West and East Lealman, FL, United States
West and East Lealman, FL, United States

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Singh A.K.,Particle Engineering Research Center | Hahn M.A.,Particle Engineering Research Center | Rule M.C.,McKnight Brain Institute | Knapik J.A.,University of Florida | And 2 more authors.
International Journal of Nanomedicine | Year: 2012

Purpose: Photothermal therapy is an emerging cancer treatment paradigm which involves highly localized heating and killing of tumor cells, due to the presence of nanomaterials that can strongly absorb near-infrared (NIR) light. In addition to having deep penetration depths in tissue, NIR light is innocuous to normal cells. Little is known currently about the fate of nanomaterials post photothermal ablation and the implications thereof. The purpose of this investigation was to defne the intratumoral fate of nanoparticles (NPs) after photothermal therapy in vivo and characterize the use of novel multidye theranostic NPs (MDT-NPs) for fractionated photothermal antitumor therapy. Methods: The photothermal and fuorescent properties of MDT-NPs were frst characterized. To investigate the fate of nanomaterials following photothermal ablation in vivo, novel MDT-NPs and a murine mammary tumor model were used. Intratumoral injection of MDT-NPs and real-time fuorescence imaging before and after fractionated photothermal therapy was performed to study the intratumoral fate of MDT-NPs. Gross tumor and histological changes were made comparing MDT-NP treated and control tumor-bearing mice. Results: The dual dye-loaded mesoporous NPs (ie, MDT-NPs; circa 100 nm) retained both their NIR absorbing and NIR fuorescent capabilities after photoactivation. In vivo MDT-NPs remained localized in the intratumoral position after photothermal ablation. With fractionated photothermal therapy, there was signifcant treatment effect observed macroscopically (P = 0.026) in experimental tumor-bearing mice compared to control treated tumor-bearing mice. Conclusion: Fractionated photothermal therapy for cancer represents a new therapeutic paradigm enabled by the application of novel functional nanomaterials. MDT-NPs may advance clinical treatment of cancer by enabling fractionated real-time image guided photothermal therapy. © 2012 Gutwein et al.

Singh A.K.,Particle Engineering Research Center | Hahn M.,Particle Engineering Research Center | Brown S.,Particle Engineering Research Center | Knapik J.,University of Florida
Nanotechnology 2010: Bio Sensors, Instruments, Medical, Environment and Energy - Technical Proceedings of the 2010 NSTI Nanotechnology Conference and Expo, NSTI-Nanotech 2010 | Year: 2010

Multifunctional theranostic nanoparticles hold promise for enabling non-invasive image guided cancer therapy such as photothermal therapy. Human breast tumor models in which response to image guided therapy can quickly and non-invasively be determined are needed to facilitate translation and application of these technologies. We hypothesize that a system utilizing a murine light-reporter mammary tumor cell line and near-infrared nanoparticles (NIR-NP) can be used to quantify response to therapy and determine fate of nanoparticles following photothermal ablation.

Somasundaran P.,Columbia University | Patra P.,Columbia University | Chernyshova I.,Columbia University | Ponnurangam S.,Columbia University | And 2 more authors.
XXV International Mineral Processing Congress 2010, IMPC 2010 | Year: 2010

Variations in phosphate ore feed quality pose a serious challenge for their sustained selective flotation. Most critical aspects of the variability of the feed can be attributed to changes in the bulk and surface mineralogy, particle size, degree of liberation of the phosphate minerals in the feed upon grinding. In this regard, similarities and dissimilarities among different relevant phosphate samples were studied using various surface and bulk characterisation techniques. XRD analysis was conducted to obtain mineralogical information on phosphate samples. FTIR studies were carried on feed, concentrate and tails both in the reflectance and transmission modes to monitor their surface and bulk chemical properties. XRD and FTIR studies indicated that phosphate minerals in various feeds are associated with different types of silicates in varying proportions. Existence of silanol groups on the surface of some of the phosphate samples was observed from FTIR results and was understood to be a major reason for the depression of phosphate minerals in flotation. Organics were found to be present on the surface of some feed samples in FTIR studies and were accounted to be another reason for the depression of phosphate minerals. These findings are supported by the results of adsorption, zetapotential and EDX studies on the same phosphate samples.

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