Reduction of photodynamic damage of blood vessels in the protected region by(–)-epigallocatechin gallate

Photodynamic therapy(PDT)has been increasingly used in the clinical treatment of neoplastic,inflammatory and infectious skin diseases.However,the generation of reactive oxygen species(ROS)may induce undesired side effects in normal tissue surrounding the treatment lesion,which is a big challenge for the clinical application of PDT.To date,(–)-Epigallocatechin gallate(EGCG)has been widely proposed as an antiangiogenic and antitumor agent for the protection of normal tissue from ROS-mediated oxidative damage.This study evaluates the regulation ability of EGCG for photodynamic damage of blood vessels during hematoporphyrin monomethyl ether(Hemoporfin)-mediated PDT.The quenching rate constants of EGCG for the triplet-state Hemoporfin and photosensitized 1O2 generation are determined to be 6.8×10^(8)M^(−1)S^(−1),respectively.The vasoconstriction of blood vessels in the protected region treated with EGCG hydrogel after PDT is lower than that of the control region treated with pure hydrogel,suggesting an efficiently reduced photodamage of Hemoporfin for blood vessels treated with EGCG.This study indicates that EGCG is an efficient quencher for triplet-state Hemoporfin and 1O2,and EGCG could be potentially used to reduce the undesired photodamage of normal tissue in clinical PDT.

Gastroscopy-conjugated photoacoustic and ultrasonic dual-mode imaging for detection of submucosal gastric cancer:in vitro study

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.

SINGLET OXYGEN QUANTUM YIELDS OF PORPHYRIN-BASED PHOTOSENSITIZERS FOR PHOTODYNAMIC THERAPY

The major cytotoxic agent with most current photosensitizers used in photodynamic therapy(PDT)is widely believed to be singlet oxygen(^(1)O_(2)).Determination of the ^(1)O_(2) quantum yields for porphyrin-based photosensitizers,including hematoporphyrin derivative(HiPorfin),hematoporphyrin monomethyl ether(HMME)and photocarcinorin(PsD-007)in air-saturated dimethylformamide(DMF)solutions were performed by the direct measurement of their near-infrared luminescence.In addition,^(1)O_(2) quencher sodium azide was employed to confirm the ^(1)O_(2) generation from the investigated photosensitizers.The maximal ^(1)O_(2) luminescence occurs at about 1280 nm with full width at half maximum of 30 nm.The ^(1)O_(2) quantum yields were found to be 0.61±0.03,0.60±0.02 and 0.59±0.03 for HiPorfin,HMME and PsD-007,respectively.These results provide that these porphyrin-based photosensitizers produce ^(1)O_(2) under irradiation,which is of significance for the study of their photodynamic action in PDT.

Scanning photoacoustic imaging of submucosal gastric tumor based on a long focused transducer in phantom and in vitro experiments

Photoacoustic imaging,which can provide the maximum intensity contrast in tissue depth imaging without ionizing radiation,will be a promising imaging trend for tumor detection.In this paper,a column diffusionfiber was employed to carry a pulsed laser for irradiating stomach directly through esophagus based on the characteristics of gastric tissue structure.A long focused ultrasonic transducer was placed outside the body to detect photoacoustic signals of gastric tissue.Phantom and in vitro experiments of submucosal gastric tumors were carried out to check the sensitivity of scanning photoacoustic tomography system,including the lateral and longitudinal resolution of the system,sensitivity of different absorption coefficient in imaging,capability of transversal detection,and probability of longitudinal detection.The results demonstrate that our innovative technique can improve the parameters of imaging.The lateral resolution reaches 2.09 mm.Then a depth of 5.5mm with a longitudinal accuracy of 0.36mm below gastric mucosa of early gastric cancer(EGC)has been achieved.In addition,the optimal absorption coefficient differences among absorbers of system are 3.3-3.9 times.Results indicate that our photoacoustic imaging(PAI)system,is based on a long focusing transducer,can provide a potential application for detecting submucosal EGC without obvious symptoms.

Second-harmonic generation as a DNA malignancy indicator of prostate glandular epithelial cells

This paper first demonstrates second-harmonic generation （SHG） in the intact cell nucleus, which acts as an optical indicator of DNA malignancy in prostate glandular epithelial cells. Within a scanning region of 2.7 μm×2.7μm in cell nuclei, SHG signals produced from benign prostatic hyperplasia （BPH） and prostate carcinoma （PC） tissues （mouse model C57BL/6） have been investigated. Statistical analyses （t test） of a total of 405 measurements （204 nuclei from BPH and 201 nuclei from PC） show that SHG signals from BPH and PC have a distinct difference （p 〈 0.05）, suggesting a potential optical method of revealing very early malignancy in prostate glandular epithelial cells based upon induced biochemical and/or biophysical modifications in DNA.

