Far-infrared therapy promotes exercise capacity and glucose metabolism in mice by modulating microbiota homeostasis and activating AMPK.

The benefits of physical exercise on human health make it desirable to identify new approaches that would mimic or potentiate the effects of exercise to treat metabolic diseases. However, whether far-infrared (FIR) hyperthermia therapy could be used as exercise mimetic to realize wide-ranging metabolic regulation, and its underling mechanisms remain unclear. Here, a specific far-infrared (FIR) rays generated from graphene-based hyperthermia devices might promote exercise capacity and metabolisms. The material characterization showed that the graphene synthesized by chemical vapour deposition (CVD) was different from carbon fiber, with single-layer structure and high electrothermal transform efficiency. The emission spectra generated by graphene-FIR device would maximize matching those adsorbed by tissues. Graphene-FIR enhanced both core and epidermal temperatures, leading to increased blood flow in the femoral muscle and the abdominal region. The combination of microbiomic and metabolomic analysis revealed that graphene-FIR modulates the metabolism of the gut-muscle axis. This modulation was characterized by an increased abundance of short-chain fatty acids (SCFA)-producing bacteria and AMP, while lactic acid levels decreased. Furthermore, the principal routes involved in glucose metabolism, such as glycolysis and gluconeogenesis, were found to be altered. Graphene-FIR managed to stimulate AMPK activity by activating GPR43, thus enhancing muscle glucose uptake. Furthermore, a microbiota disorder model also demonstrated that the graphene-FIR effectively restore the exercise endurance with enhanced p-AMPK and GLUT4. Our results provided convincing evidence that graphene-based FIR therapy promoted exercise capacity and glucose metabolism via AMPK in gut-muscle axis. These novel findings regarding the therapeutic effects of graphene-FIR suggested its potential utility as a mimetic agent in clinical management of metabolic disorders.

AUNP-12 Near-Infrared Fluorescence Probes across NIR-I to NIR-II Enable In Vivo Detection of PD-1/PD-L1 Axis in the Tumor Microenvironment.

The innovative PD-1/PD-L1 pathway strategy is gaining significant traction in cancer therapeutics. However, fluctuating response rates of 20-40% to PD-1/PD-L1 inhibitors, coupled with the risk of hyperprogression after immunotherapy, underscore the need for accurate patient selection and the identification of more beneficiaries. Molecular imaging, specifically near-infrared (NIR) fluorescence imaging, is a valuable alternative for real-time, noninvasive visualization of dynamic PD-L1 expression in vivo. This research introduces AUNP-12, a novel PD-L1-targeting peptide antagonist conjugated with Cy5.5 and CH1055 for first (NIR-I) and second near-infrared (NIR-II) imaging. These probes have proven to be effective in mapping PD-L1 expression across various mouse tumor models, offering insights into tumor-immune interactions. This study highlights the potential of AUNP-12-Cy5.5 and AUNP-12-CH1055 for guiding clinical immunotherapy through precise patient stratification and dynamic monitoring, supporting the shift toward molecular imaging for personalized cancer care.

Near Infrared-Activatable Biomimetic Nanoplatform for Tumor-Specific Drug Release, Penetration and Chemo-Photothermal Synergistic Therapy of Orthotopic Glioblastoma.

Introduction: Glioblastoma multiforme (GBM), a highly invasive and prognostically challenging brain cancer, poses a significant hurdle for current treatments due to the existence of the blood-brain barrier (BBB) and the difficulty to maintain an effective drug accumulation in deep GBM lesions. Methods: We present a biomimetic nanoplatform with angiopep-2-modified macrophage membrane, loaded with indocyanine green (ICG) templated self-assembly of SN38 (AM-NP), facilitating active tumor targeting and effective blood-brain barrier penetration through specific ligand-receptor interaction. Results: Upon accumulation at tumor sites, these nanoparticles achieved high drug concentrations. Subsequent combination of laser irradiation and release of chemotherapy agent SN38 induced a synergistic chemo-photothermal therapy. Compared to bare nanoparticles (NPs) lacking cell membrane encapsulation, AM-NPs significantly suppressed tumor growth, markedly enhanced survival rates, and exhibited excellent biocompatibility with minimal side effects. Conclusion: This NIR-activatable biomimetic camouflaging macrophage membrane-based nanoparticles enhanced drug delivery targeting ability through modifications of macrophage membranes and specific ligands. It simultaneously achieved synergistic chemo-photothermal therapy, enhancing treatment effectiveness. Compared to traditional treatment modalities, it provided a precise, efficient, and synergistic method that might have contributed to advancements in glioblastoma therapy.

