Plasmonic laser nanosurgery

dc.contributor.advisorBen-Yakar, Adela
dc.creatorEversole, Daniel Stevenen
dc.date.accessioned2013-11-18T20:23:54Zen
dc.date.accessioned2017-05-11T22:37:34Z
dc.date.available2017-05-11T22:37:34Z
dc.date.issued2011-08en
dc.date.submittedAugust 2011en
dc.date.updated2013-11-18T20:23:54Zen
dc.descriptiontexten
dc.description.abstractPlasmonic Laser Nanosurgery (PLN) is a novel photodisruption technique that exploits the large enhancement of ultrafast laser pulses in the near-field of gold nanoparticles for the nanoscale manipulation of biological structures. Excitation of surface plasmons on spherical nanoparticles by pulsed irradiation provides a platform for the confinement of photoactivated processes, while functionalized nanoparticle targeting methods provide the highest level of therapeutic selectivity. In this dissertation, we demonstrate and characterize the in vitro plasmonic optoporation of MDA-MB-468 human epithelial breast cancer cells labeled with plasmonic gold nanoparticles using NIR, femtosecond laser pulses. Using a 10 kDa FITC-Dextran probe dye, we find that the PLN can optoporate nanoparticle-labeled cellular membranes at fluences down to just a few mJ/cm², providing a 50-fold reduction in pulse energy necessary to induce membrane dysfunction as compared with unlabeled cells. Limited membrane dysfunction was found to lead to transient optoporation of cells as a possible transfection method, while more extensive, non-recoverable membrane dysfunction lead to cellular death as a possible plasmonic treatment of malicious cells. In the first regime, we found a maximum optoporation efficiency of approximately 31% ± 5.4% with 2 to 2.5 mW laser light having 80 MHz repetition rate. In the second regime, we were able to necrotically kill greater than 90% of irradiated cells with as little as 5 mW average power. We found that particle aggregation along the cellular surface is crucial for the success of PLN. High particle loadings were required, suggesting that particle aggregates provide large enhancements, leading to reduced PLN threshold energies. We provide experimental evidence suggesting photodisruption with ultra-low energy pulses is directly dependent upon the emission of electrons from the particle surface, which seed the formation of free radicals in the surrounding water. These free radicals mediate membrane dysfunction by polyunsaturated lipid and protein peroxidation.en
dc.description.departmentBiomedical Engineeringen
dc.embargo.lift8/1/2012en
dc.embargo.terms8/1/2012en
dc.format.mimetypeapplication/pdfen
dc.identifier.urihttp://hdl.handle.net/2152/22244en
dc.language.isoen_USen
dc.subjectUltrafast lasersen
dc.subjectPlasmonicsen
dc.subjectNoble-metalsen
dc.subjectCanceren
dc.subjectTransfectionsen
dc.titlePlasmonic laser nanosurgeryen

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