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Updated: May 20, 2026

Preparation and In Vitro Characterization of Dendrimer-based Contrast Agents for Magnetic Resonance Imaging
Published on: December 4, 2016
Dexamethasone conjugation to polyamidoamine dendrimers G1 and G2 for enhanced transfection efficiency with an
Jin Young Kim1, Jae Hwan Ryu, Hyesun Hyun
1Department of Bioengineering, College of Engineering, Hanyang University, 17 Haengdang-dong, Seoul , Republic of Korea.
Abstract:
Polyamidoamine (PAM) dendrimers with low generation such as PAM generation 1 (PAMG1) and PAM generation 2 (PAMG2) have been widely used as a gene carrier due to low toxicity, albeit their low transfection efficiency. In this study, dexamethasone was conjugated to PAMG1 and PAMG2 in order to increase the transfection efficiency. In a gel retardation assay, the dexamethasone conjugated PAMG1 and PAMG2 (PAMG1-Dexa and PAMG2-Dexa) retarded plasmid DNA (pDNA) completely at 5:1 and 3:1 weight ratios (polymer:pDNA), respectively. In transfection assays, PAMG1-Dexa and PAMG2-Dexa had the highest transfection efficiency at 20:1 and 10:1 weight ratios, respectively. In addition, PAMG1-Dexa and PAMG2-Dexa had higher transfection efficiencies than PAMG1, PAMG2, PEI25k, and lipofectamine. In a MTT assay, PAMG1-Dexa and PAMG2-Dexa were less cytotoxic than lipofectamine. In addition, PAMG1-Dexa and PAMG2-Dexa decreased the TNF-α level more efficiently than dexamethasone only in the lipopolysaccharide (LPS)-induced Raw264.7 cells. Therefore, PAMG1-Dexa and PAMG2-Dexa may prove to be useful as gene delivery carriers with an anti-inflammatory effect.