SLO-Net: Enhancing Multiple Sclerosis Diagnosis Beyond Optical Coherence Tomography Using Infrared Reflectance Scanning Laser Ophthalmoscopy Images.

Purpose: Several machine learning studies have used optical coherence tomography (OCT) for multiple sclerosis (MS) classification with promising outcomes. Infrared reflectance scanning laser ophthalmoscopy (IR-SLO) captures high-resolution fundus images, commonly combined with OCT for fixed B-scan positions. However, no machine learning research has utilized IR-SLO images for automated MS diagnosis. Methods: This study utilized a dataset comprised of IR-SLO images and OCT data from Isfahan, Iran, encompassing 32 MS and 70 healthy individuals. A number of convolutional neural networks (CNNs)-namely, VGG-16, VGG-19, ResNet-50, ResNet-101, and a custom architecture-were trained with both IR-SLO images and OCT thickness maps as two separate input datasets. The highest performing models for each modality were then integrated to create a bimodal model that receives the combination of OCT thickness maps and IR-SLO images. Subject-wise data splitting was employed to prevent data leakage among training, validation, and testing sets. Results: Overall, images of the 102 patients from the internal dataset were divided into test, validation, and training subsets. Subsequently, we employed a bootstrapping approach on the training data through iterative sampling with replacement. The performance of the proposed bimodal model was evaluated on the internal test dataset, demonstrating an accuracy of 92.40% ± 4.1% (95% confidence interval [CI], 83.61-98.08), sensitivity of 95.43% ± 5.75% (95% CI, 83.71-100.0), specificity of 92.82% ± 3.72% (95% CI, 81.15-96.77), area under the receiver operating characteristic (AUROC) curve of 96.99% ± 2.99% (95% CI, 86.11-99.78), and area under the precision-recall curve (AUPRC) of 97.27% ± 2.94% (95% CI, 86.83-99.83). Furthermore, to assess the model generalization ability, we examined its performance on an external test dataset following the same bootstrap methodology, achieving promising results, with accuracy of 85.43% ± 0.08% (95% CI, 71.43-100.0), sensitivity of 97.33% ± 0.06% (95% CI, 83.33-100.0), specificity of 84.6% ± 0.10% (95% CI, 71.43-100.0), AUROC curve of 99.67% ± 0.02% (95% CI, 95.63-100.0), and AUPRC of 99.65% ± 0.02% (95% CI, 94.90-100.0). Conclusions: Incorporating both modalities improves the performance of automated diagnosis of MS, showcasing the potential of utilizing IR-SLO as a complementary tool alongside OCT. Translational Relevance: Should the results of our proposed bimodal model be validated in future work with larger and more diverse datasets, diagnosis of MS based on both OCT and IR-SLO can be reliably integrated into routine clinical practice.

Protocol description and initial experience in kidney graft perfusion using infrared thermography.

PURPOSE: Protocol description for renal perfusion study using thermographic technology and description of the thermographic and clinical behavior of the transplanted kidneys before and after unclamping. METHODS: Infrared thermographic images of renal grafts are obtained before kidney reperfusion, 10 min after and just before closing the surgical wound. Thermographic data is evaluated together with the type of graft and donor, cold ischemia time, hypovascularized areas determined by the surgeon during surgical intervention, alterations in vascular flow in postoperative echo-Doppler, time at the beginning of graft function and serum creatinine monitoring during postoperative follow-up. RESULTS: 17 grafts were studied. The mean temperature of the grafts before reperfusion, 10 min after and at the end of the surgery were 18.7 °C (SD 6.27), 32.36 °C (SD1.47) and 32.07 °C (SD1.78) respectively. 4 grafts presented hypoperfused areas after reperfusion. These areas presented a lower temperature compared to the well perfused parenchyma surface using thermographic images. CONCLUSION: The study of the usefulness and applicability of thermography can allow the development of tools that provide additional objective information on organ perfusion in real time and non-invasive manner. Our protocol and initial results can contribute to provide new evidence. Further analyses should be developed to shed light on the role of this technology.

