Study of Blood Porphyrin Spectral Profile for Diagnosis of Chronic Renal Failure

The progression to end-stage renal failure is independent of the initial pathogenic mechanism. Metabolic acidosis is a common consequence of chronic renal failure that results from inadequate ammonium excretion and decreased tubular bicarbonate reabsorption. Protoporphyrin IX (PpIX) is the immediate metabolic precursor of the heme molecule. The purpose of this study was to evaluate the levels of erythrocytes protoporphyrin IX at an animal model during progressive renal disease. A total of 36 eight-week-old male Wistar rats were divided into six groups: Normal, 4 and 8 weeks after 5/6 nephrectomy (NX). Renal function was evaluated by creatinine clearance and plasma creatinine levels. The autofluorescence of erythrocytes porphyrin of healthy and NX rats was analyzed using fluorescence spectroscopy. Emission spectra were obtained by exciting the samples at 405 nm. Significant differences between normal and NX rats autofluorescence shape occurred in the 600–700 nm spectral region. A correlation was observed between emission band intensity at 635 nm and progression of renal disease.     

Erythrocyte Protoporphyrin Fluorescence as a Biomarker for Monitoring Antiangiogenic Cancer Therapy

Renal cell carcinoma (RCC) remains one of the greatest challenges of urological oncology and is the third leading cause of death in genitourinary cancers. RCCs are highly vascularized and are amenable to antiangiogenic therapy. Endostatin (ES) is a fragment of collagen XVIII that possesses antiangiogenic activity. In this study, we examined the potential of erythrocyte PpIX fluorescence spectroscopy for monitoring the efficacy of antiangiogenic therapy in metastatic renal cell carcinoma (mRCC), using an orthotopic metastatic mouse model. Balb/C-bearing Renca cells were treated with NIH/3T3-LendSN cells. Lung weight, nodule area, microvascular area (MVA), and erythrocyte PpIX fluorescence were evaluated. Emission spectra were obtained by exciting the samples at 405 nm. There was a significant decrease in lung wet weight, lung nodule area and MVA in the treated group compared to the control group (P < 0.001). Significant differences in autofluorescence shape were observed in the 620–650 nm spectral region. The most intense fluorescence peak was observed at ∼632 nm. The autofluorescence of the control samples was about 53% higher than that of normal blood (P < 0.05). In the group treated with ES, the autofluorescence was about 54% lower than in the control group (P < 0.05). Fluorescence intensity was positively correlated with the nodule area (R ² = 0.8859; P < 0.001) and MVA (R ² = 0.9431; P < 0.001) in the ES-treated group. These results demonstrate that the spectroscopic analysis method allows a selective detection of tumor masses. This preliminary study suggests that PpIX fluorescence may be useful as a biomarker for antiangiogenic cancer therapy.     

同步荧光光谱法研究肿瘤芳香族氨基酸残基含量的变化

用同步荧光光谱法评估原发性肝细胞癌患者血浆、肝癌荷瘤小鼠以及培养细胞(HepG2和HL-7702)中酪氨酸(Tyr)和色氨酸(Trp)残基水平变化。固定发射波长λ_em和激发波长λ_ex之间的波长差Δλ分别为20和60 nm,激发和发射单色器同时进行扫描,确定350 nm为Trp的同步特征发射峰位置,318 nm为Tyr的同步特征发射峰位置。结果表明,肝癌患者及荷瘤小鼠血浆蛋白质所含Tyr和Trp残基的荧光强度明显增加。相反,肝癌细胞或荷瘤小鼠肿瘤组织中Tyr和Trp残基荧光强度却随生长时间增长而减少。进一步实验表明,具有抗癌活性的苦参碱处理癌细胞后,细胞Tyr和Trp残基的荧光强度升高。这些结果表明,Tyr和Trp残基的变化可能参与了肿瘤的发生发展。     

Measurement Conditions for Flow Cytometry Analyses of Cell Lines from Urological Carcinomas

