β-Tripeptides Coassemble into Fluorescent Hydrogels for Serial Monitoring in Vivo.

β-peptides uniquely form shear thinning hydrogels which are proteolytically stable and biocompatible. Herein we describe the synthesis, material and optical characterization of a new class of fluorescently labeled hydrogelators based on a helical -acetylated β-peptide backbone. The resulting hydrogels were analyzed using fluorescence microscopy to confirm successful incorporation of the fluorophore within the fiber matrix without compromising the β-peptide self-assembly. Serial, noninvasive conscious animal imaging was used to monitor the injected hydrogel, delivered via subcutaneous injection, while tracking their degradation patterns in real-time. The hydrogels demonstrated persistent, high-intensity fluorescence when monitored over a 14-day period.