Collagen I, a natural protein found in animal tissues, can self-assemble into fibrous matrices that support cell and tissue growth. Peptide mimics of collagen are able to recapitulate this selfassembly process towards the development of biomaterials for tissue engineering. In recent years, the metal mediated self-assembly of collagen mimetic peptides (CMPs) has allowed access to various particle morphologies. Herein, two studies are presented. In the first, NCOH-FOGER, a cell adhesive CMP capable of metal-triggered self-assembly, was utilized to develop a model system to mimic natural collagen’s interactions with endothelial cells. Notably, a cobalt(III)- NCoH-FOGER assembly was able to induce endothelial cells to form network-like structures. In the second, a CMP was modified to include an unnatural amino acid, L-4-trans-fluoroproline, which increased the thermostability of its folded state. The effect of this substitution on the morphology of self-assembled particles was evaluated.