A Self-Cascade Penetrating Brain Tumor Immunotherapy Mediated by Near-Infrared II Cell Membrane-Disrupting Nanoflakes via Detained Dendritic Cells.

Immunotherapy can potentially suppress the highly aggressive glioblastoma (GBM) by promoting T lymphocyte infiltration. Nevertheless, the immune privilege phenomenon, coupled with the generally low immunogenicity of vaccines, frequently hampers the presence of lymphocytes within brain tumors, particularly in brain tumors. In this study, the membrane-disrupted polymer-wrapped CuS nanoflakes that can penetrate delivery to deep brain tumors via releasing the cell-cell interactions, facilitating the near-infrared II (NIR II) photothermal therapy, and detaining dendritic cells for a self-cascading immunotherapy are developed. By convection-enhanced delivery, membrane-disrupted amphiphilic polymer micelles (poly(methoxypoly(ethylene glycol)-benzoic imine-octadecane, mPEG-b-C18) with CuS nanoflakes enhances tumor permeability and resides in deep brain tumors. Under low-power NIR II irradiation (0.8 W/cm2), the intense heat generated by well-distributed CuS nanoflakes actuates the thermolytic efficacy, facilitating cell apoptosis and the subsequent antigen release. Then, the positively charged polymer after hydrolysis of the benzoic-imine bond serves as an antigen depot, detaining autologous tumor-associated antigens and presenting them to dendritic cells, ensuring sustained immune stimulation. This self-cascading penetrative immunotherapy amplifies the immune response to postoperative brain tumors but also enhances survival outcomes through effective brain immunotherapy.

Firefighter uncompensable heat stress results in excessive upper body temperatures measured by infrared thermography: Implications for cooling strategies.

This research sought to evaluate the thermal zones of the upper body and firefighter personal protective equipment (PPE) immediately following uncompensable heat stress (0.03 °C increase/min). We hypothesized that the frontal portion of the head and the inside of the firefighter helmet would be the hottest as measured by infrared thermography. This hypothesis was due to previous research demonstrating that the head accounts for ∼8-10% of the body surface area, but it accounts for ∼20% of the overall body heat dissipation during moderate exercise. Twenty participants performed a 21-min graded treadmill exercise protocol (Altered Modified Naughton) in an environmental chamber (35 °C, 50 % humidity) in firefighter PPE. The body areas analyzed were the frontal area of the head, chest, abdomen, arm, neck, upper back, and lower back. The areas of the PPE that were analyzed were the inside of the helmet and the jacket. The hottest areas of the body post-exercise were the frontal area of the head (mean: 37.3 ± 0.4 °C), chest (mean: 37.5 ± 0.3 °C), and upper back (mean: 37.3 ± 0.4 °C). The coldest area of the upper body was the abdomen (mean: 36.1 ± 0.4 °C). The peak temperature of the inside of the helmet increased (p < 0.001) by 9.8 °C from 27.7 ± 1.6 °C to 37.4 ± 0.7 °C, and the inside of the jacket increased (p < 0.001) by 7.3 °C from 29.2 ± 1.7 °C to 36.5 ± 0.4 °C. The results of this study are relevant for cooling strategies for firefighters.

Chronic Pain and Joint Hypermobility: A Brief Diagnostic Review for Clinicians and the Potential Application of Infrared Thermography in Screening Hypermobile Inflamed Joints.

