Magnetic silica spheres with large nanopores for nucleic acid adsorption and cellular uptake.
Template assisted fabrication of magnetic silica nanospheres with large nanopores (MSNLP) and their adsorption and delivery of nucleic acids are reported in this paper. Silica spheres with controlled particle diameter (~400 nm) and large nanopore size (13-24 nm) are prepared by using Brij56 as a template of mesopore, enabling incorporation of magnetic nanocrystals into the particles under mild neutral synthesis conditions. High resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), and field-dependent magnetisation measurements confirm that the magnetic nanocrystals have been encapsulated into the silica spheres. The saturation magnetisation values of the resulted magnetic-silica nanocomposites are tunable by adjusting the amount of Fe(3)O(4) magnetic nanocrystals used in the synthesis process. The nitrogen sorption analysis reveals that mesopores with large pore size exist in the silica matrix. After functionalisation of the silica surface with poly-(l-lysine) (PLL), the nanoparticles show strong adsorption capacity (q(m) ranging from 10 to 22.5 μg/mg) for CpG DNA. We have further demonstrated successful delivery of miRNA into rat proximal tubular epithelial cells, facilitated by efficient cellular uptake of the nanocomposites. This work provides a convenient strategy to prepare MSNLP which can offer a versatile platform for biological applications such as simultaneous drug delivery and magnetic resonance imagining under external magnetic field.
ARC Centre of Excellence for Functional Nanomaterials, Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St. Lucia, QLD 4072, Australia.
Jian
J
Liu
Bo
B
Wang
Sandy Budi
SB
Hartono
Tingting
T
Liu
Phillip
P
Kantharidis
Anton P J
AP
Middelberg
Gao Qing Max
GQ
Lu
Lizhong
L
He
Shi Zhang
SZ
Qiao
D000818:Animals; D002460:Cell Line; D058185:Magnetite Nanoparticles / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D053761:Nanocomposites / Q000737:chemistry* / Q000648:ultrastructure; D058608:Nanopores / Q000648:ultrastructure; D054118:Nanospheres / Q000737:chemistry* / Q000648:ultrastructure; D009696:Nucleic Acids / Q000737:chemistry* / Q000378:metabolism; D051381:Rats; D012822:Silicon Dioxide / Q000737:chemistry*; D014162:Transfection / Q000379:methods
D058185:Magnetite Nanoparticles; D009696:Nucleic Acids; D012822:Silicon Dioxide