Fibrin-Targeting, Peptide Amphiphile Micelles as Contrast Agents for Molecular MRI
- *Corresponding Author:
- Matthew Tirrell
Institute for Molecular Engineering
University of Chicago 5747 S. Ellis Ave. Chicago, IL, 60637, USA
E-mail: [email protected]
Received Date: July 12, 2014; Accepted Date: September 26, 2014; Published Date: September 29, 2014
Citation: Chung E, Pineda F, Nord K, Karczmar, Lee SK, et al. (2014) Fibrin- Targeting, Peptide Amphiphile Micelles as Contrast Agents for Molecular MRI. J Cell Sci Ther 5:181. doi: 10.4172/2157-7013.1000181
Copyright: © 2014 Chung E, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Magnetic resonance imaging (MRI) provides a nonionizing and safe imaging modality for cancer diagnostics. Here, we took advantage of the fibrin deposition that is characteristic of tumors and the ability to incorporate multiple functionalities within peptide amphiphile micelles (PAMs) to design a new class of contrast agents for molecular MRI. We report on synthesis, formulation, and preliminary tests for MRI of spherical PAMs that were self-assembled by combining 18:0 PE-DTPA (Gd) and peptide amphiphiles containing the fibrin-binding pentapeptide, cysteinearginine- glutamic acid-lysine-alanine, or CREKA. Conjugation of the CREKA peptide to micelles increased the average particle size and zeta potential, and T1 relaxivities of CREKA-Gd PAMs (per mmol of Gd) were found to be comparable to contrast agents which are used routinely in clinical settings at 1.5T and 3T. Moreover, when murine fibroblasts were cultured with CREKA-Gd PAMs, no cytotoxicity was demonstrated and cell viability was comparable to that of PBS-treated controls for up to 3 days.Our study provides proof-of-concept of CREKA-Gd PAMs as contrast agents for molecular MRI, and a facile strategy for incorporating contrast agents and bioactive molecules into nano carriers to develop safe, targeted diagnostic carriers for clinical application.