photoacoustic

Alzheimer's disease (AD), referring to a gradual deterioration in cognitive function, including memory loss and impaired thinking skills, has emerged as a substantial worldwide challenge with profound social and economic implications. As the prevalence of AD continues to rise and the population ages, there is an imperative demand for innovative imaging techniques to help improve our understanding of these complex conditions. Photoacoustic (PA) imaging forms a hybrid imaging modality by integrating the high-contrast of optical imaging and deep-penetration of ultrasound imaging...

Helicobacter pylori (H. pylori) is a type of bacteria that infects the stomach. The detection of H. pylori is an essential part of current clinical practices because this disease can cause peptic ulcers, chronic inflammation of the stomach lining but also stomach cancer. Helicobacter pylori has a naturally occurring enzyme that hydrolyzes urea into ammonium carbonate called urease. Many methods exist for the detection of H. pylori infection, but an innovative approach is to detect the ammonia in the breath (ABT, Ammonia Breath Test)...

Near-infrared fluorescence (NIRF)/photoacoustic (PA) dual-modality imaging integrated high-sensitivity fluorescence imaging with deep-penetration PA imaging has been recognized as a reliable tool for disease detection and diagnosis. However, it remains an immense challenge for a molecule probe to achieve the optimal NIRF and PA imaging by adjusting the energy allocation between radiative transition and nonradiative transition. Herein, a simple but effective strategy is reported to engineer a NIRF/PA dual-modality probe (Cl-HDN3 ) based on the near-infrared hemicyanine scaffold to optimize the energy allocation between radiative and nonradiative transition...

Ultrasound coupling is one of the critical challenges for traditional photoacoustic (or optoacoustic) microscopy (PAM) techniques transferred to the clinical examination of chronic wounds and open tissues. A promising alternative potential solution for breaking the limitation of ultrasound coupling in PAM is photoacoustic remote sensing (PARS), which implements all-optical non-interferometric photoacoustic measurements. Functional imaging of PARS microscopy was demonstrated from the aspects of histopathology and oxygen metabolism, while its performance in hemodynamic quantification remains unexplored...

High-frequency (greater than 30 MHz) photoacoustic computed tomography (PACT) provides the opportunity to reveal finer details of biological tissues with high spatial resolution. To record photoacoustic signals above 30 MHz, sampling rates higher than 60 MHz are required according to the Nyquist sampling criterion. However, the highest sampling rates supported by existing PACT systems are typically within the range of 40-60 MHz. Herein, we propose a novel PACT imaging method based on sub-Nyquist sampling...

In this research we present a low-cost system for breath acetone analysis based on UV-LED photoacoustic spectroscopy. We considered the end-tidal phase of exhalation, which represents the systemic concentrations of volatile organic compounds (VOCs) - providing clinically relevant information about the human health. This is achieved via the development of a CO2 -triggered breath sampling system, which collected alveolar breath over several minutes in sterile and inert containers. A real-time mass spectrometer is coupled to serve as a reference device for calibration measurements and subsequent breath analysis...

Cancer treatment requires precise tumor-specific targeting at specific sites that allows for high-resolution diagnostic imaging and long-term patient-tailorable cancer therapy while minimizing side effects largely arising from non-targetability. This can be realized by harnessing exogenous remote stimuli, such as tissue-penetrative ultrasound, magnetic field, light, and radiation, that enable local activation for cancer imaging and therapy in deep tumors. A myriad of nanomedicines can be efficiently activated when the energy of such remote stimuli can be transformed into another type of energy...

OBJECTIVES: To develop a nomogram based on photoacoustic imaging (PAI) radiomics and BI-RADs to identify breast cancer (BC) in BI-RADS 4 or 5 lesions detected by ultrasound (US). METHODS: In this retrospective study, 119 females with 119 breast lesions at US and PAI examination were included (January 2022 to December 2022). Patients were divided into the training set (n = 83) or testing set (n = 36) to develop a nomogram to identify BC in BI-RADS 4 or 5 lesions...

A miniaturized optical fiber photoacoustic gas sensor enhanced by dense multibutterfly spots is reported for the first time. The principle of space light transmission of neglecting paraxial approximation is theoretically analyzed for designing a dense multibutterfly spots-based miniature multipass cell. In a multipass photoacoustic tube with a diameter of 16 mm, the light beam is reflected about a hundred times. The light spots on the mirror surfaces at both ends of the photoacoustic tube form a dense multibutterfly distribution...

To identify the vascular alteration by photodynamic therapy (PDT), the utilization of high-resolution, high-speed, and wide-field photoacoustic microscopy (PAM) has gained enormous interest. The rapid changes in vasculature during PDT treatment and monitoring of tumor tissue activation in the orthotopic pancreatic cancer model have received limited attention in previous studies. Here, a fully two-axes waterproof galvanometer scanner-based photoacoustic microscopy (WGS-PAM) system was developed for in vivo monitoring of dynamic variations in micro blood vessels due to PDT in an orthotopic pancreatic cancer mouse model...

