obtained from 12 indeterminate samples revealed that MB Fpol accurately differentiated benign and malignant thyroid nodules. Conclusions: The developed imaging approach holds the potential to provide an accurate and objective biomarker for thyroid cancer, improve diagnostic accuracy of cytopathology, and decrease the number of lobectomy and near-total thyroidectomy procedures. Full article

(This article belongs to the Topic Biomedical Photonics)

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11 pages, 2617 KiB

Open AccessArticle

Photodynamic Antibiofilm and Antibacterial Activity of a New Gel with 5-Aminolevulinic Acid on Infected Titanium Surfaces

by Morena Petrini, Silvia Di Lodovico, Giovanna Iezzi, Luigina Cellini, Domenico Tripodi, Adriano Piattelli and Simonetta D’Ercole

Biomedicines 2022, 10(3), 572; https://doi.org/10.3390/biomedicines10030572 - 28 Feb 2022

Cited by 9 | Viewed by 2679

Abstract

The use of a new gel containing aminolevulinic acid and red light (ALAD–PDI) was tested in order to counteract bacterial biofilm growth on different titanium implant surfaces. The varying antibacterial efficacy of ALAD–PDI against biofilm growth on several titanium surfaces was also evaluated. [...] Read more.

The use of a new gel containing aminolevulinic acid and red light (ALAD–PDI) was tested in order to counteract bacterial biofilm growth on different titanium implant surfaces. The varying antibacterial efficacy of ALAD–PDI against biofilm growth on several titanium surfaces was also evaluated. A total of 60 titanium discs (30 machined and 30 double-acid etched, DAE) were pre-incubated with saliva and then incubated for 24 h with Streptococcus oralis to form bacterial biofilm. Four different groups were distinguished: two exposed groups (MACHINED and DAE discs), covered with S. oralis biofilm and subjected to ALAD + PDI, and two unexposed groups, with the same surfaces and bacteria, but without the ALAD + PDI (positive controls). Negative controls were non-inoculated discs alone and combined with the gel (ALAD) without the broth cultures. After a further 24 h of anaerobic incubation, all groups were evaluated for colony-forming units (CFUs) and biofilm biomass, imaged via scanning electron microscope, and tested for cell viability via LIVE/DEAD analysis. CFUs and biofilm biomass had significantly higher presence on unexposed samples. ALAD–PDI significantly decreased the number of bacterial CFUs on both exposed surfaces, but without any statistically significant differences among them. Live/dead staining showed the presence of 100% red dead cells on both exposed samples, unlike in unexposed groups. Treatment with ALAD + red light is an effective protocol to counteract the S. oralis biofilm deposited on titanium surfaces with different tomography. Full article

(This article belongs to the Topic Biomedical Photonics)

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15 pages, 16154 KiB

Open AccessArticle

Raman Spectroscopy of Individual Cervical Exfoliated Cells in Premalignant and Malignant Lesions

by Mariana Sarai Silva-López, César Arturo Ilizaliturri Hernández, Hugo Ricardo Navarro Contreras, Ángel Gabriel Rodríguez Vázquez, Alejandra Ortiz-Dosal and Eleazar Samuel Kolosovas-Machuca

Appl. Sci. 2022, 12(5), 2419; https://doi.org/10.3390/app12052419 - 25 Feb 2022

Cited by 4 | Viewed by 2117

Abstract

Cervical cancer is frequent neoplasia. Currently, the diagnostic approach includes cervical cytology, colposcopy, and histopathology studies; combining detection techniques increases the sensitivity and specificity of the tests. Raman spectroscopy is a high-resolution technique that supports the diagnosis of malignancies. This study aimed to [...] Read more.

