1. Articles from Zhouyi Guo

    1-24 of 24
    1. Carbon Dots with Intrinsic Bioactivities for Photothermal Optical Coherence Tomography, tumor-specific Therapy and Postoperative Wound Management

      Carbon Dots with Intrinsic Bioactivities for Photothermal Optical Coherence Tomography, tumor-specific Therapy and Postoperative Wound Management

      Carbon dots (CDs) have been considered as promising candidates with superior biocompatibilities for multimodel cancer theranostics. However, incorporation of exogenous components, such as targeting molecules and chemo/photo therapeutic drugs, are often required to improve the therapeutic efficacy. Herein, we propose an "all-in-one" CDs that exhibit intrinsic bioactivities for bioimaging, potent tumor therapy and postoperative management. The multifunctional CDs derived from gallic acid and tyrosine (GT-CDs) consist of a graphitized carbon core and N, O-rich functional groups, which endow them with a high near-infrared photothermal conversion efficiency of 33.9% and tumor-specific cytotoxicity, respectively. A new imaging modality, photothermal optical ...

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    2. The effects of electrical pulses-mediated gold and silver nanoparticles on the optical properties of ex vivo human femoral head tissue with optical coherence tomography

      The effects of electrical pulses-mediated gold and silver nanoparticles on the optical properties of ex vivo human femoral head tissue with optical coherence tomography

      This study aims to monitor and assess the penetration and accumulation of gold nanoparticles (Au NPs) or silver nanoparticles (Ag NPs) (average particle size 40 nm) and the penetration of the Au NPs or Ag NPs assisted by electrical impulses (EP) in human normal femoral head (NFH) and pathological femoral head (PFH) tissues. The results show that optical coherence tomography images can easily distinguish NFH from PFH tissues. The control group show that the average attenuation coefficient of NFH tissue is 4.895 mm −1 , and the average attenuation coefficient of PFH tissue is 8.094 mm −1 . It shows ...

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    3. Redox responsive nanoparticle encapsulating black phosphorus quantum dots for cancer theranostics

      Redox responsive nanoparticle encapsulating black phosphorus quantum dots for cancer theranostics

      Effective cancer treatment puts high demands for cancer theranostics. For cancer diagnostics, optical coherence tomography (OCT) technology (including photothermal optical coherence tomography (PT-OCT)) has been widely investigated since it induces changes in optical phase transitions in tissue through environmental changes (such as temperature change for PT-OCT). In this report, redox responsive nanoparticle encapsulating black phosphorus quantum dots was developed as a robust PT-OCT agent. Briefly, black phosphorus quantum dots (BPQDs) are incorporated into cysteine-based poly-(disulfide amide) (Cys-PDSA) to form stable and biodegradable nanoagent. The excellent photothermal feature allows BPQD/Cys-PDSA nanoparticles (NPs) as a novel contrast agent for high-resolution ...

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    4. A Correlation Study between Two Adjacent Same-Meridian Acupoints after Laser-Needle Acupuncture with Optical Coherence Tomography and Diffuse Reflectance Spectra

      A Correlation Study between Two Adjacent Same-Meridian Acupoints after Laser-Needle Acupuncture with Optical Coherence Tomography and Diffuse Reflectance Spectra

      This study is to investigate the correlations among Sanjian (LI3), Hegu (LI4), and Yangxi (LI5) acupoints and their corresponding nonacupoints on the Yangming Large Intestine Meridian of Hand before and after laser irradiation using optical coherence tomography (OCT) and diffuse reflectance spectra. The experiment was conducted on 10 healthy people. A 658 nm laser with 50 mW output power was used for irradiating LI4, LI5 acupoints and their corresponding nonacupoints. As to LI4 acupoint with laser irradiation for duration of 15 or 45 minutes, the OCT backscattered light intensities of LI4 and LI5 acupoints increased significantly, and the reflectance intensities ...

