-
Sensors (Basel, Switzerland) Feb 2024Optical microscopy techniques are among the most used methods in biomedical sample characterization. In their more advanced realization, optical microscopes demonstrate... (Review)
Review
Optical microscopy techniques are among the most used methods in biomedical sample characterization. In their more advanced realization, optical microscopes demonstrate resolution down to the nanometric scale. These methods rely on the use of fluorescent sample labeling in order to break the diffraction limit. However, fluorescent molecules' phototoxicity or photobleaching is not always compatible with the investigated samples. To overcome this limitation, quantitative phase imaging techniques have been proposed. Among these, holographic imaging has demonstrated its ability to image living microscopic samples without staining. However, for a 3D assessment of samples, tomographic acquisitions are needed. Tomographic Diffraction Microscopy (TDM) combines holographic acquisitions with tomographic reconstructions. Relying on a 3D synthetic aperture process, TDM allows for 3D quantitative measurements of the complex refractive index of the investigated sample. Since its initial proposition by Emil Wolf in 1969, the concept of TDM has found a lot of applications and has become one of the hot topics in biomedical imaging. This review focuses on recent achievements in TDM development. Current trends and perspectives of the technique are also discussed.
PubMed: 38475130
DOI: 10.3390/s24051594 -
Forensic Science International Sep 2023Hairs is a relatively environmentally resistant biological material that is often found at crime scenes. Human hair is more durable than other biological traces such as...
Hairs is a relatively environmentally resistant biological material that is often found at crime scenes. Human hair is more durable than other biological traces such as blood or urine, and its collection and storage does not require specific preservation procedures. Melanin is the hair pigment, which is the main determinant of hair colour. There are two pigments present in human hair: eumelanin, predominant in dark hair, and pheomelanin, responsible for red colour. Eumelanin is more resistant and has photoprotective properties, while pheomelanin is phototoxic and shows lower resistance to environmental factors. The differences in the properties of eu- and pheomelanin are the basis of the present study, which aimed to examine the rate and quality of taphonomic changes in hair roots in relation to the predominant melanin type, under the influence of selected environmental factors, such as soil pH, degree of exposure to solar radiation, temperature and water from a natural watercourse (river) and chemically pure water. Therefore, changes in blonde, dark, grey, red and dyed hair roots were microscopically documented for six months under the influence of the above factors. The results of the study indicated the strongest degradation potential among acidic soil and a riverine environment, as well as the protective role of eumelanin against environmental taphonomic factors. Degradation occurred most rapidly in the river environment, where microbial activity was additionally observed. Distilled water, exposure to sunlight and low temperature did not lead to decomposition changes. The results of our team's research provide the basis for an extended analysis of the changes occurring in hair under the influence of environmental factors in relation to melanin content.
Topics: Humans; Melanins; Hair; Hair Color
PubMed: 37473545
DOI: 10.1016/j.forsciint.2023.111784 -
Journal of Biomedical Optics Apr 2024Light-sheet fluorescence microscopy (LSFM) has emerged as a powerful and versatile imaging technique renowned for its remarkable features, including high-speed 3D...
SIGNIFICANCE
Light-sheet fluorescence microscopy (LSFM) has emerged as a powerful and versatile imaging technique renowned for its remarkable features, including high-speed 3D tomography, minimal photobleaching, and low phototoxicity. The interference light-sheet fluorescence microscope, with its larger field of view (FOV) and more uniform axial resolution, possesses significant potential for a wide range of applications in biology and medicine.
AIM
The aim of this study is to investigate the interference behavior among multiple light sheets (LSs) in LSFM and optimize the FOV and resolution of the light-sheet fluorescence microscope.
APPROACH
We conducted a detailed investigation of the interference effects among LSs through theoretical derivation and numerical simulations, aiming to find optimal parameters. Subsequently, we constructed a customized system of multi-LSFM that incorporates both interference light sheets (ILS) and noninterference light-sheet configurations. We performed beam imaging and microsphere imaging tests to evaluate the FOV and axial resolution of these systems.
RESULTS
Using our custom-designed light-sheet fluorescence microscope, we captured the intensity distribution profiles of both interference and noninterference light sheets (NILS). Additionally, we conducted imaging tests on microspheres to assess their imaging outcomes. The ILS not only exhibits a larger FOV compared to the NILS but also demonstrates a more uniform axial resolution.
CONCLUSIONS
By effectively modulating the interference among multiple LSs, it is possible to optimize the intensity distribution of the LSs, expand the FOV, and achieve a more uniform axial resolution.
Topics: Microscopy, Fluorescence; Microspheres; Photobleaching
PubMed: 38629030
DOI: 10.1117/1.JBO.29.4.046501 -
Inorganic Chemistry Mar 2024The combination of photodynamic therapy and radiotherapy has given rise to a modality called radiodynamic therapy (RDT), based on reactive oxygen species-producing...
