This review summarizes the historical and more recent developments of multiphoton microscopy,as applied to dermatology.Multiphoton microscopy offers several advantages over competingmicroscopy techniques:there is an i...This review summarizes the historical and more recent developments of multiphoton microscopy,as applied to dermatology.Multiphoton microscopy offers several advantages over competingmicroscopy techniques:there is an inherent axial sectioning,penetration depths that competewll with confocal microscopy on account of the use of near-infrared light,and many t wo-pho ton contrast mechanisms,such as second-harmonic generation,have no analogue in one-photonmicroscopy.While the penetration depths of photons into tissue are typically limited on the orderof hundreds of microns,this is of les concern in dermatology,as the skin is thin and readlily.accessible.As a result,multiphoton microscopy in dermatology has generated a great deal ofmterest,much of which is summarized here.The review covers the interaction of light and tissue,as well as the various considerations that must be made when designing an instrument.The stateof multiphoton microscopy in imaging skin cancer and various other diseases is also discussed,along with the investigation of aging and regeneration phenomena,and finally,the use of mul-tiphoton microscopy to analyze the transdermal transport of drugs,cosmetics and other agents issummarized.The review concludes with a look at potential future research directions,especiallythose that are necessary to push these techniques into widespread clinical acceptance.展开更多
Label-free detection of biological events at single-cell resolution in the brain can non-invasively capture brain status for medical diagnosis and basic neuroscience research.NADH is an universal coenzyme that not onl...Label-free detection of biological events at single-cell resolution in the brain can non-invasively capture brain status for medical diagnosis and basic neuroscience research.NADH is an universal coenzyme that not only plays a central role in cellular metabolism but may also be used as a biomarker to capture metabolic processes in brain cells and structures.We have developed a new label-free,multiphoton photoacoustic microscope(LF-MP-PAM)with a near-infrared femtosecond laser to observe endogenous NAD(P)H in living cells.The imaging depth of NAD(P)H in tissues with all-optical methods is limited to~100μm in brain tissue by the strong absorption of the near-ultraviolet fluorescence.Here,acoustic detection of the thermal signature of multi-photon(three-photon)excitation of NAD(P)H,a low quantum yield fluorophore,allows detection at an unprecedented depth while the focused excitation ensures high spatial resolution.We validated the photoacoustic detection of NAD(P)H by monitoring an increase in intracellular NAD(P)H in HEK293T cells and HepG2 cells incubated in NADH solution.We also demonstrated the detection of endogenous NAD(P)H photoacoustic signals in brain slices to 700μm depth and in cerebral organoids to 1100μm depth.Finally,we developed and demonstrated simultaneous photoacoustic and optical imaging of NAD(P)H in brain cells with a real-time image acquisition and processing pipeline.This approach could open a new door to monitor brain metabolic changes during development and disease,and changes due to neuronal activity,at single-cell level deep in the brains of both humans and animals.展开更多
A new optical microscopy technique,termed high spatial and temporal resolution synthetic aperture phase microscopy(HISTR-SAPM),is proposed to improve the lateral resolution of wide-field coherent imaging.Under plane w...A new optical microscopy technique,termed high spatial and temporal resolution synthetic aperture phase microscopy(HISTR-SAPM),is proposed to improve the lateral resolution of wide-field coherent imaging.Under plane wave illumination,the resolution is increased by twofold to around 260 nm,while achieving millisecond-level temporal resolution.In HISTR-SAPM,digital micromirror devices are used to actively change the sample illumination beam angle at high speed with high stability.An off-axis interferometer is used to measure the sample scattered complex fields,which are then processed to reconstruct high-resolution phase images.Using HISTR-SAPM,we are able to map the height profiles of subwavelength photonic structures and resolve the period structures that have 198 nm linewidth and 132 nm gap(i.e.,a full pitch of 330 nm).As the reconstruction averages out laser speckle noise while maintaining high temporal resolution,HISTR-SAPM further enables imaging and quantification of nanoscale dynamics of live cells,such as red blood cell membrane fluctuations and subcellular structure dynamics within nucleated cells.We envision that HISTR-SAPM will broadly benefit research in material science and biology.展开更多
Limited throughput is a key challenge in in vivo deep tissue imaging using nonlinear optical microscopy.Point scanning multiphoton microscopy,the current gold standard,is slow especially compared to the widefield imag...Limited throughput is a key challenge in in vivo deep tissue imaging using nonlinear optical microscopy.Point scanning multiphoton microscopy,the current gold standard,is slow especially compared to the widefield imaging modalities used for optically cleared or thin specimens.We recently introduced“De-scattering with Excitation Patterning”or“DEEP”as a widefield alternative to point-scanning geometries.Using patterned multiphoton excitation,DEEP encodes spatial information inside tissue before scattering.However,to de-scatter at typical depths,hundreds of such patterned excitations were needed.In this work,we present DEEP2,a deep learning-based model that can de-scatter images from just tens of patterned excitations instead of hundreds.Consequently,we improve DEEP’s throughput by almost an order of magnitude.We demonstrate our method in multiple numerical and experimental imaging studies,including in vivo cortical vasculature imaging up to 4 scattering lengths deep in live mice.展开更多
