Miniaturized sound generators are attractive to realize intriguing functions.Thermoacoustic device’s application is seriously limited due to the frequency-doubling phenomenon.To address this issue,photoacoustic sound...Miniaturized sound generators are attractive to realize intriguing functions.Thermoacoustic device’s application is seriously limited due to the frequency-doubling phenomenon.To address this issue,photoacoustic sound generator is considered as a promising alternative.Here,based on vertical single-wall carbon nanotubes(CNTs)array,we introduce a photoacoustic sound generator with internal nano-Helmholtz cavity.Different from traditional device that generates sound by periodically heating up the open space air around material,this sound generator produces an audio signal by forming a forced vibration of the air inside the CNTs.Interestingly,anomalous photoacoustic behavior is observed that the sound pressure level(SPL)curve has a resonance peak,the corresponding frequency of which is inversely proportional to the CNTs array’s height.Furthermore,the energy conversion efficiency of this photoacoustic device is 1.64 times as large as that of a graphene sponge-based photoacoustic device.Most importantly,this device can be employed for music playing,bringing a new clew for the development of musical instruments in the future.展开更多
Photoacoustic imag ing(PAI)is a nonin vasive biomedical imag ing tech no logy capable of multiscale imag ing of biological samples from orga ns dow n to cells.Multiscale PAI requires differe nt ultraso und tra nsducer...Photoacoustic imag ing(PAI)is a nonin vasive biomedical imag ing tech no logy capable of multiscale imag ing of biological samples from orga ns dow n to cells.Multiscale PAI requires differe nt ultraso und tra nsducers that are flat or focused because the current widely-used piezoelectric transducers are rigid and lack the flexibility to tune their spatial ultrasound responses.Inspired by the rapidly-developing flexible photonics,we exploited the inherent flexibility and low-loss features of optical fibers to develop a flexible fiber-laser ultrasound sensor(FUS)for multiscale PAI.By simply bending the fiber laser from straight to curved geometry,the spatial ultraso und resp onse of the FUS can be tuned for both wide-view optical-resolution photoacoustic microscopy at optical diffraction-limited depth(~1 mm)and photoacoustic computed tomography at optical dissipation-limited depth of several centimeters.A radio-frequency demodulation was employed to get the readout of the beat frequency variation of two orthogonal polarization modes in the FUS output,which ensures low-noise and stable ultrasound detection.Compared to traditional piezoelectrical transducers with fixed ultrasound responses once manufactured,the flexible FUS provides the freedom to design multiscale PAI modalities including wearable microscope,intravascular endoscopy,and portable tomography system,which is attractive to fundamental biologic-al/medical studies and clinical applications.展开更多
Photoacoustic(PA)imaging has been widely used in biomedical research and preclinical studies during the past two decades.It has also been explored for nondestructive testing and evaluation(NDT/E)and for industrial app...Photoacoustic(PA)imaging has been widely used in biomedical research and preclinical studies during the past two decades.It has also been explored for nondestructive testing and evaluation(NDT/E)and for industrial applications.This paper describes the basic principles of PA technology for NDT/E and its applications in recent years.PA technology for NDT/E includes the use of a modulated continuous-wave laser and a pulsed laser for PA wave excitation,PA-generated ultrasonic waves,and all-optical PA wave excitation and detection.PA technology for NDT/E has demonstrated broad applications,including the imaging of railway cracks and defects,the imaging of Li metal batteries,the measurements of the porosity and Young’s modulus,the detection of defects and damage in silicon wafers,and a visualization of underdrawings in paintings.展开更多
Photoacoustic imaging(PAI)is a new biomedical imaging technology that provides a mixed contrast mechanism and excellent spatial resolution in biological tissues.It is a non-invasive technology that can provide in vivo...Photoacoustic imaging(PAI)is a new biomedical imaging technology that provides a mixed contrast mechanism and excellent spatial resolution in biological tissues.It is a non-invasive technology that can provide in vivo anatomical and functional information.This technology has great application potential in microscopic imaging and endoscope system.In recent years,the devel-opment of micro electro mechanical system(MEMS)technology has promoted the improvement and miniaturization of the photoacoustic imaging system,as well as its preclinical and clinical appli-cations.This paper introduces the research progress of MEMS technology in photoacoustic micro-scope systems and the miniaturization of photoacoustic endoscope ultrasonic transducers,and points out the shortcomings of existing technology and the direction of future development.展开更多
Photoacoustic mesoscopy(PAMe) offers high-sensitivity in vivo imaging based on the rich optical contrast in biological tissues,with sub-100-micron resolutions at a few millimeters depth. By benefiting from low ultraso...Photoacoustic mesoscopy(PAMe) offers high-sensitivity in vivo imaging based on the rich optical contrast in biological tissues,with sub-100-micron resolutions at a few millimeters depth. By benefiting from low ultrasonic scattering,this emerging technology has pushed the penetration depth beyond the optical diffuse limit unprecedented for high-resolution optical methods.Here,we review ed the state-of-art implementations of PAMe and their achievements in biological and primary clinical applications. With the high-frequency focused ultrasonic detector,the high-resolution optical visualization can be achieved by utilizing various PAMe systems. These capabilities of PAMe have made it well applicable for understanding the biological mechanisms,exploring the pathological features and analyzing the characteristics of human skin. Future improvements and prospects of PAMe are also mentioned,suggesting its great potential tow ards the corresponding emerging biomedical and clinical applications.展开更多
