423 research outputs found

    Cellulose Nanoparticles are a Biodegradable Photoacoustic Contrast Agent for Use in Living Mice.

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    Molecular imaging with photoacoustic ultrasound is an emerging field that combines the spatial and temporal resolution of ultrasound with the contrast of optical imaging. However, there are few imaging agents that offer both high signal intensity and biodegradation into small molecules. Here we describe a cellulose-based nanoparticle with peak photoacoustic signal at 700 nm and an in vitro limit of detection of 6 pM (0.02 mg/mL). Doses down to 0.35 nM (1.2 mg/mL) were used to image mouse models of ovarian cancer. Most importantly, the nanoparticles were shown to biodegrade in the presence of cellulase both through a glucose assay and electron microscopy

    A Magnetic Bead-Based Sensor for the Quantification of Multiple Prostate Cancer Biomarkers.

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    Novel biomarker assays and upgraded analytical tools are urgently needed to accurately discriminate benign prostatic hypertrophy (BPH) from prostate cancer (CaP). To address this unmet clinical need, we report a piezeoelectric/magnetic bead-based assay to quantitate prostate specific antigen (PSA; free and total), prostatic acid phosphatase, carbonic anhydrase 1 (CA1), osteonectin, IL-6 soluble receptor (IL-6sr), and spondin-2. We used the sensor to measure these seven proteins in serum samples from 120 benign prostate hypertrophy patients and 100 Gleason score 6 and 7 CaP using serum samples previously collected and banked. The results were analyzed with receiver operator characteristic curve analysis. There were significant differences between BPH and CaP patients in the PSA, CA1, and spondin-2 assays. The highest AUC discrimination was achieved with a spondin-2 OR free/total PSA operation--the area under the curve was 0.84 with a p value below 10(-6). Some of these data seem to contradict previous reports and highlight the importance of sample selection and proper assay building in the development of biomarker measurement schemes. This bead-based system offers important advantages in assay building including low cost, high throughput, and rapid identification of an optimal matched antibody pair

    Molecular Optical Imaging with Radioactive Probes

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    Background: Optical imaging (OI) techniques such as bioluminescence and fluorescence imaging have been widely used to track diseases in a non-invasive manner within living subjects. These techniques generally require bioluminescent and fluorescent probes. Here we demonstrate the feasibility of using radioactive probes for in vivo molecular OI. Methodology/Principal Findings: By taking the advantages of low energy window of light (1.2–3.1 eV, 400–1000 nm) resulting from radiation, radionuclides that emit charged particles such as b + and b 2 can be successfully imaged with an OI instrument. In vivo optical images can be obtained for several radioactive probes including 2-deoxy-2- [ 18 F]fluoro-D-glucos

    Imaging Tri-Fusion Multimodality Reporter Gene Expression in Living Subjects

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    Quantum dot imaging for embryonic stem cells

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    <p>Abstract</p> <p>Background</p> <p>Semiconductor quantum dots (QDs) hold increasing potential for cellular imaging both <it>in vitro </it>and <it>in vivo</it>. In this report, we aimed to evaluate <it>in vivo </it>multiplex imaging of mouse embryonic stem (ES) cells labeled with Qtracker delivered quantum dots (QDs).</p> <p>Results</p> <p>Murine embryonic stem (ES) cells were labeled with six different QDs using Qtracker. ES cell viability, proliferation, and differentiation were not adversely affected by QDs compared with non-labeled control cells (<it>P </it>= NS). Afterward, labeled ES cells were injected subcutaneously onto the backs of athymic nude mice. These labeled ES cells could be imaged with good contrast with one single excitation wavelength. With the same excitation wavelength, the signal intensity, defined as (total signal-background)/exposure time in millisecond was 11 ± 2 for cells labeled with QD 525, 12 ± 9 for QD 565, 176 ± 81 for QD 605, 176 ± 136 for QD 655, 167 ± 104 for QD 705, and 1,713 ± 482 for QD 800. Finally, we have shown that QD 800 offers greater fluorescent intensity than the other QDs tested.</p> <p>Conclusion</p> <p>In summary, this is the first demonstration of <it>in vivo </it>multiplex imaging of mouse ES cells labeled QDs. Upon further improvements, QDs will have a greater potential for tracking stem cells within deep tissues. These results provide a promising tool for imaging stem cell therapy non-invasively <it>in vivo</it>.</p
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