Prerequisites for successful flow cytometry investigations are specific antibodies labeled with appropriate fluorochromes and negligible autofluorescence of the untreated cells at the wavelength of interest. The aim of this study was (a) to characterize frequently used urological carcinoma cell lines with regard to their autofluorescence properties, (b) to demonstrate the autofluorescence as a serious interfering factor on FACS analysis of urological carcinoma cell lines and (c) to suggest an alternative to avoid interfering autofluorescence. Twenty-one cell lines originating from prostate carcinoma, renal cell carcinoma and bladder cancer were included in this study. The various cell lines were read on a flow cytometer in comparison to human erythrocytes as cells with low fluorescence intensity. Urological cell lines show a high autofluorescence when flow cytometry analyses are performed at the frequently used excitation wavelengths at 405 and 488 nm. At excitation wavelength of 633 nm, this problem was reduced and most of the cell lines (14/21) were without autofluorescence at the emission wavelength of 785 nm. In addition, with a spectrofluorometer three exemplary cell lysates were investigated. The above observations were confirmed. The dye APC-Cy7 is one suitable fluorochrome for successful investigation under these measurement conditions.     

Cellular uptake and radiosensitization of SR-2508 loaded PLGA nanoparticles

SR-2508 (etanidazole), a hypoxic radiosensitizer, has potential applications in radiotherapy. The poly(d,l-lactide-co-glycolide)(PLGA) nanoparticles containing SR-2508 were prepared by w/o/w emulsification-solvent evaporation method. The physicochemical characteristics of the nanoparticles (i.e. encapsulation efficiency, particle size distribution, morphology, in vitro release) were studied. The cellular uptake of the nanoparticles for the two human tumor cell lines: human breast carcinoma cells (MCF-7) and human carcinoma cervices cells (HeLa), was evaluated by fluorescence microscopy and transmission electronic microscopy. Cell viability was measured by the ability of single cell to form colonies in vitro. The prepared nanoparticles were spherical in shape with size between 90 nm and 190 nm. The encapsulation efficiency was 20.06%. The drug release pattern exhibited an initial burst followed by a plateau for over 24 h. The cellular uptake of nanoparticles was observed. Co-culture of MCF-7 and HeLa cells with SR-2508 loaded nanoparticles showed that released SR-2508 retained its bioactivity and effectively sensitized two hypoxic tumor cell lines to radiation. The radiosensitization of SR-2508 loaded nanoparticles was more significant than that of free drug.     

Photodynamic damage study of HeLa cell line using ALA

The present study evaluates the photodynamic damage with 5-aminolevulinic acid (5-ALA) using HeLa as experimental model. HeLa cell line was irradiated with red light (He-Ne laser, λ = 632.8 CW nm). The influence of different incubation times and concentrations of 5-ALA, different irradiation doses and various combinations of photosensitizer and light doses on the cellular viability of HeLa cells were studied. The optimal uptake of photosensitizer ALA in HeLa cells was investigated by means of PpIX fluorescence intensity by exciting the HeLa cell suspension at 450 nm and a detection wavelength set at 690 nm. Cells viability was determined by means of trypan blue solution. The spectrometric measurements showed that the maximal cellular uptake of 5-ALA occurred after 4 h in vitro incubation. We found that the combination with 5-ALA and laser irradiation leads to time/concentration-dependent increase of cells death and also energy doses-dependent enlarge the cells death. The fluorescence intensity after PDD of carcinoma cells reduce when compared with the control group. The fluorescence emission spectral profiles after PDD of carcinoma cells showed a dip around 425–525 nm when compared with the control group. This may be due to the damage of mitochondria component of cells. The percentage of HeLa cells after PDD shows that the percentage of cells survival rate as function of laser dose (power). Hence it is clear that at 200 μg/ml ALA and 20 mW laser irradiation, more than 70% of HeLa cells were dead after 15 min.     

