The conference presentation represents a part of results on the field of magnetofection - transfection of genes with magnetic nanoparticles- in cell cultures. The procedure is based on application of stable surface functionalized magnetic nanoparticles, which form complexes with plasmides of therapeutic and reporter genes, and with use of external magnetic system successfully transfer this plasmid into cell cytoplasm. Within this project activities on design and preparation of appropriate functionalized nanoparticles and magnetic systems were done, whereas further work was necessary for development of appropriate magnetofection protocols for use in in vitro and in vivo systems. Other contributions were presented as: Magnetofection of B16F1 cells with therapeutic gene for interleukin-12, Zavod za zdravstveno varstvo; Abstract book; 2011; Str. 216; Avtorji / Authors: Prosen Lara, Prijič Sara, Žnidaršič Andrej, Čemažar Maja, Serša Gregor (Cobiss ID 1157243) Magnetic nanoparticles-mediated in vitro gene delivery, SLONANO 2011 Book of abstracts; 2011; Str. 80; Avtorji / Authors: Prosen Lara, Prijič Sara, Žnidaršič Andrej, Čemažar Maja, Serša Gregor (Cobiss ID 1173627)
F.02 Acquisition of new scientific knowledge
COBISS.SI-ID: 1185403One of major current limitations of magnetic drug targeting is to achieve efficient concentration of magnetic carrier-drug complexes at the targeted sites due to poor mobility of nanoparticles in tissue structures, therefore it is essential to know particle mobility in a given enviroment. We addressed this problem with combination of experimental measurements and numerical modeling. We used gel magnetophoresis in order to measure motilities of different magnetic NPs (Co-ferrite, c-Fe2O3) in agarose gel. Numerical modeling using FEM method was used to determine appropriate settings of magnets, which generate sufficient magnetic field gradient. Further, we used the numerical modeling to evaluate the magnetic force on the NPs for different geometries. We obtained that one of crucial factors which determines final mobility in tissue is formation of larger aggregates of nanoparticles under physiological conditions and interaction of nanoparticles with surrounding matrix. These findings and experimental and numerical models will be applied for further study of biologically relevant systems.
F.02 Acquisition of new scientific knowledge
COBISS.SI-ID: 8747860We analyzed magnetic states of agglomerates and evaluated the effect on applicability for biomedical and biotechnological applications. As key finding we showed that magnetic state of agglomerates is determined almost exclusively by state of primary nanoparticles. Hence large agglomerates that exhibit superparamagnetic state like primary nanoparticles are possible whereas response to the external magnetic fields is greatly enhanced. Further, we showed stability of functionalized single-domain nanoparticles and agglomerates and possibility of use for biotechnological applications.
B.03 Paper at an international scientific conference
COBISS.SI-ID: 8312660Within the project we collaborated with research group from Institute of Oncology Ljubljana on development and optimization of magnetofection method for uptake of DNA in cells with external magnetic field. We developed synthesis procedures and characterized nanoparticles with magnetic core that have multilayer functionalization and are biocompatible. Synthesis procedures allow upgrade of multilayer structure with different macromolecules like DNA; dispersions of such multilyer nanoparticles are stable at physiological conditions. As the magnetic core is agglomerate of nanoparticles, also the response to the external magnetic field is relatively large. Due to flexibility of composition and properties such particles are very appropriate for diverse bioengineering applications. Specifically for the magnetofection we functionalized multilayer magnetic nanoparticles and collaborated on design of magnetofection protocol. We also analyzed different options for optimization of external magnetic system.
F.09 Development of a new technological process or technology
COBISS.SI-ID: 34792709Despite considerable utilization of nanoparticles (NPs), there are still many unanswered questions concerning their interactions with cells and only few studies visualized the whole process of internalization. Using SEM, we are first to observe the first step of NPs internalization-endocytotic vesicles with NPs in process of formation. Combining fluorescence microscopy, transmission (TEM) and scanning electron microscopy (SEM) we determined time dynamics of internalization via endocytosis, in approx. 1h aggregated NPs were found enclosed in vesicles accumulated in the perinuclear region. TEM showed NPs along the whole endocytotic pathway from coated pits, over multivesicular bodies to lysosomal structures.
E.02 International awards
COBISS.SI-ID: 9319252