共查询到20条相似文献,搜索用时 268 毫秒
1.
Ying Chen 《Biochemical and biophysical research communications》2009,390(3):624-146
We synthesized YC-27 3 to provide a fluorescent imaging agent for the prostate-specific membrane antigen (PSMA), a marker for hormone-independent prostate cancer and tumor neovasculature, with suitable pharmacokinetics for use in vivo. Immediate precursor trifluoroacetate salt of 2-(3-{5-[7-(5-amino-1-carboxy-pentylcarbamoyl)-heptanoylamino]-1-carboxy-pentyl}-ureido)-pentanedioic acid 2 was conjugated with a commercially available near-infrared light-emitting dye (IRDye 800CW) to provide 3 in 72% yield. YC-27 3 demonstrated a PSMA inhibitory activity of 0.37 nM and was capable of generating target-to-nontarget ratios of at least 10 in PSMA-expressing PC3-PIP vs. PSMA-negative PC3-flu tumors in vivo. YC-27 3 may be useful for study of PSMA-expressing tissue in preclinical models or for intraoperative guidance. 相似文献
2.
《Bioorganic & medicinal chemistry letters》2020,30(3):126894
Prostate-specific membrane antigen (PSMA) is a zinc-bound metalloprotease which is highly expressed in metastatic prostate cancer. It has been considered an excellent target protein for prostate cancer imaging and targeted therapy because it is a membrane protein and its active site is located in the extracellular region. We successfully synthesized and evaluated a novel PSMA ligand conjugated with BODIPY650/665. Compound 1 showed strong PSMA-inhibitory activity and selective uptake into PSMA-expressing tumors. Compound 1 has the potential to be utilized as a near infrared (NIR) optical imaging probe targeting PSMA-expressing cancers. 相似文献
3.
Daiko Matsuoka Hiroyuki Watanabe Yoichi Shimizu Hiroyuki Kimura Yusuke Yagi Ryoko Kawai Masahiro Ono Hideo Saji 《Bioorganic & medicinal chemistry》2018,26(9):2291-2301
Prostate-specific membrane antigen (PSMA), which is overexpressed in malignant prostate cancer (PCa), is an ideal target for imaging and therapy of PCa. We previously reported a PSMA imaging probe, 800CW-SCE, based on succinimidyl-Cys-C(O)-Glu (SCE) for optical imaging of PCa. In this study, we investigated the structure–activity relationships of novel SCE derivatives with five different near-infrared (NIR) fluorophores (IRDye 680LT, IRDye 750, Indocyanine Green, Cyanine 5.5, and Cyanine 7) as optical imaging probes targeting PSMA. An in vitro binding assay revealed that 800CW-SCE, 680LT-SCE, and 750-SCE exhibited higher binding affinity than 2-PMPA, which is known as a PSMA inhibitor. These three SCE derivatives were internalized into PSMA-positive cells (LNCaP cells) but not into PSMA-negative cells (PC-3 cells). In the in vivo imaging study, 800CW-SCE and 750-SCE were highly accumulated in LNCaP tumors but not in PC-3 tumors, and the ratio of LNCaP/PC-3 accumulation of 800CW-SCE was higher than that of 750-SCE. The present study may provide valuable molecular design information for the future development of new PSMA imaging probes based on the SCE scaffold. 相似文献
4.
