Saurin Kantesaria’s research while affiliated with Center for Magnetic Resonance Research Minnesota, USA and other places

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Publications (5)


Fig. 1: Schematic flow of steps (left to right) in liter scale vitrification and rewarming. Liter volumes of a CPA (0.5-3L) in cryobags are large enough to hold a human organ. The cryobag is placed inside a controlled rate freezer (CRF) for cooling. For nanowarming (top section of the
Fig. 2: Demonstration of physical success of vitrification in multiple volumes. a Table summarizes vitrification results for all the 3 CPAs and volumes. Photos of a successful vitrified (glass) M22 inside a cryobag for b 0.5 Liter, c 1 Liter, and d 3 Liter (largest volume reported). The out-of-plane thicknesses are 5.5, 6.5, and 10.5 cm for 0.5, 1, and 3L cryobags, respectively.
Fig. 3: Thermal results from experimental and modeled liter scale CPA vitrification. a Schematic for a representative case, 0.5 L cryobag containing CPA with placement of three fiber optic temperature probes (3 cm apart). Blue arrows show the direction of LN2 flow in CRF. b Experimental and predicted temperature vs. time plot for 0.5L M22. The dashed green line shows the programmed CRF temperature profile/protocol. c CRF cooling protocols for 0.5, 1, and 3 L volumes. The regions of ice formation and fracture danger are labeled. Scatter plot of d center cooling rate and e temperature difference (ΔTmax in the glassy region) for all three volumes tested for M22 (mean ± SD; n=3). Cooling rate is calculated in ranges 0 to -100 °C and -120 to -150 °C for temperature difference plots. Mean cooling rates are greater than the CCR of M22 (~0.1°C/min). Temperature differences are within the allowable limit (dashed) (< 20°C) calculated from a simple thermal shock equation [20].
Fig. 4: Photos of the porcine liver (left) before (T = 4°C) and (right) after vitrification (T = -150°C). The pattern in the photo was due to the cryobag placement on a supporting mesh in the control rate freezer (CRF) (see Fig. S7B). The cryobag was removed for the vitrified liver photo to reduce glare and get a clear photo.
Fig. 6: Nanowarming specific absorption rate (SAR). a Plot of SARFe (SARV/ CFe) vs. magnetic field strength (H) measured at room temperature for iron-oxide nanoparticles IONPs (sIONPs in M22 shown here) at two frequencies (190 and 360kHz) (plotted mean ± SD; n=3). b Plot of SARFe vs. temperature for sIONPs in M22. Average SARFe (mean ± SD; n=3) is plotted in three different temperature regions, i.e., glass, supercooled, and liquid. SAR is measured from

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Physical vitrification and nanowarming at human organ scale to enable cryopreservation
  • Preprint
  • File available

November 2024

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101 Reads

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1 Citation

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Zonghu Han

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Cameron Scheithauer

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Organ banking by vitrification could revolutionize transplant medicine. However, vitrification and rewarming have never been demonstrated at the human organ scale. Using modeling and experimentation, we tested the ability to vitrify and rewarm 0.5–3 L volumes of three common cryoprotective agent (CPA) solutions: M22, VS55, and 40% EG+0.6M Sucrose. We first demonstrated our ability to avoid ice formation by convectively cooling faster than the critical cooling rates of these CPAs while also maintaining adequate uniformity to avoid cracking. Vitrification success was then verified by visual, thermometry, and x-ray μCT inspection. M22 and EG+sucrose were successfully vitrified in 0.5 L bags, but only M22 was vitrified at 3 L. VS55 did not vitrify at any tested volumes. As additional proof of principle, we successfully vitrified a porcine liver (~1L) after perfusion loading with 40% EG+0.6M Sucrose. Uniform volumetric rewarming was then achieved in up to 2 L volumes (M22 with ~5 mgFe/mL iron-oxide nanoparticles) using nanowarming, reaching a rate of ~88 °C/min with a newly developed 120 kW radiofrequency (RF) coil operating at 35kA/m and 360kHz. This work demonstrates that human organ scale vitrification and rewarming is physically achievable, thereby contributing to technology that enables human organ banking.