The combination of photodynamic therapy and radiotherapy has given rise to a modality called radiodynamic therapy (RDT), based on reactive oxygen species-producing radiosensitizers. The production of singlet oxygen, O(Δ), by octahedral molybdenum (Mo) clusters upon X-ray irradiation allows for simplification of the architecture of radiosensitizing systems. In this context, we prepared a radiosensitizing system using copper-free click chemistry between a Mo cluster bearing azido ligands and the homo-bifunctional linker bis-dPEG-DBCO. The resulting compound formed nanoparticles, which featured production of O(Δ) and efficient cellular uptake, leading to remarkable photo- and radiotoxic effects against the prostatic adenocarcinoma TRAMP-C2 cell line. Spheroids of TRAMP-C2 cells were also used for evaluation of toxicity and phototoxicity. In vivo experiments on a mouse model demonstrated that subcutaneous injection of the nanoparticles is a safe administration mode at a dose of up to 0.08 g kg. The reported results confirm the relevancy of Mo-based radiosensitizing nanosystems for RDT.
Topics: Animals; Mice; Molybdenum; Iodine; Photochemotherapy; Adenocarcinoma; Polyethylene Glycols
PubMed: 38364266
DOI: 10.1021/acs.inorgchem.4c00084 -
Nature Biotechnology Jun 2024Here we present a method to reduce the photobleaching of fluorescent proteins and the associated phototoxicity. It exploits a photophysical process known as reverse...
Here we present a method to reduce the photobleaching of fluorescent proteins and the associated phototoxicity. It exploits a photophysical process known as reverse intersystem crossing, which we induce by near-infrared co-illumination during fluorophore excitation. This dual illumination method reduces photobleaching effects 1.5-9.2-fold, can be easily implemented on commercial microscopes and is effective in eukaryotic and prokaryotic cells with a wide range of fluorescent proteins.
Topics: Photobleaching; Luminescent Proteins; Infrared Rays; Humans; Microscopy, Fluorescence
PubMed: 37537501
DOI: 10.1038/s41587-023-01893-7 -
Science Advances Mar 2024Synergistic phototherapy stands for superior treatment prospects than a single phototherapeutic modality. However, the combined photosensitizers often suffer from...
Synergistic phototherapy stands for superior treatment prospects than a single phototherapeutic modality. However, the combined photosensitizers often suffer from incompatible excitation mode, limited irradiation penetration depth, and lack of specificity. We describe the development of upconversion dual-photosensitizer-expressing bacteria (UDPB) for near-infrared monochromatically excitable combination phototherapy. UDPB are prepared by integrating genetic engineering and surface modification, in which bacteria are encoded to simultaneously express photothermal melanin and phototoxic KillerRed protein and the surface primary amino groups are derived to free thiols for biorthogonal conjugation of upconversion nanoparticles. UDPB exhibit a near-infrared monochromatic irradiation-mediated dual-activation characteristic as the photothermal conversion of melanin can be initiated directly, while the photodynamic effect of KillerRed can be stimulated indirectly by upconverted visible light emission. UDPB also show living features to colonize hypoxic lesion sites and inhibit pathogens via bacterial community competition. In two murine models of solid tumor and skin wound infection, UDPB separately induce robust antitumor response and a rapid wound healing effect.
Topics: Animals; Mice; Photosensitizing Agents; Melanins; Phototherapy; Bacteria; Infrared Rays
PubMed: 38446879
DOI: 10.1126/sciadv.adk9485 -
Frontiers in Neurology 2024This Mendelian randomization (MR) study identified modifiable risk factors for isolated rapid eye movement sleep behavior disorder (iRBD).
OBJECTIVES
This Mendelian randomization (MR) study identified modifiable risk factors for isolated rapid eye movement sleep behavior disorder (iRBD).
METHODS
Genome-wide association study (GWAS) datasets for 29 modifiable risk factors for iRBD in discovery and replication stages were used. GWAS data for iRBD cases were obtained from the International RBD Study Group. The inverse variance weighted (IVW) method was primarily employed to explore causality, with supplementary analyses used to verify the robustness of IVW findings. Co-localization analysis further substantiated causal associations identified via MR. Genetic correlations between mental illness and iRBD were identified using trait covariance, linkage disequilibrium score regression, and co-localization analyses.
RESULTS
Our study revealed causal associations between sun exposure-related factors and iRBD. Utilizing sun protection (odds ratio [OR] = 0.31 [0.14, 0.69], = 0.004), ease of sunburn (OR = 0.70 [0.57, 0.87], = 0.001), childhood sunburn occasions (OR = 0.58 [0.39, 0.87], = 0.008), and phototoxic dermatitis (OR = 0.78 [0.66, 0.92], = 0.003) decreased iRBD risk. Conversely, a deep skin color increased risk (OR = 1.42 [1.04, 1.93], = 0.026). Smoking, alcohol consumption, low education levels, and mental illness were not risk factors for iRBD. Anxiety disorders and iRBD were genetically correlated.
CONCLUSION
Our study does not corroborate previous findings that identified smoking, alcohol use, low education, and mental illness as risk factors for iRBD. Moreover, we found that excessive sun exposure elevates iRBD risk. These findings offer new insights for screening high-risk populations and devising preventive measures.