Photoacoustic(PA)microscopy is being increasingly used to visualize the microcirculation of the brain cortex at the micron level in living rodents.By combining it with long-term cranial window techniques,vasculature c...Photoacoustic(PA)microscopy is being increasingly used to visualize the microcirculation of the brain cortex at the micron level in living rodents.By combining it with long-term cranial window techniques,vasculature can be monitored over a period of days extending to months through a field of view.To fulfill the requirements of long-term in vivo PA imaging,the cranial window must involve a simple and rapid surgical procedure,biological compatibility,and sufficient optical-acoustic transparency,which are major challenges.Recently,several cranial window techniques have been reported for longitudinal PA imaging.Here,the development of chronic cranial windows for PA imaging is reviewed and its technical details are discussed,including window installation,imaging quality,and longitudinal stability.展开更多
This paper presents photoacoustic and ultrasonic dual-mode imaging for real-time detection of submucosal gastric cancer with a combination of gastroscopy.The diagnostic capacity was directly addressed via several phan...This paper presents photoacoustic and ultrasonic dual-mode imaging for real-time detection of submucosal gastric cancer with a combination of gastroscopy.The diagnostic capacity was directly addressed via several phantoms and ex vivo experiments.Results demonstrated that superficial and submucosal gastric cancer can be diagnosed with a perceptible depth of 6.33 mm,a lateral accuracy of 2.23 mm,and a longitudinal accuracy of 0.17 mm though capturing the morphology of angiogenesis,which is a main character of the therioma-related change.The capability of gastroscopy-conjugated photoacoustic and ultrasonic dual-mode imaging system will own great potential in improving the clinical diagnostic rate of submucosal gastric cancer.展开更多
Fiber laser technology has experienced a rapid growth over the past decade owing to increased applications in precision measurement and optical testing,medical care,and industrial applications,including laser welding,...Fiber laser technology has experienced a rapid growth over the past decade owing to increased applications in precision measurement and optical testing,medical care,and industrial applications,including laser welding,cleaning,and manufacturing.A fiber laser can output laser pulses with high energy,a high repetition rate,a controllable wavelength,low noise,and good beam quality,making it applicable in photoacoustic imaging.Herein,recent developments in fiber-laser-based photoacoustic microscopy(PAM)are reviewed.Multispectral PAM can be used to image oxygen saturation or lipid-rich biological tissues by applying a Q-switched fiber laser,a stimulated Raman scattering-based laser source,or a fiber-based supercontinuum source for photoacoustic excitation.PAM can also incorporate a single-mode fiber laser cavity as a high-sensitivity ultrasound sensor by measuring the acoustically induced lasing-frequency shift.Because of their small size and high flexibility,compact head-mounted,wearable,or hand-held imaging modalities and better photoacoustic endoscopes can be enabled using fiber-laser-based PAM.展开更多
Photoacoustic imaging(PAI)is often performed simultaneously with ultrasound imaging and can provide functional and cellular information regarding the tissues in the anatomical markers of the imaging.This paper describ...Photoacoustic imaging(PAI)is often performed simultaneously with ultrasound imaging and can provide functional and cellular information regarding the tissues in the anatomical markers of the imaging.This paper describes in detail the basic principles of photoacoustic/ultrasound(PA/US)imaging and its application in recent years.It includes near-infrared-region PA,photothermal,photodynamic,and multimode imaging techniques.Particular attention is given to the relationship between PAI and ultrasonic imaging;the latest high-frequency PA/US imaging of small animals,which involves not only B-mode,but also color Doppler mode,power Doppler mode,and nonlinear imaging mode;the ultrasonic model combined with PAI,including the formation of multimodal imaging;the preclinical imaging methods;and the most effective detection methods for clinical research for the future.展开更多
Photoacoustic technology in combination with molecular imaging is a highly effective method for accurately diagnosing brain glioma. For glioma detection at a deeper site, contrast agents with higher photoacoustic imag...Photoacoustic technology in combination with molecular imaging is a highly effective method for accurately diagnosing brain glioma. For glioma detection at a deeper site, contrast agents with higher photoacoustic imaging sensitivity are needed. Herein, we report a MoS_2–ICG hybrid with indocyanine green(ICG) conjugated to the surface of MoS_2 nanosheets. The hybrid significantly enhanced photoacoustic imaging sensitivity compared to MoS_2 nanosheets. This conjugation results in remarkably high optical absorbance across a broad near-infrared spectrum, redshifting of the ICG absorption peak and photothermal/photoacoustic conversion efficiency enhancement of ICG. A tumor mass of 3.5 mm beneath the mouse scalp was clearly visualized by using MoS_2–ICG as a contrast agent for the in vivo photoacoustic imaging of orthotopic glioma, which is nearly twofold deeper than the tumors imaged in our previous report using MoS_2 nanosheet. Thus, combined with its good stability and high biocompatibility, the MoS_2–ICG hybrid developed in this study has a great potential for high-efficiency tumor molecular imaging in translational medicine.展开更多
