Simultaneous fluorescence imaging monitoring of the programmed release of dual drugs from a hydrogel-carbon nanotube delivery system

Multispectral fluorescence imaging, from cellular imaging to in vivo imaging, represents a significant advancement for drug delivery research. Tracking multi-drug release using real-time imaging in vivo can reveal the release processes for guiding the design of an ideal drug delivery system to implement combination chemotherapy. Herein, a sustained and programmed drug delivery system was developed based on a PCL-PEG-PCL thermosensitive hydrogel combined with chitosan-multiwalled carbon nanotubes using doxorubicin (DOX) and rhodamine B (RB) as the model drugs. Dual drug delivery was monitored by fluorescence imaging at the cellular level, and in vivo fluorescence signals in nude mice were tracked by a multispectral fluorescence imaging system. The results demonstrated that the release of these two drugs can be dynamically tracked in vitro and in vivo, respectively using fluorescence imaging techniques. After loading onto carbon nanotubes, DOX exerted a significantly slower release rate compared with RB in the hydrogel due to the dual release of DOX. The hydrogel-carbon nanotube delivery system achieved programmed release of DOX and RB, which affirmed that it can be a potential drug delivery system with programmed release for combined administration.