DHL细胞中5-ALA代谢PpIX的双光子荧光光谱

双光子激发生物组织荧光,激发光仅作用于焦点区域,对生物样品的光漂白性和光毒性都很小,因而双光子荧光显微技术已成为细胞生物学研究的一种新技术。文章采用波长为820 nm飞秒激光激发孵育有5-ALA的DHL细胞,在激光扫描显微镜的Lambda模式中获得单个DHL细胞的双光子荧光光谱,并测量DHL细胞内积聚的卟啉九(PpIX)特征荧光值。获得了浓度分别为2, 4和10 mmol·L-1的5-ALA溶液中,细胞代谢的PpIX含量随孵育时间的变化情况。DHL细胞内积聚的PpIX处于动态变化过程,并呈现出两阶段性的特点：细胞内积聚的PpIX含量随着孵育时间增长而增加,在3 h附近达到最大值,随后随着孵育时间增长反而下降。结果表明,基于激光扫描显微的双光子荧光光谱可成为DHL细胞等白血病细胞摄取5-ALA并生成PpIX的动力学研究的有效方法。     

Study of Blood Porphyrin Spectral Profile for Diagnosis of Tumor Progression

Renal cell carcinoma (RCC) accounts for approximately 3% of new cancer incidence and mortality in the United States. Unfortunately many RCC masses remain asymptomatic and nonpalpable until they are advanced. Diagnosis and localization of early carcinoma play an important role in the prevention and curative treatment of RCC. The autofluorescence of blood porphyrin of healthy and tumor induced in male SCID mice was analyzed using fluorescence and excitation spectroscopy. A significant contrast between normal and tumor blood could be established. Blood porphyrin fluorophore showed enhanced fluorescence band (around 630 nm) in function of the tumor growth. This indicates that either the autofluorescence intensity of the blood fluorescence may provide a good parameter for the “first approximation” characterization of the tumor stage.     

MRI contrast agent for molecular imaging of the HER2/neu receptor using targeted magnetic nanoparticles

In this study, Trastuzumab modified Magnetic Nanoparticles (TMNs) were prepared as a new contrast agent for detecting HER2 (Human epidermal growth factor receptor-2) expression tumors by magnetic resonance imaging (MRI). TMNs were prepared based on iron oxide nanoparticles core and Trastuzumab modified dextran coating. The TMNs core and hydrodynamic size were determined by transmission electron microscopy and dynamic light scattering. TMNs stability and cytotoxicity were investigated. The ability of TMNs for HER2 detection were evaluated in breast carcinoma cell lines (SKBr3 and MCF7 cells) and tumor-bearing mice by MRI and iron uptake determination. The particles core and hydrodynamic size were 9 ± 2.5 and 41 ± 15 nm (size range: 15?C87 nm), respectively. The molar antibody/nanoparticle ratio was 3.1?C3.5. TMNs were non-toxic to the cells below the 30 ??g (Fe)/mL concentration and good stable up to 8 weeks in PBS buffer. TMNs could detect HER2 oncogenes in the cells surface with imagable contrast by MRI. The invivo study in mice bearing tumors indicated that TMNs possessed a good diagnostic ability as HER2 specific contrast agent by MRI. TMNs were demonstrated to be able to selectively accumulate in the tumor cells, with a proper signal enhancement in MRI T2 images. So, the complex may be considered for further investigations as an MRI contrast agent for detection of HER2 expression tumors in human.     

Development of Novel Nanocarrier-Based Near-Infrared Optical Probes for In Vivo Tumor Imaging

Optical imaging with near-infrared (NIR) fluorescent probes is a useful diagnostic technology for in vivo tumor detection. Our plan was to develop novel NIR fluorophore-micelle complex probes. IC7-1 and IC7-2 were synthesized as novel lipophilic NIR fluorophores, which were encapsulated in an amphiphilic polydepsipeptide micelle “lactosome”. The fluorophore-micelle complexes IC7-1 lactosome and IC7-2 lactosome were evaluated as NIR fluorescent probes for in vivo tumor imaging. IC7-1 and IC7-2 were synthesized and then encapsulated in lactosomes. The optical properties of IC7-1, IC7-2, IC7-1 lactosome and IC7-2 lactosome were measured. IC7-1 lactosome and IC7-2 lactosome were administered to tumor-bearing mice, and fluorescence images were acquired for 48 h. IC7-1 and IC7-2 were successfully synthesized in 12% and 6.3% overall yield, and maximum emission wavelengths in chloroform were observed at 858 nm and 897 nm, respectively. Aqueous buffered solutions of IC7-1 lactosome and IC7-2 lactosome showed similar fluorescence spectra in chloroform and higher or comparable quantum yields and higher photostability compared with ICG. Both lactosome probes specifically visualized tumor tissue 6 h post-administration. IC7-1 lactosome and IC7-2 lactosome could be promising NIR probes for in vivo tumor imaging.     