PubMed: 38385030
DOI: 10.3389/fneur.2024.1321216 -
RSC Advances Mar 2024Conventional Au nanomaterial synthesis typically necessitates the involvement of extensive surfactants and reducing agents, leading to a certain amount of chemical waste...
Conventional Au nanomaterial synthesis typically necessitates the involvement of extensive surfactants and reducing agents, leading to a certain amount of chemical waste and biological toxicity. In this study, we innovatively employed ultra-small graphene oxide as a reducing agent and surfactant for the generation of small Au nanoparticles under ultraviolet irradiation (UV) at ambient conditions. After ultra-small GO-Au seeds were successfully synthesized, we fabricated small star-like Au nanoparticles on the surface of GO, in which GO effectively prevented Austar from aggregation. To further use GO-Austar for cancer PTT therapy, through the modification of reduced human serum albumin-folic acid conjugate (rHSA-FA) and loading IR780, the final probe GO-Austar@rHSA-FA@IR780 was prepared. The prepared probe showed excellent biocompatibility and superb phototoxicity towards MGC-803 cells . , the final probe dramatically increased tumor temperature up to 58.6 °C after 5 minutes of irradiation by an 808 nm laser, significantly inhibiting tumor growth and nearly eradicating subcutaneous tumors in mice. This research provides a novel and simple method for the synthesis of GO-Au nanocomposites, showcasing significant potential in biological applications.
PubMed: 38567330
DOI: 10.1039/d4ra00742e -
Research (Washington, D.C.) 2024Photodynamic therapy (PDT) has emerged as a promising approach for squamous cell carcinoma treatment but hindered by tumor hypoxia, acquired resistance, phototoxicity,...
Photodynamic therapy (PDT) has emerged as a promising approach for squamous cell carcinoma treatment but hindered by tumor hypoxia, acquired resistance, phototoxicity, and so on. To address these issues, we developed a smart strategy utilizing activable photosensitizers delivered by an aptamer-functionalized DNA probe (ADP). The ADP incorporated an AS1411 aptamer for tumor targeting and a linear antisense oligonucleotide (ASO) for recognition of Survivin mRNA. In the absence of the target, PDT remained quenched, thereby avoiding phototoxicity during circulation and nonselective distribution. With the aid of the aptamer, ADP achieved selective targeting of tumors. Upon internalization, ADP targeted recognized Survivin mRNA, triggering PDT activation, and releasing ASO to down-regulate Survivin expression and reverse tumor resistance. Consequently, the activable photosensitizers exhibited an "AND" logic gate, combining tumor-targeting delivery and tumor-related gene activation, thus enhancing its specificity. Additionally, the incorporation of hemin into the ADP provided catalase activity, converting tumor-abundant HO into O, thereby ameliorating tumor hypoxia. The resulting functionalized G-quadruplex/hemin-DNA probe complex demonstrated targeted delivery and activation, minimized side effects, and enhanced PDT efficacy in both xenograft tumor-bearing mice and patient-derived xenograft models. This study offers a unique and promising platform for efficient and safe PDT, thus holding great potential for future clinical translation and improved cancer therapy.
PubMed: 38269029
DOI: 10.34133/research.0295 -
Patient Related Outcome Measures 2024Erythropoietic protoporphyria (EPP), a rare inherited disorder, presents in early childhood with severe, painful phototoxicity, with significant impacts on...
Development and Content Validation of Novel Patient-Reported Outcome Measures to Assess Disease Severity and Change in Patients with Erythropoietic Protoporphyria: The EPP Impact Questionnaire (EPIQ).
PURPOSE
Erythropoietic protoporphyria (EPP), a rare inherited disorder, presents in early childhood with severe, painful phototoxicity, with significant impacts on health-related quality of life (HRQoL). Previous studies have not captured all concepts important to patients. Therefore, this study sought to develop a novel, comprehensive, and content valid patient-reported outcome (PRO) measure to assess the efficacy of new therapies.
PATIENTS AND METHODS
Qualitative interviews were conducted with EPP participants and clinical experts to obtain views on concepts relevant to patients. Results informed the development of novel PROs, which were debriefed during subsequent combined concept elicitation and cognitive debriefing interviews.
RESULTS
Twenty-three interviews were conducted with 17 adults and 6 adolescents with EPP. Concept elicitation revealed that participants experienced many symptoms with significant variability. The most common were burning, pain, swelling, and tingling. Tingling was the most common prodromal symptom, while burning was the most bothersome, and pain was the worst full reaction symptom. Participants reported being negatively impacted in their ability to do daily activities, and social and emotional functioning. Many reported impacted ability to work and be productive at their job. Participants reviewed and completed the newly developed PRO measures assessing full reactions and ability to do activities, as well as items to assess severity and change in severity of prodromal symptoms, full reactions, and EPP overall. All measures were found to be comprehensive, clear, and relevant.
CONCLUSION
PRO measures are needed to assess important aspects of HRQoL and evaluate therapeutic response. These PRO measures are unique in assessing overall severity and change in EPP.
PubMed: 38375415
DOI: 10.2147/PROM.S438892