Ratiometric spectral imaging for fast tumor detection and chemotherapy monitoring in vivo

We report a novel in vivo spectral imaging approach to cancer detection and chemotherapy assessment. We describe and characterize a ratiometric spectral imaging and analysis method and evaluate its performance for tumor detection and delineation by quantitatively monitoring the specific accumulation of targeted gallium corrole (HerGa) into HER2-positive (HER2 +) breast tumors. HerGa temporal accumulation in nude mice bearing HER2 + breast tumors was monitored comparatively by a. this new ratiometric imaging and analysis method; b. established (reflectance and fluorescence) spectral imaging; c. more commonly used fluorescence intensity imaging. We also tested the feasibility of HerGa imaging in vivo using the ratiometric spectral imaging method for tumor detection and delineation. Our results show that the new method not only provides better quantitative information than typical spectral imaging, but also better specificity than standard fluorescence intensity imaging, thus allowing enhanced in vivo outlining of tumors and dynamic, quantitative monitoring of targeted chemotherapy agent accumulation into them

Multimode Hyperspectral Imaging for Food Quality and Safety

Food safety and quality are becoming progressively important, and a failure to implement monitoring processes and identify anomalies in composition, production, and distribution can lead to severe financial and customer health damages. If consumers were uncertain about food safety and quality, the impact could be profound; hence, we need better ways of minimizing such risks. On the data management side, the rise of artificial intelligence, data analytics, the Internet of Things, and blockchain all provide enormous opportunities for supply chain management and liability management, but the impact of any approach starts with the quality of the relevant data. Here, we present state-of-the-art spectroscopic technologies including hyperspectral reflectance, fluorescence imaging as well as Raman spectroscopy, and speckle imaging that are all validated for food safety and quality applications. We believe a multimode approach comprising of a number of these synergetic optical detection modes is needed for the highest performance. We present a plan where our implementations reflect this concept through a multimode tabletop system in the sense that a large, real-time production-level device would be based on more modes than this mid-level one, while a handheld, portable unit may only address fewer challenges, but with a lower cost and size

Bioelectronic DNA detection of human papillomaviruses using eSensor™: a model system for detection of multiple pathogens

BACKGROUND: We used human papillomaviruses (HPV) as a model system to evaluate the utility of a nucleic acid, hybridization-based bioelectronic DNA detection platform (eSensor™) in identifying multiple pathogens. METHODS: Two chips were spotted with capture probes consisting of DNA oligonucleotide sequences specific for HPV types. Electrically conductive signal probes were synthesized to be complementary to a distinct region of the amplified HPV target DNA. A portion of the HPV L1 region that was amplified by using consensus primers served as target DNA. The amplified target was mixed with a cocktail of signal probes and added to a cartridge containing a DNA chip to allow for hybridization with complementary capture probes. RESULTS: Two bioelectric chips were designed and successfully detected 86% of the HPV types contained in clinical samples. CONCLUSIONS: This model system demonstrates the potential of the eSensor platform for rapid and integrated detection of multiple pathogens

Investigating photoexcitation-induced mitochondrial damage by chemotherapeutic corroles using multimode optical imaging

We recently reported that a targeted, brightly fluorescent gallium corrole (HerGa) is highly effective for breast tumor detection and treatment. Unlike structurally similar porphryins, HerGa exhibits tumor-targeted toxicity without the need for photoexcitation. We have now examined whether photoexcitation further modulates HerGa toxicity, using multimode optical imaging of live cells, including two-photon excited fluorescence, differential interference contrast (DIC), spectral, and lifetime imaging. Using two-photon excited fluorescence imaging, we observed that light at specific wavelengths augments the HerGa-mediated mitochondrial membrane potential disruption of breast cancer cells in situ. In addition, DIC, spectral, and fluorescence lifetime imaging enabled us to both validate cell damage by HerGa photoexcitation and investigate HerGa internalization, thus allowing optimization of light dose and timing. Our demonstration of HerGa phototoxicity opens the way for development of new methods of cancer intervention using tumor-targeted corroles

Multimodality imaging in vivo for preclinical assessment of tumor-targeted doxorubicin nanoparticles.