Sleep-wake rhythm disturbances,which are characterized by abnormal sleep timing or duration,are associated with cognitive dysfunction.Photoacoustic treatments including light and sound stimulation have been found to b...Sleep-wake rhythm disturbances,which are characterized by abnormal sleep timing or duration,are associated with cognitive dysfunction.Photoacoustic treatments including light and sound stimulation have been found to be effective in modulating sleep patterns and improving cognitive behavior in abnormal sleep-wake pattern experiments.In this study,we examined whether light and sound interventions could reduce sleep-wake pattern disturbances and memory deficits in a sleep rhythm disturbance model.We established a model of sleep rhythm disturbance in C57 BL/6 J mice via a sleep deprivation method involving manual cage tapping,cage jostling,and nest disturbance.We used a Mini Mitter radio transmitter device to monitor motor activity in the mice and fear conditioning tests to assess cognitive function.Our results indicated that an intervention in which the mice were exposed to blue light(40-Hz flickering frequency)for 1 hour during their subjective daytime significantly improved the 24-hour-acrophase shift and reduced the degree of memory deficit induced by sleep deprivation.However,interventions in which the mice were exposed to a 40-Hz blue light at offset time or subjective night time points,as well as 2 Hz-blue light at 3 intervention time points(subjective day time,subjective night time,and offset time points),had no positive effects on circadian rhythm shift or memory deficits.Additionally,a 2000-Hz sound intervention during subjective day time attenuated the24-hour-acrophase shift and memory decline,while 440-Hz and 4000-Hz sounds had no effect on circadian rhythms.Overall,these results demonstrate that photoacoustic treatment effectively corrected abnormal sleep-wake patterns and cognitive dysfunction associated with sleep-deprivation-induced disturbances in sleep-wake rhythm.All animal experiments were approved by the Experimental Animal Ethics Committee of Drum Tower Hospital Affiliated to the Medical College of Nanjing University,China(approval No.20171102)on November20,2017.展开更多
Imaging based on photoacoustic effect relies on illuminating with short light pulses absorbed by tissue absorbers, resulting in thermoelastic expansion, giving rise to ultrasonic waves. The ultrasonic waves are then d...Imaging based on photoacoustic effect relies on illuminating with short light pulses absorbed by tissue absorbers, resulting in thermoelastic expansion, giving rise to ultrasonic waves. The ultrasonic waves are then detected by detectors placed around the sample. Photoacoustic endoscopy(PAE) is one of four major implementations of photoacoustic tomography that have been developed recently. The prototype PAE was based on scanning mirror system that deflected both the light and the ultrasound. A recently developed mini-probe was further miniaturized, and enabled simultaneous photoacoustic and ultrasound imaging. This PAE-endoscopic ultrasound(EUS) system can offer high-resolution vasculature information in the gastrointestinal(GI) tract and display differences between optical and mechanical contrast compared with single-mode EUS. However, PAE for endoscopic GI imaging is still at the preclinical stage. In this commentary, we describe the technological improvements in PAE for possible clinical application in endoscopic GI imaging. In addition, we discuss thetechnical details of the ultrasonic transducer incorporated into the photoacoustic endoscopic probe.展开更多
A microfiber with large evanescent field encapsulated in PDMS is proposed and demonstrated for ultrasound sensing.The compact size and large evanescent field of microfiber provide an excellent platform for the interac...A microfiber with large evanescent field encapsulated in PDMS is proposed and demonstrated for ultrasound sensing.The compact size and large evanescent field of microfiber provide an excellent platform for the interaction between optical signal and ultrasound wave,exhibiting a high sensitivity of 3.5 mV/kPa,which is approximately 10 times higher than the single-mode fiber sensor.Meanwhile,a phase feedback stabilization module is introduced into the coherent demodulation system for long-term stable measurement.In addition,a photoacoustic tomography experiment with the microfiber ultrasound sensor is implemented to verify the excellent performance on imaging,with the depth of 12 mm,the highest lateral resolution of 65μm and axial resolution of 250μm,respectively.The highly sensitive microfiber ultrasound sensor provides a competitive alternative for various applications,such as industrial non-destructive testing,biomedical ultrasound and photoacoustic imaging.展开更多
