Real-Time Imaging Tracking of a Dual Fluorescent Drug Delivery System Based on Zinc Phthalocyanine-Incorporated Hydrogel.

Real-time tracking of a drug delivery system and its therapeutic effects in vivo are crucial to designing a novel pharmaceutical system and revealing the mechanism of drug therapy. Multispectral fluorescence imaging can locate the drug and carrier simultaneously without interference. This advanced method enables the tracking of a drug delivery system. Herein, a doxorubicin (Dox) loaded zinc phthalocyanine incorporated hydrogel was developed as a dual fluorescent drug delivery system to monitor the release of the drug and the degradation of the carrier. An injectable thermosensitive hydrogel based on a four-arm poly(ethylene glycol) (PEG)-poly(ε-Caprolactone) (PCL) copolymer was prepared and characterized with a zinc phthalocyanine core as the drug carrier. The hydrogel degradation and drug delivery in vivo were tracked by a multispectral fluorescence imaging system in nude mice bearing hepatic tumors. Moreover, the real-time tumor inhibition progress was tracked in vivo for 18 days by bioluminescence imaging. A multispectral analysis can separate the fluorescence signals from the drug and carrier in the Dox loaded hydrogel and provide their location in the tumor tissue. The drug release and hydrogel degradation can be drastically tracked respectively without mutual interference. The fluorescence imaging results reveal improved tumor inhibitory effects of the Dox loaded hydrogel. Optical imaging allows for visible tracking of the entire drug delivery process. The Dox loaded phthalocyanine incorporated thermosensitive hydrogel is a potential visible drug delivery system for tumor therapy.