Electronic Posters: Molecular

Contrast Agents

Hall B Monday 14:00-16:00 Computer 70

14:00 4214. Validation of Optical Tomography in Vivo

Yuting Lin¹, Mehmet B. Unlu¹, Brian Grimmond², Anup Sood², Egidijus E. Uzgiris³, David Thayer¹, Han Yan¹, Orhan Nalcioglu¹, Gultekin Gulsen<sup>1

1</sup>Center for Functional Onco-Imaging, University of California, Irvine, CA, United States; ²GE Gobal Research, Niskayuna, NY, United States; ³Rensselaer Polytechnic Institute,, Troy, NY, United States

Multi-modality imaging is becoming a trend in developing new generation in vivo imaging techniques for diagnosis. Recently, our group has developed a high temporal resolution dynamic MRI/DOT multi-modality imaging system. In such a multi-modality system, each modality measures a different parameter set, which make it difficult to cross-validate the parameters measured by different modalities. An alternative solution is using a bi-functional contrast agent that provides contrast for both optical and MRI simultaneously. Here, our in vivo small animal study is the first to validate a true multi-modality system with a true multi-modality contrast agent.

14:30 4215. Novel Cross-Linked Liposomal Chemical Saturation Transfer or CEST Agents

Aristarchos Papagiannaros¹, Valeria Righi^1,2, George Dai², A Aria Tzika<sup>1,2

1</sup>NMR Surgical Laboratory, Department of Surgery, Massachusetts General Hospital and Shriners Burns Institute, Harvard Medical School, Boston, MA, United States; ²Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Athinoula A. Martinos Center of Biomedical Imaging, Boston, MA, United States

Liposomal CEST agents are a novel class of contrast agents that demonstrate excellent imaging capacity in phantoms and ex vivo, but their instability is preventing their use in imaging inflammation or cancer. We present cross-linked liposomal CEST agents that efficiently separated the bulk water from the intra-liposomal water signal, while offer increased stability for in vivo applications.

15:00 4216. Novel Metalloporphyrins as Molecular MR Contrast Agents

Talaignair Venkatraman¹, Ines Batinic-Haberle², Vladimir Mouraviev², Haichen Wang², Chris lascola<sup>2

1</sup>Radiology, Duke University Medical Center, Durham, NC, United States; ²Duke University Medical cener

We have investigated a new class of therapeutic metalloporphyrins for their potential as molecular MR imaging probes for prostate cancer detection. Mn(III)TE-2-Pyp5+ (meso-tetrakis(N-ethyl-2-prydil)porphyrin) and Mn(III)TnHex-2-PYP5+ (meso-terakis(N-n-hexyl-2-pyridyl)porphyrin are powerful superoxide dismutase mimics with low toxicity and antineoplastic activity. In phantom experiments, we observe unusually high T1 relaxivity. In vivo, we observe selective accumulation of these probes in prostate tumor xenografts following a single dose of either compound. Relaxation changes in prostate tumors is 10-11 fold greater than in normal prostate gland, suggesting these compounds may be particularly effective at detecting multifocal disease in situ.

15:30 4217. Controlled-Release and Magnetic Resonance Imaging of Doxorubicin-Conjugated Magnetic Nanoparticles from 3D Poly(Propylene Fumarate) Scaffolds

Jonghoon Choi^1,2, Kyobum Kim³, Taeho Kim⁴, Taeghwan Hyeon⁴, Mike T. McMahon¹, Jeff WM Bulte¹, John P. Fisher^3,5, Assaf A. Gilad<sup>1

1</sup>Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States; ²Biochemical Science, National Institute of Standard and Technology, Gaithersburg, MD, United States; ³Chemical and Biomolecular Engineering, University of Maryland, College Park, MD, United States; ⁴Chemical Engineering, Seoul National University, Seoul, Korea, Republic of; ⁵Fischell Department of Bioengineering, University of Maryland, College Park, MD, United States

Three-dimensional PPF (poly(propylene fumarate)) scaffolds carrying cancer drug-coated nanoparticles showed controlled release of drug nanoparticles and bimodal imaging (fluorescence and magnetic resonance) capabilities. This novel biopolymer matrix could be used for many biomedical applications, including MR-guided implantation, as a drug-carrying vehicle, and as a tumor treatment because of the persistent release of drugs in the vicinity of a malignancy.