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 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
We constructed a flexible gold-polydimethylsiloxane(gold-PDMS)nanocomposites film with controllable thickness and light transmittance,to realize optically-excited simultaneous photo-acoustic(PA)and ultrasound(US)imagi...We constructed a flexible gold-polydimethylsiloxane(gold-PDMS)nanocomposites film with controllable thickness and light transmittance,to realize optically-excited simultaneous photo-acoustic(PA)and ultrasound(US)imaging under a single laser pulse irradiation.Benefiting from the excellent thermoelastic properties,the gold-PDMS film absorbs part of the incident laser energy and produces a high-intensity US,which is used to realize US imaging.Meanwhile,the partly transmitted light is used to excite samples for PA imaging.By controlling the thickness of the gold-PDMS,we can control the center frequency in the US imaging.We experimentally analyzed the frequency of the produced US signal by the gold-PDMSfilm and compared it with the finite element analysis(FEA)method,where the experiments agree with the FEA results.This method is demonstrated by the experiments on phantoms and a mouse model.Our work provides a cost-effective methodology for simultaneous PA and US imaging.展开更多
Photoacoustic microscopy is an in vivo imaging technology based on the photoacoustic effect.It is widely used in various biomedical studies because it can provide high-resolution images while being label-free,safe,and...Photoacoustic microscopy is an in vivo imaging technology based on the photoacoustic effect.It is widely used in various biomedical studies because it can provide high-resolution images while being label-free,safe,and harmless to biological tissue.Polygon-scanning is an effective scanning method in photoacoustic microscopy that can realize fast imaging of biological tissue with a large field of view.However,in polygon-scanning,fluctuations of the rotating motor speed and the geometric error of the rotating mirror cause image distortions,which seriously affect the photoacoustic-microscopy imaging quality.To improve the image quality of photoacoustic microscopy using polygon-scanning,an image correction method is proposed based on accurate ultrasound positioning.In this method,the photoacoustic and ultrasound imaging data of the sample are simultaneously obtained,and the angle information of each mirror used in the polygon-scanning is extracted from the ultrasonic data to correct the photoacoustic images.Experimental results show that the proposed method can significantly reduce image distortions in photoacoustic microscopy,with the image dislocation offset decreasing from 24.774 to 10.365μm.展开更多
We present a novel noncontact ultrasound(US)and photoacoustic imaging(PAI)system,overcoming the limitations of traditional coupling media.Using a long coherent length laser,we employ a homodyne free-space Mach-Zehnder...We present a novel noncontact ultrasound(US)and photoacoustic imaging(PAI)system,overcoming the limitations of traditional coupling media.Using a long coherent length laser,we employ a homodyne free-space Mach-Zehnder setup with zero-crossing triggering,achieving a noise equivalent pressure of 703 Pa at 5 MHz and a-6 dB bandwidth of 1 to8.54 MHz.We address the phase uncertainty inherent in the homodyne method.Scanning the noncontact US probe enables photoacoustic computed tomography(PACT).Phantom studies demonstrate imaging performance and system stability,underscoring the potential of our system for noncontact US sensing and PAI.展开更多
Simultaneous photoacoustic and ultrasound(PAUS)imaging has attracted increasing attention in biomedical research to probe the optical and mechanical properties of tissue.However,the resolution for majority of the exis...Simultaneous photoacoustic and ultrasound(PAUS)imaging has attracted increasing attention in biomedical research to probe the optical and mechanical properties of tissue.However,the resolution for majority of the existing PAUS systems is on the order of 1 mm as the majority are designed for clinical use with low-frequency US detection.Here we developed a concurrent PAUS microscopy that consists of optical-resolution photoacoustic microscopy(OR-PAM)and high-frequency US pulse-echo imaging.This dual-modality system utilizes a novel coaxial dual-element ultrasonic transducer(DE-UST)and provides anatomical and functional information with complementary contrast mechanisms,achieving a spatial resolution of 7μm for PA imaging and 106μm for US imaging.We performed phantom studies to validate the system’s performance.The vasculature of a mouse’s hind paw was imaged to demonstrate the potential of this hybrid system for biomedical applications.展开更多
