Optical Attenuation Properties Research Articles

NIR-I Activated Orthogonal NIR-IIb/c Emissions in a Lanthanide-Doped Nanoparticle for Fluorescence Imaging and Information Encryption.

Applying the orthogonal principle for distinguishable second near-infrared (NIR-II) emissions has brought new dimensions for ratio fluorescence imaging (RFI) detection and information encryption, deepening the tissue detection depth and improving signal-to-noise ratio and information security. However, the orthogonal NIR-II emissions underlying these advanced optical applications have been reported only in heterogeneous structures and mixtures, limiting their practicality and potential impact. Herein, NIR-I-activated orthogonal NIR-IIb/c (1530/1825nm) emissions nanoparticles (ONNPs) are developed by spatially separated doping of Tm3+ and Er3+ emitter upon switching 808 and 980nm excitations. RFI techniques and orthogonal NIR-II emission ONNPs are used to demonstrate vessel depth detection based on wavelength-dependent optical attenuation properties in tissue. The superiority of the optical coding and encoding process in a 4×1 binary matrix is demonstrated for anticounterfeiting and decryption imaging of quick-response (QR) code for information storage. The research progress of this NIR-II orthogonal emissions probe will drive the development of biomedical sensing, imaging safety, and future biophotonics technologies.

Customized Enhancement of Thermal Sensitivity of Tumors at Different Subcutaneous Depths by Multichannel Lanthanide Nanocomposites.

The photothermal therapeutic effect on tumors located at different subcutaneous depths varies due to the attenuation of light by tissue. Here, based on the wavelength-dependent optical attenuation properties of tissues, the tumor depth is assessed using a multichannel lanthanide nanocomposite. A zeolitic imidazolate framework (ZIF-8)-coated nanocomposite is able to deliver high amounts of the hydrophilic heat shock protein 90 inhibitor epigallocatechin gallate through a hydrogen-bonding network formed by the encapsulated highly polarized polyoxometalate guest. It is superior to both bare and PEGylated ZIF-8 for drug delivery. With the assessment of tumor depth and accumulated amount of nanocomposite by fluorescence, an irradiation prescription can be customized to release sufficient HSP90 inhibitor and generate heat for sensitized photothermal treatment of tumors, which not only ensured therapeutic efficacy but also minimized damage to the surrounding tissues.

Assessing silver nanoparticle uptake dynamics in young zebrafish using swept source optical coherence tomography

Understanding the uptake and accumulation of nanoparticles in living organisms is crucial for assessing their potential effects on health and the environment. In this study, we employed a Swept Source Optical Coherence Tomography (SSOCT) system to investigate the dynamics of silver nanoparticle (AgNP) uptake during various developmental stages of zebrafish. Silver nanoparticles in the 20 nm range were synthesized and their uptake and accumulation in developing zebrafish embryos were studied over time. Changes in optical attenuation properties observed in SSOCT images allowed identification of nanoparticle uptake and accumulation in the eye, intestine, and gill region of developing zebrafish. The changes were quantified by deriving average local attenuation coefficient values. To validate our findings, inductively-coupled plasma optical emission spectrometry (ICP-OES) analysis was performed.

459 Neuro-Oncology Spectral Fingerprint Biorepository: A Novel Approach Leveraging a Surgical and Clinical Detailed Repository in a Diverse Patient Population

INTRODUCTION: Despite advances in the understanding of brain cancer, surgery and extent of resection (EOR) continue to be the main predictors of patient outcome. However, currently available public biorepositories do not include extent of resection for individual patients raising important questions regarding confounding effects for some molecular markers. Further, emerging data has supported important novel biomarkers in tumor’s lipidome and optical attenuation properties which could serve as new therapeutic opportunities. METHODS: All neuro-oncology surgical cases at our institution were eligible for collection since 2016. Blood was collected from every patient pre-operatively. Cerebrospinal fluid was collected whenever surgically safe. Genomic and transcriptomic analysis was performed. Intra-operative spectral and optical attenuation data was obtained through desorption electrospray ionization mass spectrometry (DESI-MS) over 0 to 1000 m/z and optical coherence tomography, respectively, for biomarker discovery. RESULTS: A total of 912 unique patient collections have been performed including 286 gliomas and 205 other rare brain tumors. Demographic, clinical, imaging, surgical and survival data was curated for each individual patient. Extent of resection (EOR) was determined for each patient, with an average of 78.6% for chordomas, 85.9% in glioblastoma, 88.3% in other high-grade gliomas and 72% in low-grade gliomas with predictive of progression-free survival (p < 0.01) and overall survival (p < 0.01). Comprehensive sequencing has been completed for 131 gliomas. Of those, lipid and optical profiling has been completed for multiple tumor samples (330) from a total of 79 patients. CONCLUSIONS: We have curated a large biorepository of neuro-oncology tumors with detailed patient information including for the first time to our knowledge detailed surgical, imaging, spectral and optical information. Efforts are ongoing at large-scale biomarker discovery leveraging the unique spectral and optical fingerprint of each tumor to their genomic/transcriptomic profile.