Correlation of in vivo tumor response and singlet oxygen luminescence detection in mTHPC-mediated photodynamic therapy

Excited-state singlet axygen(^(1)O_(2)),generated during photodynamic therapy(PDT),is believed to be the primary cytotoxic agent with a number of clinically approved photosensitizers.Its relative concentration in cells or tissues can be measured directly through its near-infrared(NIR)luminescence emission,which has correlated well with in vitro cell and in triro normal skin treatment responses.Here,its correlation with the response of tumor tiss1e in vito is examined,using the photosensitizer meso-tetralydroxyphenylchlorin(mTHPC)in an animal model comprising luciferase-and green fluorescent protein(GFP)-transduced gliosarcoma grown in a dorsal window chamber.The change in the bioluminescence signal,imaged pre-treatment and at 2,5 and 9 d post treatment,was used as a quantitative measure of the tumor response,which was classified in individual tumors as"non","moderate"and"strong"in order to reduce the variance in the data.Plotting the bioluminescence-based response vs the^(1)O_(2)counts demonstrated clear correlation,indicating tha^(1)O_(2)luminescence provides a valid do-simetric technique for PDT in tumor tissue.

Beam Parameters for End Diffraction of TE_0 Mode of Planar Waveguide

在绕射的横梁参数和规范的频率之间的关系被分析那为分叉角度以及横梁繁殖因素为二种模式地一半宽度和几个公式导致二个改进公式。数字计算显示最大的相对错误在一个合理参数范围以内是不到 0.5% 。

Analysis on Far-Field of Slab Waveguide and Its Gaussian Approximation

这篇论文研究平板波导然后匹配的效率在之间的结束衍射远地并且它的 Gaussian 近似的地被分析导致分叉一半角度的一个新定义。最后，远地的罐头为什么被 Gaussian 功能接近，根据横梁繁殖因素的特征被介绍。

MULTIPHOTON MICROSCOPIC IMAGING OF MOUSE INTESTINAL MUCOSA BASED ON TWO-PHOTON EXCITED FLUORESCENCE AND SECOND HARMONIC GENERATION

Multiphoton microscopy(MPM),based on two-photon excited fuorescence and second harmonic generation,enables direct noninvasive visualization of tissue architecture and cell morphology in live tissues without the administration of exogenous contrast agents.In this paper,we used MPM to image the microstructures of the mucosa in fresh,unfixed,and unstained intestinal tissue of mouse.The morphology and distribution of the main components in mucosa layer such as columnar cells,goblet cells,intestinal glands,and a little collagen fibers were clearly observed in MPM images,and then compared with standard H&:E images from paired specimens.Our results indicate that MPM combined with endoscopy and miniaturization probes has the potential application in the clinical diagnosis and in vivo monitoring of early intestinal cancer.

Mode-field half-widths of Gaussian approximation for the fundamental mode of two kinds of optical waveguides

This paper analyzes the characteristic of matching efficiency between the fundamental mode of two kinds of optical waveguides and its Gaussian approximate field.Then, it presents a new method where the mode-field half-width of Caussian approximation for the fundamental mode should be defined according to the maximal matching efficiency method. The relationship between the mode-field half-width of the Gaussian approximate field obtained from the maximal matching efficiency and normalized frequency is studied; furthermore, two formulas of mode-field half-widths as a function of normalized frequency are proposed.

CHARACTERIZING FLUORESCENCE LIFETIME OF NAD(P)H IN HUMAN LEUKEMIC MYELOID CELLS AND MONONUCLEAR CELLS

The aim of this er vito study was to explore the potential of using the fluorescence lifetime of intraellular reduced nicotinamide adenine dinucleotide(phosphate)(NAD(P)H)as a label-free indicator to characterize the di ferencs between human leukemic myeloid cells and normal mononuclear cells(MNC).The steady-state and time-resolved autofuorescence of two human leukemic myeloid cell lines(K562,HL60)and MNC were measured by a spectrofuorimeter.According to excitation-enmission matrix(EEM)analysis,the optimal emission of NAD(P)H in these cells suspensions occurred at 445 nm.Furthermore,the fuorescence lifetimes of NAD(P)H in leukemic myeloid cells and MNC were determined by fitting the time-resolved autofuorescence data.The mean fuorescence lifetimes of NAD(P)H in K562,HL60,and MNC cells were 557±1.19,4.45±0.71,and 7.31±0.60 ns,respectively.There was a significant diference in the mean lifetime of NAD(P)H between leukemic myeloid cells and MNC(p<0.05).The difference was essentally caused by the change in relative concentration of free and protein-bound NAD(P)H.This study suggests that the mean fuorescence lifetime of NAD(P)H might be a potential label-free indicator for differentiating leukemic myeloid cells from MNC.