Based on the energy conversion of light into sound,photoacoustic computed tomography(PACT)is an emerging biomedical imaging modality and has unique applications in a range of biomedical fields.In PACT,image formation ...Based on the energy conversion of light into sound,photoacoustic computed tomography(PACT)is an emerging biomedical imaging modality and has unique applications in a range of biomedical fields.In PACT,image formation relies on a process called acoustic inversion from received photoacoustic signals.While most PACT systems perform this inversion with a basic assumption that biological tissues are acoustically homogeneous,the community gradually rea-lizes that the intrinsic acoustic heterogeneity of tissues could pose distortions and artifacts to finally formed images.This paper surveys the most recent research progress on acoustic het-erogeneity correction in PACT.Four major strategies are reviewed in detail,including half-time or partial-time reconstruction,autofocus reconstruction by optimizing sound speed maps,joint reconstruction of optical absorption and sound speed maps,and ultrasound computed tomog-raphy(USCT)enhanced reconstruction.The correction of acoustic heterogeneity helps improve the imaging performance of PACT.展开更多
Early detection of vulnerable plaques is the critical step in the prevention of acute coronary events.Morphology,composition,and mechanical property of a coronary artery have been demonstrated to be the key characteri...Early detection of vulnerable plaques is the critical step in the prevention of acute coronary events.Morphology,composition,and mechanical property of a coronary artery have been demonstrated to be the key characteristics for the identification of vulnerable plaques.Several intravascular multimodal imaging technologies providing co-registered simultaneous images have been developed and applied in clinical studies to improve the characterization of atherosclerosis.In this paper,the authors review the present system and probe designs of representative intra-vascular multimodal techniques.In addition,the scientific innovations,potential limitations,and future directions of these technologies are also discussed.展开更多
Optical whispering-gallery microresonators have attracted considerable interest for ultrasensitive ultrasound detection and photoacoustic imaging because of the combination of high quality factors and small cavity siz...Optical whispering-gallery microresonators have attracted considerable interest for ultrasensitive ultrasound detection and photoacoustic imaging because of the combination of high quality factors and small cavity sizes.In the last decade,ultrasonic sensors with on-chip microcavities have been extensively developed;however,they are unsuitable for the near-field photoacoustic microscopy of micro/nanoscale objects in complex biological environments and endoscopic imaging.In this work,we developed ultrasonic sensors using two types of encapsulated microsphere resonators with different cavity materials.A noise equivalent pressure of as low as 160 Pa at 20 MHz was achieved with the acoustic response up to 70 MHz at-6 d B.Furthermore,the microsensor was used for photoacoustic microscopy in which we successfully performed 3 D imaging of hairs and leaf veins.The microsphere ultrasonic sensor has considerable potential as a probe-type ultrasonic detector for near-field photoacoustic microscopy of micro/nanoscale objects such as subcellular structures and high-resolution endoscopic photoacoustic imaging with its high sensitivity and wide bandwidth.展开更多