Simultaneous ultra-high frequency photoacoustic microscopy and photoacoustic radiometry of zebrafish larvae in vivo

With their optically transparent appearance, zebrafish larvae are readily imaged with optical-resolution photoacoustic (PA) microscopy (OR-PAM). Previous OR-PAM studies have mapped endogenous chromophores (e.g. melanin and hemoglobin) within larvae; however, anatomical features cannot be imaged with OR-PAM alone due to insufficient optical absorption. We have previously reported on the photoacoustic radiometry (PAR) technique, which can be used simultaneously with OR-PAM to generate images dependent upon the optical attenuation properties of a sample. Here we demonstrate application of the duplex PAR/PA technique for label-free imaging of the anatomy and vasculature of zebrafish larvae in vivo at 200 and 400 MHz ultrasound detection frequencies. We then use the technique to assess the effects of anti-angiogenic drugs on the development of the larval vasculature. Our results demonstrate the effectiveness of simultaneous PAR/PA for acquiring anatomical images of optically transparent samples in vivo, and its potential applications in assessing drug efficacy and embryonic development.

Triplex micron-resolution acoustic, photoacoustic, and optical transmission microscopy via photoacoustic radiometry.

We present a new sensing technique, termed photoacoustic radiometry (PAR), for mapping the optical attenuation properties of a sample. In PAR, laser pulses attenuated via transmission through the sample impinge on the ultrasound transducer and generate a photoacoustic (PA) signal within it. Spatial variation of the optical attenuation properties of the sample influences the amplitude of the PAR signal, providing image contrast. Performed simultaneously with pulse-echo ultrasound and PA imaging, this triplex imaging technique enables rapid characterization of samples with micrometer-resolution in a single scan. In this work, we demonstrate that the PAR technique can be easily integrated into existing PA microscopy systems, with applications in imaging biological samples and non-destructive evaluation of optically opaque materials such as silicon wafers.

WE-C-217BCD-08: Rapid Monte Carlo Simulations of DQE(f) of Scintillator-Based Detectors.

Monte Carlo simulations of DQE(f) can greatly aid in the design of scintillator-based detectors by helping optimize key parameters including scintillator material and thickness, pixel size, surface finish, and septa reflectivity. However, the additional optical transport significantly increases simulation times, necessitating a large number of parallel processors to adequately explore the parameter space. To address this limitation, we have optimized the DQE(f) algorithm, reducing simulation times per design iteration to 10 minutes on a single CPU. DQE(f) is proportional to the ratio, MTF(f)̂2 /NPS(f). The LSF-MTF simulation uses a slanted line source and is rapidly performed with relatively few gammas launched. However, the conventional NPS simulation for standard radiation exposure levels requires the acquisition of multiple flood fields (nRun), each requiring billions of input gamma photons (nGamma), many of which will scintillate, thereby producing thousands of optical photons (nOpt) per deposited MeV. The resulting execution time is proportional to the product nRun x nGamma x nOpt. In this investigation, we revisit the theoretical derivation of DQE(f), and reveal significant computation time savings through the optimization of nRun, nGamma, and nOpt. Using GEANT4, we determine optimal values for these three variables for a GOS scintillator-amorphous silicon portal imager. Both isotropic and Mie optical scattering processes were modeled. Simulation results were validated against the literature. We found that, depending on the radiative and optical attenuation properties of the scintillator, the NPS can be accurately computed using values for nGamma below 1000, and values for nOpt below 500/MeV. nRun should remain above 200. Using these parameters, typical computation times for a complete NPS ranged from 2-10 minutes on a single CPU. The number of launched particles and corresponding execution times for a DQE simulation can be dramatically reduced allowing for accurate computation with modest computer hardware. NIHRO1 CA138426. Several authors work for Varian Medical Systems.