Photosynthesis rates in phytoplankton depend on light intensity and its spectral composition, however their relation changes with photoacclimation. During the photoacclimation process algal cells optimize their har-ve...Photosynthesis rates in phytoplankton depend on light intensity and its spectral composition, however their relation changes with photoacclimation. During the photoacclimation process algal cells optimize their har-vesting and utilization of available light through series of related physical, biophysical, biochemical and physiological changes. These changes result in the ability of phytoplankton to survive under dim light when transported to the depth of the water column and avoid photodynamic damage when exposed to the intense radiation at the surface. Any reduction in the efficiency of light utilization results in decreased rates of pho-tosynthesis rate and slow growth. We present here the study of changes in photosynthetic energy storage efficiency of three phytoplankton species upon photoacclimation to low and high light, as measured by photo-acoustics. Our results illustrate the power of photoacoustics as a tool in aquatic ecology and in the physiological research of phytoplankton.展开更多
In this paper,a novel four-prong quartz tuning fork(QTF)was designed with enlarged deformation area,large prong gap,and low resonant frequency to improve its performance in laser spectroscopy sensing.A theoretical sim...In this paper,a novel four-prong quartz tuning fork(QTF)was designed with enlarged deformation area,large prong gap,and low resonant frequency to improve its performance in laser spectroscopy sensing.A theoretical simulation model was established to optimize the design of the QTF structure.In the simulation of quartz-enhanced photoacoustic spectroscopy(QEPAS)technology,the maximum stress and the surface charge density of the four-prong QTF demonstrated increases of 11.1-fold and 15.9-fold,respectively,compared to that of the standard two-prong QTF.In the simulation of light-induced thermoelastic spectroscopy(LITES)technology,the surface temperature difference of the four-prong QTF was found to be 11.4 times greater than that of the standard QTF.Experimental results indicated that the C_(2)H_(2)-QEPAS system based on this innovative design improved the signal-to-noise-ratio(SNR)by 4.67 times compared with the standard QTF-based system,and the SNR could increase up to 147.72 times when the four-prong QTF was equipped with its optimal acoustic micro-resonator(AmR).When the average time of the system reached 370 s,the system achieved a MDL as low as 21 ppb.The four-prong QTF-based C_(2)H_(2)-LITES system exhibited a SNR improvement by a factor of 4.52,and a MDL of 96 ppb was obtained when the average time of the system reached 100 s.The theoretical and experimental results effectively demonstrated the superiority of the four-prong QTF in the field of laser spectroscopy sensing.展开更多
To investigate the mechanisms underlying the onset and progression of ischemic stroke,some methods have been proposed that can simultaneously monitor and create embolisms in the animal cerebral cortex.However,these me...To investigate the mechanisms underlying the onset and progression of ischemic stroke,some methods have been proposed that can simultaneously monitor and create embolisms in the animal cerebral cortex.However,these methods often require complex systems and the effect of age on cerebral embolism has not been adequately studied,although ischemic stroke is strongly age-related.In this study,we propose an optical-resolution photoacoustic microscopy-based visualized photothrombosis methodology to create and monitor ischemic stroke in mice simultaneously using a 532 nm pulsed laser.We observed the molding process in mice of different ages and presented age-dependent vascular embolism differentiation.Moreover,we integrated optical coherence tomography angiography to investigate age-associated trends in cerebrovascular variability following a stroke.Our imaging data and quantitative analyses underscore the differential cerebrovascular responses to stroke in mice of different ages,thereby highlighting the technique's potential for evaluating cerebrovascular health and unraveling age-related mechanisms involved in ischemic strokes.展开更多
Photoacoustic computed tomography(PACT)is an innovative biomedical imaging technique that has gained significant application in the field of biomedicine due to its ability to visualize optical contrast with high resol...Photoacoustic computed tomography(PACT)is an innovative biomedical imaging technique that has gained significant application in the field of biomedicine due to its ability to visualize optical contrast with high resolution and deep tissue penetration.However,the inherent challenges associated with photoacoustic signal excitation,propagation and detection often result in suboptimal image quality.To overcome these limitations,researchers have developed various advanced algorithms that span the entire image reconstruction pipeline.This review paper aims to present a detailed analysis of the latest advancements in PACT algorithms and synthesize these algorithms into a coherent framework.We provide tripartite analysis—from signal processing to reconstruction solution to image processing,covering a spectrum of techniques.The principles and methodologies,as well as their applicability and limitations,are thoroughly discussed.The primary objective of this study is to provide a thorough review of advanced algorithms applicable to PACT,offering both theoretical foundations and practical guidance for enhancing the imaging effect of PACT.展开更多
Spinal cord injury is a severe neurological disorder;however,current treatment methods often fail to restore nerve function effectively.Spinal cord stimulation via electrical signals is a promising therapeutic modalit...Spinal cord injury is a severe neurological disorder;however,current treatment methods often fail to restore nerve function effectively.Spinal cord stimulation via electrical signals is a promising therapeutic modality for spinal cord injury.Based on similar principles,this review aims to explore the potential of optical and acoustic neuromodulation techniques,emphasizing their benefits in the context of spinal cord injury.Photoacoustic imaging,renowned for its noninvasive nature,high-resolution capabilities,and cost-effectiveness,is well recognized for its role in early diagnosis,dynamic monitoring,and surgical guidance in stem cell therapies for spinal cord injury.Moreover,photoacoustodynamic therapy offers multiple pathways for tissue regeneration.Optogenetics and sonogenetics use genetic engineering to achieve precise neuronal activation,while photoacoustoelectric therapy leverages photovoltaic materials for electrical modulation of the nervous system,introducing an innovative paradigm for nerve system disorder management.Collectively,these advancements represent a transformative shift in the diagnosis and treatment of spinal cord injury,with the potential to significantly enhance nerve function remodeling and improve patient outcomes.展开更多
