Browsing by Author "Caldwell, John L."

Now showing 1 - 4 of 4
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    Devices and methods for contactless dielectrophoresis for cell or particle manipulation
    (United States Patent and Trademark Office, 2018-09-18)
    Devices and methods for performing dielectrophoresis are described. The devices contain sample channel which is separated by physical barriers from electrode channels which receive electrodes. The devices and methods may be used for the separation and analysis of particles in solution, including the separation and isolation of cells of a specific type. As the electrodes do not make contact with the sample, electrode fouling is avoided and sample integrity is better maintained.
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    Devices and methods for contactless dielectrophoresis for cell or particle manipulation
    (United States Patent and Trademark Office, 2015-03-03)
    Devices and methods for performing dielectrophoresis are described. The devices contain sample channel which is separated by physical barriers from electrode channels which receive electrodes. The devices and methods may be used for the separation and analysis of particles in solution, including the separation and isolation of cells of a specific type. As the electrodes do not make contact with the sample, electrode fouling is avoided and sample integrity is better maintained.
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    High-frequency irreversible electroporation (H-FIRE) for non-thermal ablation without muscle contraction
    Arena, Christopher B.; Sano, Michael B.; Rossmeisl, John H. Jr.; Caldwell, John L.; Garcia, Paulo A.; Rylander, M. Nichole; Davalos, Rafael V. (2011-11-21)
    Background Therapeutic irreversible electroporation (IRE) is an emerging technology for the non-thermal ablation of tumors. The technique involves delivering a series of unipolar electric pulses to permanently destabilize the plasma membrane of cancer cells through an increase in transmembrane potential, which leads to the development of a tissue lesion. Clinically, IRE requires the administration of paralytic agents to prevent muscle contractions during treatment that are associated with the delivery of electric pulses. This study shows that by applying high-frequency, bipolar bursts, muscle contractions can be eliminated during IRE without compromising the non-thermal mechanism of cell death. Methods A combination of analytical, numerical, and experimental techniques were performed to investigate high-frequency irreversible electroporation (H-FIRE). A theoretical model for determining transmembrane potential in response to arbitrary electric fields was used to identify optimal burst frequencies and amplitudes for in vivo treatments. A finite element model for predicting thermal damage based on the electric field distribution was used to design non-thermal protocols for in vivo experiments. H-FIRE was applied to the brain of rats, and muscle contractions were quantified via accelerometers placed at the cervicothoracic junction. MRI and histological evaluation was performed post-operatively to assess ablation. Results No visual or tactile evidence of muscle contraction was seen during H-FIRE at 250 kHz or 500 kHz, while all IRE protocols resulted in detectable muscle contractions at the cervicothoracic junction. H-FIRE produced ablative lesions in brain tissue that were characteristic in cellular morphology of non-thermal IRE treatments. Specifically, there was complete uniformity of tissue death within targeted areas, and a sharp transition zone was present between lesioned and normal brain. Conclusions H-FIRE is a feasible technique for non-thermal tissue ablation that eliminates muscle contractions seen in IRE treatments performed with unipolar electric pulses. Therefore, it has the potential to be performed clinically without the administration of paralytic agents.
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    Integration of very short electric pulses for minimally to noninvasive electroporation
    (United States Patent and Trademark Office, 2015-01-06)
    The present invention provides methods, devices, and systems for in vivo treatment of cell proliferative disorders. The invention can be used to treat solid tumors, such as brain tumors. The methods rely on non-thermal irreversible electroporation (IRE) or supra-poration to cause cell death in treated tumors. In embodiments, the methods comprise the integration of ultra-short electric pulses, both temporally and spatially, to achieve the desired modality of cell death.