Maija P. Valta Johanna Tuomela Heikki Vuorikoski Niina Loponen Riina‐Minna Väänänen Kim Pettersson H. Kalervo Väänänen Pirkko L. Härkönen 《Journal of cellular biochemistry》2009,107(4):769-784
Fibroblast growth factor 8 (FGF‐8) is expressed at an increased level in a high proportion of prostate cancers and it is associated with a poor prognosis of the disease. Our aim was to study the effects of FGF‐8b on proliferation of PC‐3 prostate cancer cells and growth of PC‐3 tumors, and to identify FGF‐8b‐associated molecular targets. Expression of ectopic FGF‐8b in PC‐3 cells caused a 1.5‐fold increase in cell proliferation in vitro and a four‐ to fivefold increase in the size of subcutaneous and orthotopic prostate tumors in nude mice. Tumors expressing FGF‐8b showed a characteristic morphology with a very rich network of capillaries. This was associated with increased spread of the cancer cells to the lungs as measured by RT‐qPCR of FGF‐8b mRNA. Microarray analyses revealed significantly altered, up‐ and downregulated, genes in PC‐3 cell cultures (169 genes) and in orthotopic PC‐3 tumors (61 genes). IPA network analysis of the upregulated genes showed the strongest association with development, cell proliferation (CRIP1, SHC1), angiogenesis (CCL2, DDAH2), bone metastasis (SPP1), cell‐to‐cell signaling and energy production, and the downregulated genes associated with differentiation (DKK‐1, VDR) and cell death (CYCS). The changes in gene expression were confirmed by RT‐qPCR. In conclusion, our results demonstrate that FGF‐8b increases the growth and angiogenesis of orthotopic prostate tumors. The associated gene expression signature suggests potential mediators for FGF‐8b actions on prostate cancer progression and metastasis. J. Cell. Biochem. 107: 769–784, 2009. © 2009 Wiley‐Liss, Inc. 相似文献
5.
Alexey E. Machulkin Dmitry A. Skvortsov Yan A. Ivanenkov Anton P. Ber Mikhail V. Kavalchuk Anastasia V. Aladinskaya Anastasia A. Uspenskaya Radik R. Shafikov Ekaterina A. Plotnikova Raisa I. Yakubovskaya Ekaterina A. Nimenko Nikolay U. Zyk Elena K. Beloglazkina Nikolay V. Zyk Victor E Koteliansky Alexander G. Majouga 《Bioorganic & medicinal chemistry letters》2019,29(16):2229-2235
Prostate cancer (PC) is the second most commonly occurring cancer in men. Conventional chemotherapy has wide variety of disadvantages such as high systemic toxicity and low selectivity. Targeted drug delivery is a promising approach to decrease side effects of therapy. Prostate specific membrane antigen (PSMA) is overexpressed in prostate cancer cells while low level of expression is observed in normal cells. In this study we describe the development of Glu-urea-Lys based PSMA-targeting conjugates with paclitaxel. A series of new PSMA targeting conjugates with paclitaxel was designed and synthesized. The cytotoxicity of conjugates was evaluated against prostate (LNCaP, 22Rv1 and PC-3) and non-prostate (Hek293T, VA13, A549 and MCF-7) cell lines. The most promising conjugate 21 was examined in vivo using 22Rv1 xenograft mice model. It demonstrated good efficiency comparable with paclitaxel, while reduced toxicity. 3D molecular docking study was also performed to understand underlying mechanism of binding and further optimization of the linker substructure and conjugates structure for improving the target affinity. These conjugates may be useful for further design of novel PSMA targeting delivery systems for PC. 相似文献
6.
Van Phuc Nguyen Suhyun Park Junghwan Oh Hyun Wook Kang 《Journal of biophotonics》2017,10(8):1053-1061
Photoacoustic imaging (PAI) is a hybrid imaging modality with high resolution and sensitivity that can be beneficial for cancer staging. Due to insufficient endogenous photoacoustic (PA) contrast, the development of exogenous agents is critical in targeting cancerous tumors. The current study demonstrates the feasibility of marine‐oriented material, astaxanthin, as a biocompatible PA contrast agent. Both silicon tubing phantoms and ex vivo bladder tissues are tested at various concentrations (up to 5 mg/ml) of astaxanthin to quantitatively explore variations in PA responses. A Q‐switched Nd : YAG laser (λ = 532 nm) in conjunction with a 5 MHz ultrasound transducer is employed to generate and acquire PA signals from the samples. The phantom results presented that the PA signal amplitudes increase linearly with the astaxanthin concentrations (threshold detection = 0.31 mg/ml). The tissue injected with astaxanthin yields up to 16‐fold higher PA signals, compared with that with saline. Due to distribution of the injected astaxanthin, PAI can image the margin of astaxanthin boles as well as quantify their volume in 3D reconstruction. Further investigations on selective tumor targeting are required to validate astaxanthin as a potential biocompatible contrast agent for PAI‐assisted bladder cancer detection.
