Photo-cured PMMA/PEI core/shell nanoparticles surface-modified with Gd-DTPA for T1 MR imaging

초록

Hepatic lesion targeting & MR imaging photo-crosslinked nanoparticles were fabricated and its functional studies were performed. Amine-functionalized core-shell nanoparticles (Polymethyl methacrylate /Polyethyleneimine; PMMA/PEI) with surface primary amines (3.15×105 groups/particle) and uniform size distribution (150-200 nm) that were prepared by one-step photo-induced emulsion polymerization. Further PEI-surface was modified with diethylenetriamine pentaacetic acid (DTPA) and introduced with Gd(III). The content of Gd was measured on a atomic absorption spectroscopy. In vitro MR functionalities on the phantom and cytotoxicity against hepatic cells were evaluated in this study. The modified particles possessing DTPA can entrap a high content of Gd(III) ions of over 5.5 ×104 Gd/particle. The Gd-DTPA-conjugated core-shell nanoparticles (PMMA/PEI-DTPA-Gd NPs) enhanced the MRI intensity more than Primovist (a commercial hepatic contrast agent). Moreover, the PMMA/PEI-DTPA-Gd NPs showed non-cytotoxicity up to 250 µM in normal liver cells. Thus, in vitro data suggested the PMMA/PEI-DTPA-Gd NPs is promising delivery system as a superior MRI contrast agent, especially for hepatic lesion targeted MR imaging.