Magnetic resonance imaging of self-assembled biomaterial scaffolds

Current interest in biomaterials for tissue engineering and drug delivery applications have spurred research into self-assembling peptide amphiphiles (PAs). Nanofiber networks formed from self-assembling PAs can be used as biomaterial scaffolds with the advantage of specificity by the incorporation of peptide-epitopes. Imaging the materials noninvasively will give information as to their fate in vivo. We report here the synthesis and in vitro MR images of self-assembling peptide amphiphile contrast agents (PACAs) that form nanofibers. At 400 MHz using a 0.1 mM Gd(III) conjugate of the PA we observed a TI three times that of a control gel. The PA derivative was doped into various epitope bearing PA solutions and upon gelling resulted in a homogeneous biomaterial as imaged by MRI.