Varieties of contrast agents have been developed for photoacoustic(PA)and ultrasound(US)imaging of cancers in vivo.However,access of traditional contrast agents into the sites of tumors has been principally through pa...Varieties of contrast agents have been developed for photoacoustic(PA)and ultrasound(US)imaging of cancers in vivo.However,access of traditional contrast agents into the sites of tumors has been principally through passive infiltration without any external force,preventing their deep penetration into the tissues of the tumors,and hindering the use of PA and US for deep tumor imaging.The concept of micro/nanomotors has been the focus of increasing attention as active theranostic agents due to their active movement in particular fluids,thereby conducting assigned tasks.Herein,US-propelled Janus mesoporous SiO_(2)partially coated gold nanorods(Au NR-mSiO_(2))were fabricated for deep tumor NIR-II PA imaging and synergistic sonodynamic-gas therapy.Following US irradiation,2,2-azobis[2-(2-imidazolin-2-yl)propane]dihydrochloride(AIPH)loaded in mSiO_(2)(Au NR-mSiO_(2)/AIPH)generated N_(2)microbubbles with high efficiency to achieve nanomotor drive.Due to the deep penetration of US,the nanomotors exhibited a capability to travel deep within sites of tumors,providing enhanced PA/US imaging inside the tumors.Furthermore,the nanomotor based cancer therapy was demonstrated through synergistic N_(2)gas and sonodynamic therapy.The US-propelled nanomotors demonstrated a novel strategy for the simultaneous PA/US dual imaging deep within tumor tissues and precise therapy of large tumors.展开更多
Laser-activated perfluorocarb on n anodroplets are an emerging class of phase-cha nge, dual-c ontrast age nts that can be utilized in ultraso und and photoacoustic imaging. Through the ability to differe ntiate subpop...Laser-activated perfluorocarb on n anodroplets are an emerging class of phase-cha nge, dual-c ontrast age nts that can be utilized in ultraso und and photoacoustic imaging. Through the ability to differe ntiate subpopulations of nano droplets via laser activatio n at differe nt wavelengths of n ear-infrared light, optically-triggered color-coded perfluorocarb on nano droplets prese nt themselves as an attractive tool for multiplexed ultrasound and photoacoustic imaging. In particular, laser-activated droplets can be used to provide quantitative spatiotemporal information regarding distinct biological targets, allowing for their potential use in a wide range of diagnostic and therapeutic applications. In the work prese nted, laser-activated color-coded perfluorocarb on nan odroplets are syn thesized to selectively resp ond to laser irradiati on at corresp on ding wavele ngths. The dyn amic ultraso und and photoacoustic signals produced by laser-activated perfluorocarbon nano droplets are evaluated in situ prior to implementation in a murine model. In vivo, these particles are used to distinguish unique particle trafficking mechanisms and are show n to provide ultraso und and photoacoustic contrast for up to 72 hours within lymphatics. Overall, the con ducted studies show that laser-activated color-coded perfluorocarbo n nano droplets are a promising agent for multiplexed ultraso und and photoacoustic imaging.展开更多
In vivo imaging of cerebral ischemia/reperfusion injury remains an important challenge.We injected porous Ag/Au@SiO_(2) bimetallic hollow nanoshells carrying anti-tropomyosin 4 as a molecular probe into mice with cere...In vivo imaging of cerebral ischemia/reperfusion injury remains an important challenge.We injected porous Ag/Au@SiO_(2) bimetallic hollow nanoshells carrying anti-tropomyosin 4 as a molecular probe into mice with cerebral ischemia/reperfusion injury and observed microvascular changes in the brain using photoacoustic imaging with ultrasonography.At each measured time point,the total photoacoustic signal was significantly higher on the affected side than on the healthy side.Twelve hours after reperfusion,cerebral perfusion on the affected side increased,cerebrovascular injury worsened,and anti-tropomyosin 4 expression increased.Twenty-four hours after reperfusion and later,perfusion on the affected side declined slowly and stabilized after 1 week;brain injury was also alleviated.Histopathological and immunohistochemical examinations confirmed the brain injury tissue changes.The nanoshell molecular probe carrying anti-tropomyosin 4 has potential for use in early diagnosis of cerebral ischemia/reperfusion injury and evaluating its progression.展开更多
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.
