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Senescence is an intricate physiological progression that can be instigated by a multiplicity of factors. Aberrant cellular senescence is capable of precipitating a substantial array of diseases. During chemotherapy, drugs typically tend to gradually accumulate in the liver, thereby inducing liver senescence and leading to a successive deterioration in its physiological function. β-galactosidase (β-gal), serving as a significant index in the exploration of senescence, has attracted considerable attention. In this study, a fluorescence/photoacoustic (FL/PA) biomodal probe (Gal-QCS) was developed based on a hemicyanine fluorophore for the imaging of β-gal in the process of drug-induced liver senescence. Gal-QCS demonstrates rapid responsiveness, high sensitivity, and remarkable selectivity in detecting β-gal in aqueous solutions. After incubation with β-gal, the fluorescence signal at 810 nm significantly increases, and concurrently, the photoacoustic signal at 775 nm also exhibits a substantial increment. Upon the induction of cell senescence with camptothecin, Gal-QCS can expeditiously and selectively image senescent cells. Moreover, after administering this probe to mice with liver senescence, the FL/PA signals in the livers of senescent mice were enhanced by 10.53-fold and 1.43-fold, respectively. This work robustly substantiates the potential and application prospects of Gal-QCS in detecting drug-induced liver senescence, with β-gal serving as a biomarker. [ABSTRACT FROM AUTHOR]

Transcranial ultrasound imaging is a popular method to study cerebral functionality and diagnose brain injuries. However, the detected ultrasound signal is greatly distorted due to the aberration caused by the skull bone. The aberration mechanism mainly depends on thickness and porosity, two important skull physical characteristics. Although skull bone thickness and porosity can be estimated from CT or MRI scans, there is significant value in developing methods for obtaining thickness and porosity information from ultrasound itself. Here, we extracted various features from ultrasound signals using physical skull‐mimicking phantoms of a range of thicknesses with embedded porosity‐mimicking acoustic mismatches and analyzed them using machine learning (ML) and deep learning (DL) models. The performance evaluation demonstrated that both ML‐ and DL‐trained models could predict the physical characteristics of a variety of skull phantoms with reasonable accuracy. The proposed approach could be expanded upon and utilized for the development of effective skull aberration correction methods. [ABSTRACT FROM AUTHOR]

Senescence is an intricate physiological progression that can be instigated by a multiplicity of factors. Aberrant cellular senescence is capable of precipitating a substantial array of diseases. During chemotherapy, drugs typically tend to gradually accumulate in the liver, thereby inducing liver senescence and leading to a successive deterioration in its physiological function. β-galactosidase (β-gal), serving as a significant index in the exploration of senescence, has attracted considerable attention. In this study, a fluorescence/photoacoustic (FL/PA) biomodal probe (Gal-QCS) was developed based on a hemicyanine fluorophore for the imaging of β-gal in the process of drug-induced liver senescence. Gal-QCS demonstrates rapid responsiveness, high sensitivity, and remarkable selectivity in detecting β-gal in aqueous solutions. After incubation with β-gal, the fluorescence signal at 810 nm significantly increases, and concurrently, the photoacoustic signal at 775 nm also exhibits a substantial increment. Upon the induction of cell senescence with camptothecin, Gal-QCS can expeditiously and selectively image senescent cells. Moreover, after administering this probe to mice with liver senescence, the FL/PA signals in the livers of senescent mice were enhanced by 10.53-fold and 1.43-fold, respectively. This work robustly substantiates the potential and application prospects of Gal-QCS in detecting drug-induced liver senescence, with β-gal serving as a biomarker.

[Display omitted] • First demonstration of high-Q and SNR of Helmholtz PA cell for VOC biomarkers in THz domain. • ppbV order Low detection limits (LOD) of methanol, ethanol and isopropanol using UV, Mid-IR and THz sources. • Comparative superior performance of VOC detection in THz range. • Dual phase detection of biomarkers using Tunable resonance frequency Helmholtz photoacoustic spectroscopy system. This paper reports the trace-level detection of volatile organic compounds (VOCs) like methanol, ethanol, and isopropanol, which are biomarkers for various diseases like diabetes, breast cancer, lung cancer, chronic pulmonary diseases, squamous cancer, cystic fibrosis, chronic liver diseases, chronic kidney diseases and so on. Here, the photoacoustic spectroscopy technique was used for the trace-level detection of these biomarkers using an indigenously designed tunable frequency (1.4 to 4 kHz range) Helmholtz photoacoustic (PA) cell. The study was carried out with UV (266 nm), Mid IR (5.4–7.3 µm) and THz (0.11 THz) range sources to explore and compare the PA signal generated by mentioned samples for different electronic vibrational and rotational level excitations. We achieved a low detection limit (LoD) of the order of 39.3 ppbV, 29.7 ppbV, and 11.6 ppbV for methanol, ethanol, and isopropanol, respectively using this non-invasive cost-effective, and fast technique. In addition, THz-based PA signal for these samples is reported for the first time. [ABSTRACT FROM AUTHOR]