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    5. In Vivo Detection of the Effect of Electroacupuncture on “Zusanli” Acupoint in Rats with Adjuvant-Induced Arthritis through Optical Coherence Tomography

      In Vivo Detection of the Effect of Electroacupuncture on “Zusanli” Acupoint in Rats with Adjuvant-Induced Arthritis through Optical Coherence Tomography

      This study aimed to investigate the effect of electroacupuncture (EA) treatment through optical coherence tomography (OCT) in vivo on rats with adjuvant-induced arthritis. OCT images were obtained from the ankle of the right hind paws of the rats in control, model, and EA groups before modelling and 1 day, 8 days, 15 days, 22 days, and 29 days after modelling. Results demonstrated that the OCT signal of the ankle of the right hind paws of the rats was indistinct compared to 1 day after modelling and before modelling in the EA group. In the EA group, the light averaged attenuation ...

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    6. Polyaniline nanoparticles: potential optical coherence tomography contrast agents

      Polyaniline nanoparticles: potential optical coherence tomography contrast agents

      Polyaniline, an organic conducting polymer, exhibits strong light absorption in the near-infrared region. Herein, the potential of polyaniline nanoparticles as the contrast agents for optical coherence tomography imaging was investigated. Polyaniline nanoparticles were synthesized by a facile chemical oxidative method. The optical coherence tomography images obtained from ex vivo swine liver tissues showed the concentration-dependent contrast effect of polyaniline nanoparticles. Then the nanoagents were applied to in vivo optical coherence tomography imaging of tumor tissues using a xenograft tumor mouse model. The penetration depth of the optical coherence tomography signals from tumors injected with polyaniline nanoparticles was significantly lower than ...

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    7. Effects of titanium dioxide nanoparticles coupled with diode laser on optical properties of in vitro normal and cancerous human lung tissues studied with optical coherence tomography and diffuse reflectance spectra

      Effects of titanium dioxide nanoparticles coupled with diode laser on optical properties of in vitro normal and cancerous human lung tissues studied with optical coherence tomography and diffuse reflectance spectra

      The objective is to investigate the effects of two different sized (60 and 100 nm) titanium dioxide ( TiO 2 ) nanoparticles (NPs) penetration and accumulation in in vitro human normal lung (NL) tissue, lung squamous cell carcinoma (LSCC) tissue, and 650-nm diode laser-pretreated tissue on their optical properties studied with optical coherence tomography monitoring and diffuse reflectance (DR) spectra measurement. As with TiO 2 NPs penetrating into the tissues, the intensities of DR of the samples increase, and then the enhancements of DR and the attenuation coefficients of the tissues were quantitatively calculated. The results suggest that 650-nm diode laser pretreatment ...

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    8. Influence of nanoparticles accumulation on optical properties of human normal and cancerous liver tissue in vitro estimated by OCT

      Influence of nanoparticles accumulation on optical properties of human normal and cancerous liver tissue in vitro estimated by OCT

      In this work, the potential use of nanoparticles as contrast agents by using spectral domain optical coherence tomography (SD-OCT) in liver tissue was demonstrated. Gold nanoparticles (average size of 25 and 70 nm), were studied in human normal and cancerous liver tissues in vitro , respectively. Each sample was monitored with SD-OCT functional imaging for 240 min. Continuous OCT monitoring showed that, after application of gold nanoparticles, the OCT signal intensities of normal liver and cancerous liver tissue both increase with time, and the larger nanoparticles tend to produce a greater signal enhancement in the same type of tissue. The results ...

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    9. Monitoring of permeability of different analytes in human normal and cancerous bladder tissues invitro using optical coherence tomography

      Monitoring of permeability of different analytes in human normal and cancerous bladder tissues invitro using optical coherence tomography

      We report our preliminary results on quantification of glucose and dimethyl sulfoxide (DMSO) diffusion in normal and cancerous human bladder tissues in vitro by using a spectral domain optical coherence tomography (SD-OCT). The permeability coefficients (PCs) of a 30% aqueous solution of glucose are found to be (7.92 ± 0.81) × 10 -6 cm s -1 and (1.19 ± 0.13) × 10 -5 cm s -1 in normal and cancerous bladder tissues, respectively. The PCs of 50% DMSO are calculated to be (8.99 ± 0.93) × 10 -6 cm s -1 and (1.43 ± 0.17) × 10 -5 cm s ...