Foundation models(FMs)have rapidly evolved and have achieved signicant accomplishments in computer vision tasks.Specically,the prompt mechanism conveniently allows users to integrate image prior information into the m...Foundation models(FMs)have rapidly evolved and have achieved signicant accomplishments in computer vision tasks.Specically,the prompt mechanism conveniently allows users to integrate image prior information into the model,making it possible to apply models without any training.Therefore,we proposed a workflow based on foundation models and zero training to solve the tasks of photoacoustic(PA)image processing.We employed the Segment Anything Model(SAM)by setting simple prompts and integrating the model's outputs with prior knowledge of the imaged objects to accomplish various tasks,including:(1)removing the skin signal in three-dimensional PA image rendering;(2)dual speed-of-sound reconstruction,and(3)segmentation ofnger blood vessels.Through these demonstrations,we have concluded that FMs can be directly applied in PA imaging without the requirement for network design and training.This potentially allows for a hands-on,convenient approach to achieving efficient and accurate segmentation of PA images.This paper serves as a comprehensive tutorial,facilitating the mastery of the technique through the provision of code and sample datasets.展开更多
We theoretically investigate the feasibility of reconstructing the transverse structures of femtosecond laser filaments in air by photoacoustic tomography.To simulate the emission and transmission of filament-induced ...We theoretically investigate the feasibility of reconstructing the transverse structures of femtosecond laser filaments in air by photoacoustic tomography.To simulate the emission and transmission of filament-induced ultrasonic signals more truly,a series of experimentally recorded cross-sectional images are used to simulate the initial pressure rise from multiple filaments(MFs).The aperture size and sensitivity of the detector was incorporated into the reconstruction algorithm.The results show that frequency of acoustic signals induced by MFs with maximum volumetric energy density~100 k J/m^(3)is about 2 MHz below.The initial spatial distribution of optical filaments can be clearly reconstructed with the back projection based algorithm.We recommend a PAT system with transducers of a lower central frequency and a stronger apodization working at a longer scanning radius can be used in photoacoustic image reconstruction of femtosecond laser multifilaments.This study demonstrates the feasibility of using photoacoustic tomography to reconstruct femtosecond multifilament images,which is helpful for studying the complex dynamic processes of multifilament and multifilament manipulation and is also valuable for the remote applications of laser filaments.展开更多
Diabetic liver injury is a widespread complication of diabetes and carries a high risk to liver function.Therefore,early diagnosis of diabetic liver injury is of great significance for providing quality of life for di...Diabetic liver injury is a widespread complication of diabetes and carries a high risk to liver function.Therefore,early diagnosis of diabetic liver injury is of great significance for providing quality of life for diabetic patients.Most of the activated dual-modal probes are usually activated by single factor stimulation,which greatly reduces the diagnostic accuracy of liver injury.Here,a novel cysteine(Cys)/homocysteine(Hcy)and viscosity-enhanced dual-modal probe DAL was developed for the first time to monitor diabetic liver injury and its repair process.In the presence of Cys/Hcy,the near-infrared fluorescence(NIRF)and photoacoustic(PA)signals of the probe DAL were activated,with further signal enhancement in high viscosity environments.This Cys/Hcy and viscosity cascade probe exhibits heightened sensitivity and enhanced anti-interference capabilities,contributing to the advancement of liver injury diagnosis accuracy.In addition,the probe DAL shows exceptional mitochondrial targeting ability,enabling sensitive monitoring of Cys/Hcy and viscosity alterations within mitochondria.Based on NIRF/PA dual-modal imaging technology,the probe was successfully used for the first time in a mouse diabetic liver injury model to evaluate the extent of liver damage and the repair process by tracking the levels of Cys/Hcy and viscosity.Therefore,the two-factor activated dual-modal probe developed in this study provides a powerful instrument for accurate diagnosis and efficacy evaluation of complications related to diabetes.展开更多
Broadband photothermal and photoacoustic agents in the near-infrared(NIR)biowindow are of significance for cancer phototheranostics.In this work,Pt Cu nanosheets with an average lateral size of less than 10 nm are syn...Broadband photothermal and photoacoustic agents in the near-infrared(NIR)biowindow are of significance for cancer phototheranostics.In this work,Pt Cu nanosheets with an average lateral size of less than 10 nm are synthesized as NIR photothermal and photoacoustic agents in vivo,which show strong light absorption from NIR-I to NIR-II biowindows with the photothermal conversion efficiencies of 20.4%under 808 nm laser and 32.7%under 1064 nm laser.Pt Cu nanosheets functionalized with folic acidmodified thiol-poly(ethylene glycol)(SH-PEG-FA)present good biocompatibility and 4T1 tumor-targeted effect,which give high-contrast photoacoustic imaging and efficient photothermal ablation of 4T1 tumor in both NIR-I and NIR-II biowindows.Our work significantly broadens applications of noble metal-based nanomaterials in the fields of cancer phototheranostics by rationally designing their structures and modulating their physicochemical properties.展开更多
The temperature of an organism provides key insights into its physiological and pathological status.Temperature monitoring can effectively assess potential health issues and plays a critical role in thermal treatment....The temperature of an organism provides key insights into its physiological and pathological status.Temperature monitoring can effectively assess potential health issues and plays a critical role in thermal treatment.Photoacoustic imaging(PAI)has enabled multi-scale imaging,from cells to tissues and organs,where its high contrast,deep penetration,and high resolution make it an emerging tool in biomedical imaging field.Benefiting from the linear correlation between the Grüneisen parameter and temperature within the range of 10–55∘C,the PAI has been developed as novel noninvasive label-free tool for temperature monitoring especially for thermotherapy mediated by laser,ultrasound,and microwave.Additionally,by utilizing temperature-responsive photoacoustic nanoprobes,the temperature information of the targeted organism can also be extracted with enhanced imaging contrast and specificity.This review elucidates the basic principles of temperature monitoring technology implemented by PAI,further highlighting the limitations of traditional photoacoustic thermometry,and summarizes recent technological advancements in analog simulation,calibration method,measurement accuracy,nanoprobe design,and wearable improvement.Furthermore,we discuss the biomedical applications of PA temperature monitoring technology in photothermal therapy and ultrasound therapy,finally,anticipating future developments in the field.展开更多
Photoacoustic imaging(PAI)employs short laser pulses to excite absorbing materials,producing ultrasonic waves spanning a broad spectrum of frequencies.These ultrasonic waves are captured surrounding the sample and uti...Photoacoustic imaging(PAI)employs short laser pulses to excite absorbing materials,producing ultrasonic waves spanning a broad spectrum of frequencies.These ultrasonic waves are captured surrounding the sample and utilized to reconstruct the initial pressure distribution tomographically.Despite the wide spectral range of the laser-generated photoacoustic signal,an individual transducer can only capture a limited segment of the signal due to its constrained bandwidth.Herein,we have developed a multi-bandwidth ring array photoacoustic computed tomography(PACT)system,incorporating a probe with two semi-ring arrays:one for high frequency and the other for low frequency.Utilizing the two semi-ring array PAIs,we have devised a specialized deep learning model,comprising two serially connected U-net architectures,to autonomously generate multi-bandwidth full-view PAIs.Preliminary results from simulations and in vivo experiments illustrate the system's robust multi-bandwidth imaging capabilities,achieving an excellent PSNR of 34.78 dB and a structural similarity index measure(SSIM)of 0.94 in the high-frequency reconstruction of complex mouse abdominal structures.This innovative PACT system is notable for its capability to seamlessly acquire multi-bandwidth full-view PAIs,thereby advancing the application of PAI technology in the biomedical domain.展开更多