This study presents a new multimodal imaging approach that includes high-frequency ultrasound, fluorescence intensity, confocal, and spectral imaging to improve the preclinical evaluation of new therapeutics in vivo. Here we use this approach to assess in vivo the therapeutic efficacy of the novel chemotherapy construct, HerDox during and after treatment. HerDox is comprised of doxorubicin non-covalently assembled in a viral-like particle targeted to HER2+ tumor cells, causing tumor cell death at over 10-fold lower dose compared to the untargeted drug, while sparing the heart. Whereas our initial proof-of-principle studies on HerDox used tumor growth/shrinkage rates as a measure of therapeutic efficacy, here we show that multimodal imaging deployed during and after treatment can supplement traditional modes of tumor monitoring to further characterize the particle in tissues of treated mice. Specifically, we show here that tumor cell apoptosis elicited by HerDox can be monitored in vivo during treatment using high frequency ultrasound imaging, while in situ confocal imaging of excised tumors shows that HerDox indeed penetrated tumor tissue and can be detected at the subcellular level, including in the nucleus, via Dox fluorescence. In addition, ratiometric spectral imaging of the same tumor tissue enables quantitative discrimination of HerDox fluorescence from autofluorescence in situ. In contrast to standard approaches of preclinical assessment, this new method provides multiple/complementary information that may shorten the time required for initial evaluation of in vivo efficacy, thus potentially reducing the time and cost for translating new drug molecules into the clinic

Tumor detection and elimination by a targeted gallium corrole

Sulfonated gallium(III) corroles are intensely fluorescent macrocyclic compounds that spontaneously assemble with carrier proteins to undergo cell entry. We report in vivo imaging and therapeutic efficacy of a tumor-targeted corrole noncovalently assembled with a heregulin-modified protein directed at the human epidermal growth factor receptor (HER). Systemic delivery of this protein-corrole complex results in tumor accumulation, which can be visualized in vivo owing to intensely red corrole fluorescence. Targeted delivery in vivo leads to tumor cell death while normal tissue is spared. These findings contrast with the effects of doxorubicin, which can elicit cardiac damage during therapy and required direct intratumoral injection to yield similar levels of tumor shrinkage compared with the systemically delivered corrole. The targeted complex ablated tumors at >5 times a lower dose than untargeted systemic doxorubicin, and the corrole did not damage heart tissue. Complexes remained intact in serum and the carrier protein elicited no detectable immunogenicity. The sulfonated gallium(III) corrole functions both for tumor detection and intervention with safety and targeting advantages over standard chemotherapeutic agents

Multimode optical imaging for translational chemotherapy: in vivo tumor detection and delineation by targeted gallium corroles

We report the feasibility of tumor detection and delineation in vivo using multimode optical imaging of targeted gallium corrole (HerGa). HerGa is highly effective for targeted HER2+ tumor elimination in vivo, and it emits intense fluorescence. These unique characteristics of HerGa prompted us to investigate the potential of HerGa for tumor detection and delineation, by performing multimode optical imaging ex vivo and in vivo; the imaging modes included fluorescence intensity, spectral (including ratiometric), lifetime, and two-photon excited fluorescence, using our custombuilt imaging system. While fluorescence intensity imaging provided information about tumor targeting capacity and tumor retention of HerGa, ratiometric spectral imaging offered more quantitative and specific information about HerGa location and accumulation. Most importantly, the fluorescence lifetime imaging of HerGa allowed us to discriminate between tumor and non-tumor regions by fluorescence lifetime differences. Finally, two-photon excited fluorescence images provided highly resolved and thus topologically detailed information around the tumor regions where HerGa accumulates. Taken together, the results shown in this report suggest the feasibility of tumor detection and delineation by multimode optical imaging of HerGa, and fluorescent chemotherapy agents in general. Specifically, the multimode optical imaging can offer complementary and even synergetic information simultaneously in the tumor detection and delineation by HerGa, thus enhancing contrast