Joint hypermobility syndromes, particularly chronic pain associated with this condition, including Hypermobile Ehlers-Danlos Syndrome (hEDS) and Hypermobility Spectrum Disorders (HSD), present diagnostic challenges due to their multifactorial origins and remain poorly understood from biomechanical and genomic-molecular perspectives. Recent diagnostic guidelines have differentiated hEDS, HSD, and benign joint hypermobility, providing a more objective diagnostic framework. However, incorrect diagnoses and underdiagnoses persist, leading to prolonged journeys for affected individuals. Musculoskeletal manifestations, chronic pain, dysautonomia, and gastrointestinal symptoms illustrate the multifactorial impact of these conditions, affecting both the physical and emotional well-being of affected individuals. Infrared thermography (IRT) emerges as a promising tool for joint assessment, especially in detecting inflammatory processes. Thermal distribution patterns offer valuable insights into joint dysfunctions, although the direct correlation between pain and inflammation remains challenging. The prevalence of neuropathies among hypermobile individuals accentuates the discordance between pain perception and thermographic findings, further complicating diagnosis and management. Despite its potential, the clinical integration of IRT faces challenges, with conflicting evidence hindering its adoption. However, studies demonstrate objective temperature disparities between healthy and diseased joints, especially under dynamic thermography, suggesting its potential utility in clinical practice. Future research focused on refining diagnostic criteria and elucidating the underlying mechanisms of hypermobility syndromes will be essential to improve diagnostic accuracy and enhance patient care in this complex and multidimensional context.

NIR-II-Absorbing NDI Polymer with Superior Penetration Depth for Enhanced Photothermal Therapy Efficiency of Hepatocellular Carcinoma.

Introduction: Hepatocellular carcinomas (HCC) have a high morbidity and mortality rate, and is difficult to cure and prone to recurrence when it has already developed. Therefore, early detection and efficient treatment of HCC is necessary. Methods: In this study, we synthesized a novel NDI polymer with uniform size, long-term stability, and high near-infrared two-zone (NIR-II) absorption efficiency, which can greatly enhance the effect of photothermal therapy (PTT) after intravenous injection into Huh-7-tumor bearing mice. Results: The in vitro and in vivo studies showed that NDI polymer exhibited excellent NIR-guided PTT treatment, and the antitumor effect was approximately 88.5%, with obvious antimetastatic effects. Conclusion: This study developed an NDI polymer-mediated integrated diagnostic and therapeutic modality for NIR-II fluorescence imaging and photothermal therapy.

Antibacterial Property and Mechanisms of Au@Ag Core-Shell Nanoparticles with Near-Infrared Absorption Against E. faecalis Infection of Dentin.

Background: Enterococcus faecalis (E. faecalis) is one of the main pathogens responsible for refractory root canal infections in the teeth and shows resistance against various antibacterial managements. Effective control of E. faecalis infection is a prerequisite for successful treatment of refractory apical periodontitis. This study aimed to analyze the antibacterial activity and mechanisms of Au@Ag nanoparticles (NPs) combined with photothermal therapy (PTT) against the original and Ag+-resistant E. faecalis. Methods: Au@AgNPs with optimal shell thicknesses were synthesized and characterized. The antibacterial activity of Au@AgNPs with PTT against the original or Ag+-resistant E. faecalis was evaluated, and the antibiofilm activity was tested on E. faecalis biofilm on the dentin of teeth. The potential antibacterial mechanisms of Au@AgNPs combined with PTT against E. faecalis have also been studied. Moreover, its influence on dentin microhardness and cytotoxicity was assessed. Results: This study revealed that Au@AgNPs combined with PTT showed enhanced antibacterial and antibiofilm effects, no negative effects on dentin microhardness, and low cytotoxicity toward human periodontal ligament cells (hPDLCs). Moreover, Au@AgNPs combined with PTT effectively inhibited the growth of Ag+-resistant E. faecalis. Its antibacterial effects may be exerted through the release of silver ions (Ag+), destruction of the cell membrane, production of reactive oxygen species (ROS) and inhibition of adenosine triphosphate (ATP) production. Hyperthermia generated by Au@AgNPs with PTT reduced membrane fluidity and enhanced Ag+ sensitivity by downregulating fabF expression. The upregulated expression of heat shock genes demonstrated that the Ag+ released from Au@AgNPs compromised the heat adaptation of E. faecalis. Conclusion: PTT significantly enhanced Ag+ sensitivity of the original and Ag+-resistant E. faecalis. Au@AgNPs combined with PTT may have the potential to be developed as a new antibacterial agent to control E. faecalis infections in teeth.

Sensorless adaptive optics in the second near-infrared window for deep vascular imaging in vivo.