AIM To image stomach wall blood vessels and tissue, layerby-layer.METHODS We built up the acoustic resolution photoacoustic microscopy(AR-PAM) system for imaging layered tissues, such as the stomach wall. A tunable dy...AIM To image stomach wall blood vessels and tissue, layerby-layer.METHODS We built up the acoustic resolution photoacoustic microscopy(AR-PAM) system for imaging layered tissues, such as the stomach wall. A tunable dye laser system was coupled to a fiber bundle. The fibers of the bundle were placed in nine directions with an incident angle of 45° around a high-frequency ultrasound transducer attached to the acoustic lens. This structure formed a dark field on the tissue surface under the acoustic lens and the nine light beams from the fibers to be combined near the focal point of the acoustic lens. The sample piece was cut from a part of the porcine stomach into a petri dish. In order to realize photoacoustic depth imaging of tumor, we designed a tumor model based on indocyanine green(ICG) dye. The ICG solution(concentration of 129 μM/m L)was mixed into molten gel, and then a gel mixture of ICG(concentration of 12.9 μM/mL) was injected into the stomach submucosa. The injection quantity was controlled by 0.1 mL to make a small tumor model. RESULTS An acoustic resolution photoacoustic microscopy based on fiber illumination was established and an axial resolution of 25 μm and a lateral resolution of 50 μm in its focal zone range of 500 μm has been accomplished. We tuned the laser wavelength to 600 nm. The photoacoustic probe was driven to do B-scan imaging in tissue thickness of 200 μm. The photoacoustic micro-image of mucosa and submucosa of the tissue have been obtained and compared with a pathological photograph of the tissue stained by hematoxylin-eosin staining. We have observed more detailed internal structure of the tissue. We also utilized this photoacoustic microscopy to image blood vessels inside the submucosa. High contrast imaging of the submucosa tumor model was obtained using ICG dye. CONCLUSION This AR-PAM is able to image layer-by-layer construction and some blood vessels under mucosa in the stomach wall without any contrast agents.展开更多
Semiconducting conjugated polymer nanoparticles(SPNs)represent an emerging class of phototheranostic materi-als with great promise for cancer treatment.In this report,low-bandgap electron donoracceptor(DA)-conjugated ...Semiconducting conjugated polymer nanoparticles(SPNs)represent an emerging class of phototheranostic materi-als with great promise for cancer treatment.In this report,low-bandgap electron donoracceptor(DA)-conjugated SPNs with sur-face cloaked by red blood cell membrane(RBCM)are developed for highly e ective photoacoustic imaging and photothermal therapy.The resulting RBCM-coated SPN(SPN@RBCM)displays remarkable near-infrared light absorption and good photosta-bility,as well as high photothermal conver-sion e ciency for photoacoustic imaging and photothermal therapy.Particularly,due to the small size(<5 nm),SPN@RBCM has the advantages of deep tumor penetration and rapid clearance from the body with no appreciable toxicity.The RBCM endows the SPNs with prolonged systematic circulation time,less reticuloendothelial system uptake and reduced immune-recognition,hence improving tumor accumulation after intravenous injection,which provides strong photoacoustic signals and exerts excellent photothermal therapeutic e ects.Thus,this work provides a valuable paradigm for safe and highly e cient tumor pho-toacoustic imaging and photothermal therapy for further clinical translation.展开更多
Follicular thyroid carcinoma(FTC)is the second most common form of thyroid malignancy,and it is associated with more aggressive growth and worse long-term survival outcomes relative to papillary thyroid carcinoma(PTC)...Follicular thyroid carcinoma(FTC)is the second most common form of thyroid malignancy,and it is associated with more aggressive growth and worse long-term survival outcomes relative to papillary thyroid carcinoma(PTC).Reliable approaches to preoperative FTC detection,however,remain to be established.Herein,a targeted Affibody-Au-Tripod nanoprobe was developed and successfully utilized to facilitate the targeted photoacoustic imaging(PAI)of epidermal growth factor receptor(EGFR)-positive cells and tumors.These Affibody-Au-Tripods were found to be highly sensitive and specific for cells expressing EGFR when used as a PA contrast agent in vitro,and studies conducted in an FTC-133 subcutaneous tumor model system in mice further revealed that these Affibody-Au-Tripods were able to specifically target these EGFR-expressing tumors while providing a strong photoacoustic signal in vivo.Importantly,these nanoprobes exhibited negligible cytotoxicity and robust chemical and physical stability,making Affibody-Au-Tripods promising candidates for targeted PAI-based FTC diagnosis.In addition,these nanoprobes have the potential to facilitate the individualized treatment of patients harboring EGFRpositive tumors.展开更多
文摘Miniaturized sound generators are attractive to realize intriguing functions.Thermoacoustic device’s application is seriously limited due to the frequency-doubling phenomenon.To address this issue,photoacoustic sound generator is considered as a promising alternative.Here,based on vertical single-wall carbon nanotubes(CNTs)array,we introduce a photoacoustic sound generator with internal nano-Helmholtz cavity.Different from traditional device that generates sound by periodically heating up the open space air around material,this sound generator produces an audio signal by forming a forced vibration of the air inside the CNTs.Interestingly,anomalous photoacoustic behavior is observed that the sound pressure level(SPL)curve has a resonance peak,the corresponding frequency of which is inversely proportional to the CNTs array’s height.Furthermore,the energy conversion efficiency of this photoacoustic device is 1.64 times as large as that of a graphene sponge-based photoacoustic device.Most importantly,this device can be employed for music playing,bringing a new clew for the development of musical instruments in the future.