• Presented model analyzes the shock wave resulting from the laser plasma when the nanosecond laser interacts with water. • Simulation the properties of the mechanical wave, including the shock wave emission time from the wall of the plasma sphere, the initial pressure and frequency of the shock wave. • Verified the presented model by an experimental shadow-graphic experiment. Photoacoustic phenomenon offers an efficient means of generating sound pulses. The interaction of laser and plasma is a very crucial subject in the study of the photoacoustic phenomenon. However, existing researches based on the plasma sphere approach, often neglect this interaction, treating the sound wave as a simple output from the plasma. This paper presents a model for analyzing the shock wave resulting from the laser plasma when the nanosecond laser interacts with water. The model calculates key mechanical wave properties, including the shock wave emission time from the the plasma sphere boundary, the initial pressure of the shock wave, and the wave frequency, based on the characteristics of the created plasma. According to the investigations, a laser with a power density of 6 GW.cm−2 creates a shock wave with an initial pressure of 4.3 MPa and 4520 kHz frequency. [ABSTRACT FROM AUTHOR]

Accurate and early detection of atherosclerosis (AS) is imperative for their effective treatment. However, fluorescence probes for efficient diagnosis of AS often encounter insufficient deep tissue penetration, which hinders the reliable assessment of plaque vulnerability. In this work, a reactive oxygen species (ROS) activated near-infrared (NIR) fluorescence and photoacoustic (FL/PA) dual model probe TPA-QO-B is developed by conjugating two chromophores (TPA-QI and O–OH) and ROS-specific group phenylboronic acid ester. The incorporation of ROS-specific group not only induces blue shift in absorbance, but also inhibits the ICT process of TPA-QO-OH, resulting an ignorable initial FL/PA signal. ROS triggers the convertion of TPA-QO-B to TPA-QO-OH, resulting in the concurrent amplification of FL/PA signal. The exceptional selectivity of TPA-QO-B towards ROS makes it effectively distinguish AS mice from the healthy. The NIR emission can achieve a tissue penetration imaging depth of 0.3 cm. Moreover, its PA 775 signal possesses the capability to penetrate tissues up to a thickness of 0.8 cm, ensuring deep in vivo imaging of AS model mice in early stage. The ROS-triggered FL/PA dual signal amplification strategy improves the accuracy and addresses the deep tissue penetration problem simultaneously, providing a promising tool for in vivo tracking biomarkers in life science and preclinical applications. [ABSTRACT FROM AUTHOR]

Lipid metabolism diseases, particularly obesity (OB) and atherosclerosis (AS), pose significant global health challenges. This study introduces the Hcy-GGT probe, a novel hemicyanine-based sensor for real-time, high-sensitivity detection of glutamyl transpeptidase (GGT), crucial for assessing liver function and systemic lipid disorders like obesity (OB) and atherosclerosis (AS). The probe, activated by GGT, shows enhanced absorption, fluorescence, and photoacoustic signals, providing a linear response to GGT concentration with a detection limit of 57.5 ng/mL. Applied in cellular models and in vivo, Hcy-GGT effectively monitors GGT activity, demonstrating its potential for early disease diagnosis and monitoring, particularly in OB and AS contexts. Importantly, Hcy-GGT probe effectively distinguished between obese and non-obese in polycystic ovary syndrome (PCOS) patients by demonstrating stronger fluorescence intensity in the serum of the obese group, highlighting its utility in assessing obesity-associated metabolic risks. This probe's specificity and stability under physiological conditions underscore its utility for clinical diagnostics and biomedical research, offering a promising tool for non-invasive, dynamic disease monitoring and early intervention., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2025 Elsevier B.V. All rights reserved.)

Stable neutral metal radicaloid complexes have been synthesized from a modified tetrapyrrolic pigment, bilatriene, with iridium(I) and rhodium(I) cyclooctadiene (COD) synthons. The bilatriene skeleton contains α-linked conjugated pyrrole units, whereas an N-confused analogue used in this work possesses β-linked pyrrole moieties at the terminal, demonstrating a unique metal binding capability. Unprecedentedly, the metal-COD cations are accommodated at the outer nitrogen sites, which induced the formation of open-shell metal-radicaloid species. The resulting compounds are highly stable under ambient conditions and demonstrated facile redox conversion to afford the corresponding cation and anion species. Furthermore, the radicaloid complexes showed a distinct second near-infrared absorption (NIR-II) capability extending up to 1500 nm along with high photostability. These features emphasized that the complexes can be potential NIR-II light-responsible photothermal and photoacoustic imaging contrast agents based on the metal-radicaloid dye platform., (© 2024 The Author(s). Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

In practical applications within the human body, it is often challenging to fully encompass the target tissue or organ, necessitating the use of limited-view arrays, which can lead to the loss of crucial information. Addressing the reconstruction of photoacoustic sensor signals in limited-view detection spaces has become a focal point of current research. In this study, we introduce a self-supervised network termed HIgh-quality Self-supervised neural representation (HIS), which tackles the inverse problem of photoacoustic imaging to reconstruct high-quality photoacoustic images from sensor data acquired under limited viewpoints. We regard the desired reconstructed photoacoustic image as an implicit continuous function in 2D image space, viewing the pixels of the image as sparse discrete samples. The HIS's objective is to learn the continuous function from limited observations by utilizing a fully connected neural network combined with Fourier feature position encoding. By simply minimizing the error between the network's predicted sensor data and the actual sensor data, HIS is trained to represent the observed continuous model. The results indicate that the proposed HIS model offers superior image reconstruction quality compared to three commonly used methods for photoacoustic image reconstruction., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2025 The Authors.)