Ultrasonic neuromodulation has gained recognition as a promising therapeutic approach.A miniature transducer capable of generating suitable-strength and broadband ultrasound is of great significance for achieving high...Ultrasonic neuromodulation has gained recognition as a promising therapeutic approach.A miniature transducer capable of generating suitable-strength and broadband ultrasound is of great significance for achieving high spatial precision ultrasonic neural stimulation.However,the ultrasound transducer with the above integrated is yet to be challenged.Here,we developed a fiber-optic photoacoustic emitter(FPE)with a diameter of 200μm,featuring controllable sound intensity and a broadband response(−6 dB bandwidth:162%).The device integrates MXene(Ti_(3)C_(2)Tx),known for its exceptional photothermal properties,and polydimethylsiloxane,which offers a high thermal expansion coefficient.This FPE,exhibiting high spatial precision(lateral:163.3μm,axial:207μm),is capable of selectively activating neurons in targeted regions.Using the TetTagging method to selectively express a cfos-promoter-inducible mCHERRY gene within the medial prefrontal cortex(mPFC),we found that photoacoustic stimulation significantly and temporarily activated the neurons.In vivo fiber photometry demonstrated that photoacoustic stimulation induced substantial calcium transients in mPFC neurons.Furthermore,we confirmed that photoacoustic stimulation of the mPFC using FPE markedly alleviates acute social defeat stress-induced emotional stress in mice.This work demonstrates the potential of FPEs for clinical applications,with a particular focus on modulating neural activity to regulate emotions.展开更多
Deep learning(DL)is making significant inroads into biomedical imaging as it provides novel and powerful ways of accurately and efficiently improving the image quality of photoacoustic microscopy(PAM).Off-the-shelf DL...Deep learning(DL)is making significant inroads into biomedical imaging as it provides novel and powerful ways of accurately and efficiently improving the image quality of photoacoustic microscopy(PAM).Off-the-shelf DL models,however,do not necessarily obey the fundamental governing laws of PAM physical systems,nor do they generalize well to scenarios on which they have not been trained.In this work,a physics-embedded degeneration learning(PEDL)approach is proposed to enhance the image quality of PAM with a self-attention enhanced U-Net network,which obtains greater physical consistency,improves data efficiency,and higher adaptability.The proposed method is demonstrated on both synthetic and real datasets,including animal experiments in vivo(blood vessels of mouse's ear and brain).And the results show that compared with previous DL methods,the PEDL algorithm exhibits good performance in recovering PAM images qualitatively and quantitatively.It overcomes the challenges related to training data,accuracy,and robustness which a typical data-driven approach encounters,whose exemplary application envisions to provide a new perspective for existing DL tools of enhanced PAM.展开更多
Rational design of multifunctional nanoplatforms capable of combining therapeutic effects with real-time monitoring of drug distribution and tumor status is emerging as a promising approach in cancer nanomedicine.Here...Rational design of multifunctional nanoplatforms capable of combining therapeutic effects with real-time monitoring of drug distribution and tumor status is emerging as a promising approach in cancer nanomedicine.Here,we introduce pyropheophorbide a-bisaminoquinoline conjugate lipid nanoparticles(PPBC LNPs)as a bimodal system for image-guided phototherapy in bladder cancer treatment.PPBC LNPs not only demonstrate both powerful photodynamic and photothermal effects upon light activation,but also exhibit potent autophagy blockage,effectively inducing bladder cancer cell death.Furthermore,PPBC LNPs possess remarkable photoacoustic(PA)and fluorescence(FL)imaging capabilities,enabling imaging with high-resolution,deep tissue penetration and high sensitivity for tracking drug biodistribution and phototherapy efficacy.Specifically,PA imaging confirms the efficient accumulation of PPBC LNPs within tumor and predicts therapeutic outcomes of photodynamic therapy,while FL imaging confirms their prolonged retention at the tumor site for up to 6 days.PPBC LNPs significantly suppress bladder tumor growth,with several tumors completely ablated following just two doses of the nanoparticles and laser treatment.Additionally,PPBC LNPs were formulated with lipid-based excipients and assembled using microfluidic technology to enhance biocompatibility,stability,and scalability,showing potential for clinical translation.This versatile nanoparticle represents a promising candidate for further development in bladder cancer therapy.展开更多
The brain lymphatic system plays a crucial role in maintaining homeostasis,clearing metabolic waste,and regulating neuroinflammation.Its dysfunction is strongly linked to neurodegenerative diseases such as Alzheimer&#...The brain lymphatic system plays a crucial role in maintaining homeostasis,clearing metabolic waste,and regulating neuroinflammation.Its dysfunction is strongly linked to neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease.In this study,we employed dual-contrast functionalphotoacoustic microscopy to evaluate the impact of lipopolysaccharide-induced central nervous system inflammation on brain lymphatic function and to explore the protective effects of the P2X7 receptor(P2X7R)antagonist.Our findings demonstrated that lipopolysac-charide intervention led to impaired function of the meningeal lymphatic vessels,which was par-tially restored by the P2X7R antagonist,whereas its effects on the glymphatic system and cerebral vessels were minimal.This study further supports the feasibility of photoacoustic microscopy for assessing brain lymphatic function and highlights the therapeutic potential of P2X7R antagonism.These findings suggest that P2X7R may serve as a key target for modulating brain-lymphatic interactions,providing an experimental foundation for developing intervention strategies for neuroinflammatory and neurodegenerative diseases.展开更多
Acoustic-resolution photoacoustic microscopy(AR-PAM)suffers from degraded lateral resolution due to acoustic diffraction.Here,a resolution enhancement strategy for AR-PAM via a mean-reverting diffusion model was propo...Acoustic-resolution photoacoustic microscopy(AR-PAM)suffers from degraded lateral resolution due to acoustic diffraction.Here,a resolution enhancement strategy for AR-PAM via a mean-reverting diffusion model was proposed to achieve the transition from acoustic resolution to optical resolution.By modeling the degradation process from high-resolution image to low-resolution AR-PAM image with stable Gaussian noise(i.e.,mean state),a mean-reverting diffusion model is trained to learn prior information of the data distribution.Then the learned prior is employed to generate a high-resolution image from the AR-PAM image by iteratively sampling the noisy state.The performance of the proposed method was validated utilizing the simulated and in vivo experimental data under varying lateral resolutions and noise levels.The results show that an over 3.6-fold enhancement in lateral resolution was achieved.The image quality can be effectively improved,with a notable enhancement of∼66%in PSNR and∼480%in SSIM for in vivo data.展开更多
