Synthesis and Characterization of mPEG-PCL-g-PEI and Self-Assembled Nanoparticle Uptake in Vitro and in Vivo

To understand in vitro and in vivo uptake of nanoparticle and enrichment is important for the improvement of therapeutic drug delivery. mPEG-PCL is a kind of biodegradable and biocompatible polymer suitable as a drug carrier, and many studies have been done to improve its bioavailability and loading capability. In this paper, a novel triblock mPEG-PCL-g-PEI polymer was synthesized and characterized. As compared with mPEG-PCL polymer, the developed copolymer also could self-assemble into nanoparticle with low ζ-potential at 50 °C. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay indicated that the obtained copolymer was low cytotoxicity in vitro. As labeled with FITC, in vitro cellular uptake of these nanoparticles was observed as a function with time. The in vivo fate of these nanoparticles was also observed in zebrafish model. On tumor-bearing mice, the nanoparticles were metabolized from kidney and were enriched in solid tumor in vivo. This study indicated that the triblock copolymer mPEG-PCL-g-PEI could be self-assembled into a nanoparticle with good biocompatibility suitable for a drug carrier.