7.
Nrusingh C. Biswal Xiaoyong Fu Jaidip M. Jagtap Martin J. Shea Vijetha Kumar Tamika Lords Ronita Roy Rachel Schiff Amit Joshi 《Journal of biophotonics》2020,13(1)
Endocrine therapy resistance in breast cancer is a major obstacle in the treatment of patients with estrogen receptor‐positive (ER+) tumors. Herein, we demonstrate the feasibility of longitudinal, noninvasive and semiquantitative in vivo molecular imaging of resistance to three endocrine therapies by using an inducible fluorescence‐labeled short hairpin RNA (shRNA) system in orthotopic mice xenograft tumors. We employed a dual fluorescent doxycycline (Dox)‐regulated lentiviral inducer system to transfect ER+ MCF7L breast cancer cells, with green fluorescent protein (GFP) expression as a marker of transfection and red fluorescent protein (RFP) expression as a surrogate marker of Dox‐induced tumor suppressor phosphatase and tensin homolog deleted on chromosome 10 (PTEN) knockdown. Xenografted MCF7L tumor‐bearing nude mice were randomized to therapies comprising estrogen deprivation, tamoxifen or an ER degrader (fulvestrant) and an estrogen‐treated control group. Longitudinal imaging was performed by a home‐built multispectral imaging system based on a cooled image intensified charge coupled device camera. The GFP signal, which corresponds to number of viable tumor cells, exhibited excellent correlation to caliper‐measured tumor size (P << .05). RFP expression was substantially higher in mice exhibiting therapy resistance and strongly and significantly (P < 1e‐7) correlated with the tumor size progression for the mice with shRNA‐induced PTEN knockdown. PTEN loss was strongly correlated with resistance to estrogen deprivation, tamoxifen and fulvestrant therapies. 相似文献
8.
In‐vivo multicolor photoacoustic (PA) flow cytometry for ultrasensitive molecular detection of the CD44+ circulating tumor cells (CTCs) is demonstrated on a mouse model of human breast cancer. Targeting of CTCs with stem‐like phenotype, which are naturally shed from parent tumors, was performed with functionalized gold and magnetic nanoparticles. Results in vivo were verified in vitro with a multifunctional microscope, which integrates PA, photothermal (PT), fluorescent and transmission modules. Magnet‐induced clustering of magnetic nanoparticles in individual cells significantly amplified PT and PA signals. The novel noninvasive platform, which integrates multispectral PA detection and PT therapy with a potential for multiplex targeting of many cancer biomarkers using multicolor nanoparticles, may prospectively solve grand challenges in cancer research for diagnosis and purging of undetectable yet tumor‐initiating cells in circulation before they form metastasis. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
9.
Image‐derived arterial input function for quantitative fluorescence imaging of receptor‐drug binding in vivo 下载免费PDF全文
Jonathan T. Elliott Kimberley S. Samkoe Scott C. Davis Jason R. Gunn Keith D. Paulsen David W. Roberts Brian W. Pogue 《Journal of biophotonics》2016,9(3):282-295
Receptor concentration imaging (RCI) with targeted‐untargeted optical dye pairs has enabled in vivo immunohistochemistry analysis in preclinical subcutaneous tumors. Successful application of RCI to fluorescence guided resection (FGR), so that quantitative molecular imaging of tumor‐specific receptors could be performed in situ, would have a high impact. However, assumptions of pharmacokinetics, permeability and retention, as well as the lack of a suitable reference region limit the potential for RCI in human neurosurgery. In this study, an arterial input graphic analysis (AIGA) method is presented which is enabled by independent component analysis (ICA). The percent difference in arterial concentration between the image‐derived arterial input function (AIFICA) and that obtained by an invasive method (ICACAR) was 2.0 ± 2.7% during the first hour of circulation of a targeted‐untargeted dye pair in mice. Estimates of distribution volume and receptor concentration in tumor bearing mice (n = 5) recovered using the AIGA technique did not differ significantly from values obtained using invasive AIF measurements (p = 0.12). The AIGA method, enabled by the subject‐specific AIFICA, was also applied in a rat orthotopic model of U‐251 glioblastoma to obtain the first reported receptor concentration and distribution volume maps during open craniotomy.
