New surface-modified iron oxide nanoparticles were developed by precipitation of Fe(II) and Fe(III) salts with ammonium hydroxide and oxidation of the resulting magnetite with sodium hypochlorite, followed by the addition of poly( L-lysine) (PLL) solution. PLL of several molecular weights ranging from 146 ( L-lysine) to 579 000 was tested as a coating to boost the intracellular uptake of the nanoparticles. The nanoparticles were characterized by TEM, dynamic light scattering, FTIR, and ultrasonic spectrometry. TEM revealed that the particles were ca. 6 nm in diameter, while FTIR showed that their surfaces were well-coated with PLL. The interaction of PLL-modified iron oxide nanoparticles with DMEM culture medium was verified by UV-vis spectroscopy. Rat bone marrow stromal cells (rMSCs) and human mesenchymal stem cells (hMSC) were labeled with PLL-modified iron oxide nanoparticles or with Endorem (control). Optical microscopy and TEM confirmed the presence of PLL-modified iron oxide nanoparticles inside the cells. Cellular uptake was very high (more than 92%) for PLL-modified nanoparticles that were coated with PLL (molecular weight 388 00) at a concentration of 0.02 mg PLL per milliliter of colloid. The cellular uptake of PLL-modified iron oxide was facilitated by its interaction with the negatively charged cell surface and subsequent endosomolytic uptake. The relaxivity of rMSCs labeled with PLL-modified iron oxide and the amount of iron in the cells were determined. PLL-modified iron oxide-labeled rMSCs were imaged in vitro and in vivo after intracerebral grafting into the contralateral hemisphere of the adult rat brain. The implanted cells were visible on magnetic resonance (MR) images as a hypointense area at the injection site and in the lesion. In comparison with Endorem, nanoparticles modified with PLL of an optimum molecular weight demonstrated a higher efficiency of intracellular uptake by MSC cells.

Institute of Macromolecular Chemistry v v i Academy of Sciences of the Czech Republic Heyrovský Sq 2 162 06 Prague 6 Czech Republic

Citace poskytuje Crossref.org

Iron-based compounds coordinated with phospho-polymers as biocompatible probes for dual 31P/1H magnetic resonance imaging and spectroscopy

Hydrophilic Copolymers with Hydroxamic Acid Groups as a Protective Biocompatible Coating of Maghemite Nanoparticles: Synthesis, Physico-Chemical Characterization and MRI Biodistribution Study

Photoacoustic Properties of Polypyrrole Nanoparticles

Influence of Dextran Molecular Weight on the Physical Properties of Magnetic Nanoparticles for Hyperthermia and MRI Applications

Scavenging of reactive oxygen species by phenolic compound-modified maghemite nanoparticles

Manganese-Zinc Ferrites: Safe and Efficient Nanolabels for Cell Imaging and Tracking In Vivo

Cytotoxicity of doxorubicin-conjugated poly[N-(2-hydroxypropyl)methacrylamide]-modified γ-Fe2O3 nanoparticles towards human tumor cells

Interaction of poly-l-lysine coating and heparan sulfate proteoglycan on magnetic nanoparticle uptake by tumor cells

The effects of grafted mesenchymal stem cells labeled with iron oxide or cobalt-zinc-iron nanoparticles on the biological macromolecules of rat brain tissue extracts

Enhanced antitumor activity of surface-modified iron oxide nanoparticles and an α-tocopherol derivative in a rat model of mammary gland carcinosarcoma

The effect of magnetic nanoparticles on neuronal differentiation of induced pluripotent stem cell-derived neural precursors

Using ferromagnetic nanoparticles with low Curie temperature for magnetic resonance imaging-guided thermoablation

Improved biocompatibility and efficient labeling of neural stem cells with poly(L-lysine)-coated maghemite nanoparticles

Oxidative stress response in neural stem cells exposed to different superparamagnetic iron oxide nanoparticles

Surface coating affects behavior of metallic nanoparticles in a biological environment

Influence of surface-modified maghemite nanoparticles on in vitro survival of human stem cells

Highly efficient magnetic targeting of mesenchymal stem cells in spinal cord injury

The use of dopamine-hyaluronate associate-coated maghemite nanoparticles to label cells