69 research outputs found
Rapid Stereomicroscopic Imaging of HER2 Overexpression in Ex Vivo Breast Tissue Using Topically Applied Silica-Based Gold Nanoshells
Tumor margin detection for patients undergoing breast conservation surgery primarily occurs postoperatively. Previously, we
demonstrated that gold nanoshells rapidly enhance contrast of HER2 overexpression in ex vivo tissue sections. Our ultimate
objective, however, is to discern HER2 overexpressing tissue from normal tissue in whole, nonsectioned, specimens to facilitate
rapid diagnoses. Here, we use targeted nanoshells to quickly and effectively visualize HER2 receptor expression in intact ex vivo
human breast tissue specimens. Punch biopsies of human breast tissue were analyzed after a brief 5-minute incubation with and
without HER2-targeted silica-gold nanoshells using two-photon microscopy and stereomicroscopy. Labeling was subsequently
verified using reflectance confocal microscopy, darkfield hyperspectral imaging, and immunohistochemistry to confirm levels
of HER2 expression. Our results suggest that anti-HER2 nanoshells used in tandem with a near-infrared reflectance confocal
microscope and a standard stereomicroscope may potentially be used to discern HER2-overexpressing cancerous tissue from
normal tissue in near real time and offer a rapid supplement to current diagnostic techniques
Changes in Optical Properties of Plasmonic Nanoparticles in Cellular Environments are Modulated by Nanoparticle PEGylation and Serum Conditions
When plasmonic nanoparticles (NPs) are internalized by cells and agglomerate within intracellular vesicles, their optical spectra can shift and broaden as a result of plasmonic coupling of NPs in close proximity to one another. For such optical changes to be accounted for in the design of plasmonic NPs for light-based biomedical applications, quantitative design relationships between designable factors and spectral shifts need to be established. Here we begin building such a framework by investigating how functionalization of gold NPs (AuNPs) with biocompatible poly(ethylene) glycol (PEG), and the serum conditions in which the NPs are introduced to cells impact the optical changes exhibited by NPs in a cellular context. Utilizing darkfield hyperspectral imaging, we find that PEGylation decreases the spectral shifting and spectral broadening experienced by 100 nm AuNPs following uptake by Sk-Br-3 cells, but up to a 33 ± 12 nm shift in the spectral peak wavelength can still occur. The serum protein-containing biological medium also modulates the spectral changes experienced by cell-exposed NPs through the formation of a protein corona on the surface of NPs that mediates NP interactions with cells: PEGylated AuNPs exposed to cells in serum-free conditions experience greater spectral shifts than in serum-containing environments. Moreover, increased concentrations of serum (10, 25, or 50 %) result in the formation of smaller intracellular NP clusters and correspondingly reduced spectral shifts after 5 and 10 h NP-cell exposure. However, after 24 h, NP cluster size and spectral shifts are comparable and become independent of serum concentration. By elucidating the impact of PEGylation and serum concentration on the spectral changes experienced by plasmonic NPs in cells, this study provides a foundation for the optical engineering of plasmonic NPs for use in biomedical environments
Incidental detection of an occult oral malignancy with autofluorescence imaging: a case report
BACKGROUND: Autofluorescence imaging is used widely for diagnostic evaluation of various epithelial malignancies. Cancerous lesions display loss of autofluorescence due to malignant changes in epithelium and subepithelial stroma. Carcinoma of unknown primary site presents with lymph node or distant metastasis, for which the site of primary tumour is not detectable. We describe here the use of autofluorescence imaging for detecting a clinically innocuous appearing occult malignancy of the palate which upon pathological examination was consistent with a metastatic squamous cell carcinoma.