Aging is a natural physiological process with various challenges, related to the loss of homeostasis within the organism, which is not a disease, but a significantly strong risk factor for multiple diseases, including...Aging is a natural physiological process with various challenges, related to the loss of homeostasis within the organism, which is not a disease, but a significantly strong risk factor for multiple diseases, including myocardial infarction, stroke, some age-related cancers, macular degeneration, osteoarthritis, neurodegeneration, and many others. In the body, the main manifestation of aging is cellular aging, which exists within tissues and has a local or global impact on tissue function. However, the lack of effective aging detection tools has always been an issue that cannot be ignored in the field of aging research. Therefore,it is necessary to construct a non-invasive tool for in vivo detection of aging. Here, we show that the photoacoustic probe(LGAL), which has peak excitation and emission wavelengths in the near-infrared optical window, binds in vivo and at high contrast to the hallmark of aging, and allows for the microscopic imaging of aging through the intact mice. Firstly, this tool LGAL has been successfully applied to detect senescence in cells, displaying stronger photoacoustic signals than normal cells. Then, by using the photoacoustic probe, the blood vessels and tissues inside the mice can be visualized. Young and elderly mice exhibit varying intensities of photoacoustic signals, marking the first time a probe has been used to explore the aging of blood vessels and tissues inside the mice. Finally, we monitored the changes in the degree of aging during tumor treatment under photoacoustic(PA) imaging for the first time. As the treatment time increased, the degree of aging of the tumor gradually deepened. We expect the powerful tool could be a noninvasive and powerful tool for the study of aging biology.展开更多
In this work,we present an intravascular dual-mode endoscopic system capable of both intravascular photoacoustic imaging(IVPAI)and intravascular optical coherence tomography(IVOCT)for recognizing spontaneous coronary ...In this work,we present an intravascular dual-mode endoscopic system capable of both intravascular photoacoustic imaging(IVPAI)and intravascular optical coherence tomography(IVOCT)for recognizing spontaneous coronary artery dissection(SCAD)phantoms.IVPAI provides high-resolution and high-penetration images of intramural hematoma(IMH)at different depths,so it is especially useful for imaging deep blood clots associated with imaging phantoms.IVOCT can readily visualize the double-lumen morphology of blood vessel walls to identify intimal tears.We also demonstrate the capability of this dual-mode endoscopic system using mimicking phantoms and biological samples of blood clots in ex vivo porcine arteries.The results of the experiments indicate that the combined IVPAI and IVOCT technique has the potential to provide a more accurate SCAD assessment method for clinical applications.展开更多
Cancer has long been amajor threat to human health.Recent advancements inmolecular imaging have revolutionized cancer research by enabling early and precise disease localization,essential for effective management.In p...Cancer has long been amajor threat to human health.Recent advancements inmolecular imaging have revolutionized cancer research by enabling early and precise disease localization,essential for effective management.In particular,optical molecular imaging is an invaluable cancer detection tool in preoperative planning,intraoperative guidance,and postoperative monitoring owing to its noninvasive nature,rapid turnover,safety,and ease of use.The tumor microenvironment and cells within it express distinct biomarkers.Optical imaging technology leverages these markers to differentiate tumor tissues from surrounding tissues and capture real-time images with high resolution.Nevertheless,a robust understanding of these cancer-relatedmolecules and their dynamic changes is crucial for effectivelymanaging cancer.Recent advancements in opticalmolecular imaging technologies offer novel approaches for cancer investigation in research and practice.This review investigates themodern opticalmolecular imaging techniques employed in both preclinical and clinical research,including bioluminescence,fluorescence,chemiluminescence,photoacoustic imaging,and Raman spectroscopy.We explore the current paradigm of optical molecular imaging modalities,their current status in preclinical cancer research and clinical applications,and future perspectives in the fields of cancer research and treatment.展开更多
Photothermal therapy(PTT)is a cutting-edge cancer treatment that can kill cancer cells in hypoxic environments without relying on oxygen.Seeking of the ideal photothermal agents with a high absorption coefficient in t...Photothermal therapy(PTT)is a cutting-edge cancer treatment that can kill cancer cells in hypoxic environments without relying on oxygen.Seeking of the ideal photothermal agents with a high absorption coefficient in the near-infrared region,and a high excellent photothermal conversion efficiency is of great significance.Sulfone-Rhodanmine dye has showed an impressive absorption wavelength over 700 nm,but suffered from a stability issue.In this study,we synthesized five sulfone rhodamines and investigated the substitution effects on stability.SO_(2)R2 showed high stability and strong absorbance at 714 nm with an excellent photothermal conversion efficiency of 53.06%,making it suitable for accurate photoacoustic imaging-guided photothermal therapy in vivo.展开更多
文摘Photosynthesis rates in phytoplankton depend on light intensity and its spectral composition, however their relation changes with photoacclimation. During the photoacclimation process algal cells optimize their har-vesting and utilization of available light through series of related physical, biophysical, biochemical and physiological changes. These changes result in the ability of phytoplankton to survive under dim light when transported to the depth of the water column and avoid photodynamic damage when exposed to the intense radiation at the surface. Any reduction in the efficiency of light utilization results in decreased rates of pho-tosynthesis rate and slow growth. We present here the study of changes in photosynthetic energy storage efficiency of three phytoplankton species upon photoacclimation to low and high light, as measured by photo-acoustics. Our results illustrate the power of photoacoustics as a tool in aquatic ecology and in the physiological research of phytoplankton.
基金supports from the National Natural Science Foundation of China(Grant Nos.62335006,62022032,62275065,and 62405078)Key Laboratory of Opto-Electronic Information Acquisition and Manipulation(Anhui University),Ministry of Education(Grant No.OEIAM202202)+2 种基金Fundamental Research Funds for the Central Universities(Grant No.HIT.OCEF.2023011)China Postdoctoral Science Foundation(Grant No.2024M764172)Heilongjiang Postdoctoral Fund(Grant No.LBH-Z23144).
