Compared to the cellular proteome, extracellular matrix (ECM) proteins harbor unique forms of post-translational modification. These modifications reflect tissue state and are re-modeled during disease progression, e.g. tumorigenesis and fibrosis. How do these modifications affect ECM self-assembly? And how might they be used for next-generation biomaterials? Our approach to these questions is to synthesize and characterize modified forms of ECM. In parallel, we pursue creative methods for detecting ECM modifications in patient samples as a new diagnostic platform.