DEVELOPMENT OF CELL CULTURE PLATES COMPRISING EMBEDDED ARRAYS OF MINIATURE ELECTROMAGNETS FOR MAGNETIC TRANSFECTION APPLICATIONS
Gülşen Zal
Materials Science and Nano Engineering, MSc Thesis, 2025
Thesis Jury
Assoc. Prof. Dr. Murat Kaya Yapıcı (Thesis Advisor)
Prof. Dr. Devrim Gözüaçık
Assoc. Prof. Dr. Özlem Kutlu
Date & Time: July 22nd, 2025 – 4:00 PM
Place: FENS L027
Zoom link: https://sabanciuniv.zoom.us/j/6958795963
Keywords : Magnetic Transfection, Cell Culture, Gene Delivery, HEK 293T, Bobbin, Electromagnet, Cell Culture Plate, Magnetic Field, Direct Current (DC), Alternating Current (AC)
Abstract
Magnet-assisted transfection, also trademarked as magnetofection, is a non-viral gene delivery method which employs external magnetic fields generated by permanent magnet plates to guide superparamagnetic iron oxide nanoparticle (SPION)-bound complexes of nucleic acids into target cells. In this procedure, properties of the magnetic field, in particular, the magnetic flux density (
), gradient of the magnetic flux density (
), and the duration of magnetic field exposure, can vary the transfection efficiency. To date, commercial magnet-assisted transfection systems heavily rely on rare-earth magnets (magnet plates) to expose SPION-conjugated genes to strong, yet time-invariant (static) field gradients and concentrate them above the target cell surfaces after which they are taken into the cells by endocytosis. More recently though, a magnet system capable of providing time-varying (alternating) magnetic fields was demonstrated (US Patent: 11,160,884 B2) which provided higher transfection efficiency. Building onto this patented technology, this thesis introduces a new, user-friendly magnetofection platform that is compact and readily portable allowing direct cell culturing on the plate. The developed platform was evaluated by benchmarking it against commercial magnet plates, through transfection of green fluorescent protein (GFP) in human embryonic kidney (HEK 293T) cells. As such, the platform was used to investigate the effects of various magnetic field conditions, including only static (DC), only alternating (50 Hz AC, ~6mT at 50 mA), and combinations of DC/AC fields on transfection efficiency over 20-minute durations. After 48 hours of incubation in a 5% CO2 humidified incubator at 37°C, GFP expression was analyzed. The results demonstrated that the highest transfection efficiency; quantified by the fluorescence intensity of the transfected GFP in HEK 293T cells, was achieved using the condition of 20 minutes exposure to AC magnetic field (AC 20), which displayed up-to 3-fold higher fluorescence compared to the “no-field” condition; and up to 2-fold higher compared to 20 minutes exposure to DC magnetic field through the commercial magnet plate.