文摘In this paper,a novel four-prong quartz tuning fork(QTF)was designed with enlarged deformation area,large prong gap,and low resonant frequency to improve its performance in laser spectroscopy sensing.A theoretical simulation model was established to optimize the design of the QTF structure.In the simulation of quartz-enhanced photoacoustic spectroscopy(QEPAS)technology,the maximum stress and the surface charge density of the four-prong QTF demonstrated increases of 11.1-fold and 15.9-fold,respectively,compared to that of the standard two-prong QTF.In the simulation of light-induced thermoelastic spectroscopy(LITES)technology,the surface temperature difference of the four-prong QTF was found to be 11.4 times greater than that of the standard QTF.Experimental results indicated that the C_(2)H_(2)-QEPAS system based on this innovative design improved the signal-to-noise-ratio(SNR)by 4.67 times compared with the standard QTF-based system,and the SNR could increase up to 147.72 times when the four-prong QTF was equipped with its optimal acoustic micro-resonator(AmR).When the average time of the system reached 370 s,the system achieved a MDL as low as 21 ppb.The four-prong QTF-based C_(2)H_(2)-LITES system exhibited a SNR improvement by a factor of 4.52,and a MDL of 96 ppb was obtained when the average time of the system reached 100 s.The theoretical and experimental results effectively demonstrated the superiority of the four-prong QTF in the field of laser spectroscopy sensing.
基金supported by University of Macao,China,Nos.MYRG2022-00054-FHS and MYRG-GRG2023-00038-FHS-UMDF(to ZY)the Macao Science and Technology Development Fund,China,Nos.FDCT0048/2021/AGJ and FDCT0020/2019/AMJ and FDCT 0011/2018/A1(to ZY)Natural Science Foundation of Guangdong Province of China,No.EF017/FHS-YZ/2021/GDSTC(to ZY)。
文摘To investigate the mechanisms underlying the onset and progression of ischemic stroke,some methods have been proposed that can simultaneously monitor and create embolisms in the animal cerebral cortex.However,these methods often require complex systems and the effect of age on cerebral embolism has not been adequately studied,although ischemic stroke is strongly age-related.In this study,we propose an optical-resolution photoacoustic microscopy-based visualized photothrombosis methodology to create and monitor ischemic stroke in mice simultaneously using a 532 nm pulsed laser.We observed the molding process in mice of different ages and presented age-dependent vascular embolism differentiation.Moreover,we integrated optical coherence tomography angiography to investigate age-associated trends in cerebrovascular variability following a stroke.Our imaging data and quantitative analyses underscore the differential cerebrovascular responses to stroke in mice of different ages,thereby highlighting the technique's potential for evaluating cerebrovascular health and unraveling age-related mechanisms involved in ischemic strokes.
基金supported by Beijing Natural Science Foundation(7232146)National Natural Science Foundation of China(NSFC)Grant(62475277,62105355,82122034,82327805,81927807,62275062)+4 种基金Strategic Priority Research Program of the Chinese Academy of Sciences(XDB0930000)Shenzhen Science and Technology Innovation Grant(JCYJ20220531100409023,JCYJ20210324101403010,JCYJ20220818101403008)Project of Shandong Innovation and Startup Community of High-end Medical Apparatus and Instruments Grant(2021-SGTTXM005)Shandong Province Technology Innovation Guidance Plan(Central Leading Local Science and Technology Development Fund,YDZX2023115)Taishan Scholar Special Funding Project of Shandong Province.
文摘Photoacoustic computed tomography(PACT)is an innovative biomedical imaging technique that has gained significant application in the field of biomedicine due to its ability to visualize optical contrast with high resolution and deep tissue penetration.However,the inherent challenges associated with photoacoustic signal excitation,propagation and detection often result in suboptimal image quality.To overcome these limitations,researchers have developed various advanced algorithms that span the entire image reconstruction pipeline.This review paper aims to present a detailed analysis of the latest advancements in PACT algorithms and synthesize these algorithms into a coherent framework.We provide tripartite analysis—from signal processing to reconstruction solution to image processing,covering a spectrum of techniques.The principles and methodologies,as well as their applicability and limitations,are thoroughly discussed.The primary objective of this study is to provide a thorough review of advanced algorithms applicable to PACT,offering both theoretical foundations and practical guidance for enhancing the imaging effect of PACT.
基金supported by the National Key R&D Program of China,No.2023YFC2509700the Beijing Natural Science Foundation-Haidian Original Innovation Joint Fund,No.L232141the Research and Application of Clinical Characteristic Diagnosis and Treatment Program,No.Z221100007422019(all to WD)。
文摘Spinal cord injury is a severe neurological disorder;however,current treatment methods often fail to restore nerve function effectively.Spinal cord stimulation via electrical signals is a promising therapeutic modality for spinal cord injury.Based on similar principles,this review aims to explore the potential of optical and acoustic neuromodulation techniques,emphasizing their benefits in the context of spinal cord injury.Photoacoustic imaging,renowned for its noninvasive nature,high-resolution capabilities,and cost-effectiveness,is well recognized for its role in early diagnosis,dynamic monitoring,and surgical guidance in stem cell therapies for spinal cord injury.Moreover,photoacoustodynamic therapy offers multiple pathways for tissue regeneration.Optogenetics and sonogenetics use genetic engineering to achieve precise neuronal activation,while photoacoustoelectric therapy leverages photovoltaic materials for electrical modulation of the nervous system,introducing an innovative paradigm for nerve system disorder management.Collectively,these advancements represent a transformative shift in the diagnosis and treatment of spinal cord injury,with the potential to significantly enhance nerve function remodeling and improve patient outcomes.
基金support from Strategic Project of Precision Surgery,Tsinghua UniversityInitiative Scientific Research Program,Institute for Intelligent Healthcare,Tsinghua University+5 种基金Tsinghua-Foshan Institute of Advanced ManufacturingNational Natural Science Foundation of China(61735016)Beijing Nova Program(20230484308)Young Elite Scientists Sponsorship Program by CAST(2023QNRC001)Youth Elite Program of Beijing Friendship Hospital(YYQCJH2022-9)Science and Technology Program of Beijing Tongzhou District(KJ2023CX012).
