skip to main content


Title: Projection method as a probe for multiplexing/demultiplexing of magnetically enriched biological tissues
The unmet demand for cheap, accurate, and fast multiplexing of biomarkers has urged nanobiotechnology to prioritize the invention of new biomarkers that make feasible the remote detection, identification, and quantification of biological units, such as regenerative tissues. Here, we introduce a novel approach that highlights magnetic nanowires (MNWs) with such capabilities. This method employs the stable magnetization states of MNWs as a unique characteristic that can be realized by projecting the MNWs' switching field on the backward field ( P Hb ), also known as the irreversible switching field. Experimentally, several types of MNWs were directly synthesized inside polycarbonate tissues and their P Hb characteristics were measured and analyzed. Our results show that the P Hb gives an excellent identification and quantification characteristic for demultiplexing MNWs embedded in these tissues. Furthermore, this method significantly improves the characterization speed by a factor of 50×–100× that makes it superior to the current state of the art that ceased the progression of magnetic nanoparticles in multiplexing/demultiplexing applications.  more » « less
Award ID(s):
1642268
NSF-PAR ID:
10209704
Author(s) / Creator(s):
;
Date Published:
Journal Name:
RSC Advances
Volume:
10
Issue:
22
ISSN:
2046-2069
Page Range / eLocation ID:
13286 to 13292
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. MRI leverages multiple modes of contrast to characterize stroke. High‐magnetic‐field systems enhance the performance of these MRI measurements. Previously, we have demonstrated that individually sodium and stem cell tracking metrics are enhanced at ultrahigh field in a rat model of stroke, and we have developed robust single‐scan diffusion‐weighted imaging approaches that utilize spatiotemporal encoding (SPEN) of the apparent diffusion coefficient (ADC) for these challenging field strengths. Here, we performed a multiparametric study of middle cerebral artery occlusion (MCAO) biomarker evolution focusing on comparison of these MRI biomarkers for stroke assessment during sub‐acute recovery in rat MCAO models at 21.1 T.T2‐weighted MRI was used as the benchmark for identification of the ischemic lesion over the course of the study. The number of MPIO‐induced voids measured by gradient‐recalled echo, the SPEN measurement of ADC, and23Na MRI values were determined in the ischemic area and contralateral hemisphere, and relative performances for stroke classification were compared by receiver operator characteristic analysis. These measurements were associated with unique time‐dependent trajectories during stroke recovery that changed the sensitivity and specificity for stroke monitoring during its evolution. Advantages and limitations of these contrasts, and the use of ultrahigh field for multiparametric stroke assessment, are discussed.

     
    more » « less
  2. Abstract

    Non-invasive measurement of absolute temperature is important for proper characterization of various pathologies and for evaluation of thermal dose during interventional procedures. The proton (hydrogen nucleus) magnetic resonance (MR) frequency shift method can be used to map relative temperature changes. However, spatiotemporal variations in the main magnetic field and the lack of local internal frequency reference challenge the determination of absolute temperature. Here, we introduce a multinuclear method for absolute MR thermometry, based on the fact that the hydrogen and sodium nuclei exhibit a unique and distinct characteristic frequency dependence with temperature and with electrolyte concentration. A one-to-one mapping between the precession frequency difference of the two nuclei and absolute temperature is demonstrated. Proof-of-concept experiments were conducted in aqueous solutions with different NaCl concentrations, in agarose gel samples, and in freshly excised ex vivo mouse tissues. One-dimensional chemical shift imaging experiments also demonstrated excellent agreement with infrared measurements.

     
    more » « less
  3. Abstract

    Neuropeptides have tremendous potential for application in modern medicine, including utility as biomarkers and therapeutics. To overcome the inherent challenges associated with neuropeptide identification and characterization, data‐independent acquisition (DIA) is a fitting mass spectrometry (MS) method of choice to achieve sensitive and accurate analysis. It is advantageous for preliminary neuropeptidomic studies to occur in less complex organisms, with crustacean models serving as a popular choice due to their relatively simple nervous system. With spectral libraries serving as a means to interpret DIA‐MS output spectra, andCancer borealisas a model of choice for neuropeptide analysis, we performed the first spectral library mapping of crustacean neuropeptides. Leveraging pre‐existing data‐dependent acquisition (DDA) spectra, a spectral library was built using PEAKS Online. The library is comprised of 333 unique neuropeptides. The identification results obtained through the use of this spectral library were compared with those achieved through library‐free analysis of crustacean brain, pericardial organs (PO), and thoracic ganglia (TG) tissues. A statistically significant increase (Student'st‐test,Pvalue < 0.05) in the number of identifications achieved from the TG data was observed in the spectral library results. Furthermore, in each of the tissues, a distinctly different set of identifications was found in the library search compared to the library‐free search. This work highlights the necessity for the use of spectral libraries in neuropeptide analysis, illustrating the advantage of spectral libraries for interpreting DIA spectra in a reproducible manner with greater neuropeptidomic depth.

     
    more » « less
  4. Abstract

    Tissues and engineered biomaterials exhibit exquisite local variation in stiffness that defines their function. Conventional elastography quantifies stiffness in soft (e.g. brain, liver) tissue, but robust quantification in stiff (e.g. musculoskeletal) tissues is challenging due to dissipation of high frequency shear waves. We describe new development offinite deformation elastographythat utilizes magnetic resonance imaging of low frequency, physiological-level (large magnitude) displacements, coupled to an iterative topology optimization routine to investigate stiffness heterogeneity, including spatial gradients and inclusions. We reconstruct 2D and 3D stiffness distributions in bilayer agarose hydrogels and silicon materials that exhibit heterogeneous displacement/strain responses. We map stiffness in porcine and sheep articular cartilage deep within the bony articular joint spacein situfor the first time. Elevated cartilage stiffness localized to the superficial zone is further related to collagen fiber compaction and loss of water content during cyclic loading, as assessed by independentT2measurements. We additionally describe technical challenges needed to achievein vivoelastography measurements. Our results introduce new functional imaging biomarkers, which can be assessed nondestructively, with clinical potential to diagnose and track progression of disease in early stages, including osteoarthritis or tissue degeneration.

     
    more » « less
  5. null (Ed.)
    Nuclear Magnetic Resonance (NMR) spectroscopy is a quantitative analytical tool commonly utilized for metabolomics analysis. Quantitative NMR (qNMR) is a field of NMR spectroscopy dedicated to the measurement of analytes through signal intensity and its linear relationship with analyte concentration. Metabolomics-based NMR exploits this quantitative relationship to identify and measure biomarkers within complex biological samples such as serum, plasma, and urine. In this review of quantitative NMR-based metabolomics, the advancements and limitations of current techniques for metabolite quantification will be evaluated as well as the applications of qNMR in biomedical metabolomics. While qNMR is limited by sensitivity and dynamic range, the simple method development, minimal sample derivatization, and the simultaneous qualitative and quantitative information provide a unique landscape for biomedical metabolomics, which is not available to other techniques. Furthermore, the non-destructive nature of NMR-based metabolomics allows for multidimensional analysis of biomarkers that facilitates unambiguous assignment and quantification of metabolites in complex biofluids. 
    more » « less