Silica-modified Fe-doped calcium sulfide nanoparticles for in vitro and in vivo cancer hyperthermia

In this study, sulfide-based magnetic Fe-doped CaS nanoparticles modified with a silica layer were investigated for cancer hyperthermia. A polyvinyl pyrrolidone polymer was used as the coupling agent. The developed nanoparticles contained 11.6 wt% iron concentration, and their X-ray diffraction pattern was similar to those of CaS and Fe–CaS nanoparticles. The average particle size was approximately 47.5 nm and homogeneously dispersed in aqueous solutions. The major absorption bands of silica were observed from the FTIR spectrum. The magnetic properties and heating efficiency were also examined. The specific absorption ratio of nanoparticles at a concentration of 10 mg/mL at 37 °C in an ethanol carrier fluid was 37.92 W/g, and the nanoparticles would raise the temperature to over 45 °C within 15 min. A cytotoxicity analysis revealed that the nanoparticles had good biocompatibility, which indicated that the nanoparticles did not affect cell viability. The therapeutic effects of the nanoparticles were investigated using in vitro and animal studies. Cells seeded with nanoparticles and treated under an AC magnetic field revealed a percentage of cytotoxicity (60%) that was significantly higher from that in other groups. In the animal study, during a hyperthermia period of 15 days, tumor-bearing Balb/c mice that were subcutaneously injected with nanoparticles and exposed to an AC magnetic field manifested a reduction in tumor volume. The newly developed silica-modified Fe–CaS nanoparticles can thus be considered a promising and attractive hyperthermia thermoseed.     

Biodegradable self-assembled PEG-PCL-PEG micelles for hydrophobic drug delivery,part 2: in vitro and in vivo toxicity evaluation

Polymeric micelles, prepared by self-assembly of biodegradable poly(ethylene glycol)-poly(ε-caprolactone)-poly(ethylene glycol) (PEG–PCL–PEG, PECE) copolymer in aqueous solution, were proved to be a potential carrier for hydrophobic drug honokiol in our previous contribution. In this study, the safety of blank PECE micelles was evaluated in vitro and in vivo before its further application in biomedical field. The average particle size of obtained micelle was 83.47 ± 0.44 nm, and polydisperse index was 0.27 ± 0.01. Also, the zeta potential of prepared micelles was about −0.41 ± 0.02 mV. Otherwise, cytotoxicity of PECE micelles was evaluated by cell viability assay using L929 cells, and in vitro hemolytic test was also performed. In vivo acute toxicity evaluation and histopathological study of PECE micelles were conducted in BALB/c mice by intravenous administration. Furthermore, serum chemistry profile and complete blood count test were performed. In acute toxicity test, the mice were observed continuously for 7 days. For histopathological study, samples including heart, liver, spleen, lung, and kidneys were histochemical prepared and stained with hematoxylin-eosin (H&E). No mortality or significant signs of acute toxicity was observed during the whole observation period, and there is no significant lesion to be shown in histopathological study of major organs. The maximal tolerance dose of PECE micelles (100 mg/mL) by intravenous administration was calculated to be higher than 10 g/kg body weight (b.w.). The results indicated that the obtained PECE micelles was non-toxic after intravenous administration, and could be a safe candidate for hydrophobic drug delivery system.     

Protoporphyrin IX-mediated sonodynamic action induces apoptosis of K562 cells

Objectives

The present study aims to investigate apoptosis of human leukemia K562 cells induced by protoporphyrin IX (PpIX)-mediated sonodynamic therapy (PpIX-SDT).

Methods

The uptakes of intracellular PpIX in K562 cells were detected by flow cytometry. The sub-cellular localization of PpIX was imaged by confocal microscope. The cytotoxic effect of PpIX-SDT was assessed by MTT (3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenylter-trazolium bromide tetrazolium) assay. Apoptosis was evaluated by chromatin condensation with DAPI (4′-6-diamidino-2-phenylindole) staining, decrease of mitochondria membrane potential (MMP), re-distribution of Bax, and the expression changes of the key apoptosis-associated protein (Caspase-3 and polypeptide poly (ADP-robose) polymerase). The possible mechanism of SDT-induced apoptosis was investigated by detecting by intracellular ROS (reactive oxygen species) generation and effect of ROS scavenger-NAC (N-acetylcysteine) on SDT induced apoptosis.