文摘Foundation models(FMs)have rapidly evolved and have achieved signicant accomplishments in computer vision tasks.Specically,the prompt mechanism conveniently allows users to integrate image prior information into the model,making it possible to apply models without any training.Therefore,we proposed a workflow based on foundation models and zero training to solve the tasks of photoacoustic(PA)image processing.We employed the Segment Anything Model(SAM)by setting simple prompts and integrating the model's outputs with prior knowledge of the imaged objects to accomplish various tasks,including:(1)removing the skin signal in three-dimensional PA image rendering;(2)dual speed-of-sound reconstruction,and(3)segmentation ofnger blood vessels.Through these demonstrations,we have concluded that FMs can be directly applied in PA imaging without the requirement for network design and training.This potentially allows for a hands-on,convenient approach to achieving efficient and accurate segmentation of PA images.This paper serves as a comprehensive tutorial,facilitating the mastery of the technique through the provision of code and sample datasets.
基金Project supported by the National Natural Science Foundation of China(Grant No.42105176)the National University of Defense Technology Independent Research Project(Grant No.ZK21-40)。
文摘We theoretically investigate the feasibility of reconstructing the transverse structures of femtosecond laser filaments in air by photoacoustic tomography.To simulate the emission and transmission of filament-induced ultrasonic signals more truly,a series of experimentally recorded cross-sectional images are used to simulate the initial pressure rise from multiple filaments(MFs).The aperture size and sensitivity of the detector was incorporated into the reconstruction algorithm.The results show that frequency of acoustic signals induced by MFs with maximum volumetric energy density~100 k J/m^(3)is about 2 MHz below.The initial spatial distribution of optical filaments can be clearly reconstructed with the back projection based algorithm.We recommend a PAT system with transducers of a lower central frequency and a stronger apodization working at a longer scanning radius can be used in photoacoustic image reconstruction of femtosecond laser multifilaments.This study demonstrates the feasibility of using photoacoustic tomography to reconstruct femtosecond multifilament images,which is helpful for studying the complex dynamic processes of multifilament and multifilament manipulation and is also valuable for the remote applications of laser filaments.
基金financially supported by the National Natural Science Foundation of China(Nos.21877048,22077048,and 22277014)Guangxi Natural Science Foundation(Nos.2021GXNSFDA075003,AD21220061)the Startup Fund of Guangxi University(No.A3040051003).
文摘Diabetic liver injury is a widespread complication of diabetes and carries a high risk to liver function.Therefore,early diagnosis of diabetic liver injury is of great significance for providing quality of life for diabetic patients.Most of the activated dual-modal probes are usually activated by single factor stimulation,which greatly reduces the diagnostic accuracy of liver injury.Here,a novel cysteine(Cys)/homocysteine(Hcy)and viscosity-enhanced dual-modal probe DAL was developed for the first time to monitor diabetic liver injury and its repair process.In the presence of Cys/Hcy,the near-infrared fluorescence(NIRF)and photoacoustic(PA)signals of the probe DAL were activated,with further signal enhancement in high viscosity environments.This Cys/Hcy and viscosity cascade probe exhibits heightened sensitivity and enhanced anti-interference capabilities,contributing to the advancement of liver injury diagnosis accuracy.In addition,the probe DAL shows exceptional mitochondrial targeting ability,enabling sensitive monitoring of Cys/Hcy and viscosity alterations within mitochondria.Based on NIRF/PA dual-modal imaging technology,the probe was successfully used for the first time in a mouse diabetic liver injury model to evaluate the extent of liver damage and the repair process by tracking the levels of Cys/Hcy and viscosity.Therefore,the two-factor activated dual-modal probe developed in this study provides a powerful instrument for accurate diagnosis and efficacy evaluation of complications related to diabetes.
基金the National Natural Science Foundation of China(Nos.22275096,W2432015)Natural Science Key Fund for Universities in Jiangsu Province(No.22KJA430007)Qinglan Project of Jiangsu Province of China。
文摘Broadband photothermal and photoacoustic agents in the near-infrared(NIR)biowindow are of significance for cancer phototheranostics.In this work,Pt Cu nanosheets with an average lateral size of less than 10 nm are synthesized as NIR photothermal and photoacoustic agents in vivo,which show strong light absorption from NIR-I to NIR-II biowindows with the photothermal conversion efficiencies of 20.4%under 808 nm laser and 32.7%under 1064 nm laser.Pt Cu nanosheets functionalized with folic acidmodified thiol-poly(ethylene glycol)(SH-PEG-FA)present good biocompatibility and 4T1 tumor-targeted effect,which give high-contrast photoacoustic imaging and efficient photothermal ablation of 4T1 tumor in both NIR-I and NIR-II biowindows.Our work significantly broadens applications of noble metal-based nanomaterials in the fields of cancer phototheranostics by rationally designing their structures and modulating their physicochemical properties.
基金supported by the National Natural Science Foundation of China(No.12174125)Guangdong Basic and Applied Basic Research Foundation(Nos.2024A1515010522 and 2021A1515011874).
文摘The temperature of an organism provides key insights into its physiological and pathological status.Temperature monitoring can effectively assess potential health issues and plays a critical role in thermal treatment.Photoacoustic imaging(PAI)has enabled multi-scale imaging,from cells to tissues and organs,where its high contrast,deep penetration,and high resolution make it an emerging tool in biomedical imaging field.Benefiting from the linear correlation between the Grüneisen parameter and temperature within the range of 10–55∘C,the PAI has been developed as novel noninvasive label-free tool for temperature monitoring especially for thermotherapy mediated by laser,ultrasound,and microwave.Additionally,by utilizing temperature-responsive photoacoustic nanoprobes,the temperature information of the targeted organism can also be extracted with enhanced imaging contrast and specificity.This review elucidates the basic principles of temperature monitoring technology implemented by PAI,further highlighting the limitations of traditional photoacoustic thermometry,and summarizes recent technological advancements in analog simulation,calibration method,measurement accuracy,nanoprobe design,and wearable improvement.Furthermore,we discuss the biomedical applications of PA temperature monitoring technology in photothermal therapy and ultrasound therapy,finally,anticipating future developments in the field.