Resolving three-dimensional morphological features in thick specimens remains a significant challenge for label-free imaging.We report a new speckle diffraction tomography(SDT)approach that can image thick biological ...Resolving three-dimensional morphological features in thick specimens remains a significant challenge for label-free imaging.We report a new speckle diffraction tomography(SDT)approach that can image thick biological specimens with~500 nm lateral resolution and~1μm axial resolution in a reflection geometry.In SDT,multiple-scattering background is rejected through spatiotemporal gating provided by dynamic speckle-field interferometry,while depth-resolved refractive index maps are reconstructed by developing a comprehensive inverse-scattering model that also considers specimen-induced aberrations.Benefiting from the high-resolution and full-field quantitative imaging capabilities of SDT,we successfully imaged red blood cells and quantified their membrane fluctuations behind a turbid medium with a thickness of 2.8 scattering mean-free paths.Most importantly,we performed volumetric imaging of cornea inside an ex vivo rat eye and quantified its optical properties,including the mapping of nanoscale topographic features of Dua’s and Descemet’s membranes that had not been previously visualized.展开更多
基金PTCSO acknowledges support from:NII 9P41EB015871-26A1,R01-EX017656,5 R01 NS051320,4R.44EB012415-02,NSF CBET-0939511,the Sin-gapore-MIT Alliance 2 and the MIT SkolTech in-itiativeEYYS issupported by the National Research Foundation Singapore through the Singapore MIT Alliance for Research and Technology's Bio Symresearch programmeCJR is funded by a Wellcome Trust,MIT Pastdoctoral Research Fellow ship 093831/Z/10/Z.
文摘This review summarizes the historical and more recent developments of multiphoton microscopy,as applied to dermatology.Multiphoton microscopy offers several advantages over competingmicroscopy techniques:there is an inherent axial sectioning,penetration depths that competewll with confocal microscopy on account of the use of near-infrared light,and many t wo-pho ton contrast mechanisms,such as second-harmonic generation,have no analogue in one-photonmicroscopy.While the penetration depths of photons into tissue are typically limited on the orderof hundreds of microns,this is of les concern in dermatology,as the skin is thin and readlily.accessible.As a result,multiphoton microscopy in dermatology has generated a great deal ofmterest,much of which is summarized here.The review covers the interaction of light and tissue,as well as the various considerations that must be made when designing an instrument.The stateof multiphoton microscopy in imaging skin cancer and various other diseases is also discussed,along with the investigation of aging and regeneration phenomena,and finally,the use of mul-tiphoton microscopy to analyze the transdermal transport of drugs,cosmetics and other agents issummarized.The review concludes with a look at potential future research directions,especiallythose that are necessary to push these techniques into widespread clinical acceptance.
基金T.O.was supported by NIH grant R01MH085802(MS).W.D.L.Was supported by the Peter So Lab and the Simons Center for the Social Brain(M.S.)R.Z.was supported by the NIH training grant TL1DK143273+1 种基金Experiments and equipment were supported by NIH grants R01MH085802,R01NS130361,and R01MH133066the Picower Institute Innovation Fund(M.S.).
文摘Label-free detection of biological events at single-cell resolution in the brain can non-invasively capture brain status for medical diagnosis and basic neuroscience research.NADH is an universal coenzyme that not only plays a central role in cellular metabolism but may also be used as a biomarker to capture metabolic processes in brain cells and structures.We have developed a new label-free,multiphoton photoacoustic microscope(LF-MP-PAM)with a near-infrared femtosecond laser to observe endogenous NAD(P)H in living cells.The imaging depth of NAD(P)H in tissues with all-optical methods is limited to~100μm in brain tissue by the strong absorption of the near-ultraviolet fluorescence.Here,acoustic detection of the thermal signature of multi-photon(three-photon)excitation of NAD(P)H,a low quantum yield fluorophore,allows detection at an unprecedented depth while the focused excitation ensures high spatial resolution.We validated the photoacoustic detection of NAD(P)H by monitoring an increase in intracellular NAD(P)H in HEK293T cells and HepG2 cells incubated in NADH solution.We also demonstrated the detection of endogenous NAD(P)H photoacoustic signals in brain slices to 700μm depth and in cerebral organoids to 1100μm depth.Finally,we developed and demonstrated simultaneous photoacoustic and optical imaging of NAD(P)H in brain cells with a real-time image acquisition and processing pipeline.This approach could open a new door to monitor brain metabolic changes during development and disease,and changes due to neuronal activity,at single-cell level deep in the brains of both humans and animals.
