Selective nanoparticle-directed photothermalablation of the canine prostate

Selective nanoparticle-directed photothermalablation of the canine prostate


Author(s): Jon A. Schwartz, Nanospectra Biosciences, Inc. (United States);Roger E. Price D.V.M., Baylor College of Medicine (United States); Kelly L.Gill-Sharp, Krystina L. Sang, Jennifer D. Khorchani, J. Donald Payne,Nanospectra Biosciences, Inc. (United States); Bradford S. Goodwin, The Univ.of Texas Health Science Ctr. at Houston (United States)
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This study adapted AuroLase® Therapy, previously reported for the treatment ofbrain tumors, to the treatment of prostate disease by 1) using normal canineprostate in vivo, directly injected with a solution of nanoparticles as a proxyfor prostate tumor and, 2) developing an appropriate laser dosimetry for prostatewhich is which is sub-ablative in native prostate while simultaneouslyproducing photothermal coagulation in prostate tissue containing therapeuticnanoshells. Healthy, mixed-breed hound dogs were given surgical laparotomiesduring which nanoshells were injected directly into one or both prostatehemispheres. Laser energy was delivered percutaneously to the parenchyma of theprostate along 1-5 longitudinal tracts via a liquid-cooled optical fibercatheter terminated with a 1-cm isotropic diffuser after which the incision wasclosed and sutured using standard surgical techniques. The photothermal lesionswere permitted to resolve for up to 8 days, after which each animal waseuthanized, necropsied, and the prostate taken for histopathological analysis.We developed a laser dosimetry which is sub-ablative in native prostate andsimultaneously ablative of prostate tissue containing nanoshells which wouldindicate a viable means of treating tumors of the prostate which are known fromother studies to accumulate nanoshells. Secondly, we determined that multiplelaser treatments of nanoshell-containing prostate tissue could be accomplishedwhile sparing the urethra and prostate capsule thermal damage. Finally, wedetermined that the extent of damage zone radii correlate positively withnanoshell concentration, and negatively to the length of time between nanoshellinjection and laser treatment.

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