基金supported by the National Key R&D Program of China[Grant No.2023YFF0713600]the National Natural Science Foundation of China[Grant No.62275062]+2 种基金the Project of Shandong Innovation and Startup Community of High-end Medical Apparatus and Instruments[Grant No.2021-SGTTXM-005]the Shandong Province Technology Innovation Guidance Plan(Central Leading Local Science and Technology Development Fund)[Grant No.YDZX2023115]the Taishan Scholar Special Funding Project of Shandong Province,and the Shandong Laboratory of Advanced Biomaterials and Medical Devices in Weihai[Grant No.ZL202402].
文摘Photoacoustic imaging(PAI)employs short laser pulses to excite absorbing materials,producing ultrasonic waves spanning a broad spectrum of frequencies.These ultrasonic waves are captured surrounding the sample and utilized to reconstruct the initial pressure distribution tomographically.Despite the wide spectral range of the laser-generated photoacoustic signal,an individual transducer can only capture a limited segment of the signal due to its constrained bandwidth.Herein,we have developed a multi-bandwidth ring array photoacoustic computed tomography(PACT)system,incorporating a probe with two semi-ring arrays:one for high frequency and the other for low frequency.Utilizing the two semi-ring array PAIs,we have devised a specialized deep learning model,comprising two serially connected U-net architectures,to autonomously generate multi-bandwidth full-view PAIs.Preliminary results from simulations and in vivo experiments illustrate the system's robust multi-bandwidth imaging capabilities,achieving an excellent PSNR of 34.78 dB and a structural similarity index measure(SSIM)of 0.94 in the high-frequency reconstruction of complex mouse abdominal structures.This innovative PACT system is notable for its capability to seamlessly acquire multi-bandwidth full-view PAIs,thereby advancing the application of PAI technology in the biomedical domain.
基金supported by the National Nature Science Foundation of China(Grant Number:U24A20306,12102140,6227031087,62035006,and 6207030117).
文摘Ultrasonic neuromodulation has gained recognition as a promising therapeutic approach.A miniature transducer capable of generating suitable-strength and broadband ultrasound is of great significance for achieving high spatial precision ultrasonic neural stimulation.However,the ultrasound transducer with the above integrated is yet to be challenged.Here,we developed a fiber-optic photoacoustic emitter(FPE)with a diameter of 200μm,featuring controllable sound intensity and a broadband response(−6 dB bandwidth:162%).The device integrates MXene(Ti_(3)C_(2)Tx),known for its exceptional photothermal properties,and polydimethylsiloxane,which offers a high thermal expansion coefficient.This FPE,exhibiting high spatial precision(lateral:163.3μm,axial:207μm),is capable of selectively activating neurons in targeted regions.Using the TetTagging method to selectively express a cfos-promoter-inducible mCHERRY gene within the medial prefrontal cortex(mPFC),we found that photoacoustic stimulation significantly and temporarily activated the neurons.In vivo fiber photometry demonstrated that photoacoustic stimulation induced substantial calcium transients in mPFC neurons.Furthermore,we confirmed that photoacoustic stimulation of the mPFC using FPE markedly alleviates acute social defeat stress-induced emotional stress in mice.This work demonstrates the potential of FPEs for clinical applications,with a particular focus on modulating neural activity to regulate emotions.
基金supported by National Natural Science Foundation of China(62227818,12204239,62275121)Youth Foundation of Jiangsu Province(BK20220946)+1 种基金Fundamental Research Funds for the Central Universities(30923011024)Open Research Fund of Jiangsu Key Laboratory of Spectral Imaging&Intelligent Sense(JSGP202201).
文摘Deep learning(DL)is making significant inroads into biomedical imaging as it provides novel and powerful ways of accurately and efficiently improving the image quality of photoacoustic microscopy(PAM).Off-the-shelf DL models,however,do not necessarily obey the fundamental governing laws of PAM physical systems,nor do they generalize well to scenarios on which they have not been trained.In this work,a physics-embedded degeneration learning(PEDL)approach is proposed to enhance the image quality of PAM with a self-attention enhanced U-Net network,which obtains greater physical consistency,improves data efficiency,and higher adaptability.The proposed method is demonstrated on both synthetic and real datasets,including animal experiments in vivo(blood vessels of mouse's ear and brain).And the results show that compared with previous DL methods,the PEDL algorithm exhibits good performance in recovering PAM images qualitatively and quantitatively.It overcomes the challenges related to training data,accuracy,and robustness which a typical data-driven approach encounters,whose exemplary application envisions to provide a new perspective for existing DL tools of enhanced PAM.
文摘Rational design of multifunctional nanoplatforms capable of combining therapeutic effects with real-time monitoring of drug distribution and tumor status is emerging as a promising approach in cancer nanomedicine.Here,we introduce pyropheophorbide a-bisaminoquinoline conjugate lipid nanoparticles(PPBC LNPs)as a bimodal system for image-guided phototherapy in bladder cancer treatment.PPBC LNPs not only demonstrate both powerful photodynamic and photothermal effects upon light activation,but also exhibit potent autophagy blockage,effectively inducing bladder cancer cell death.Furthermore,PPBC LNPs possess remarkable photoacoustic(PA)and fluorescence(FL)imaging capabilities,enabling imaging with high-resolution,deep tissue penetration and high sensitivity for tracking drug biodistribution and phototherapy efficacy.Specifically,PA imaging confirms the efficient accumulation of PPBC LNPs within tumor and predicts therapeutic outcomes of photodynamic therapy,while FL imaging confirms their prolonged retention at the tumor site for up to 6 days.PPBC LNPs significantly suppress bladder tumor growth,with several tumors completely ablated following just two doses of the nanoparticles and laser treatment.Additionally,PPBC LNPs were formulated with lipid-based excipients and assembled using microfluidic technology to enhance biocompatibility,stability,and scalability,showing potential for clinical translation.This versatile nanoparticle represents a promising candidate for further development in bladder cancer therapy.
基金supported by STI2030-Major Projects(No.2022ZD0212200)National Natural Science Foundation of China(No.62305118)+1 种基金Guangdong Basic and Applied Basic Research Foundation(No.2025A1515010953)China Postdoctoral Science Foundation(No.2022M721223).
文摘The brain lymphatic system plays a crucial role in maintaining homeostasis,clearing metabolic waste,and regulating neuroinflammation.Its dysfunction is strongly linked to neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease.In this study,we employed dual-contrast functionalphotoacoustic microscopy to evaluate the impact of lipopolysaccharide-induced central nervous system inflammation on brain lymphatic function and to explore the protective effects of the P2X7 receptor(P2X7R)antagonist.Our findings demonstrated that lipopolysac-charide intervention led to impaired function of the meningeal lymphatic vessels,which was par-tially restored by the P2X7R antagonist,whereas its effects on the glymphatic system and cerebral vessels were minimal.This study further supports the feasibility of photoacoustic microscopy for assessing brain lymphatic function and highlights the therapeutic potential of P2X7R antagonism.These findings suggest that P2X7R may serve as a key target for modulating brain-lymphatic interactions,providing an experimental foundation for developing intervention strategies for neuroinflammatory and neurodegenerative diseases.