In recent years, there has been a growing interest in plant pigments as readily available nutraceuticals. Photosynthetic pigments, specifically chlorophylls and carotenoids, renowned for their non-toxic antioxidant properties, are increasingly finding applications beyond their health-promoting attributes. Consequently, there is an ongoing need for cost-effective methods of isolation. This study employs a co-precipitation method to synthesize magnetic iron oxide nanoparticles. Scanning electron microscopy (SEM) coupled with energy dispersive spectrometry (EDS) confirms that an aqueous environment and oxidizing conditions yield nanosized iron oxide with particle sizes ranging from 80 to 140 nm...

Bone tissue engineering using osteoconductive scaffolds holds promise for regeneration, with pearl powder gaining interest for its bioactive qualities. This study used freeze drying to create chitosan (CS) scaffolds with pearl/calcium phosphate (p/CaP) powders, mimicking bone tissue structurally and compositionally. Characterization included scanning electron microscopy (SEM) and mechanical testing. X-ray diffraction (XRD) Fourier-transform infrared-photoacoustic photo-acoustic sampling (FTIR-PAS), and FTIR- attenuated total reflectance (FTIR-ATR) were used to characterize p/CaP...

Optical-based imaging has improved from early single-location research to further sophisticated imaging in 2D topography and 3D tomography. These techniques have the benefit of high specificity and non-radiative safety for brain detection and therapy. However, their performance is limited by complex tissue structures. To overcome the difficulty in successful brain imaging applications, we conducted a simulation using 16 optical source types within a brain model that is based on the Monte Carlo method. In addition, we propose an evaluation method of the optical propagating depth and resolution, specifically one based on the optical distribution for brain applications...

Photoacoustic molecular imaging technology has a wide range of applications in biomedical research. In practical scenarios, both the probes and blood generate signals, resulting in the saliency of the probes in the blood environment being diminished, impacting imaging quality. Although several methods have been proposed for saliency enhancement, they inevitably suffer from moderate generality and detection speed. The Grüneisen relaxation (GR) nonlinear effect offers an alternative for enhancing saliency and can improve generality and speed...

BACKGROUND: Spinal muscular atrophy is a progressive neuromuscular disorder and among the most frequent genetic causes of infant mortality. While recent advancements in gene therapy provide the potential to ameliorate the disease severity, there is currently no modality in clinical use to visualize dynamic pathophysiological changes in disease progression and regression after therapy. METHODS: In this prospective diagnostic clinical study, ten pediatric patients with spinal muscular atrophy and ten age- and sex-matched controls have been examined with three-dimensional optoacoustic imaging and clinical standard examinations to compare the spectral profile of muscle tissue and correlate it with motor function (ClinicalTrials...

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...

Recurrence and metastasis of gastric cancer is a major therapeutic challenge for treatment. The presence of cancer stem cells (CSCs) is a major obstacle to the success of current cancer therapy, often leading to treatment resistance and tumor recurrence and metastasis. Therefore, it is important to develop effective strategies to eradicate CSCs. In this study, we developed a combined therapeutic strategy of photothermal therapy (PTT) and gastric cancer stem cells (GCSCs) inhibition by successfully synthesizing nanoliposomes loaded with IR780 (photosensitizer) and EN4 (c-Myc inhibitor)...

Triple negative breast cancer (TNBCs), known as an immunologically cold tumor, is difficult to completely eliminate with existing monotherapies, let alone metastasis and recurrence. It is urgent to design a rational combination of multiple therapies to programmatically reconstitute tumor microenvironment (TME) and reverse the immune "cold" into "hot" inflammatory tumors to improve the therapeutic effect. Hence, in this work, a multifunctional nanosystem (FeSH NPs) that integrates metal-polyphenol coordination complex as a photothermal agent and polyphenol, salvianolic acid B (SAB) as immunomodulator is designed and fabricated for synergistic photothermal-immunotherapy of TNBCs combined with anti-PD-L1 antibody...

Photothermal agents (PTAs) with desirable near-infrared (NIR) absorption and excellent photothermal conversion efficiency (PCE) are ideal candidates for cancer treatment. However, numerous PTAs still require high-intensity and long-duration laser irradiation to completely ablate the tumor during photothermal therapy (PTT) process, resulting in light damage to healthy skin and tissue as well as limiting their biomedical applications. Integrating intense NIR absorption and high PCE into a single small-molecule PTA is an important prerequisite for realizing efficient PTT, but is a serious challenge...

Nitroxyl (HNO) plays a vital role in various biological functions and pharmacological activities, so the development of an excellent near-infrared fluorescent (NIRF) and photoacoustic (PA) dual-modality probe is crucial for understanding HNO-related physiological and pathological progression. Herein, we proposed and synthesized a novel NIRF/PA dual probe (QL-HNO) by substituting an indole with quinolinium in hemicyanine for the sensitive detection of exogenous and endogenous HNO in vivo . The designed probe showed the highest sensitivity in NIRF mode and a desirable PA signal-to-noise ratio for HNO detection in vitro and was further applied for NIRF/PA dual-modal imaging of HNO with high contrast in living cells and tumor-bearing animals...