10.
Aleksandr A. Lanin Artem S. Chebotarev Matvei S. Pochechuev Ilya V. Kelmanson Daria A. Kotova Dmitry S. Bilan Yulia G. Ermakova Andrei B. Fedotov Anatoly A. Ivanov Vsevolod V. Belousov Aleksei M. Zheltikov 《Journal of biophotonics》2020,13(3)
We demonstrate an accurate quantitative characterization of absolute two‐ and three‐photon absorption (2PA and 3PA) action cross sections of a genetically encodable fluorescent marker Sypher3s. Both 2PA and 3PA action cross sections of this marker are found to be remarkably high, enabling high‐brightness, cell‐specific two‐ and three‐photon fluorescence brain imaging. Brain imaging experiments on sliced samples of rat's cortical areas are presented to demonstrate these imaging modalities. The 2PA action cross section of Sypher3s is shown to be highly sensitive to the level of pH, enabling pH measurements via a ratiometric readout of the two‐photon fluorescence with two laser excitation wavelengths, thus paving the way toward fast optical pH sensing in deep‐tissue experiments. 相似文献
11.
Objectives
Previously, we found that long intergenic non‐coding RNA‐p21 (lincRNA‐p21) inhibited the development of human prostate cancer. However, the underlying molecular mechanisms are poorly understood. Here, we attempted to investigate the downstream targets of lincRNA‐p21 in prostate cancer.Materials and methods
Expression of lincRNA‐p21 and PKM2 was determined by qRT‐PCR and Western blot. Lentivirus expressing shPKM2 or shCtrl was used to explore the role of PKM2 on the enhanced cell proliferation and glycolysis of lincRNA‐p21‐silenced prostate cancer cells. A xenograft mouse model was performed to investigate the effect of PKM2 suppression, glycolytic or mammalian target of rapamycin (mTOR) inhibitor on the tumorigenic capacity of lincRNA‐p21‐silenced prostate cancer cells.Results
We revealed that lincRNA‐p21 silencing in DU145 and LNCaP cells induced up‐regulation of PKM2 and activation of glycolysis, which could be reversed by PKM2 knockdown or rapamycin treatment. We also found that the proliferation and tumorigenesis of lincRNA‐p21‐silenced prostate cancer cells were significantly inhibited after knocking down PKM2. 3‐bromopyruvate (3‐Brpa) or rapamycin treatment largely decreased the tumour burden. Importantly, PKM2 expression was inversely correlated with the lincRNA‐p21 level and the survival of prostate cancer patients.Conclusions
We demonstrated that lincRNA‐p21 blunted the prostate cancer cell proliferation and tumorigenic capacity through down‐regulation of PKM2. Therefore, targeting PKM2 or glycolysis might be a therapeutic strategy in prostate cancer patients with lowly expressed lincRNA‐p21.12.
Multi‐modal acousto‐optic/ultrasound imaging of ex vivo liver tumors at 790 nm using a Sn2P2S6 wavefront adaptive holographic setup 下载免费PDF全文
Jean‐Baptiste Laudereau Emilie Benoit à La Guillaume Vincent Servois Pascale Mariani Alexander A. Grabar Mickaël Tanter Jean‐Luc Gennisson François Ramaz 《Journal of biophotonics》2015,8(5):429-436
Biological tissues are very strong light‐scattering media. As a consequence, current medical imaging devices do not allow deep optical imaging unless invasive techniques are used. Acousto‐optic imaging is a light‐ultrasound coupling technique that takes advantage of the ballistic propagation of ultrasound in biological tissues to access optical contrast with a millimeter resolution. We have developed a photorefractive‐crystal‐based system that performs self‐adaptive wavefront holography and works within the optical therapeutic window. As it works at an appropriate wavelength range for biological tissues imaging, it was tested on ex vivo liver samples containing tumors as a pre‐clinical study. Optical contrast was obtained even if acoustical one was not significant.