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Injectable and Repeatable Inductive Heating of Iron Oxide Nanoparticle-Enhanced "PHIL" Embolic toward Tumor Treatment

September 2022

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35 Reads

ACS Applied Materials & Interfaces

Deep-seated tumors of the liver, brain, and other organ systems often recur after initial surgical, chemotherapeutic, radiation, or focal treatments. Repeating these treatments is often invasive and traumatic. We propose an iron oxide nanoparticle (IONP)-enhanced precipitating hydrophobic injectable liquid (PHIL, MicroVention inc.) embolic as a localized dual treatment implant for nutrient deprivation and multiple repeatable thermal ablation. Following a single injection, multiple thermal treatments can be repeated as needed, based on monitoring of tumor growth/recurrence. Herein we show the ability to create an injectable stable PHIL-IONP solution, monitor deposition of the PHIL-IONP precipitate dispersion by μCT, and gauge the IONP distribution within the embolic by magnetic resonance imaging. Once precipitated, the implant could be heated to reach therapeutic temperatures >8 °C for thermal ablation (clinical temperature of ∼45 °C), in a model disk and a 3D tumor bed model. Heat output was not affected by physiological conditions, multiple heating sessions, or heating at intervals over a 1 month duration. Further, in ex vivo mice hind-limb tumors, we could noninvasively heat the embolic to an "ablative" temperature elevation of 17 °C (clinically 54 °C) in the first 5 min and maintain the temperature rise over +8 °C (clinically a temperature of 45 °C) for longer than 15 min.


A Frequency-Swept, Longitudinal Detection EPR System for Measuring Short Electron Spin Relaxation Times at Ultra-low Fields

August 2022

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16 Reads

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3 Citations

Journal of Magnetic Resonance

A frequency-swept longitudinal detection (LOD) EPR system is described for ultra-low field spectroscopy and relaxometry. With the capability of performing simultaneous transmit and receive with -80 dB isolation, this LOD-EPR can capture signals with decay constants in the nanosecond range and in theory even sub-nanosecond range, at fields close to the earth’s magnetic field. The theoretical principles underlying this LOD-EPR are based on a fictitious field that accounts for the Z-axis magnetization polarized by a radiofrequency field alone. The electron spin relaxation time is obtained directly from a previously derived equation that describes the relationship between the relaxation time and the spectral peak position. Herein, the first frequency-swept LOD-EPR system is described in detail, along with experimental measurements of the short relaxation time (∼30 ns) of the free radical, 2,2-diphenyl-1-picrylhydrazyl, at zero to low field.

Citations (2)


... Second, the proposed method implies to insert the column into the bore of an NMR device, which is not easily feasible with most of conventional ion exchange columns. But with the incredible evolution of portable low field NMR [27,28], one can reasonably imagine using a larger bore, or even a large single sided NMR sensor [29] to follow the water proton relaxation inside the column from the outside. Of course, this last step will be the most challenging because the obtained signal will not originate from the whole column but only from a zone close to the NMR sensor. ...

Reference:

NMR Relaxometry to Monitor In Situ the Loading of Amberlite IR120 and Dowex Marathon MSC Resins With Ni2+ and Cu2+ During a Column Experiment
Development of a Compact NMR System to Measure pO2 in a Tissue-Engineered Graft
  • Citing Article
  • November 2023

Journal of Magnetic Resonance

... The ubiquity of such detection is emphasized by the existence of longitudinal detection of EPR, in which the pickup coil detects the signal caused by perturbing the system with resonant microwave pulses. [22][23][24][25] The original method for generating temperature jumps (T-jumps) described in ref. 26 is based on electrical discharge of a capacitor through a conducting solution. A more robust alternative to the discharge technique is the direct heating of the sample by a powerful light pulse, which is absorbed by the solvent, matrix, or dye and converted to heat. ...

A Frequency-Swept, Longitudinal Detection EPR System for Measuring Short Electron Spin Relaxation Times at Ultra-low Fields
  • Citing Article
  • August 2022

Journal of Magnetic Resonance