基金This work was supported by the National Natural Science Foundation of China(61775083,61705082,61805102,and 61860206002)the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(2019BT02X105)Guangzhou Science and Technology Plan(201904020032).
文摘Photoacoustic imag ing(PAI)is a nonin vasive biomedical imag ing tech no logy capable of multiscale imag ing of biological samples from orga ns dow n to cells.Multiscale PAI requires differe nt ultraso und tra nsducers that are flat or focused because the current widely-used piezoelectric transducers are rigid and lack the flexibility to tune their spatial ultrasound responses.Inspired by the rapidly-developing flexible photonics,we exploited the inherent flexibility and low-loss features of optical fibers to develop a flexible fiber-laser ultrasound sensor(FUS)for multiscale PAI.By simply bending the fiber laser from straight to curved geometry,the spatial ultraso und resp onse of the FUS can be tuned for both wide-view optical-resolution photoacoustic microscopy at optical diffraction-limited depth(~1 mm)and photoacoustic computed tomography at optical dissipation-limited depth of several centimeters.A radio-frequency demodulation was employed to get the readout of the beat frequency variation of two orthogonal polarization modes in the FUS output,which ensures low-noise and stable ultrasound detection.Compared to traditional piezoelectrical transducers with fixed ultrasound responses once manufactured,the flexible FUS provides the freedom to design multiscale PAI modalities including wearable microscope,intravascular endoscopy,and portable tomography system,which is attractive to fundamental biologic-al/medical studies and clinical applications.
基金S.-L.Chen acknowledges funding from the National Natural Science Foundation of China,No.61775134C.Tian acknowledges funding from the National Natural Science Foundation of China,No.61705216the Anhui Science and Technology Department,No.18030801138.
文摘Photoacoustic(PA)imaging has been widely used in biomedical research and preclinical studies during the past two decades.It has also been explored for nondestructive testing and evaluation(NDT/E)and for industrial applications.This paper describes the basic principles of PA technology for NDT/E and its applications in recent years.PA technology for NDT/E includes the use of a modulated continuous-wave laser and a pulsed laser for PA wave excitation,PA-generated ultrasonic waves,and all-optical PA wave excitation and detection.PA technology for NDT/E has demonstrated broad applications,including the imaging of railway cracks and defects,the imaging of Li metal batteries,the measurements of the porosity and Young’s modulus,the detection of defects and damage in silicon wafers,and a visualization of underdrawings in paintings.
基金supported by the National Natural Science Foundation of China(No.32101153)the Fundamental Research Funds for the Central Universities(No.2021CX11018).
文摘Photoacoustic imaging(PAI)is a new biomedical imaging technology that provides a mixed contrast mechanism and excellent spatial resolution in biological tissues.It is a non-invasive technology that can provide in vivo anatomical and functional information.This technology has great application potential in microscopic imaging and endoscope system.In recent years,the devel-opment of micro electro mechanical system(MEMS)technology has promoted the improvement and miniaturization of the photoacoustic imaging system,as well as its preclinical and clinical appli-cations.This paper introduces the research progress of MEMS technology in photoacoustic micro-scope systems and the miniaturization of photoacoustic endoscope ultrasonic transducers,and points out the shortcomings of existing technology and the direction of future development.
基金the National Natural Science Foundation of China (Grant Nos.81401453,81371602,61475115,61475116,61575140,81571723,and 81671728)the Tianjin Municipal Government of China (Grant Nos.14JCQNJC14400,15JCZDJC31800,15JCQNJC14500,and 16JCZDJC31200)
文摘Photoacoustic mesoscopy(PAMe) offers high-sensitivity in vivo imaging based on the rich optical contrast in biological tissues,with sub-100-micron resolutions at a few millimeters depth. By benefiting from low ultrasonic scattering,this emerging technology has pushed the penetration depth beyond the optical diffuse limit unprecedented for high-resolution optical methods.Here,we review ed the state-of-art implementations of PAMe and their achievements in biological and primary clinical applications. With the high-frequency focused ultrasonic detector,the high-resolution optical visualization can be achieved by utilizing various PAMe systems. These capabilities of PAMe have made it well applicable for understanding the biological mechanisms,exploring the pathological features and analyzing the characteristics of human skin. Future improvements and prospects of PAMe are also mentioned,suggesting its great potential tow ards the corresponding emerging biomedical and clinical applications.
