Investigating the Translational Potential of Nano-based Contrast Agents for Cancer Imaging

Friday, June 14, 2019, 11:00 am - 12:00 pm PDTiCal
This event is open to the public.
AI Seminar
Cristina Zavaleta, USC
Video Recording:

Nanoparticles have great potential as diagnostic contrast agents for cancer detection. Compared to their small molecule counterparts they can offer increased sensitivity due to their loading capacity and increased tumor binding efficiency due to the multiple targeting ligands displayed on their surface. Ongoing attempts towards developing new nano-based contrast agents have faced major problems in gaining regulatory approval due to their potential systemic toxicity and prolonged accumulation in vital organs.  My lab has investigated the biodistribution of gold-silica Raman nanoparticles after several administration routes (ie. intravenous (IV), intrarectal (IR), and oral ingestion) in living mice. The IR and oral routes are meant to mimic a topical administration to the gastrointestinal tract as a potentially less toxic alternative to IV injection. Recently, Raman imaging with surface enhanced Raman scattering (SERS) nanoparticles has gained interest in the molecular imaging community due to its ultra-high sensitivity properties as well as its unique multiplexing capabilities. Several groups have demonstrated the use of this optical imaging technique with tumor targeting SERS nanoparticles. Some researchers choose to administer these nanoparticles topically to epithelial targets in order to mitigate the potential systemic administration toxicity issues. This approach is highly advantageous when coupled with endoscopy as it resolves the low depth of penetration constraint often associated with optical imaging strategies and provides molecular information to clinicians during routine endoscopic examination for dysplastic lesions on epithelial tissues. We’ve also begun translating this Raman imaging approach to the operating room for guiding surgical resection during lumpectomy.  The focus of this talk will predominantly cover the preclinical evaluation of our gold-silica nanoparticles as we assess their biodistribution and systemic toxicity using a multitude of pre-existing and new imaging techniques.

Dr. Zavaleta received her BS in Nuclear Medicine from University of Incarnate Word, San Antonio, TX where she spent a year of clinical rotations in the Nuclear Medicine Department at Brooke Army Medical Center.  After graduating, she started in the Medical Physics graduate program at the University of Texas Health Science Center in San Antonio (UTHSCSA), where she studied under Dr. Beth Goins. Her dissertation focused on utilizing a novel theranostic (dual diagnostic/therapeutic) approach to administer radioactive liposomes for the treatment of peritoneal ovarian metastases. It was there that she was introduced to the field of biomedical nanotechnology research. After receiving her PhD from UTHSCSA, she immediately began a postdoctoral fellowship at Stanford University in Professor Sam Gambhir’s Multimodality Molecular Imaging Laboratory. She dedicated the majority of her postdoctoral career toward developing an entirely new molecular imaging strategy that utilizes Raman spectroscopy in conjunction with Raman nanoparticles as a novel approach for cancer imaging. She is currently an Assistant Professor at the University of Southern California in the department of Biomedical Engineering. Her current research interests bring together chemistry, engineering and biology to develop new nano-based molecular imaging strategies. The lab focuses on providing physicians with better functional imaging tools to detect cancers with better sensitivity and specificity. These tools are directed at: 1) Improving early cancer detection during routine screening procedures and 2) Helping surgeons identify and resect tumor margins with better precision and accuracy.

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