Thin-Film Assembly of Totally Designed Lipidic Materials as Gene Carrier in Mouse Embryonic Neural Stem Cells: Thin-Film Assembly of Lipidic Material as Potential Gene Carrier

Abstract

Neural stem cells present in developing embryonic and adult nervous systems are immature and uncommitted cells that possess self-renewal potential and produce a vast array of highly specialized neural cells belonging to the central nervous system. Several studies have reported the development of gene delivery system for these neural cells as a potential application in gene therapy for neurodegenerative diseases and for understanding the genetic basis of brain development and function. Gene delivery system based on a variety of materials such as lipids, polypeptides, amino-dendrimers, and polyethylenimine have been used in mammalian cells, and currently, these systems are known to possess therapeutic applications. However, the transfer efficiencies of most lipidic materials with regard to neural cells, including neural stem cells, progenitor cells, neurons, and glia, are less than 5% compared to those of virus vectors. Understanding of lipidic materials used for gene delivery system is essential for the effective design and development of potential applications in basic and therapeutic research. This study aimed to evaluate the biological activity of totally synthesized ditetradecylacetyldiethanolaminetrimethylammonium (TMA-C2-DEA-C14) as gene carriers for neural stem cells. The transfer abilities were estimated by expressing green fluorescent protein (GFP) in mouse embryonic neural stem cells. Here, we demonstrate that lipidic assembly of TMA-C2-DEA-C14, which was self-organized by incubation in water for a month at 25°C, can provide an efficient gene delivery with low cytotoxicity (approximately 40% of GFP-expressed neural stem cells). Moreover, electron microscopic analysis showed that TMA-C2-DEA-C14 assembly is characterized by thin-film structures with polygonal shapes (approximately 2.7 μm), and after association with DNA, their structures dramatically changes to form liposome complexes that can effectively deliver DNA into the cellular cytoplasm of neural stem cells. Our findings suggest that this approach can serve as a novel model for the development of lipidic materials on nonviral gene delivery system.