基金This study was supported by the National Natural Science Foundation of China,Nos.62022037,61775028,81571722,61528401Department of Science and Technology of Guangdong Province,Nos.2019ZT08Y191,SZBL2020090501013+1 种基金Shenzhen Science and Technology ProgramNos.KQTD20190929172743294,JCYJ20200109141222892Startup grant from Southern University of Science and Technology。
文摘Photoacoustic(PA)microscopy is being increasingly used to visualize the microcirculation of the brain cortex at the micron level in living rodents.By combining it with long-term cranial window techniques,vasculature can be monitored over a period of days extending to months through a field of view.To fulfill the requirements of long-term in vivo PA imaging,the cranial window must involve a simple and rapid surgical procedure,biological compatibility,and sufficient optical-acoustic transparency,which are major challenges.Recently,several cranial window techniques have been reported for longitudinal PA imaging.Here,the development of chronic cranial windows for PA imaging is reviewed and its technical details are discussed,including window installation,imaging quality,and longitudinal stability.
基金National Natural Science Foundation of China(Grant Nos.61675043,81571726,and 81901787)the Natural Science Foundation of Fujian Province,China(Grant Nos.2018J01785 and 2018J01659).
文摘This paper presents photoacoustic and ultrasonic dual-mode imaging for real-time detection of submucosal gastric cancer with a combination of gastroscopy.The diagnostic capacity was directly addressed via several phantoms and ex vivo experiments.Results demonstrated that superficial and submucosal gastric cancer can be diagnosed with a perceptible depth of 6.33 mm,a lateral accuracy of 2.23 mm,and a longitudinal accuracy of 0.17 mm though capturing the morphology of angiogenesis,which is a main character of the therioma-related change.The capability of gastroscopy-conjugated photoacoustic and ultrasonic dual-mode imaging system will own great potential in improving the clinical diagnostic rate of submucosal gastric cancer.
基金This work was supported by the National Natural Science Foundation of China,Nos.61775083 and 61805102.
文摘Fiber laser technology has experienced a rapid growth over the past decade owing to increased applications in precision measurement and optical testing,medical care,and industrial applications,including laser welding,cleaning,and manufacturing.A fiber laser can output laser pulses with high energy,a high repetition rate,a controllable wavelength,low noise,and good beam quality,making it applicable in photoacoustic imaging.Herein,recent developments in fiber-laser-based photoacoustic microscopy(PAM)are reviewed.Multispectral PAM can be used to image oxygen saturation or lipid-rich biological tissues by applying a Q-switched fiber laser,a stimulated Raman scattering-based laser source,or a fiber-based supercontinuum source for photoacoustic excitation.PAM can also incorporate a single-mode fiber laser cavity as a high-sensitivity ultrasound sensor by measuring the acoustically induced lasing-frequency shift.Because of their small size and high flexibility,compact head-mounted,wearable,or hand-held imaging modalities and better photoacoustic endoscopes can be enabled using fiber-laser-based PAM.
文摘Photoacoustic imaging(PAI)is often performed simultaneously with ultrasound imaging and can provide functional and cellular information regarding the tissues in the anatomical markers of the imaging.This paper describes in detail the basic principles of photoacoustic/ultrasound(PA/US)imaging and its application in recent years.It includes near-infrared-region PA,photothermal,photodynamic,and multimode imaging techniques.Particular attention is given to the relationship between PAI and ultrasonic imaging;the latest high-frequency PA/US imaging of small animals,which involves not only B-mode,but also color Doppler mode,power Doppler mode,and nonlinear imaging mode;the ultrasonic model combined with PAI,including the formation of multimodal imaging;the preclinical imaging methods;and the most effective detection methods for clinical research for the future.
基金National Natural Science Foundation of China (NSFC) Grants 91739117, 81522024, 81427804, 61405234, 81430038 and 61475182National Key Basic Research (973) Program of China Grant 2014CB744503 and 2015CB755500+3 种基金Guangdong Natural Science Foundation Grant 2014B050505013 and 2014A030312006Shenzhen Science and Technology Innovation Grant JCYJ20170413153129570, JCYJ20160531175040976, JCYJ 20150521144321005, JCYJ20160608214524052, JCYJ201604221 53149834 JCYJ20150731154850923SIAT Innovation Program for Excellent Young Researchers 201510
文摘Photoacoustic technology in combination with molecular imaging is a highly effective method for accurately diagnosing brain glioma. For glioma detection at a deeper site, contrast agents with higher photoacoustic imaging sensitivity are needed. Herein, we report a MoS_2–ICG hybrid with indocyanine green(ICG) conjugated to the surface of MoS_2 nanosheets. The hybrid significantly enhanced photoacoustic imaging sensitivity compared to MoS_2 nanosheets. This conjugation results in remarkably high optical absorbance across a broad near-infrared spectrum, redshifting of the ICG absorption peak and photothermal/photoacoustic conversion efficiency enhancement of ICG. A tumor mass of 3.5 mm beneath the mouse scalp was clearly visualized by using MoS_2–ICG as a contrast agent for the in vivo photoacoustic imaging of orthotopic glioma, which is nearly twofold deeper than the tumors imaged in our previous report using MoS_2 nanosheet. Thus, combined with its good stability and high biocompatibility, the MoS_2–ICG hybrid developed in this study has a great potential for high-efficiency tumor molecular imaging in translational medicine.