13.
Yuanpeng Li Xiaojuan Xie Xinhao Yang Liu Guo Zhao Liu Xiaoping Zhao Ying Luo Wei Jia Furong Huang Siqi Zhu Zhenqiang Chen Xingdan Chen Zhong Wei Weimin Zhang 《Journal of biophotonics》2019,12(5)
This study investigated the feasibility of using fluorescence hyperspectral imaging technology to diagnose of early‐stage gastric cancer. Fluorescence spectral images of 76 patients who were pathologically diagnosed as non‐atrophic gastritis, premalignant lesions and gastric cancer were collected. Fluorescence spectra at 100‐pixel points were randomly extracted after binarization. Diagnostic models of non‐atrophic gastritis, premalignant lesions and gastric cancer were constructed through partial‐least‐square discriminant analysis (PLS‐DA) and support vector machine (SVM) algorithms. The prediction effects of PLS‐DA and SVM models were compared. Results showed that the average spectra of normal, precancerous and gastric cancer tissues significantly differed at 496, 546, 640 and 670 nm, and regular changes in fluorescence intensity at 546 nm were in the following order: normal > precancerous lesions > gastric cancer. Additionally, the effect of the diagnostic model established by SVM is significantly better than PLS‐DA which accuracy, specificity and sensitivity are above 94%. Experimental results revealed that the fast diagnostic model of early gastric cancer by combining fluorescence hyperspectral imaging technology and improved SVM was effective and feasible, thereby providing an accurate and rapid method for diagnosing early‐stage gastric cancer. 相似文献
14.
Wide‐field color imaging of scatter‐based tissue contrast using both high spatial frequency illumination and cross‐polarization gating 下载免费PDF全文
Mackenzie L. Carlson David M. McClatchy III Jason R. Gunn Jonathan T. Elliott Keith D. Paulsen Stephen C. Kanick Brian W. Pogue 《Journal of biophotonics》2018,11(2)
This study characterizes the scatter‐specific tissue contrast that can be obtained by high spatial frequency (HSF) domain imaging and cross‐polarization (CP) imaging, using a standard color imaging system, and how combining them may be beneficial. Both HSF and CP approaches are known to modulate the sensitivity of epi‐illumination reflectance images between diffuse multiply scattered and superficially backscattered photons, providing enhanced contrast from microstructure and composition than what is achieved by standard wide‐field imaging. Measurements in tissue‐simulating optical phantoms show that CP imaging returns localized assessments of both scattering and absorption effects, while HSF has uniquely specific sensitivity to scatter‐only contrast, with a strong suppression of visible contrast from blood. The combination of CP and HSF imaging provided an expanded sensitivity to scatter compared with CP imaging, while rejecting specular reflections detected by HSF imaging. ex vivo imaging of an atlas of dissected rodent organs/tissues demonstrated the scatter‐based contrast achieved with HSF, CP and HSF‐CP imaging, with the white light spectral signal returned by each approach translated to a color image for intuitive encoding of scatter‐based contrast within images of tissue. The results suggest that visible CP‐HSF imaging could have the potential to aid diagnostic imaging of lesions in skin or mucosal tissues and organs, where just CP is currently the standard practice imaging modality. 相似文献
15.
