Size-controlled preparation of magnetic iron oxidenanocrystals within hyperbranched polymers and their magnetofection in vitro

Abstract

A new strategy for the size-controlled preparation of magnetic iron oxide nanocrystals (NCs) within hyperbranched poly(ethylenimine)s (HPEIs) has been described. HPEI was not only utilized as the nanoreactors and stabilizers to prepare size-controlled magnetic NCs, but also skillfully used as a base supplier to avoid introducing alkali hydroxide or ammonia. By changing the weight ratio of FeSO 4 $7H 2 O to HPEI, magnetic iron oxide NCs with various sizes were obtained. Owing to the efficient gene transfection properties of HPEI, the resulting iron oxide/HPEI nanocomposites were used as magnetic nonviral gene vectors for magnetofection and showed to be good gene vectors. It was found that the size of magnetic iron oxide had a significant effect on the magnetofection properties while a pure HPEI transfection enhancer was not introduced. When the mean size of magnetic iron oxide increased, the transfection efficiency was enhanced. With the addition of a pure HPEI transfection enhancer, the size of magnetic iron oxide showed a slight impact on the magnetofection properties. The luciferase expression levels mediated by iron oxide/HPEI nanocomposites with various iron oxide sizes in COS-7 cells under a magnetic gradient field were all more than 115 fold of that of standard HPEI transfection.

Fabrication of new Fe-phthalocyanine oligomer–magnetite hybrid magnetic nano particles and their effects on the LCST behavior of thermo-sensitive poly(N-isopropylacrylamide-co-acrylic acid) magnetic nanocomposites

“…However, inorganic particles (such as Fe 3 O 4 ) trend to oxidation and aggregate easily in the polymer matrixes due to poor compatibility with the pristine polymers [10]. So, many approaches have focused on the coating of Fe 3 O 4 nanoparticles to form hybrid materials [11][12]. Recently, Liu and co-workers have prepared Fe-phthalocyanine oligomer/Fe 3 O 4 hybrid microspheres from bis-phthalonitrile and FeCl 3 ·6H 2 O through a solvent thermal route and investigated their application in the microwave absorbing performances.…”

Nanocrystal Encapsulation, Release and Application Based on pH-Sensitive Covalent Dynamic Hyperbranched Polymers

“…Dendritic polymers have three-dimensional structures and many functional groups at terminal. They are of great interest in various applications such as self-assembly [1][2][3][4][5][6][7], control-release of guest molecules [8][9][10][11][12][13], drug and protein delivery [14][15][16][17], gene transfection [18][19][20][21][22], bio-imaging [23], and so on.…”

“…Nanocrystal (NC) synthesis and NC encapsulation have been important applications of dendritic polymers over the years [24][25][26]. Until now, dendritic poly(amidoamine)s (PAMAM) [27][28][29][30][31][32], poly(ethylenimine)s (PEI) [20,[33][34][35][36][37][38], poly(propylenimine)s (PPI) [39], polyglycerols (PG) [40], poly(amine ester)s (PAE) [41] and their derivatives have often been used as stabilizers for NC synthesis. By preparing or encapsulating nanocrystals (NCs) within dendritic polymers, the properties of NCs (such as optical, electrical and magnetic properties) and the characteristics of dendritic polymers (such as biocompatibility, gene transfection, guest delivery and mechanical property) can be effectively integrated together.…”

Increased Efficacies in Magnetofection and Gene Delivery to Hepatocellular Carcinoma Cells with Ternary Organic–Inorganic Hybrid Nanocomposites

“…The magnet attracts the magnetic NP-containing ternary complexes and generates a small force that is sufficient for their penetration through the cell membrane of HepG2 cells membrane and for their transport inside the cells. [17][18][19] In particular, with the two ternary complexes 0.1 ng PEI/DNA/0.2 mg NP and 0.1 ng PEI/DNA/1.0 mg NP, a significant increase in luciferase expression in the cell nucleus of more than an order of magnitude was obtained by magnetofection. By contrast, three ternary complexes (0.1 ng PEI/DNA/0.1 mg NP, 0.2 ng PEI/DNA/0.1 mg NP, and 0.2 ng PEI/DNA/0.2 mg NP) led to a slightly lowered luciferase expression upon magnetofection.…”