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supported by the National Natural Science Foundation of China(NSFC)(61805085)The Natural Science Foundation of Guangdong Province(2018A030310519)+1 种基金The Young innovative talents project of general colleges and universities in Guangdong ProvinceThe Guangzhou Science and technology plan project(201904010321)
文摘We constructed a flexible gold-polydimethylsiloxane(gold-PDMS)nanocomposites film with controllable thickness and light transmittance,to realize optically-excited simultaneous photo-acoustic(PA)and ultrasound(US)imaging under a single laser pulse irradiation.Benefiting from the excellent thermoelastic properties,the gold-PDMS film absorbs part of the incident laser energy and produces a high-intensity US,which is used to realize US imaging.Meanwhile,the partly transmitted light is used to excite samples for PA imaging.By controlling the thickness of the gold-PDMS,we can control the center frequency in the US imaging.We experimentally analyzed the frequency of the produced US signal by the gold-PDMSfilm and compared it with the finite element analysis(FEA)method,where the experiments agree with the FEA results.This method is demonstrated by the experiments on phantoms and a mouse model.Our work provides a cost-effective methodology for simultaneous PA and US imaging.
基金This work was supported by the National Natural Science Foundation of ChinaNos.91739117 and 81927807+3 种基金Shenzhen Science and Technology Innovation,No.JCYJ20170413153129570Chinese Academy of Sciences Nos.YJKYYQ20190078 and GJJSTD20180002Shenzhen Key Laboratory for Molecular Imaging,No.ZDSY20130401165820357Guangdong Provincial Key Laboratory of Biomedical Optical Imaging,No.2020B121201010.
文摘Photoacoustic microscopy is an in vivo imaging technology based on the photoacoustic effect.It is widely used in various biomedical studies because it can provide high-resolution images while being label-free,safe,and harmless to biological tissue.Polygon-scanning is an effective scanning method in photoacoustic microscopy that can realize fast imaging of biological tissue with a large field of view.However,in polygon-scanning,fluctuations of the rotating motor speed and the geometric error of the rotating mirror cause image distortions,which seriously affect the photoacoustic-microscopy imaging quality.To improve the image quality of photoacoustic microscopy using polygon-scanning,an image correction method is proposed based on accurate ultrasound positioning.In this method,the photoacoustic and ultrasound imaging data of the sample are simultaneously obtained,and the angle information of each mirror used in the polygon-scanning is extracted from the ultrasonic data to correct the photoacoustic images.Experimental results show that the proposed method can significantly reduce image distortions in photoacoustic microscopy,with the image dislocation offset decreasing from 24.774 to 10.365μm.
基金supported by the National Key Research and Development Program of China(No.2017YFE0104200)the Beijing Natural Science Foundation(No.JQ18023)+1 种基金the National Natural Science Foundation of China(Nos.81421004 and 61971447)the National Key Instrumentation Development Project of China(No.2013YQ030651)。
文摘We present a novel noncontact ultrasound(US)and photoacoustic imaging(PAI)system,overcoming the limitations of traditional coupling media.Using a long coherent length laser,we employ a homodyne free-space Mach-Zehnder setup with zero-crossing triggering,achieving a noise equivalent pressure of 703 Pa at 5 MHz and a-6 dB bandwidth of 1 to8.54 MHz.We address the phase uncertainty inherent in the homodyne method.Scanning the noncontact US probe enables photoacoustic computed tomography(PACT).Phantom studies demonstrate imaging performance and system stability,underscoring the potential of our system for noncontact US sensing and PAI.
文摘Simultaneous photoacoustic and ultrasound(PAUS)imaging has attracted increasing attention in biomedical research to probe the optical and mechanical properties of tissue.However,the resolution for majority of the existing PAUS systems is on the order of 1 mm as the majority are designed for clinical use with low-frequency US detection.Here we developed a concurrent PAUS microscopy that consists of optical-resolution photoacoustic microscopy(OR-PAM)and high-frequency US pulse-echo imaging.This dual-modality system utilizes a novel coaxial dual-element ultrasonic transducer(DE-UST)and provides anatomical and functional information with complementary contrast mechanisms,achieving a spatial resolution of 7μm for PA imaging and 106μm for US imaging.We performed phantom studies to validate the system’s performance.The vasculature of a mouse’s hind paw was imaged to demonstrate the potential of this hybrid system for biomedical applications.