We have experimentally validated the use of sensorless adaptive optics (AO) to enhance laser scanning confocal microscopy in the second near-infrared (NIR II) spectral range, termed as AO-NIR II confocal microscopy. This approach harnesses a NIR II fluorophore, excited by an 808 nm wavelength and emitting beyond 1000 nm, to visualize intricate structures in deep brain tissues with the intact skull. By leveraging the reduced scattering and aberrations in the NIR II spectrum, we successfully captured a three-dimensional (3D) vascular structure map extending 310 µm beneath the skull. AO typically boosts the fluorescence signal by approximately 2-3 times, leading to a superior contrast and diminished smearing effects. Consequently, small blood vessels at various depths can be clearly visualized, which might otherwise remain undetectable without AO corrections.

Organic photovoltaic biomaterial with fullerene derivatives for near-infrared light sensing in neural cells.

Retinal degenerative diseases, which can lead to photoreceptor cell apoptosis, have now become the leading irreversible cause of blindness worldwide. In this study, we developed an organic photovoltaic biomaterial for artificial retinas, enabling neural cells to detect photoelectric stimulation. The biomaterial was prepared using a conjugated polymer donor, PCE-10, and a non-fullerene receptor, Y6, both known for their strong near-infrared light absorption capabilities. Additionally, a fullerene receptor, PC61BM, was incorporated, which possesses the ability to absorb reactive oxygen species. We conducted a comprehensive investigation into the microstructure, photovoltaic properties, and photothermal effects of this three-component photovoltaic biomaterial. Furthermore, we employed Rat adrenal pheochromocytoma cells (PC-12) as a standard neural cell model to evaluate the in vitro photoelectric stimulation effect of this photovoltaic biomaterial. The results demonstrate that the photovoltaic biomaterial, enriched with fullerene derivatives, can induce intracellular calcium influx in PC-12 cells under 630 nm (red light) and 780 nm (near-infrared) laser irradiation. Moreover, there were lower levels of oxidative stress and higher levels of mitochondrial activity compared to the non-PC61BM group. This photovoltaic biomaterial proves to be an ideal substrate for near-infrared photoelectrical stimulation of neural cells and holds promise for restoring visual function in patients with photoreceptor apoptosis.

White-light activatable organic NIR-II luminescence nanomaterials for imaging-guided surgery.

While second near-infrared (NIR-II) fluorescence imaging is a promising tool for real-time surveillance of surgical operations, the previously reported organic NIR-II luminescent materials for in vivo imaging are predominantly activated by expensive lasers or X-ray with high power and poor illumination homogeneity, which significantly limits their clinical applications. Here we report a white-light activatable NIR-II organic imaging agent by taking advantages of the strong intramolecular/intermolecular D-A interactions of conjugated Y6CT molecules in nanoparticles (Y6CT-NPs), with the brightness of as high as 13315.1, which is over two times that of the brightest laser-activated NIR-II organic contrast agents reported thus far. Upon white-light activation, Y6CT-NPs can achieve not only in vivo imaging of hepatic ischemia reperfusion, but also real-time monitoring of kidney transplantation surgery. During the surgery, identification of the renal vasculature, post-reconstruction assessment of renal allograft vascular integrity, and blood supply analysis of the ureter can be vividly depicted by using Y6CT-NPs with high signal-to-noise ratios upon clinical laparoscopic LED white-light activation. Our work provides efficient molecular design guidelines towards white-light activatable imaging agent and highlights an opportunity for precision imaging theranostics.

Effect of combined red and infrared wavelengths on inflammation, hemorrhage, and muscle damage caused by Bothrops leucurus snake venom.