Results

The intracellular PpIX increased quickly within 2 h after PpIX administration and PpIX mainly localized in the mitochondria. Compared with PpIX alone and ultrasound alone groups, the synergistic cytotoxicity of PpIX plus ultrasound was significantly boosted. In addition, the ultrasound induced some extent of chromatin condensation and MMP loss was greatly enhanced by the presence of 2 μg/ml PpIX, where PpIX alone treatment showed no or only slight effect. Time-dependent Bax translocation, caspase-3 activation and PARP cleavage were detected in SDT treatment groups. Besides, intracellular ROS production was significantly enhanced after SDT, and the general ROS scavenger NAC could obviously alleviate the SDT-caused cell viability loss, MMP loss, Bax redistribution and nuclear changes.

Conclusions

These results indicated that PpIX-mediated sonodynamic action could induce apoptosis on K562 cells, and the intracellular ROS was involved in the PpIX-SDT induced apoptosis.     

肝、肝癌及肝纤维细胞的荧光光谱及其荧光饱和强度分析

对肝细胞及肝病变细胞进行荧光光谱特性研究,能为早期筛查与攻克肝癌提供光谱学依据。实验目的包括,通过光谱实验获得细胞特异性荧光光谱;结合流式细胞仪获得最大饱和荧光强度与细胞直径的相关性。实验过程,首先使用荧光光谱仪来检测肝细胞、肝纤维细胞以及两种肝癌细胞;采用去拉曼散射的方法消除背景噪声,获得五种浓度下细胞荧光光谱;其次,使用流式细胞仪检测四种细胞直径的大小,根据双参数散点图分析四种细胞的直径特点;最后,利用高斯多峰拟合对比光谱差异,并且分析细胞直径对荧光饱和强度变化趋势的影响,得出细胞大小对荧光饱和强度非线性拟合曲线的影响规律。光谱实验发现,在550~750 nm之间,肝细胞存在两个特异性荧光峰,第一个峰值位于592 nm处,第二个峰位于682 nm处,且前者明显高于后者;肝癌,肝纤维细胞除具备与肝细胞相同位置的两个峰外,在726 nm处出现第三个特异性荧光峰,并在592 nm处获得最大激发光强,在726 nm处的荧光峰高于在682 nm处的第二个荧光峰;结合高斯多峰拟合法对峰值和各峰位置,以及峰型展宽进行分析。肝癌细胞和肝纤维细胞三个峰的展宽基本相同,正常肝细胞最大激发峰展宽略小于另三种细胞,但是682 nm处的小峰展宽略大于病变细胞;流式细胞仪实验结果显示,肝癌细胞直径大于肝纤维细胞大于肝细胞,同种浓度下荧光强度也是肝癌细胞高于肝纤维细胞高于肝细胞;利用非线性曲线拟合细胞最大荧光强度随浓度变化曲线,根据曲线斜率的变化规律,发现四种细胞的最大荧光强度会随着细胞浓度增大而增强,但是逐渐呈现荧光饱和状态。随着细胞直径增加,最大荧光强度饱和趋势更为明显,单个细胞自激发效率降低。结果显示,将细胞形态学与光谱学有机的融合,结合两种分析方式,能提高细胞判断的准确性和有效性。通过对肝细胞、肝癌细胞以及肝纤维细胞的荧光光谱特性进行研究,并结合细胞直径分析荧光饱和变化趋势,能够为肝病变细胞的研究提供一定的光谱学依据。     

Comparison of molecular images as defined by Raman spectra between normal mucosa and squamous cell carcinoma in the oral cavity