基金supported in part by the National Natural Science Foundation of China(NSFC)under Grant No.61705216in part by the Major Science and Technology Project of Anhui Province under Grant No.18030801138+4 种基金in part by the Zhe-jiang Lab under Grant No.2019MC0AB01in part by the Research Funds of the Double First-Class Initiativein part by the Research Fund of the USTC Smart City Institutein part by the CAS Pioneer Hundred Talents Programin part by the Startup Fund of the University of Science and Technology of China(USTC)
文摘Based on the energy conversion of light into sound,photoacoustic computed tomography(PACT)is an emerging biomedical imaging modality and has unique applications in a range of biomedical fields.In PACT,image formation relies on a process called acoustic inversion from received photoacoustic signals.While most PACT systems perform this inversion with a basic assumption that biological tissues are acoustically homogeneous,the community gradually rea-lizes that the intrinsic acoustic heterogeneity of tissues could pose distortions and artifacts to finally formed images.This paper surveys the most recent research progress on acoustic het-erogeneity correction in PACT.Four major strategies are reviewed in detail,including half-time or partial-time reconstruction,autofocus reconstruction by optimizing sound speed maps,joint reconstruction of optical absorption and sound speed maps,and ultrasound computed tomog-raphy(USCT)enhanced reconstruction.The correction of acoustic heterogeneity helps improve the imaging performance of PACT.
基金Theauthors acknowledge funding from National Institutes of Health(R01HL-125084.R01HL-127271,R01EY-026091,R01EY-028662)American Heart Association(18PRE34050021)the National Science Foundation(DGE-1839285).
文摘Early detection of vulnerable plaques is the critical step in the prevention of acute coronary events.Morphology,composition,and mechanical property of a coronary artery have been demonstrated to be the key characteristics for the identification of vulnerable plaques.Several intravascular multimodal imaging technologies providing co-registered simultaneous images have been developed and applied in clinical studies to improve the characterization of atherosclerosis.In this paper,the authors review the present system and probe designs of representative intra-vascular multimodal techniques.In addition,the scientific innovations,potential limitations,and future directions of these technologies are also discussed.
基金supported by the National Key Research and Development Program of China(Grant No.2017YFE0104200)National Natural Science Foundation of China(Grant Nos.81421004,62105006)supported by the China Postdoctoral Science Foundation(Grant Nos.2020M680187,2021T140023)。
文摘Optical whispering-gallery microresonators have attracted considerable interest for ultrasensitive ultrasound detection and photoacoustic imaging because of the combination of high quality factors and small cavity sizes.In the last decade,ultrasonic sensors with on-chip microcavities have been extensively developed;however,they are unsuitable for the near-field photoacoustic microscopy of micro/nanoscale objects in complex biological environments and endoscopic imaging.In this work,we developed ultrasonic sensors using two types of encapsulated microsphere resonators with different cavity materials.A noise equivalent pressure of as low as 160 Pa at 20 MHz was achieved with the acoustic response up to 70 MHz at-6 d B.Furthermore,the microsensor was used for photoacoustic microscopy in which we successfully performed 3 D imaging of hairs and leaf veins.The microsphere ultrasonic sensor has considerable potential as a probe-type ultrasonic detector for near-field photoacoustic microscopy of micro/nanoscale objects such as subcellular structures and high-resolution endoscopic photoacoustic imaging with its high sensitivity and wide bandwidth.
