The development of an optical system for combinatorial
theranostics
is of significant interest. Clinical translation of such theranostic
agents need to cross several barriers. Herein, we have developed a
facile method for the preparation of J-aggregates using FDA approved
agents, namely, NIR fluorophore indocyanine green (ICG) and a chemotherapeutic
drug, cisplatin (CDDP), which induces ICG to form indocyanine green
J-aggregates (IJAs). The formation of IJAs has been characterized
by the formation of a new absorption peak centered at ∼896
nm. The existing methods to synthesize IJAs have used several harsh
reaction conditions, such as elevated temperatures, for a prolonged
time duration (∼60 days). To the best of our knowledge, for
the first time, we have reported the formation of IJAs assisted by
CDDP at 37 °C temperature within 12 h. The presence of CDDP in
ICG favors IJA formation and thereby reduces the harshness of the
reaction conditions in the conventionally followed protocols. Moreover,
the presence of CDDP can facilitate photoactivated combinatorial therapy.
The as synthesized IJA optical system has superior properties to those
of free ICG, in terms of diagnostic and therapeutic capabilities (being
activatable at ∼896 nm wavelength, which can achieve deeper
tissue penetration) and excellent optical and storage stability. The
facile synthesis proposed along with CDDP incorporation makes the
optical system a clinically relevant one-component theranostic agent.