A pinboard by
Leon Wang

PhD. Student, Princeton University


My goal is to make nanoparticles "light up" to many traditional medical imaging methods. The nanoparticles will bind to cancer cells and can be used to detect and diagnose cancers. Eventually, I would also like to include drugs inside the nanoparticles to kill off the cancer cells.


Copper-64 radiopharmaceuticals for PET imaging of cancer: advances in preclinical and clinical research.

Abstract: Copper-64 (T(1/2) = 12.7 hours; beta(+), 0.653 MeV [17.8 %]; beta(-), 0.579 MeV [38.4 %]) has decay characteristics that allow for positron emission tomography (PET) imaging and targeted radiotherapy of cancer. The well-established coordination chemistry of copper allows for its reaction with a wide variety of chelator systems that can potentially be linked to peptides and other biologically relevant small molecules, antibodies, proteins, and nanoparticles. The 12.7-hours half-life of 64Cu provides the flexibility to image both smaller molecules and larger, slower clearing proteins and nanoparticles. In a practical sense, the radionuclide or the 64Cu-radiopharmaceuticals can be easily shipped for PET imaging studies at sites remote to the production facility. Due to the versatility of 64Cu, there has been an abundance of novel research in this area over the past 20 years, primarily in the area of PET imaging, but also for the targeted radiotherapy of cancer. The biologic activity of the hypoxia imaging agent, 60/64Cu-ATSM, has been described in great detail in animal models and in clinical PET studies. An investigational new drug application for 64Cu-ATSM was recently approved by the U.S. Food and Drug Administration (FDA) in the United States, paving the way for a multicenter trial to validate the utility of this agent, with the hopeful result being FDA approval for routine clinical use. This article discusses state-of-the-art cancer imaging with 64Cu radiopharmaceuticals, including 64Cu-ATSM for imaging hypoxia, 64Cu-labeled peptides for tumor-receptor targeting, (64)Cu-labeled monoclonal antibodies for targeting tumor antigens, and 64Cu-labeled nanoparticles for cancer targeting. The emphasis of this article will be on the new scientific discoveries involving (64)Cu radiopharmaceuticals, as well as the translation of these into human studies.

Pub.: 22 Aug '09, Pinned: 29 Jun '17

Real-Time and Multiplexed Photoacoustic Imaging of Internally Normalized Mixed-Targeted Nanoparticles

Abstract: Photoacoustic (PA) imaging is a developing diagnostic technique where multiple species can be simultaneously imaged with high spatial resolution in 3D if the absorbance spectrum of each species is distinct and separable. However, multiplexed PA imaging has been greatly limited by the availability of spectrally separable contrast agents that can be used in vivo. Toward this end, we present the formation and application of a series of poly ethylene glycol (PEG)-coated nanoparticles (NPs) with unique separable absorbance profiles suitable for simultaneous multiplexed imaging. As a proof-of-concept, we demonstrate this form of mixed-sample multiplexed imaging, using cRGD peptide surface-modified NPs with nonmodified NPs in a murine subcutaneous Lewis lung carcinoma tumor model. The simultaneous imaging of nonmodified NPs provides an “internal standard”, to deconvolute the contributions of active-ligand and passive-NP targeting effects. Particles with 25% surface cRGD modification display 52 ± 22 fold higher liver to tumor ratio accumulation levels, while the same set of particles display only 9.8 ± 4 fold accumulation levels when internally normalized. The pharmacokinetic profiles of targeted and nontargeted NPs can be simultaneously tracked in real-time to study how biodistribtions of particles are affected by ligand modification. The internal normalization of control particles greatly enhances the precision and decreases the number of animals needed in studies of nanoparticle targeting. These new dyes are an enabling technology for PA imaging of NP fate and targeting. This is the first demonstration of real-time multiplexed PA imaging of mixed-targeted samples in vivo.

Pub.: 05 Jan '17, Pinned: 29 Jun '17