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    10. In vitro assessment of effects of hyperglycemia on the optical properties of blood during coagulation using optical coherence tomography

      In vitro assessment of effects of hyperglycemia on the optical properties of blood during coagulation using optical coherence tomography

      No published reports have demonstrated the capability of the optical coherence tomography technique for quantifying the optical coherence tomography signal slope, 1/e light penetration depth, and attenuation coefficient of hyperglycemic blood by an in vitro assessment. The purpose of this study was to investigate the effects of hyperglycemia on optical properties during in vitro blood coagulation by optical coherence tomography. Normal whole blood acted as the control group. After 1-h coagulation, the average optical coherence tomography signal slope decreased approximately 23.3 and 16.7 %, and the 1/e light penetration depths increased approximately 21.5 and 19.2 ...

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    11. Continuous noninvasive monitoring of changes in human skin optical properties during oral intake of different sugars with optical coherence tomography

      Continuous noninvasive monitoring of changes in human skin optical properties during oral intake of different sugars with optical coherence tomography

      The objective of this study was to evaluate the effects of blood glucose concentration (BGC) on in vivo human skin optical properties after oral intake of different sugars. In vivo optical properties of human skin were measured with a spectral domain optical coherence tomography (SD-OCT). Experimental results show that increase of BGC causes a decrease in the skin attenuation coefficient. And the maximum decrements in mean attenuation coefficient of skin tissue after drinking glucose, sucrose and fructose solution are 47.0%, 36.4% and 16.5% compared with that after drinking water, respectively (p < 0.05). The results also show ...

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    12. Assessment of the effects of ultrasound-mediated glucose on permeability of normal, benign, and cancerous human lung tissues with the Fourier-domain optical coherence tomography

      Assessment of the effects of ultrasound-mediated glucose on permeability of normal, benign, and cancerous human lung tissues with the Fourier-domain optical coherence tomography

      The objective of this study was to evaluate the effects of ultrasound-mediated analyte diffusion on permeability of normal, benign, and cancerous human lung tissue in vitro and to find more effective sonophoretic (SP) delivery in combination with the optical clearing agents (OCAs) method to distinguish normal and diseased lung tissues. The permeability coefficients of SP in combination with OCAs diffusion in lung tissue were measured with Fourier-domain optical coherence tomography (FD-OCT). 30% glucose and SP with a frequency of 1 MHz and an intensity of 0.80     W / cm 2 over a 3 cm probe was simultaneously applied for 15 ...

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    13. Quantification of Glucose Diffusion in Human Lung Tissues by Using Fourier Domain Optical Coherence Tomography

      Quantification of Glucose Diffusion in Human Lung Tissues by Using Fourier Domain Optical Coherence Tomography

      In this study, we report permeability coefficients of 30% glucose diffusion by the optical coherence tomography signal slope (OCTSS) method in four kind of human lung tissue in vitro: normal lung tissue, benign granulomatosis lung tissue, squamous cell carcinoma, and adenocarcinoma tumor. To quantify the permeability coefficient of the agent, the monitored region was the 80 um thickness at a tissue depth of approximately 230 um from the surface. The permeability coefficients of 30% glucose from 10 independent experiments were averaged and found to be (1.35 ± 0.13)×10 −5 cm/s from the normal lung tissue, (1.78 ...

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    14. Depth-resolved monitoring of diffusion of hyperosmotic agents in normal and malignant human esophagus tissues using optical coherence tomography in-vitro

      Depth-resolved monitoring of diffusion of hyperosmotic agents in normal and malignant human esophagus tissues using optical coherence tomography in-vitro

      Depth-resolved monitoring with differentiation and quantification of glucose diffusion in healthy and abnormal esophagus tissues has been studied in vitro. Experiments have been performed using human normal esophagus and esophageal squamous cell carcinoma (ESCC) tissues by the optical coherence tomography (OCT). The images have been continuously acquired for 120 min in the experiments, and the depth-resolved and average permeability coefficients of the 40 % glucose solution have been calculated by the OCT amplitude (OCTA) method. We demonstrate the capability of the OCT technique for depth-resolved monitoring, differentiation, and quantifying of glucose diffusion in normal esophagus and ESCC tissues. It is found ...