To evaluate the effects of red and infrared wavelengths, separately and combined, on the inflammatory process and collagen deposition in muscle damage caused by B. leucurus venom. 112 mice were inoculated with diluted venom (0.6mg/kg) in the gastrocnemius muscle. The animals were divided into four groups: one control (CG) and three treatments, namely: 1) red laser (λ=660 nm) (RG), 2) infrared laser (λ=808 nm) (IG) and 3) red laser (λ=660 nm) + infrared (λ=808 nm) (RIG). Each group was subdivided into four subgroups, according to the duration of treatment application (applications every 24 hours over evaluation times of up to 144 hours). A diode laser was used (0.1 W, CW, 1J/point, ED: 10 J/cm2). Both wavelengths reduced the intensity of inflammation and the combination between them significantly intensified the anti-inflammatory response. Photobiomodulation also changed the type of inflammatory infiltrate observed and RIG had the highest percentage of mononuclear cells in relation to the other groups. Hemorrhage intensity was significantly lower in treated animals and RIG had the highest number of individuals in which this variable was classified as mild. As for collagen deposition, there was a significant increase in RG in relation to CG, in RIG in relation to CG and in RIG in relation to IG. Photobiomodulation proved to be effective in the treatment of inflammation and hemorrhage caused by B. leucurus venom and stimulated collagen deposition. Better results were obtained with the combined wavelengths.

Polaron engineering promotes NIR-II absorption of carbon quantum dots for bioimaging and cancer therapy.

Recent years have witnessed a surge of interest in tuning the optical properties of organic semiconductors for diverse applications. However, achieving control over the optical bandgap in the second near-infrared (NIR-II) window has remained a major challenge. To address this, here we report a polaron engineering strategy that introduces diverse defects into carbon quantum dots (CQDs). These defects induce lattice distortions resulting in the formation of polarons, which can absorb the near-field scattered light. Furthermore, the formed polarons in N-related vacancies can generate thermal energy through the coupling of lattice vibrations, while the portion associated with O-related defects can return to the ground state in the form of NIR-II fluorescence. On the basis of this optical absorption model, these CQDs have been successfully applied to NIR-II fluorescence imaging and photothermal therapy. This discovery could open a promising route for the polarons of organic semiconductor materials as NIR-II absorbers in nanomedical applications.

Nanoparticles destabilizing the cell membranes triggered by NIR light for cancer imaging and photo-immunotherapy.

Cationic polymers have great potential for cancer therapy due to their unique interactions with cancer cells. However, their clinical application remains limited by their high toxicity. Here we show a cell membrane-targeting cationic polymer with antineoplastic activity (Pmt) and a second near-infrared (NIR-II) fluorescent biodegradable polymer with photosensitizer Bodipy units and reactive oxygen species (ROS) responsive thioketal bonds (PBodipy). Subsequently, these two polymers can self-assemble into antineoplastic nanoparticles (denoted mt-NPBodipy) which could further accumulate at the tumor and destroy cell membranes through electrostatic interactions, resulting in cell membrane destabilization. Meanwhile, the photosensitizer Bodipy produces ROS to induce damage to cell membranes, proteins, and DNAs to kill cancer cells concertedly, finally resulting in cell membrane lysis and cancer cell death. This work highlights the use of near-infrared light to spatially and temporarily control cationic polymers for photodynamic therapy, photo-immunotherapy, and NIR-II fluorescence for bio-imaging.

NIR-responsive electrospun nanofiber dressing promotes diabetic-infected wound healing with programmed combined temperature-coordinated photothermal therapy.

BACKGROUND: Diabetic wounds present significant challenges, specifically in terms of bacterial infection and delayed healing. Therefore, it is crucial to address local bacterial issues and promote accelerated wound healing. In this investigation, we utilized electrospinning to fabricate microgel/nanofiber membranes encapsulating MXene-encapsulated microgels and chitosan/gelatin polymers. RESULTS: The film dressing facilitates programmed photothermal therapy (PPT) and mild photothermal therapy (MPTT) under near-infrared (NIR), showcasing swift and extensive antibacterial and biofilm-disrupting capabilities. The PPT effect achieves prompt sterilization within 5 min at 52 °C and disperses mature biofilm within 10 min. Concurrently, by adjusting the NIR power to induce local mild heating (42 °C), the dressing stimulates fibroblast proliferation and migration, significantly enhancing vascularization. Moreover, in vivo experimentation successfully validates the film dressing, underscoring its immense potential in addressing the intricacies of diabetic wounds. CONCLUSIONS: The MXene microgel-loaded nanofiber dressing employs temperature-coordinated photothermal therapy, effectively amalgamating the advantageous features of high-temperature sterilization and low-temperature promotion of wound healing. It exhibits rapid, broad-spectrum antibacterial and biofilm-disrupting capabilities, exceptional biocompatibility, and noteworthy effects on promoting cell proliferation and vascularization. These results affirm the efficacy of our nanofiber dressing, highlighting its significant potential in addressing the challenge of diabetic wounds struggling to heal due to infection.