Perfusion‐based fluorescence imaging method delineates diverse organs and identifies multifocal tumors using generic near‐infrared molecular probes 下载免费PDF全文
Jessica Miller Steven T. Wang Inema Orukari Julie Prior Gail Sudlow Xinming Su Kexian Liang Rui Tang Elizabeth M.C. Hillman Katherine N. Weilbaecher Joseph P. Culver Mikhail Y. Berezin Samuel Achilefu 《Journal of biophotonics》2018,11(4)
Rapid detection of multifocal cancer without the use of complex imaging schemes will improve treatment outcomes. In this study, dynamic fluorescence imaging was used to harness differences in the perfusion kinetics of near‐infrared (NIR) fluorescent dyes to visualize structural characteristics of different tissues. Using the hydrophobic nontumor‐selective NIR dye cypate, and the hydrophilic dye LS288, a high tumor‐to‐background contrast was achieved, allowing the delineation of diverse tissue types while maintaining short imaging times. By clustering tissue types with similar perfusion properties, the dynamic fluorescence imaging method identified secondary tumor locations when only the primary tumor position was known, with a respective sensitivity and specificity of 0.97 and 0.75 for cypate, and 0.85 and 0.81 for LS288. Histological analysis suggests that the vasculature in the connective tissue that directly surrounds the tumor was a major factor for tumor identification through perfusion imaging. Although the hydrophobic dye showed higher specificity than the hydrophilic probe, use of other dyes with different physical and biological properties could further improve the accuracy of the dynamic imaging platform to identify multifocal tumors for potential use in real‐time intraoperative procedures. 相似文献
16.
Meng Zhou Huangxuan Zhao Haibo Xia Jiayao Zhang Zhicheng Liu Chengbo Liu Fei Gao 《Journal of biophotonics》2019,12(8)
Photoacoustic (PA) imaging breaks the diffusion limit of conventional optical imaging by listening to the PA wave. As a new kind of functional imaging method, it has experienced tremendous growth in research community with wide range of applications. However, it is still an open and fundamental challenge that the conversion efficiency from light to sound based on PA effect is extremely low. The consequence is the poor signal‐to‐noise ratio (SNR) of PA signal especially in scenarios of low laser power and deep penetration. Conventional approach to enhance the SNR of PA signal in these noisy scenarios is data averaging, which is quite time‐consuming. To improve the signal fidelity and imaging speed, an algorithm of using empirical mode decomposition and independent component analysis de‐noising methods in PA imaging is proposed. The simulation and in vivo experimental results show obvious SNR enhancement of the PA signal and image contrast. The proposed method provides the potential to develop real‐time low‐cost PA imaging system with low‐power laser source. 相似文献
17.
Mikael T. Erkkil Bianca Bauer Nancy Hecker‐Denschlag Maria J. Madera Medina Rainer A. Leitgeb Angelika Unterhuber Johanna Gesperger Thomas Roetzer Christoph Hauger Wolfgang Drexler Georg Widhalm Marco Andreana 《Journal of biophotonics》2019,12(6)
Achieving a maximal safe extent of resection during brain tumor surgery is the goal for improved patient prognosis. Fluorescence‐guided neurosurgery using 5‐aminolevulinic acid (5‐ALA) induced protoporphyrin IX has thereby become a valuable tool enabling a high frequency of complete resections and a prolonged progression‐free survival in glioblastoma patients. We present a widefield fluorescence lifetime imaging device with 250 mm working distance, working under similar conditions such as surgical microscopes based on a time‐of‐flight dual tap CMOS camera. In contrast to intensity‐based fluorescence imaging, our method is invariant to light scattering and absorption while being sensitive to the molecular composition of the tissue. We evaluate the feasibility of lifetime imaging of protoporphyrin IX using our system to analyze brain tumor phantoms and fresh 5‐ALA‐labeled human tissue samples. The results demonstrate the potential of our lifetime sensing device to go beyond the limitation of current intensity‐based fluorescence‐guided neurosurgery. 相似文献
18.