Raman spectroscopy has been effectively applied to clinically differentiate normal and cancerous mucosal tissues. Micro‐Raman spectroscopy provides a tool to better understand the molecular basis for the Raman clinical signal. The objective of the current study was to utilize micro‐Raman spectroscopy to define the molecular/spectral differences between normal and abnormal squamous cell carcinoma (SCC) in oral mucosa (in vitro). Understanding this may help in identifying unique spectra or may be useful for in vivo application of this technology. Micro‐Raman (confocal) spectroscopy was used to obtain molecular images of normal and SCC cells of human oral mucosa. Four fresh flashed‐frozen tumor and four matched normal tongue specimens were studied. The spectra covered a wavenumber range from 300 to 4000 cm⁻¹ with a spectral resolution of 8 cm⁻¹ and a spatial resolution of 1.0 µm. The cells were located within thin sections of tongue mucosa biopsies. The excitation wavelength of 515 nm was used. We were able to obtain Raman images with rich information about the spectroscopic and structural features within the cytoplasm, cell membrane, and cell nuclei. Significant spectral differences were observed between the Raman images of normal and malignant squamous cells. The heterogeneity of tumor cells within the abnormal tissue was also demonstrated. Spectral differences demonstrated between both tissue types have provided important information regarding the origins of specific signals within the cells of each tissue type. In our search for specific spectral biomarkers, we believe that a cell surface protein, greatly upregulated in SCC cells, was discovered at 1583 cm⁻¹. Copyright © 2010 John Wiley & Sons, Ltd.     

A novel magnetic fluid based on starch-coated magnetite nanoparticles functionalized with homing peptide

Preparation and characterization in vitro and in vivo of a novel magnetic fluid based on starch-coated magnetite nanoparticles functionalized with homing peptide is reported in this paper. Precursory magnetic fluids stabilized with starch were prepared, in a polymeric starch matrix, by controlled chemical coprecipitation of magnetite phase from aqueous solutions. The average hydrodynamic diameter of starch-coated iron oxide nanoparticles (SIONs) was 46 nm. As a homing peptide, A54 is the most effective peptide specific to the human hepatocellular carcinoma cell line BEL-7402. Final magnetic fluids were obtained through chemical coupling of homing peptide labeled with 5-carboxyl-fluorescein (FAM-A54) and SIONs. Magnetic measurements showed the saturation magnetization value of SIONs amounted to 45 emu/g and the FAM-A54-coupled SIONs showed a good magnetic response in magnetic field. The results of experiments in vitro and in vivo showed that SIONs were endowed with specific affinity to corresponding tumor cells after coupling with FAM-A54 and the FAM-A54-coupled SIONs could be accumulated in the tumor tissue with more efficiency than individual magnetic targeting or biomolecular targeting. This novel magnetic fluid with dual function has great potential applications in diagnostics and therapeutics of human tumor such as drug targeting, magnetic hyperthermia, and magnetic resonance imaging.     

Rapid extra-/intracellular biosynthesis of gold nanoparticles by the fungus <Emphasis Type="Italic">Penicillium</Emphasis> sp.

In this work, the fungus Penicillium was used for rapid extra-/intracellular biosynthesis of gold nanoparticles. AuCl₄ ⁻ ions reacted with the cell filtrate of Penicillium sp. resulting in extracellular biosynthesis of gold nanoparticles within 1 min. Intracellular biosynthesis of gold nanoparticles was obtained by incubating AuCl₄ ⁻ solution with fungal biomass for 8 h. The gold nanoparticles were characterized by means of visual observation, UV–Vis absorption spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). The extracellular nanoparticles exhibited maximum absorbance at 545 nm in UV–Vis spectroscopy. The XRD spectrum showed Bragg reflections corresponding to the gold nanocrystals. TEM exhibited the formed spherical gold nanoparticles in the size range from 30 to 50 nm with an average size of 45 nm. SEM and TEM revealed that the intracellular gold nanoparticles were well dispersed on the cell wall and within the cell, and they are mostly spherical in shape with an average diameter of 50 nm. The presence of gold was confirmed by EDX analysis.     