Updates on the Molecular Basis of Photoaging in All Skin Types.

Photoaging is a complex, ongoing process that clinically manifests as cutaneous rhytides, atrophy, laxity, dyspigmentation, telangiectasias, roughness, and mottled appearance of the skin. There is an abundance of research establishing the mechanism of ultraviolet (UV) - induced photodamage as it is a significant source of photoaging and skin cancers. While UV damage is known to induce photoaging, it is important to understand how other forms of light radiation also contribute to this process. UV only constitutes 5 to 10% of solar radiation that reaches the earth's surface. The remaining nearly 90% is evenly split between infrared and visible light radiation. Early research shows that varied skin types may elicit different photobiologic responses to light. This article presents the mechanisms and biomarkers of photodamage induced by light from across the spectrum, including UV, visible light, and infrared to better prevent and reverse the damage of photoaging in all skin types.J Drugs Dermatol. 2024;23(7):504-509.  doi:10.36849/JDD.7438.

A near-infrared fluorescent probe for differentiating cancer cells from normal cells and early diagnosis of liver cirrhosis.

BACKGROUND: Cirrhosis represents the terminal stage of liver disease progression and timely intervention in a diseased liver can enhance the likelihood of recovery. Viscosity, a crucial parameter of the cellular microenvironment, is intricately linked to the advancement of cirrhosis. However, viscosity monitoring still faces significant challenges in achieving non-invasive and rapid early diagnosis of cirrhosis. Near-infrared (NIR) fluorescence imaging has the advantages of high sensitivity, non-destructive detection, and ignoring background fluorescence interference, plays an important role in diagnosing and treating various biological diseases. Hence, monitoring cellular viscosity changes with NIR fluorescence probe holds great significance in the early diagnosis of cirrhosis. RESULTS: In this study, the NIR fluorescence probe based on the intramolecular charge transfer (TICT) mechanism was developed for imaging applications in mouse model of liver cirrhosis. A molecular rotor-type viscosity-responsive probe was synthesized by linking dioxanthracene groups via carbon-carbon double bonds. The probe demonstrated remarkable sensitivity, high selectivity and photostability, with its responsiveness to viscosity largely unaffected by factors such as polarity, pH, and interfering ions. The probe could effectively detect various drug-induced changes in cellular viscosity, enabling the differentiation between normal cells and cancerous cells. Furthermore, the enhanced tissue penetration capabilities of probe facilitated its successful application in mouse model of liver cirrhosis, allowing for the assessment of liver disease severity based on fluorescence intensity and providing a powerful tool for early diagnosis of cirrhosis. SIGNIFICANCE: A NIR viscosity-sensitive fluorescent probe was specifically designed to effectively monitor alterations in cellular and organ viscosity, which could advance the understanding of the biological characteristics of cancer and provide theoretical support for the early diagnosis of cirrhosis. Overall, this probe held immense potential in monitoring viscosity-related conditions, expanding the range of biomedical tools available.

Cytometry in the Short-Wave Infrared.

Cytometry plays a crucial role in characterizing cell properties, but its restricted optical window (400-850 nm) limits the number of stained fluorophores that can be detected simultaneously and hampers the study and utilization of short-wave infrared (SWIR; 900-1700 nm) fluorophores in cells. Here we introduce two SWIR-based methods to address these limitations: SWIR flow cytometry and SWIR image cytometry. We develop a quantification protocol for deducing cellular fluorophore mass. Both systems achieve a limit of detection of ∼0.1 fg cell-1 within a 30 min experimental time frame, using individualized, high-purity (6,5) single-wall carbon nanotubes as a model fluorophore and macrophage-like RAW264.7 as a model cell line. This high-sensitivity feature reveals that low-dose (6,5) serves as an antioxidant, and cell morphology and oxidative stress dose-dependently correlate with (6,5) uptake. Our SWIR cytometry holds immediate applicability for existing SWIR fluorophores and offers a solution to the issue of spectral overlapping in conventional cytometry.