Real-Time Imaging and Quantification of Peptide Uptake in Vitro and in Vivo

Peptides constitute an important class of drugs for the treatment of multiple metabolic, oncological and neurodegenera-tive diseases, and several hundred novel therapeutic peptides are currently in the preclinical and clinical stages of devel-opment. However, many leads fail to advance clinically because of poor cellular membrane and tissue permeability. There-fore, assessment of the ability of a peptide to cross cellular membranes is critical when developing novel peptide-based therapeutics. Current methods to assess peptide cellular permeability are limited by multiple factors, such as the need to introduce rather large modifications (e.g., fluorescent dyes) that require complex chemical reactions as well as an inability to provide kinetic information on the internalization of a compound or distinguish between internalized and membrane-bound compounds. In addition, many of these methods are based on endpoint assays and require multiple sample ma-nipulation steps. Herein, we report a novel “Split Lucifer...