Feasibility of in-vivo semi-LASER renal magnetic resonance spectroscopy (MRS): Pilot study in healthy volunteers

PurposeTo evaluate the feasibility of semi-LASER renal magnetic resonance spectroscopy (MRS) in healthy volunteers and establish signature chemical composition of normal renal tissue towards future application for renal carcinoma characterization and grading.Materials and methods14 healthy volunteers were recruited after informed consent. Single voxel ¹H spectra were acquired on a 3 T MRI system using a semi-LASER sequence, employing outer-volume suppression and VAPOR water suppression with multiple averages in multiple breath-holds. Off-line processing and automatic correction for zero-order phase and frequency using the water resonance or residual water resonance for water-suppressed acquisitions was performed.Results11 volunteers successfully completed the entire examination. Phase and frequency correction was necessary to obtain optimal data quality prior to signal summation in few datasets. No lipid resonance was observed in any spectra from the unsuppressed water acquisitions, either in individual transients or in corrected summed spectra opposed to previously reported studies. No signal from other metabolites, such as choline-containing compounds, was observed in any dataset.ConclusionSemi-LASER renal MRS is technically feasible. Normal renal parenchyma does not demonstrate detectable levels of lipid or choline. This may provide a reference point for future application of this technique for noninvasive renal carcinoma histologic subtype characterization and grade.     

2-NBDG Fluorescence Imaging of Hypermetabolic Circulating Tumor Cells in Mouse Xenograft model of Breast Cancer

Objectives

To determine use of 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxy-D-glucose (2-NBDG) as a tracer for detection of hypermetabolic circulating tumor cells (CTC) by fluorescence imaging.

Procedures

Human breast cancer cells were implanted in the mammary gland fat pad of athymic mice to establish orthotopic human breast cancer xenografts as a mouse model of circulating breast cancer cells. Near-infrared fluorescence imaging of the tumor-bearing mice injected with 2-DeoxyGlucosone 750 (2-DG 750) was conducted to assess glucose metabolism of xenograft tumors. Following incubation with fluorescent 2-NBDG, circulating breast cancer cells in the blood samples collected from the tumor-bearing mice were collected by magnetic separation, followed by fluorescence imaging for 2-NBDG uptake by circulating breast cancer cells, and correlation of the number of hypermetabolic circulating breast cancer cells with tumor size at the time when the blood samples were collected.

Results

Human breast cancer xenograft tumors derived from MDA-MB-231, BT474, or SKBR-3 cells were visualized on near-infrared fluorescence imaging of the tumor-bearing mice injected with 2-DG 750. Hypermetabolic circulating breast cancer cells with increased uptake of fluorescent 2-NBDG were detected in the blood samples from tumor-bearing mice and visualized by fluorescence imaging, but not in the blood samples from normal control mice. The number of hypermetabolic circulating breast cancer cells increased along with growth of xenograft tumors, with the number of hypermetabolic circulating breast cancer cells detected in the mice bearing MDA-MB231 xenografts larger than those in the mice bearing BT474 or SKBR-3 xenograft tumors.

Conclusions

Circulating breast cancer cells with increased uptake of fluorescent 2-NBDG were detected in mice bearing human breast cancer xenograft tumors by fluorescence imaging, suggesting clinical use of 2-NBDG as a tracer for fluorescence imaging of hypermetabolic circulating breast cancer cells.     

Photoacoustic Spectroscopy to determine <Emphasis Type="Italic">in vitro</Emphasis> the non radiative relaxation time of protoporphyrin IX solution containing gold metallic nanoparticles

In order to compare the non radiative relaxation time (NRRT) between standard protoporphyrin IX (PpIX) and protoporphyrin PpIX(1) solution containing gold metallic nanoparticles, we measured the photoacoustic spectroscopy (PAS) signal phase to determine, for each solution, the NRRT by using the Rosencwaig-Gesho theory, modified to include the effect of a finite non radiative deexcitation time. A NRRT average value, obtained for each solution, is reported and compared with some NRRT of triplet states reported in the literature for molecules with the same tetrapyrrolic structure. In the study was used PpIX disodium salt (DS) solution of 25% HCL. From each solution it was obtained its optical absorption spectrum, by using a UV-Vis spectrophotometer. After this, in the maximum observed optical absorption peak (404 nm), it was obtained the Photoacoustic (PA) signal phase as a function of the light modulation frequency, from 17 to 80 Hz. Our investigations are devoted to the improvement of the thermal treatments of drugs for medical applications.