基金supported by the National Natural Science Foundation of China,No.81730033(to XPG),No.81701371(to TJX),No.81801380(to XZ)the Natural Science Foundation of Jiangsu Province of China,No.BK20170654(to TJX),No.BK20170129(to XZ)the Key Talent’s 13th Five-Year Plan for Strengthening Health of Jiangsu Province of China,No.ZDRCA2016069(to XPG)
文摘Sleep-wake rhythm disturbances,which are characterized by abnormal sleep timing or duration,are associated with cognitive dysfunction.Photoacoustic treatments including light and sound stimulation have been found to be effective in modulating sleep patterns and improving cognitive behavior in abnormal sleep-wake pattern experiments.In this study,we examined whether light and sound interventions could reduce sleep-wake pattern disturbances and memory deficits in a sleep rhythm disturbance model.We established a model of sleep rhythm disturbance in C57 BL/6 J mice via a sleep deprivation method involving manual cage tapping,cage jostling,and nest disturbance.We used a Mini Mitter radio transmitter device to monitor motor activity in the mice and fear conditioning tests to assess cognitive function.Our results indicated that an intervention in which the mice were exposed to blue light(40-Hz flickering frequency)for 1 hour during their subjective daytime significantly improved the 24-hour-acrophase shift and reduced the degree of memory deficit induced by sleep deprivation.However,interventions in which the mice were exposed to a 40-Hz blue light at offset time or subjective night time points,as well as 2 Hz-blue light at 3 intervention time points(subjective day time,subjective night time,and offset time points),had no positive effects on circadian rhythm shift or memory deficits.Additionally,a 2000-Hz sound intervention during subjective day time attenuated the24-hour-acrophase shift and memory decline,while 440-Hz and 4000-Hz sounds had no effect on circadian rhythms.Overall,these results demonstrate that photoacoustic treatment effectively corrected abnormal sleep-wake patterns and cognitive dysfunction associated with sleep-deprivation-induced disturbances in sleep-wake rhythm.All animal experiments were approved by the Experimental Animal Ethics Committee of Drum Tower Hospital Affiliated to the Medical College of Nanjing University,China(approval No.20171102)on November20,2017.
基金The National Research Foundation of Korea grant funded by the Korea government,No.NRF-2010-0023295
文摘Imaging based on photoacoustic effect relies on illuminating with short light pulses absorbed by tissue absorbers, resulting in thermoelastic expansion, giving rise to ultrasonic waves. The ultrasonic waves are then detected by detectors placed around the sample. Photoacoustic endoscopy(PAE) is one of four major implementations of photoacoustic tomography that have been developed recently. The prototype PAE was based on scanning mirror system that deflected both the light and the ultrasound. A recently developed mini-probe was further miniaturized, and enabled simultaneous photoacoustic and ultrasound imaging. This PAE-endoscopic ultrasound(EUS) system can offer high-resolution vasculature information in the gastrointestinal(GI) tract and display differences between optical and mechanical contrast compared with single-mode EUS. However, PAE for endoscopic GI imaging is still at the preclinical stage. In this commentary, we describe the technological improvements in PAE for possible clinical application in endoscopic GI imaging. In addition, we discuss thetechnical details of the ultrasonic transducer incorporated into the photoacoustic endoscopic probe.
基金financial supports from National Natural Science Foundation of China (NSFC)(No.61922033)Foundation for Innovative Research Groups of Hubei Province of China (2018CFA004)Innovation Fund of WNLO
文摘A microfiber with large evanescent field encapsulated in PDMS is proposed and demonstrated for ultrasound sensing.The compact size and large evanescent field of microfiber provide an excellent platform for the interaction between optical signal and ultrasound wave,exhibiting a high sensitivity of 3.5 mV/kPa,which is approximately 10 times higher than the single-mode fiber sensor.Meanwhile,a phase feedback stabilization module is introduced into the coherent demodulation system for long-term stable measurement.In addition,a photoacoustic tomography experiment with the microfiber ultrasound sensor is implemented to verify the excellent performance on imaging,with the depth of 12 mm,the highest lateral resolution of 65μm and axial resolution of 250μm,respectively.The highly sensitive microfiber ultrasound sensor provides a competitive alternative for various applications,such as industrial non-destructive testing,biomedical ultrasound and photoacoustic imaging.
