Emily Alexandria Waters1, Lindsay Karfeld-Sulzer2, Ellen Kohlmeir3, Hermann Kissler4, Xiaomin Zhang4, Dixon Kaufman4, Annelise Barron1,2, Thomas Meade1,3
1Chemistry, Northwestern University, Evanston, IL, USA; 2Chemical and Biological Engineering, Northwestern University, Evanston, IL, USA; 3Biochemistry, Molecular and Cell Biology, Northwestern University, Evanston, IL, USA; 4Transplant Surgery, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
Biomaterial scaffolds are employed for controlled-release drug delivery and as extracellular matrices to support cellular therapies, but are difficult to track over time. Biomaterial scaffolds with covalently incorporated T1-shortening agents could improve contrast with surrounding tissues. We have developed artificial protein polymers generated by recombinant protein expression in E. Coli. These proteins have evenly spaced lysine residues which can be modified with Gd(III) chelators and enzymatically cross-linked into hydrogels. The relaxivity can be tuned by varying the lysine spacing and number of repeats in the polymer. We demonstrate in vivo MRI tracking of degradation of a hydrogel containing these polymers.