基金We acknowledge financial support from Hong Kong Innovation and Technology Fund(Nos.ITS/394/17 and ITS/098/18FP)Shun Hing Institute of Advanced Engineering(No.BME-p3-18)Croucher Innovation Awards 2019,and the U.S.National Institutes of Health(No.5P41EB015871-33).
文摘A new optical microscopy technique,termed high spatial and temporal resolution synthetic aperture phase microscopy(HISTR-SAPM),is proposed to improve the lateral resolution of wide-field coherent imaging.Under plane wave illumination,the resolution is increased by twofold to around 260 nm,while achieving millisecond-level temporal resolution.In HISTR-SAPM,digital micromirror devices are used to actively change the sample illumination beam angle at high speed with high stability.An off-axis interferometer is used to measure the sample scattered complex fields,which are then processed to reconstruct high-resolution phase images.Using HISTR-SAPM,we are able to map the height profiles of subwavelength photonic structures and resolve the period structures that have 198 nm linewidth and 132 nm gap(i.e.,a full pitch of 330 nm).As the reconstruction averages out laser speckle noise while maintaining high temporal resolution,HISTR-SAPM further enables imaging and quantification of nanoscale dynamics of live cells,such as red blood cell membrane fluctuations and subcellular structure dynamics within nucleated cells.We envision that HISTR-SAPM will broadly benefit research in material science and biology.
基金supported by the Center for Advanced Imaging at Harvard University(D.N.W.,N.W.,M.A.)5-P41EB015871-32(D.N.W.,P.T.C.S.)+3 种基金R21 MH130067(P.T.C.S.,D.N.W.)R21 NS105070(P.T.C.S.)R00EB027706(M.Y.)supported by the John Harvard Distinguished Science Fellowship Program within the FAS Division of Science of Harvard University.
文摘Limited throughput is a key challenge in in vivo deep tissue imaging using nonlinear optical microscopy.Point scanning multiphoton microscopy,the current gold standard,is slow especially compared to the widefield imaging modalities used for optically cleared or thin specimens.We recently introduced“De-scattering with Excitation Patterning”or“DEEP”as a widefield alternative to point-scanning geometries.Using patterned multiphoton excitation,DEEP encodes spatial information inside tissue before scattering.However,to de-scatter at typical depths,hundreds of such patterned excitations were needed.In this work,we present DEEP2,a deep learning-based model that can de-scatter images from just tens of patterned excitations instead of hundreds.Consequently,we improve DEEP’s throughput by almost an order of magnitude.We demonstrate our method in multiple numerical and experimental imaging studies,including in vivo cortical vasculature imaging up to 4 scattering lengths deep in live mice.
基金S.K.,Y.L.,P.T.C.S.,and Z.Y.acknowledge support from National Institutes of Health(NIH)funding 5-P41-EB015871-27 and Hamamatsu CorporationP.T.C.S.further acknowledges support from the Singapore-Massachusetts Institute of Technology Alliance for Research and Technology(SMART)Center,Critical Analytics for Manufacturing Personalized-Medicine IRG.P.T.C.S.and Z.Y.further acknowledge support from NIH R01DA045549,R21GM140613-02,R01HL158102.R.Z.acknowledges support from Croucher Innovation Awards 2019(Grant No.CM/CT/CF/CIA/0688/19ay)+2 种基金Hong Kong Innovation and Technology Commission(ITS/148/20 and ITS/178/20FP)Hong Kong General Research Fund(14209521)The Chinese University of Hong Kong Research Sustainability of Major RGC Funding Schemes-Strategic Areas.
文摘Resolving three-dimensional morphological features in thick specimens remains a significant challenge for label-free imaging.We report a new speckle diffraction tomography(SDT)approach that can image thick biological specimens with~500 nm lateral resolution and~1μm axial resolution in a reflection geometry.In SDT,multiple-scattering background is rejected through spatiotemporal gating provided by dynamic speckle-field interferometry,while depth-resolved refractive index maps are reconstructed by developing a comprehensive inverse-scattering model that also considers specimen-induced aberrations.Benefiting from the high-resolution and full-field quantitative imaging capabilities of SDT,we successfully imaged red blood cells and quantified their membrane fluctuations behind a turbid medium with a thickness of 2.8 scattering mean-free paths.Most importantly,we performed volumetric imaging of cornea inside an ex vivo rat eye and quantified its optical properties,including the mapping of nanoscale topographic features of Dua’s and Descemet’s membranes that had not been previously visualized.