CASE DESCRIPTION: A submucosal nodule was noted on the right posterior hard palate of a 59-year-old white female during clinical examination. Examination of this lesion using a multispectral oral cancer screening device revealed loss of autofluorescence at 405 nm illumination. An excisional biopsy of this nodule, confirmed the presence of a metastatic squamous cell carcinoma. Four years ago, this patient was diagnosed with metastatic squamous cell carcinoma of the right mid-jugular lymph node of unknown primary. She was treated with external beam irradiation and remained disease free until current presentation.
CONCLUSION: This case illustrates the important role played by autofluorescence tissue imaging in diagnosing a metastatic palatal tumour that appeared clinically innocuous and otherwise would not have been biopsied
Systematically probing the bottom-up synthesis of AuPAMAM conjugates for enhanced transfection efficiency
Comparison of mouse mammary gland imaging techniques and applications: Reflectance confocal microscopy, GFP Imaging, and ultrasound
<p>Abstract</p> <p>Background</p> <p>Genetically engineered mouse models of mammary gland cancer enable the <it>in vivo </it>study of molecular mechanisms and signaling during development and cancer pathophysiology. However, traditional whole mount and histological imaging modalities are only applicable to non-viable tissue.</p> <p>Methods</p> <p>We evaluated three techniques that can be quickly applied to living tissue for imaging normal and cancerous mammary gland: reflectance confocal microscopy, green fluorescent protein imaging, and ultrasound imaging.</p> <p>Results</p> <p>In the current study, reflectance confocal imaging offered the highest resolution and was used to optically section mammary ductal structures in the whole mammary gland. Glands remained viable in mammary gland whole organ culture when 1% acetic acid was used as a contrast agent. Our application of using green fluorescent protein expressing transgenic mice in our study allowed for whole mammary gland ductal structures imaging and enabled straightforward serial imaging of mammary gland ducts in whole organ culture to visualize the growth and differentiation process. Ultrasound imaging showed the lowest resolution. However, ultrasound was able to detect mammary preneoplastic lesions 0.2 mm in size and was used to follow cancer growth with serial imaging in living mice.</p> <p>Conclusion</p> <p>In conclusion, each technique enabled serial imaging of living mammary tissue and visualization of growth and development, quickly and with minimal tissue preparation. The use of the higher resolution reflectance confocal and green fluorescent protein imaging techniques and lower resolution ultrasound were complementary.</p
Refractive index tomography of turbid media by bifocal optical coherence refractometry
We demonstrate tomographic imaging of the refractive index of turbid media using bifocal optical coherence refractometry (BOCR). The technique, which is a variant of optical coherence tomography, is based on the measurement of the optical pathlength difference between two foci simultaneously present in a medium of interest. We describe a new method to axially shift the bifocal optical pathlength that avoids the need to physically relocate the objective lens or the sample during an axial scan, and present an experimental realization based on an adaptive liquid-crystal lens. We present experimental results, including video clips, which demonstrate refractive index tomography of a range of turbid liquid phantoms, as well as of human skin in vivo.<br /
Enhanced Raman Scattering from Nanoparticle-Decorated Nanocone Substrates: A Practical Approach to Harness In-Plane Excitation
Omics-based molecular techniques in oral pathology centred cancer: Prospect and challenges in Africa
: The completion of the human genome project and the accomplished milestones in the human
proteome project; as well as the progress made so far in computational bioinformatics and “big data” processing have
contributed immensely to individualized/personalized medicine in the developed world.At the dawn of precision medicine, various omics-based therapies and bioengineering can now be
applied accurately for the diagnosis, prognosis, treatment, and risk stratifcation of cancer in a manner that was
hitherto not thought possible. The widespread introduction of genomics and other omics-based approaches into
the postgraduate training curriculum of diverse medical and dental specialties, including pathology has improved
the profciency of practitioners in the use of novel molecular signatures in patient management. In addition, intricate
details about disease disparity among diferent human populations are beginning to emerge. This would facilitate the
use of tailor-made novel theranostic methods based on emerging molecular evidences
Parallel FDTD Simulation of the Scattering of Light in Media Containing Cylindrical Scatterers
- …