Plasmonic nanomaterials are effective photoacoustic (PA) contrast agents with diverse biomedical applications. While silica coatings on gold nanoparticles (AuNPs) have been demonstrated to increase PA efficiency, the underlying mechanism remains elusive. Here, we systematically investigated the impact of silica coatings on PA generation under picosecond and nanosecond laser pulses. Experimentally, we demonstrated a record high PA amplification of up to 400% under noncavitation conditions with a thin silica coating and only under picosecond laser pulses. We provide a clear mechanism for the observed PA amplification that identifies two competing effects, including transient absorption, which reduces photon energy absorption, and electron-phonon energy transfer at the gold-silica interface, which partly reverses the transient absorption effect. This study provides the first evidence and mechanistic insight on the impact of nonlinear optical effects on the nanomaterial-property relationship in PA contrast agents and offers insights for designing highly efficient contrast agents for biomedical applications.

Photoacoustic tomography (PAT) is an emerging imaging modality with widespread applications in both preclinical and clinical studies. Despite its promising capabilities to provide high-resolution images, the visualization of vessels might be hampered by skin signals and attenuation in tissues. In this study, we have introduced a framework to retrieve deep vessels. It combines a deep learning network to segment skin layers and an adaptive weighting algorithm to compensate for attenuation. Evaluation of enhancement using vessel occupancy metrics and signal-to-noise ratio (SNR) demonstrates that the proposed method significantly recovers deep vessels across various body positions and skin tones. These findings indicate the method's potential to enhance quantitative analysis in preclinical and clinical photoacoustic research., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2025 The Authors.)

Thinning of anterolateral thigh flap is challenging. Anatomical studies have shown variations in arterial branching patterns in the subcutaneous layer, which were suspected to be the reason for the high frequency of thinning failures. We attempted to visualize subcutaneous arterial courses preoperatively and perform thinning of perforator flaps using this information appropriately. We accumulated evidence on the accuracy of noninvasive vascular visualization using photoacoustic tomography (PAT). In the present case, we applied a medical imaging projection system (MIPS), which enabled real-time surgical navigation using indocyanine green (ICG) emission signals, to use photoacoustic information intraoperatively during the flap thinning procedure. A 69-year-old woman underwent half-tongue resection using the pull-through method for right-sided tongue cancer. Preoperative PAT was performed 5 days before surgery. The 12 × 6-cm area took ~8 min to scan. We used an ICG test card containing ICG-positive control material cut into strips to show tentative artery lines by projection mapping. The transparent vascular map was laminated and sterilized. MIPS captured ICG fluorescence signals that penetrated the anterolateral thigh flap and continuously projected the purple area on the reverse side of the flap, guiding the position of the tentative arteries. A 20 × 6.5-cm anterolateral thigh flap was elevated with the distal part of the reconstructed tongue and proximal de-epithelialized part to fill the pull-thorough tunnel in the submandibular region. Active bleeding was observed when cutting marginal fat tissue near the purple line of the distal ALT flap projected by MIPS. The study protocol did not include a highly invasive trial for MIPS-guided thinning; therefore, we removed minimal marginal fat tissue. The ALT flap showed no postoperative complications while maintaining conversation and swallowing functions. We present the concept of subcutaneous arterial real-time navigation surgery using PAT and MIPS for safe, easy, and fast flap thinning procedures in the future., (© 2025 The Author(s). Microsurgery published by Wiley Periodicals LLC.)

Carbon-based nanomaterials (CBNM) have been widely used in various fields due to their excellent physicochemical properties. In particular, in the area of tumor diagnosis and treatment, researchers have frequently reported them for their potential fluorescence, photoacoustic (PA), and ultrasound imaging performance, as well as their photothermal, photodynamic, sonodynamic, and other therapeutic properties. As the functions of CBNM are increasingly developed, their excellent imaging properties and superior tumor treatment effects make them extremely promising theranostic agents. This review aims to integrate the considered and researched information in a specific field of this research topic and systematically present, summarize, and comment on the efforts made by authoritative scholars. In this review, we summarized the work exploring carbon-based materials in the field of tumor imaging and therapy, focusing on PA imaging-guided photothermal therapy (PTT) and discussing their imaging and therapeutic mechanisms and developments. Finally, the current challenges and potential opportunities of carbon-based materials for PA imaging-guided PTT are presented, and issues that researchers should be aware of when studying CBNM are provided., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)