Nanoscale carbon materials, including fullerenes, carbon nanotubes, graphene nanosheets, and small carbon nanoparticles, have interesting and/or unique properties. We have been studying these nanomaterials, from fullerene conjugates with anticancer drugs and bulkseparated metallic/semiconducting single-walled carbon nanotubes for electrical/electronic materials and applications to more recently graphene nanosheets for thermal and mechanical nanocomposites and carbon-based photoluminescent nanoparticles (“carbon dots”) as effective imaging agents. In this talk, some interesting and representative results from our research will be highlighted.
NanoSEC Seminar : Nano-Carbon: Fundamental Exploration and Technological Development, Prof. Ya-Ping SunWhen: Friday, September 3, 2010 4:00 pm - 5:00 pm Where: Riverbend Research South Laboratory Auditorium
Departmental Colloquium : Quantum computing with Bose--Einstein condensate Bragg interferometry, Dr. Mark EdwardsWhen: Thursday, September 9, 2010 4:00 pm - 5:00 pm Where: Physics 202
Quantum computers use the interferences of different computational paths to enhance correct outcomes. Quantum computation can be viewed as multi-particle computational interference . I will describe how quantum circuits can be mapped to interferometry experiments performed on Bose-Einstein condensates (BECs) using Bragg pulses. I further describe an extension to an approach, originally developed to prototype Bragg interferometry of BECs , to describe new interferometers inspired by quantum information concepts. This approach follows ideas recently introduced in neutron inter- ferometry . Using techniques that have been well calibrated by experiments in con- ventional BEC interferometry , experiments associated with some simple quantum circuits using the prototyping method mentioned above are modeled. We prototype ex- tensions to standard Mach-Zehnder configurations, analogous to the four-blade designs of neutron interferometry.
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When: Friday, September 10, 2010 4:00 pm - 5:00 pm
Where: Riverbend Research South Laboratory Auditorium
Three platinum(II) complexes, cisplatin, carboplatin, and oxaliplatin, have been approved by the US FDA for the treatment of cancer. Structural and mechanistic studies have elucidated four early steps that describe their action, cell entry, activation, DNA binding, and transcription inhibition while eluding repair. In spite of the clinical success of cisplatin, there are many occasions where treatment must be discontinued due to drug resistance, acquired or intrinsic, arises from reduced cellular uptake, enhanced DNA repair, drug deactivation, or a combination of these mechanisms. One strategy to overcome resistance is to design specific functionalities onto platinum to enhance uptake and delivery via drug targeting. Oxidation of cisplatin affords Pt(IV) species, known as prodrugs, that can be derivatized with axial ligands for attaching the resulting complexes to carriers for targeted delivery to cancer cells. Upon entry into the cell, the platinum(IV) is reduced, liberating cisplatin and the axial ligands, which can potentiate the cell-killing properties of the construct. In this manner we have functionalized single-walled carbon nanotubes as “longboat” carriers of Pt(IV) constructs into cells, specifically targeted the folate receptor on cancer cells and delivered platinum complexes with extraordinary potency against folate receptor overexpressing cancer cells.1 Dose limiting toxicities or resistance also limit application of cisplatin in many types of cancer including prostate. We devised a unique strategy to deliver cisplatin to prostate cancer cells by constructing Pt(IV)-encapsulated prostate-specific membrane antigen (PSMA) targeted nanoparticles (NPs) of poly(D,L-lactic-co-glycolic acid) (PLGA)-poly(ethylene glycol) (PEG)-functionalized controlled release polymers. By using PLGA-b-PEG nanoparticles with PSMA targeting aptamers (Apt) on the surface as a vehicle for a platinum(IV) prodrug, a lethal dose of cisplatin was delivered specifically to prostate cancer cells.2 By appending axial ligands that destroy the mitochondrial function of the cancer cell while platinum simultaneously impeding DNA-mediated processes in the nucleus, we have synthesized a novel compound mitaplatin, and this new construct is currently being evaluated for anticancer activity vs. normal cells.3 Our technologies provide a potentially important platform for spatiotemporal, controlled release of two or more drugs for future applications in human cancer chemotherapy.4
1. Dhar, S.; Liu, Z.; Thomale, J.; Dai, H. and Lippard, S. J. “Targeted Single Walled Carbon Nanotube Mediated Pt(IV) Prodrug Delivery using Folate as Homing Device”, J. Am. Chem. Soc. 2008, 130, 11467‐11476.
2. Dhar, S.; Gu, F. X.; Langer, R.; Farokhzad, O. C. and Lippard, S. J. “Targeted Delivery of Cisplatin to Prostate Cancer Cells by Aptamer Functionalized Pt(IV) Prodrug‐PLGA–PEG Nanoparticles”,Proc. Natl. Acad. Sci. USA, 2008, 105, 17356‐17361.
3. Dhar, S. and Lippard, S. J. Proc. Natl. Acad. Sci. USA, 2009, 106, 22199‐22204.
4. Kolishetti, N.; Dhar, S.; Pedro, V.; Lin, L.; Karnik, R.; Lippard, S. J. Langer, R.; Farokhzad, O. C. and “Engineering of Self‐assembled Nanoparticle Platform for Precisely‐controlled Combination Drug Therapy”, Proc. Natl. Acad. Sci. USA, 2010, in press.
When: Tuesday, September 14, 2010 12:30 pm - 1:30 pm
Where: CSP Conference Room (322)
Departmental Colloquium : Implementing and Sustaining Curricular Reform in a Large Introductory Physics Course at Georgia Tech, Dr. Mike SchatzWhen: Thursday, September 16, 2010 4:00 pm - 5:00 pm Where: Physics 202
A novel physics curriculum, Matter and Interactions (M&I), was introduced into Georgia Tech engineering physics courses in Summer 2006; today the curriculum is taught to approximately one thousand students each semester. We will highlight some key issues associated with implementing the M&I curriculum. We will also describe efforts to measure the new curriculum's impact using both standardized assessment tools (concept inventories) and in-depth student interviews (think-aloud protocol studies). The presentation will highlight barriers to implementing and to sustaining reform curricula in university physics courses.