Cervical cancer is frequent neoplasia. Currently, the diagnostic approach includes cervical cytology, colposcopy, and histopathology studies; combining detection techniques increases the sensitivity and specificity of the tests. Raman spectroscopy is a high-resolution technique that supports the diagnosis of malignancies. This study aimed to evaluate the Raman spectroscopy technique discriminating between healthy and premalignant/malignant cervical cells. We included 81 exfoliative cytology samples, 29 in the “healthy group” (negative cytology), and 52 in the “CIN group” (premalignant/malignant lesions). We obtained the nucleus and cytoplasm Raman spectra of individual cells. We tested the spectral differences between groups using Permutational Multivariate Analysis of Variance (PERMANOVA) and Canonical Analysis of Principal Coordinates (CAP). We found that Raman spectra have increased intensity in premalignant/malignant cells compared with healthy cells. The characteristic Raman bands corresponded to proteins and nucleic acids, in concordance with the increased replication and translation processes in premalignant/malignant states. We found a classification efficiency of 76.5% and 82.7% for cytoplasmic and nuclear Raman spectra, respectively; cell nucleus Raman spectra showed a sensitivity of 84.6% in identifying cervical anomalies. The classification efficiency and sensitivity obtained for nuclear spectra suggest that Raman spectroscopy could be helpful in the screening and diagnosis of premalignant lesions and cervical cancer. Full article

(This article belongs to the Topic Biomedical Photonics)

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14 pages, 1530 KiB

Open AccessArticle

Simultaneous Noninvasive Detection and Therapy of Atherosclerosis Using HDL Coated Gold Nanorods

by Rinat Ankri, Dorit Leshem-Lev, Hamootal Duadi, Emanuel Harari, Menachem Motiei, Edith Hochhauser, Eli I. Lev and Dror Fixler

Diagnostics 2022, 12(3), 577; https://doi.org/10.3390/diagnostics12030577 - 23 Feb 2022

Cited by 4 | Viewed by 2329

Abstract

Cardiovascular disease (CVD) is a major cause of death and disability worldwide. A real need exists in the development of new, improved therapeutic methods for treating CVD, while major advances in nanotechnology have opened new avenues in this field. In this paper, we [...] Read more.

Cardiovascular disease (CVD) is a major cause of death and disability worldwide. A real need exists in the development of new, improved therapeutic methods for treating CVD, while major advances in nanotechnology have opened new avenues in this field. In this paper, we report the use of gold nanoparticles (GNPs) coated with high-density lipoprotein (HDL) (GNP-HDL) for the simultaneous detection and therapy of unstable plaques. Based on the well-known HDL cardiovascular protection, by promoting the reverse cholesterol transport (RCT), injured rat carotids, as a model for unstable plaques, were injected with the GNP-HDL. Noninvasive detection of the plaques 24 h post the GNP injection was enabled using the diffusion reflection (DR) method, indicating that the GNP-HDL particles had accumulated in the injured site. Pathology and noninvasive CT measurements proved the recovery of the injured artery treated with the GNP-HDL. The DR of the GNP-HDL presented a simple and highly sensitive method at a low cost, resulting in simultaneous specific unstable plaque diagnosis and recovery. Full article

(This article belongs to the Topic Biomedical Photonics)

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12 pages, 5256 KiB

Open AccessArticle

Optical Design of a Quantitative Microvolume Nucleic Acid Spectrophotometer with Non-Optical Fiber and All Radiation-Hardened Lens Elements

by Sheng-Feng Lin

Photonics 2022, 9(1), 5; https://doi.org/10.3390/photonics9010005 - 22 Dec 2021

Cited by 3 | Viewed by 2671

Abstract

The purity of the nucleic acid samples obtained by extraction/precipitation or adsorption chromatography must be verified with microvolume spectrophotometry to ensure a high success rate of the subsequent nucleic acid sequencing while exploring the trace rare nucleic acids in space exploration with in-situ [...] Read more.

The purity of the nucleic acid samples obtained by extraction/precipitation or adsorption chromatography must be verified with microvolume spectrophotometry to ensure a high success rate of the subsequent nucleic acid sequencing while exploring the trace rare nucleic acids in space exploration with in-situ life detection. This paper reports an optical design for a radiation-hardened quantitative microvolume spectrophotometer with all radiation-hardened lens elements for space exploration instruments by using a non-optical fiber optical path with radiation-hardened optical glass elements. The results showed that the mean absolute error rate of the measured standard ribonucleic acid samples at concentrations between 50 ng/μL and 2300 ng/μL was within 2% when compared with a LINKO LKU–6000 ultraviolet–visible spectrophotometer. Full article

(This article belongs to the Topic Biomedical Photonics)

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