基金Supported by the National Nature Science Foundation of China,No.61378060
文摘AIM To image stomach wall blood vessels and tissue, layerby-layer.METHODS We built up the acoustic resolution photoacoustic microscopy(AR-PAM) system for imaging layered tissues, such as the stomach wall. A tunable dye laser system was coupled to a fiber bundle. The fibers of the bundle were placed in nine directions with an incident angle of 45° around a high-frequency ultrasound transducer attached to the acoustic lens. This structure formed a dark field on the tissue surface under the acoustic lens and the nine light beams from the fibers to be combined near the focal point of the acoustic lens. The sample piece was cut from a part of the porcine stomach into a petri dish. In order to realize photoacoustic depth imaging of tumor, we designed a tumor model based on indocyanine green(ICG) dye. The ICG solution(concentration of 129 μM/m L)was mixed into molten gel, and then a gel mixture of ICG(concentration of 12.9 μM/mL) was injected into the stomach submucosa. The injection quantity was controlled by 0.1 mL to make a small tumor model. RESULTS An acoustic resolution photoacoustic microscopy based on fiber illumination was established and an axial resolution of 25 μm and a lateral resolution of 50 μm in its focal zone range of 500 μm has been accomplished. We tuned the laser wavelength to 600 nm. The photoacoustic probe was driven to do B-scan imaging in tissue thickness of 200 μm. The photoacoustic micro-image of mucosa and submucosa of the tissue have been obtained and compared with a pathological photograph of the tissue stained by hematoxylin-eosin staining. We have observed more detailed internal structure of the tissue. We also utilized this photoacoustic microscopy to image blood vessels inside the submucosa. High contrast imaging of the submucosa tumor model was obtained using ICG dye. CONCLUSION This AR-PAM is able to image layer-by-layer construction and some blood vessels under mucosa in the stomach wall without any contrast agents.
基金supported by the National Natural Science Foundation of China(Grant Nos.61727823,51873160)the joint research project of Health and Education Commission of Fujian Province(Grant No.2019-WJ-20).
文摘Semiconducting conjugated polymer nanoparticles(SPNs)represent an emerging class of phototheranostic materi-als with great promise for cancer treatment.In this report,low-bandgap electron donoracceptor(DA)-conjugated SPNs with sur-face cloaked by red blood cell membrane(RBCM)are developed for highly e ective photoacoustic imaging and photothermal therapy.The resulting RBCM-coated SPN(SPN@RBCM)displays remarkable near-infrared light absorption and good photosta-bility,as well as high photothermal conver-sion e ciency for photoacoustic imaging and photothermal therapy.Particularly,due to the small size(<5 nm),SPN@RBCM has the advantages of deep tumor penetration and rapid clearance from the body with no appreciable toxicity.The RBCM endows the SPNs with prolonged systematic circulation time,less reticuloendothelial system uptake and reduced immune-recognition,hence improving tumor accumulation after intravenous injection,which provides strong photoacoustic signals and exerts excellent photothermal therapeutic e ects.Thus,this work provides a valuable paradigm for safe and highly e cient tumor pho-toacoustic imaging and photothermal therapy for further clinical translation.
基金supported by the National Natural Science Foundation of China(81421004,81301268)Beijing Nova Program Interdisciplinary Cooperation Project (xxjc201812)+2 种基金International S&T Cooperation Program of China(2015DFA30440)Beijing Nova Program(Z131107000413063)CAMS Innovation Fund for Medical Sciences(CIFMS 2020-I2M-C&T-B-035)。
文摘Follicular thyroid carcinoma(FTC)is the second most common form of thyroid malignancy,and it is associated with more aggressive growth and worse long-term survival outcomes relative to papillary thyroid carcinoma(PTC).Reliable approaches to preoperative FTC detection,however,remain to be established.Herein,a targeted Affibody-Au-Tripod nanoprobe was developed and successfully utilized to facilitate the targeted photoacoustic imaging(PAI)of epidermal growth factor receptor(EGFR)-positive cells and tumors.These Affibody-Au-Tripods were found to be highly sensitive and specific for cells expressing EGFR when used as a PA contrast agent in vitro,and studies conducted in an FTC-133 subcutaneous tumor model system in mice further revealed that these Affibody-Au-Tripods were able to specifically target these EGFR-expressing tumors while providing a strong photoacoustic signal in vivo.Importantly,these nanoprobes exhibited negligible cytotoxicity and robust chemical and physical stability,making Affibody-Au-Tripods promising candidates for targeted PAI-based FTC diagnosis.In addition,these nanoprobes have the potential to facilitate the individualized treatment of patients harboring EGFRpositive tumors.