Difference in the action spectra for UVR8 monomerisation and HY5 transcript accumulation in Arabidopsis

The photoreceptor UV RESISTANCE LOCUS 8 (UVR8) activates photomorphogenic responses when plants are exposed to ultraviolet-B (UV-B) light. However, whereas the absorption spectrum of UVR8 peaks at 280 nm, action spectra for several photomorphogenic UV-B responses show maximal photon effectiveness at 290–300 nm. To investigate this apparent discrepancy we measured the effectiveness of UV wavelengths in initiating two responses in Arabidopsis: photoconversion of homodimeric UVR8 into the monomeric form, which is active in signaling, and accumulation of transcripts of the ELONGATED HYPOCOTYL 5 (HY5) transcription factor, which has a key role in UVR8-mediated responses. When purified UVR8 or Arabidopsis leaf extracts were exposed to UV light monomerisation was maximal at approximately 280 nm, which correlates with the UVR8 absorption spectrum. When intact plants were exposed to UV, monomerisation was most strongly initiated at approximately 290 nm, and this shift in maximal effectiveness could be explained by strong absorption or reflectance at 280 nm by leaf tissue. Notably, the action spectrum for accumulation of HY5 transcripts in the same leaf tissue samples used to assay UVR8 dimer/monomer status peaked at approximately 300 nm. Possible reasons for the difference in maximal photon effectiveness of UVR8 monomerisation and HY5 transcript accumulation in leaf tissue are discussed

Large field of view scanning fluorescence lifetime imaging system for multimode optical imaging of small animals

We describe a scanning fluorescence lifetime imaging (SFLIM) system that provides a large field of view (LFOV), using a femtosecond (fs) pulsed laser, for multi-mode optical imaging of small animals. Fluorescence lifetime imaging (FLIM) can be a useful optical method to distinguish between fluorophores inside small animals. However, difficulty arises when LFOV is required in FLIM using a fs pulsed laser for the excitation of the fluorophores at low wavelengths (<500nm), primarily because the field of view of the pulsed blue excitation light generated from the second harmonic of the fs pulsed light is limited to about a centimeter in diameter due to the severe scattering and absorption of the light inside tissues. Here, we choose a scanning method in order to acquire a FLIM image with LFOV as one alternative. In the SFLIM system, we used a conventional cooled CCD camera coupled to an ultra-fast time-gated intensifier, a tunable femtosecond laser for the excitation of fluorophores, and an x-y moving stage for scanning. Images acquired through scanning were combined into a single image and then this reconstructed image was compared with images obtained by spectral imaging. The resulting SFLIM system is promising as an alternative method for the FLIM imaging of small animals, containing fluorophores exited by blue light, for LFOV applications such as whole animal imaging

Large field of view scanning fluorescence lifetime imaging system for multimode optical imaging of small animals

We describe a scanning fluorescence lifetime imaging (SFLIM) system that provides a large field of view (LFOV), using a femtosecond (fs) pulsed laser, for multi-mode optical imaging of small animals. Fluorescence lifetime imaging (FLIM) can be a useful optical method to distinguish between fluorophores inside small animals. However, difficulty arises when LFOV is required in FLIM using a fs pulsed laser for the excitation of the fluorophores at low wavelengths (<500nm), primarily because the field of view of the pulsed blue excitation light generated from the second harmonic of the fs pulsed light is limited to about a centimeter in diameter due to the severe scattering and absorption of the light inside tissues. Here, we choose a scanning method in order to acquire a FLIM image with LFOV as one alternative. In the SFLIM system, we used a conventional cooled CCD camera coupled to an ultra-fast time-gated intensifier, a tunable femtosecond laser for the excitation of fluorophores, and an x-y moving stage for scanning. Images acquired through scanning were combined into a single image and then this reconstructed image was compared with images obtained by spectral imaging. The resulting SFLIM system is promising as an alternative method for the FLIM imaging of small animals, containing fluorophores exited by blue light, for LFOV applications such as whole animal imaging