Real-time imaging of the specific markers of lesions in the living body will provide valuable information in various physiopathological situations. Clinically, real-time imaging will definitely aid accurate diagnosis and rational therapy, especially in the surgical field.
In this chapter, we describe some unique optical probes for “biological imaging” and our recent challenge in undertaking development of a new type of in vivo probe. The reduction-oxidation-sensitive green fluorescent protein (roGFP) and bioluminescent luciferase probe for caspase-3 activity have been useful for understanding of the dynamic changes of liver redox states and apoptotic cell death. To overcome the difficulty of imaging in deeper lesions by optical probes, we newly developed a far-red bioluminescent probe. Lastly, we have undertaken the challenge to develop an innovative optical probe that switches “on” only when the probe recognizes a target molecule to reduce non-specific signals in vivo. The project of developing this unique probe is still underway.
Regarding a carrying system of the probe into cells in vivo, we have developed a liposome with cell-penetrating octa-arginine peptides (R8) and a pH-sensitive fusogenic peptide (GALA), which delivers the functional proteins into cells efficiently and rapidly in vivo.
We believe that these optical probes will provide a new avenue toward new diagnosis and therapy to come in the future.
Copyright 2015, The Author(s).