基金pported by the National Natural Science Foundation of China(62265011 and 62122033)Jiangxi Provincial Natural Science Foundation(20224BAB212006 and 20232BAB 202038)National Key Research and Develop-ment Program of China(2023YFF1204302)。
文摘Acoustic-resolution photoacoustic microscopy(AR-PAM)suffers from degraded lateral resolution due to acoustic diffraction.Here,a resolution enhancement strategy for AR-PAM via a mean-reverting diffusion model was proposed to achieve the transition from acoustic resolution to optical resolution.By modeling the degradation process from high-resolution image to low-resolution AR-PAM image with stable Gaussian noise(i.e.,mean state),a mean-reverting diffusion model is trained to learn prior information of the data distribution.Then the learned prior is employed to generate a high-resolution image from the AR-PAM image by iteratively sampling the noisy state.The performance of the proposed method was validated utilizing the simulated and in vivo experimental data under varying lateral resolutions and noise levels.The results show that an over 3.6-fold enhancement in lateral resolution was achieved.The image quality can be effectively improved,with a notable enhancement of∼66%in PSNR and∼480%in SSIM for in vivo data.
基金financially supported by National Natural Science Foundation of China (Nos.21877048, 22077048, and 22277014)Guangxi Natural Science Foundation (Nos.2021GXNSFDA075003,AD21220061)the startup fund of Guangxi University (No.A3040051003)。
文摘Aging is a natural physiological process with various challenges, related to the loss of homeostasis within the organism, which is not a disease, but a significantly strong risk factor for multiple diseases, including myocardial infarction, stroke, some age-related cancers, macular degeneration, osteoarthritis, neurodegeneration, and many others. In the body, the main manifestation of aging is cellular aging, which exists within tissues and has a local or global impact on tissue function. However, the lack of effective aging detection tools has always been an issue that cannot be ignored in the field of aging research. Therefore,it is necessary to construct a non-invasive tool for in vivo detection of aging. Here, we show that the photoacoustic probe(LGAL), which has peak excitation and emission wavelengths in the near-infrared optical window, binds in vivo and at high contrast to the hallmark of aging, and allows for the microscopic imaging of aging through the intact mice. Firstly, this tool LGAL has been successfully applied to detect senescence in cells, displaying stronger photoacoustic signals than normal cells. Then, by using the photoacoustic probe, the blood vessels and tissues inside the mice can be visualized. Young and elderly mice exhibit varying intensities of photoacoustic signals, marking the first time a probe has been used to explore the aging of blood vessels and tissues inside the mice. Finally, we monitored the changes in the degree of aging during tumor treatment under photoacoustic(PA) imaging for the first time. As the treatment time increased, the degree of aging of the tumor gradually deepened. We expect the powerful tool could be a noninvasive and powerful tool for the study of aging biology.
基金funding from the National Natural Science Foundation of China(NSFC)under grants 61627827,61705068the Natural Science Foundation of Fujian Province 2021J01813the Fujian Medical University Research Foundation of Talented Scholars XRCZX2021004.
文摘In this work,we present an intravascular dual-mode endoscopic system capable of both intravascular photoacoustic imaging(IVPAI)and intravascular optical coherence tomography(IVOCT)for recognizing spontaneous coronary artery dissection(SCAD)phantoms.IVPAI provides high-resolution and high-penetration images of intramural hematoma(IMH)at different depths,so it is especially useful for imaging deep blood clots associated with imaging phantoms.IVOCT can readily visualize the double-lumen morphology of blood vessel walls to identify intimal tears.We also demonstrate the capability of this dual-mode endoscopic system using mimicking phantoms and biological samples of blood clots in ex vivo porcine arteries.The results of the experiments indicate that the combined IVPAI and IVOCT technique has the potential to provide a more accurate SCAD assessment method for clinical applications.
基金supported by the National Key R&D Program(the 14th Five-Year Plan)(no.2023YFC2706001 and no.2023YFC2706003).
文摘Cancer has long been amajor threat to human health.Recent advancements inmolecular imaging have revolutionized cancer research by enabling early and precise disease localization,essential for effective management.In particular,optical molecular imaging is an invaluable cancer detection tool in preoperative planning,intraoperative guidance,and postoperative monitoring owing to its noninvasive nature,rapid turnover,safety,and ease of use.The tumor microenvironment and cells within it express distinct biomarkers.Optical imaging technology leverages these markers to differentiate tumor tissues from surrounding tissues and capture real-time images with high resolution.Nevertheless,a robust understanding of these cancer-relatedmolecules and their dynamic changes is crucial for effectivelymanaging cancer.Recent advancements in opticalmolecular imaging technologies offer novel approaches for cancer investigation in research and practice.This review investigates themodern opticalmolecular imaging techniques employed in both preclinical and clinical research,including bioluminescence,fluorescence,chemiluminescence,photoacoustic imaging,and Raman spectroscopy.We explore the current paradigm of optical molecular imaging modalities,their current status in preclinical cancer research and clinical applications,and future perspectives in the fields of cancer research and treatment.
基金the National Natural Science Foundation of China(Nos.21762045,21911540466)Shandong Provincial Natural Science Foundation(No.ZR2019YQ12)+1 种基金China Postdoctoral Science Foundation(No.219M652306)Taishan Scholar Project(No.tsqn201812049)for supporting this work。
文摘Photothermal therapy(PTT)is a cutting-edge cancer treatment that can kill cancer cells in hypoxic environments without relying on oxygen.Seeking of the ideal photothermal agents with a high absorption coefficient in the near-infrared region,and a high excellent photothermal conversion efficiency is of great significance.Sulfone-Rhodanmine dye has showed an impressive absorption wavelength over 700 nm,but suffered from a stability issue.In this study,we synthesized five sulfone rhodamines and investigated the substitution effects on stability.SO_(2)R2 showed high stability and strong absorbance at 714 nm with an excellent photothermal conversion efficiency of 53.06%,making it suitable for accurate photoacoustic imaging-guided photothermal therapy in vivo.