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    15. Monitoring skin photodamage using quantitative optical coherence tomography

      Monitoring skin photodamage using quantitative optical coherence tomography
      Noninvasive, real-time imaging technology assists UV light therapy of skin diseases and facilitates reduction of the associated photodamage. In clinical medicine, 8-methoxypsoralen (8-MOP) combined with ultraviolet A (UVA; 320–400nm) (PUVA) therapy is an effective and widely used treatment for several types of dermatose, including psoriasis, mycosis fungoides, and vitiligo. However, many studies have shown that PUVA has both potent mutagenic and carcinogenic effects and also immunosuppressive consequences. The latter can allow tumor development or changes to the immune function in both immuno-suppressed and healthy individuals.1,2 Long-term PUVA therapy significantly increases the risk of skin-cancer development.3,4
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    16. In Vivo Comparison of the Optical Clearing Efficacy of Optical Clearing Agents in Human Skin by Quantifying Permeability Using Optical Coherence Tomography

      In Vivo Comparison of the Optical Clearing Efficacy of Optical Clearing Agents in Human Skin by Quantifying Permeability Using Optical Coherence Tomography

      The objective of the present work is to quantify and compare the optical clearing efficacy of glucose, propylene glycol, glycerol solutions through the human skin tissue in vivo by calculating permeability coefficient of three solutions. Currently, the permeability coefficient of agent in tissues was extracted from OCT amplitude data mainly through the OCT signal slope (OCTSS) and the OCT amplitude (OCTA) methods. In this study, we report the OCT attenuation coefficient (OCTAC) method which is relatively novel and rarely reported methodology to measure the permeability coefficient during the optical skin clearing procedure. The permeability coefficients for 40% propylene glycol, glucose ...

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    17. Quantitative optical coherence tomography of skin lesions induced by different ultraviolet B sources

      Quantitative optical coherence tomography of skin lesions induced by different ultraviolet B sources

      Ultraviolet B (UVB) has been widely used in dermatological phototherapy. Narrowband UVB (NB-UVB), with a peak at 311 nm, is considered to be more effective than broadband UVB (BB-UVB). However, the safety of NB-UVB is controversial. In this study, we first introduced optical coherence tomography (OCT), a novel, non-invasive in vivo imaging technology, to assess the effect of NB-UVB and BB-UVB on skin. Balb/c mice dorsal skin was exposed with increasing UVB doses (1MED, 3MEDs and 5MEDs), and then OCT images of the tissues were obtained by an OCT system with 1310 nm central wavelength. Quantitative parameters (skin thickness ...

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    18. In vitro study of ultrasound and different-concentration glycerolinduced changes in human skin optical attenuation assessed with optical coherence tomography

      In vitro study of ultrasound and different-concentration glycerolinduced changes in human skin optical attenuation assessed with optical coherence tomography

      Previous studies have demonstrated the ultrasound-induced skin optical clearing enhancement with topical application of 60% glycerol (G) on in vitro porcine skin and in vivo human skin. Our purpose was to find the relation between the effect of optical skin clearing and different concentrations of glycerol and to find more effective ultrasound-glycerol combinations on optical skin clearing. The enhancement effect of ultrasound [Sonophoresis (SP) delivery] in combination with 40% G, 60% G, and 80% G on in vitro human skin optical clearing was investigated. Light imaging depths of skin were measured using optical coherence tomography. Different concentrations of glycerol and ...

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    19. Synergistic Effect of Ultrasound and Thiazone–PEG 400 on Human Skin Optical Clearing In Vivo

      Synergistic Effect of Ultrasound and Thiazone–PEG 400 on Human Skin Optical Clearing In Vivo

      In this paper, we propose a new physical method in combination with mixed solution of thiazone and polyethylene glycol 400 (thiazone PEG 400 solution) penetration into tissue to assess the skin optical clearing. Four treatments were performed: (1) control group (C); (2) polyethylene glycol 400 (PEG400); (3) 0.25% thiazone (0.25%T); (4) 0.25% thiazone and 5-min ultrasound (0.25%T/SP). The diffuse reflectance spectra and imaging depth of human skin in vivo at different times were measured by spectroscopy and optical coherence tomography (OCT). The optical clearing efficacy of skin was qualitatively and quantitatively analyzed. The ...