Spectroscopic analysis of the interaction between tetra-(p-sulfoazophenyl-4-aminosulfonyl)-substituted aluminum(Ⅲ)phthalocyanines and serum albumins

The binding interaction between tetra-(p-sulfoazophenyl-4-aminosulfonyl)-substituted aluminum(Ⅲ)phthalocyanine(AIPc),and two-serum albumins(bovine serum albumin(BSA)and human serum albumin(HSA))has been investigated.AlPc could quench the intrinsic fuorescence of BSA and HSA through a static quenching process.The primary and secondary binding sites of AlPc on BSA were domainⅠandⅢof BSA.The primary binding site of AIPc on HSA was domainⅠ,and the secondary binding sites of AlPc on HSA were found at domainsⅠandⅡ.Our results suggest that AIPc readily interact with BSA and HSA implying that the amphiphilic substituents AIPc may contribute to their transportation in the blood.

Expression and contribution of microphthalmia-associated transcription factor to the melanin deposition in Liancheng white ducks

The present study investigates the expression of microphthalmia-associated transcription factor(MITF) and its contribution to the melanin deposition in Liancheng white ducks.Nested PCR was used to clone the MITF gene sequence from the skin tissue of female Liancheng white ducks.Ultraviolet spectrophotometry was used to detect the melanin deposition.MITF mRNA expression and melanin deposition in different tissues and organs were detected and their correlation was analyzed.The MITF gene(GenBank number: MG516570) was 1 323 bp in length,contains a complete CDS region(34-1 323 bp) and codes 429 amino acids with 100% homology to the MITF of Anas platyrhynchos and over 95% homology to those of Gallus gallus and Coturnix japonica.Genetic evolution analysis reveals a close relationship of Liancheng white ducks with A.platyrhynchos,and also to lesser extents with Anser cygnoides,silky fowl and G.gallus,as well as Sus scrofa,Ovis aries and other mammals.Real-time quantitative PCR(qPCR) analysis demonstrated that MITF was expressed in skin,gizzard,liver,kidney and muscle,and of these tissues,its expression was the highest in the skin tissue(skin>gizzard>liver>kidney>muscle).Ultraviolet spectrophotometry showed that melanin deposition was positively correlated with the MITF expression level in these five tissues and organs(P<0.05).Together,these results demonstrated a tissue-specific pattern of MITF expression and a positive correlation between MITF expression and melanin deposition,indicating that MITF expression may contribute to the melanin deposition in Liancheng white ducks.

COMPARISON OF AMINOLEVULINIC ACID AND ITS METHYL ESTER MEDIATED PHOTOCYTOTOXICITY ON HUMAN NASOPHARYNGEAL CARCINOMA CELLS

Nasopharyngeal carcinoma(NPC)is a prevalent cancer in some areas of southern Asia.To explore the potential of photodynamic therapy(PDT)for the treatment of NPC,a small molecule prodrug 5-aminolevulinic acid(ALA)and its methyl ester(MAL)mediated PDT was studied in vitro.The results showed that human NPC cells were sensitive to both ALA-and MAL-mediated PDT.However,ALA was more effective than MAL,possiblly due to a higher efficiency of ALA on producing endogenous protoporphyrin(PpIX)in NPC cells.Neither ALA nor MAL caused any significant genotoxicity.The ALA-based PDT might be a useful modality in the treatment ofNPC.

RAMAN SPECTROSCOPY OF HUMAN HEMOGLOBIN FOR DIABETES DETECTION

Glycat ed hemoglobin(HbAlc)has been increasingly accepted as the gold standard for diabetesmonit oring.In this study,Raman spect roso was tentatively emplo yed for human hemoglobin(b)bioc hemical analysis aimed at de veloping a a simple blood test for diabetes monitoring.Ramanspectroscopy measurementsperformed oWereglobimples of patients(n=39)withconfirmed diabetes and healthyvolulhetentatiassignments of the measuredRaman bands were perfortwogegroups.Meanwhile,principal componentaminant analysis(LDA)wereemployed to develop effective weell1ormal controls andpatients with diabetes.Asat wo groups demonstrated twodistinct clust ers with a sensitivity and specificity d 73%,respectively.Then the effectiveness of the diagnostic algorithm based onechnique was confirmed by receiveroperating characteristic(ROC)curve.The area under the ROC curve was 0.92,indicating a good diagnostic result.In summary,our preliminary results demonstrate that proposing Raman spectroscopy can provide a significant potential for the noninvasive detection of diabetes.