Nakajima T Mitsunaga M Bander NH Heston WD Choyke PL Kobayashi H 《Bioconjugate chemistry》2011,22(8):1700-1705
In patients with prostate cancer, a positive surgical margin is associated with an increased risk of cancer recurrence and poorer outcome, yet margin status cannot be determined during the surgery. An in vivo optical imaging probe that could identify the tumor margins during surgery could result in improved outcomes. The design of such a probe focuses on a highly specific targeting moiety and a near-infrared (NIR) fluorophore that is activated only when bound to the tumor. In this study, we successfully synthesized an activatable monoclonal antibody-fluorophore conjugate consisting of a humanized anti-Prostate-Specific Membrane Antigen (PSMA) antibody (J591) linked to an indocyanine green (ICG) derivative. Prior to binding to PSMA and cellular internalization, the conjugate yielded little light; however, after binding an 18-fold activation was observed permitting the specific detection of PSMA+ tumors up to 10 days after injection of a low dose (0.25 mg/kg) of the reagent. This agent demonstrates promise as a method to image the extent of prostate cancer in vivo and could assist with real-time resection of extracapsular extension of tumor and positive lymph nodes. 相似文献
19.
Seong Young Kwon Sheng‐Nan Jiang Jin Hai Zheng Hyon E. Choy Jung‐Joon Min 《Microbiology and immunology》2014,58(3):172-179
Several optical imaging techniques have been used to monitor bacterial tropisms for cancer. Most such techniques require genetic engineering of the bacteria to express optical reporter genes. This study investigated a novel tumor‐targeting strain of bacteria, Rhodobacter sphaeroides 2.4.1 (R. sphaeroides), which naturally emits near‐infrared fluorescence, thereby facilitating the visualization of bacterial tropisms for cancer. To determine the penetration depth of bacterial fluorescence, various numbers of cells (from 108 to 1010 CFU) of R. sphaeroides and two types of Escherichia coli, which stably express green fluorescent protein (GFP) or red fluorescent protein (RFP), were injected s.c. or i.m. into mice. Bacterial tropism for cancer was determined after i.v. injection of R. sphaeroides (108 CFU) into mice implanted s.c. with eight types of tumors. The intensity of the fluorescence signal in deep tissue (muscle) from R. sphaeroides was much stronger than from E. coli‐expressing GFP or RFP. The near‐infrared fluorescence signal from R. sphaeroides was visualized clearly in all types of human or murine tumors via accumulation of bacteria. Analyses of C‐reactive protein and procalcitonin concentrations and body weights indicated that i.v. injection of R. sphaeroides does not induce serious systemic immune reactions. This study suggests that R. sphaeroides could be used as a tumor‐targeting microorganism for the selective delivery of drugs to tumor tissues without eliciting a systemic immune reaction and for visualizing tumors. 相似文献
20.
Quantitative phase‐filtered wavelength‐modulated differential photoacoustic radar tumor hypoxia imaging toward early cancer detection 下载免费PDF全文
Edem Dovlo Bahman Lashkari Sung soo Sean Choi Andreas Mandelis Wei Shi Fei‐Fei Liu 《Journal of biophotonics》2017,10(9):1134-1142
Overcoming the limitations of conventional linear spectroscopy used in multispectral photoacoustic imaging, wherein a linear relationship is assumed between the absorbed optical energy and the absorption spectra of the chromophore at a specific location, is crucial for obtaining accurate spatially‐resolved quantitative functional information by exploiting known chromophore‐specific spectral characteristics. This study introduces a non‐invasive phase‐filtered differential photoacoustic technique, wavelength‐modulated differential photoacoustic radar (WM‐DPAR) imaging that addresses this issue by eliminating the effect of the unknown wavelength‐dependent fluence. It employs two laser wavelengths modulated out‐of‐phase to significantly suppress background absorption while amplifying the difference between the two photoacoustic signals. This facilitates pre‐malignant tumor identification and hypoxia monitoring, as minute changes in total hemoglobin concentration and hemoglobin oxygenation are detectable. The system can be tuned for specific applications such as cancer screening and SO2 quantification by regulating the amplitude ratio and phase shift of the signal. The WM‐DPAR imaging of a head and neck carcinoma tumor grown in the thigh of a nude rat demonstrates the functional PA imaging of small animals in vivo. The PA appearance of the tumor in relation to tumor vascularity is investigated by immunohistochemistry. Phase‐filtered WM‐DPAR imaging is also illustrated, maximizing quantitative SO2 imaging fidelity of tissues.