基金supported by the National Natural Science Foundation of China(21874024,22027805,21804068)the National Key R&D Program of China(2020YFA0210800)+1 种基金the joint re-search projects of Health and Education Commission of Fujian Province(2019-WJ-20)the Natural Science Foundation of Fujian Province(2020J02012)。
文摘Varieties of contrast agents have been developed for photoacoustic(PA)and ultrasound(US)imaging of cancers in vivo.However,access of traditional contrast agents into the sites of tumors has been principally through passive infiltration without any external force,preventing their deep penetration into the tissues of the tumors,and hindering the use of PA and US for deep tumor imaging.The concept of micro/nanomotors has been the focus of increasing attention as active theranostic agents due to their active movement in particular fluids,thereby conducting assigned tasks.Herein,US-propelled Janus mesoporous SiO_(2)partially coated gold nanorods(Au NR-mSiO_(2))were fabricated for deep tumor NIR-II PA imaging and synergistic sonodynamic-gas therapy.Following US irradiation,2,2-azobis[2-(2-imidazolin-2-yl)propane]dihydrochloride(AIPH)loaded in mSiO_(2)(Au NR-mSiO_(2)/AIPH)generated N_(2)microbubbles with high efficiency to achieve nanomotor drive.Due to the deep penetration of US,the nanomotors exhibited a capability to travel deep within sites of tumors,providing enhanced PA/US imaging inside the tumors.Furthermore,the nanomotor based cancer therapy was demonstrated through synergistic N_(2)gas and sonodynamic therapy.The US-propelled nanomotors demonstrated a novel strategy for the simultaneous PA/US dual imaging deep within tumor tissues and precise therapy of large tumors.
基金D. Y. S. acknowledges fellowship funding from the National Institutes of Health (No. T32 EB007507) and the National Science Foundation Graduate Research Fellowship ProgramK. A. H. acknowledges fellowship funding from the National Institutes of Health (No. T32 EB007507)+1 种基金S. K. Y. acknowledges fellowship funding from the National Institutes of Health (No. F30 CA216939)The work was supported in part by the National Institutes of Health under Grants CAI5859& EB008101 and CAI49740 as well as the Breast Cancer Research Foundation Grant (No. BCRF-17-043).
文摘Laser-activated perfluorocarb on n anodroplets are an emerging class of phase-cha nge, dual-c ontrast age nts that can be utilized in ultraso und and photoacoustic imaging. Through the ability to differe ntiate subpopulations of nano droplets via laser activatio n at differe nt wavelengths of n ear-infrared light, optically-triggered color-coded perfluorocarb on nano droplets prese nt themselves as an attractive tool for multiplexed ultrasound and photoacoustic imaging. In particular, laser-activated droplets can be used to provide quantitative spatiotemporal information regarding distinct biological targets, allowing for their potential use in a wide range of diagnostic and therapeutic applications. In the work prese nted, laser-activated color-coded perfluorocarb on nan odroplets are syn thesized to selectively resp ond to laser irradiati on at corresp on ding wavele ngths. The dyn amic ultraso und and photoacoustic signals produced by laser-activated perfluorocarbon nano droplets are evaluated in situ prior to implementation in a murine model. In vivo, these particles are used to distinguish unique particle trafficking mechanisms and are show n to provide ultraso und and photoacoustic contrast for up to 72 hours within lymphatics. Overall, the con ducted studies show that laser-activated color-coded perfluorocarbo n nano droplets are a promising agent for multiplexed ultraso und and photoacoustic imaging.
基金supported by the National Natural Science Foundation of China,No.81730050(to WH).
文摘In vivo imaging of cerebral ischemia/reperfusion injury remains an important challenge.We injected porous Ag/Au@SiO_(2) bimetallic hollow nanoshells carrying anti-tropomyosin 4 as a molecular probe into mice with cerebral ischemia/reperfusion injury and observed microvascular changes in the brain using photoacoustic imaging with ultrasonography.At each measured time point,the total photoacoustic signal was significantly higher on the affected side than on the healthy side.Twelve hours after reperfusion,cerebral perfusion on the affected side increased,cerebrovascular injury worsened,and anti-tropomyosin 4 expression increased.Twenty-four hours after reperfusion and later,perfusion on the affected side declined slowly and stabilized after 1 week;brain injury was also alleviated.Histopathological and immunohistochemical examinations confirmed the brain injury tissue changes.The nanoshell molecular probe carrying anti-tropomyosin 4 has potential for use in early diagnosis of cerebral ischemia/reperfusion injury and evaluating its progression.