Effects of pulse width and repetition rate of pulsed laser on kinetics and production of singlet oxygen luminescence

Pulsed and continuous-wave(CW)lasers have been widely used as the light sources for photodynamic therapy(PDT)treatment.Singlet oxygen(^(1)O_(2))is known to be a major cytotoxic agent in type-II PDT and can be directly detected by its near-infrared luminescence at 1270 nm.As compared to CW laser excitation,the effiects of pulse width and repetition rate of pulsed laser on the kinetics and production of^(1)O_(2)luminescence were quantitatively studied during photosensitization of Rose Bengal.Significant di®erence in kinetics of^(1)O_(2)luminescence was found under the excitation with various pulse widths of nanosecond,microsecond and CW irradiation with power of 20mW.The peak intensity and duration of^(1)O_(2)production varied with the pulse widths for pulsed laser excitation,while the^(1)O_(2)was generated continuously and its production reached a steady state with CW excitation.However,no significant di®erence(P>0:05)in integral^(1)O_(2)production was observed.The results suggest that the PDT efficacy using pulsed laser may be identical to the CW laser with the same wavelength and the same average°uence rate below a threshold in solution.

Interstitial photoacoustic technique and computational simulation for temperature distribution and tissue optical properties in interstitial laser photothermal interaction

Interstitial laser immunotherapy(ILIT)is designed to use photothermal and immunological inter-actions for treatment of metastatic cancers.The photothermal ffect is crucial in inducing anti-tumorimmune responses in the host.Tissue temperature and tssue optical properties are important factorsin this process.In this study,a device combining interstitial photoacoustic(PA)technique andinterstitial laser photothermal interaction is proposed.Together with computational simulation,thisdevice was designed to determine temperature distributions and tissue optical properties during lasertreatment.Experiments were performed usinger-ivoFporcine liver tissue.Our results demonstratedthat interstitial PA signal amplitude was linearly dependent on tisue temperature in the tempera-ture ranges of 20-60℃,as wll as 65-80℃,with a dfferent slope,due to the change of tissue opticalproperties.Using the directly measured temperature in the tissue around the interstitial optical fiberdiffusion tip for calibration,the theoretical temperature distribution predicted by the bioheatequation was used to extract optical properties of tssue.Finally,the three-dimensional temperature distribution was simulated to guide tumor destruction and immunological stimulation,Thus,thisnovel device and method could be used for monitoring and controlling ILIT for cancer treatment.

Real-time co-registered photoacoustic and ultrasonic imaging for early endometrial cancer detection driven by cylindrical diffuser

In illuminating tissues,a cylindrical diffuser(CD)has an advantage over regular laser sources due to its ability to illuminate a larger volume of the target tissue.This paper presents a co-registered large volume photoacoustic(PA)and ultrasonic(US)imaging for early endometrial cancer(EEC)detection using CD.It has the advantage that the US imaging system is outside the body and only the PA excitation device is inside the body,which makes the system more efficient and less invasive for EEC detection.The paper reports on two sets of experiments.Thefirst set produced real-time PA images of blood vessel phantom.The second set demonstrated the imaging of pig uterus ex vivo.The results show that the system has the potential for imaging and characterizing of EEC.

Optical second-harmonic generation imaging for identifying gastrointestinal stromal tumors

Gastrointestinal stromal tumors(GISTs)are the most common mesenchymal tumors arising in the digest tract.It brings a challenge to diagnosis because it is asymptomatic clinically.It is well known that tumor development is often accompanied by the changes in the morphology of collagen fibers.Nowadays,an emerging optical imaging technique,second-harmonic generation(SHG),can directly identify collagen fibers without staining due to its noncentrosymmetric properties.Therefore,in this study,we attempt to assess the feasibility of SHG imaging for detecting GISTs by monitoring the morphological changes of collagen fibers in tumor microenvironment.We found that collagen alterations occurred obviously in the GISTs by comparing with normal tissues,and furthermore,two morphological features from SHG images were extracted to quantitatively assess the morphological difference of collagen fibers between normal muscular layer and GISTs by means of automated image analysis.Quantitative analyses show a significant difference in the two collagen features.This study demonstrates the potential of SHG imaging as an adjunctive diagnostic tool for label-free identification of GISTs.

Quantitative analysis of collagen morphology in breast cancer from millimeter scale using multiphoton microscopy

The tumor microenvironment(TME)is now recognized as an important participant of tumor progression.As the most abundant extracellular matrix component in TME,collagen plays an important role in tumor development.The imaging study of collagen morphological feature in TME is of great significance for understanding the state of tumor.Multiphoton microscopy(MPM),based on second harmonic generation(SHG)and two-photon excitation fluorescence(TPEF),can be used to monitor the morphological changes of biological tissues without labeling.In this study,we used MPM for large-scale imaging of early invasive breast cancer from the tumor center to normal tissues far from the tumor.We found that there were signi¯cant di®erences in collagen morphology between breast cancer tumor boundary,near tumor transition region and normal tissues far from the tumor.Furthermore,the morphological feature of eight collagen¯bers was extracted to quantify the variation trend of collagen in three regions.These results may provide a new perspective for the optimal negative margin width of breast-conserving surgery and the understanding of tumor metastasis.