Photoacoustic Imaging Quantifies Drug Release from Nanocarriers via Redox Chemistry of Dye‐Labeled Cargo
Ananthakrishnan Soundaram Jeevarathinam, Jeanne E. Lemaster, Fang Chen, Eric Zhao, Jesse V. JokerstAngewandte Chemie International Edition2020
We report a new approach to monitor drug release from nanocarriers via a paclitaxel–methylene blue conjugate (PTX-MB) with redox activity. This construct is in a photoacoustically silent reduced state inside poly(lactic-co-glycolic acid) (PLGA) nanoparticles (PTX-MB@PLGA NPs). During release, PTX-MB is spontaneously oxidized to produce a concentration-dependent photoacoustic signal. An in vitro drug-release study showed an initial burst release (25 %) between 0–24 h and a sustained release between 24–120 h with a cumulative release of 40.6 % and a 670-fold increase in photoacoustic signal. An in vivo murine drug release showed a photoacoustic signal enhancement of up to 649 % after 10 hours. PTX-MB@PLGA NPs showed an IC50 of 78 μg mL−1 and 44.7±4.8 % decrease of tumor burden in an orthotopic model of colon cancer via luciferase-positive CT26 cells.