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    20. Quantitative analysis on PUVA-induced skin photodamages using optical coherence tomography

      Psoralen plus ultraviolet A radiation (PUVA) therapy is a very important clinical treatment of skin diseases such as vitiligo and psoriasis, but associated with an increased risk of skin photodamages especially photoaging. Since skin biopsy alters the original skin morphology and always requires an iatrogenic trauma, optical coherence tomography (OCT) appears to be a promising technique to study skin damage in vivo. In this study, the Balb/c mice had 8-methoxypsralen (8-MOP) treatment prior to UVA radiation was used as PUVA-induced photo-damaged modal. The OCT imaging of photo-damaged group (modal) and normal group (control) in vivo was obtained of mice ...
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    21. Assessment of the effect of narrowband UVB and broadband UVB on mice skin using optical coherence tomography

      Ultraviolet B (UVB) has been used in dermatological phototherapy widely. Narrowband UVB (NB-UVB), with a peak at 311nm, is considered more effective than broadband UVB (BB-UVB). However, the safety of NB-UVB is controversial. Optical coherence tomography (OCT), a novel, non-invasive and depth-resolved imaging technology, is a useful tool for detection of the skin structure in vivo. This study assessed the effect of NB-UVB and BB-UVB on the skin using OCT for the first time. In this study, Balb/c mouse model was surveyed by an OCT system with 1310 nm central wavelength. The two UVB sources were applied on mice ...
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    22. Application of hyperosmotic agent to determine gastric cancer with optical coherence tomography ex vivo in mice

      Noninvasive tumor imaging could lead to the early detection and timely treatment of cancer. Optical coherence tomography (OCT) has been reported as an ideal diagnostic tool for distinguishing tumor tissues from normal tissues based on structural imaging. In this study, the capability of OCT for functional imaging of normal and tumor tissues based on time- and depth-resolved quantification of the permeability of biomolecules through these tissues is investigated. The orthotopic graft model of gastric cancer in nude mice is used, normal and tumor tissues from the gastric wall are imaged, and a diffusion of 20% aqueous solution of glucose in ...
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    23. Potential ability of hematoporphyrin to enhance an optical coherence tomographic image of gastric cancer in vivo in mice

      Abstract. An ideal diagnostic system for the tumor tissues should be able to detect and define the location of tumor tissues and the early development of malignant diseases. There is great need for enhancement of imaging ability to tumor tissues. Optical coherence tomography (OCT) is used in detection and location of varied tumor tissues. In order to improve the sensitivity and specificity of an OCT image, hematoporphyrin as a new type of contrast agent was used in this study. The orthotopic graft model of gastric cancer in nude mice was used. The image formations of the tumor tissues without and ...

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    24. Quantitative analysis on tongue inspection in traditional Chinese medicine using optical coherence tomography

      Tongue inspection (TI) is an important and unique diagnostic method in traditional Chinese medicine (TCM), because significant connections between various viscerae diseases and abnormalities in the tongue have been verified. In TCM, TI is simple and non invasive, but in clinical applications, TI is subjectively based on the experience and technique of physicians. To avoid this problem, optical coherence tomography (OCT) imaging is introduced here for TI. We study OCT imaging in rats in vivo from chronic gastritis group (model) and normal group (control) and quantitatively analyze the relative parameters, such as the thickness and the moisture degree of TI ...

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    1-24 of 24
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    Synergistic Effect of Ultrasound and Thiazone–PEG 400 on Human Skin Optical Clearing In Vivo In vitro study of ultrasound and different-concentration glycerolinduced changes in human skin optical attenuation assessed with optical coherence tomography Quantitative optical coherence tomography of skin lesions induced by different ultraviolet B sources In Vivo Comparison of the Optical Clearing Efficacy of Optical Clearing Agents in Human Skin by Quantifying Permeability Using Optical Coherence Tomography Monitoring skin photodamage using quantitative optical coherence tomography Depth-resolved monitoring of diffusion of hyperosmotic agents in normal and malignant human esophagus tissues using optical coherence tomography in-vitro Quantification of Glucose Diffusion in Human Lung Tissues by Using Fourier Domain Optical Coherence Tomography Influence of scan direction on subfoveal choroidal vascularity index using optical coherence tomography Subthreshold Nanosecond Laser for Non-resolving Central Serous Chorioretinopathy: A Double-masked Sham-controlled Randomised Trial Optical Coherence Tomography Angiography (OCTA) to Assess Cardiac Output and Cerebral Perfusion at the Time of Children's Cardiac Surgery Recent advances in optical coherence tomography for anterior segment imaging in small animals and their clinical implications Intraoperative optical coherence tomography-guided donor corneal tissue assessment and preparation