Biocompatible Polymer-Nanoparticle-Based Bimodal Imaging Contrast Agents for the Labeling and Tracking of Dendritic Cells

Disulfonated inldocyanine green (ICG) was chosen as the optical modality in the synthesis of bimodal imaging contrast agents for the labeling and tracking of dendritic cells (DC). ICG and iron oxide nanoparticles were encapsulated by using biocompatible polymer poly(lactide-co-glycolide) (PLGA), and ICG molecules were non-covalently bond with human serum albumin (HSA). The results show that binding of HSA proteins with ICG would enhance the compatibility of PLGA in the organic phase with ICG in the aqueous phase. The PLGA nanoparticles are found to generate MR contrast signals, and the increase in the contamination of the nanoparticles led to a decrease in the signal integrity. It is confirmed that PLGA nanoparticles containing iron oxide nanoparticles internalized into DCs, while a decrease in the signal integrity of DCs labels with PLGA nanoparticles is also observed.