Exposed and sham-exposed cells were investigated with or without co-exposure to gold nanoparticles (20 nm and 100 nm diameter) on extracellular matrix structures. The gold nanoparticles were bound covalently to the extracellular matrix structures via crosslinks with the help of a reagent. For the control, only the crosslink reagent was used without gold nanoparticles and it was referred to as the crosslinked group. The study was conducted in view of a possible use in tissue engineering.
Exposure duration: continuous for 0.5, 1 or 2 hours daily for up to 10 days
|Exposure duration||continuous for 0.5, 1 or 2 hours daily for up to 10 days|
|Chamber||cells were incubated in a polyvinyl chloride cell culture chamber within a pair of Helmholtz coils in multi-well cell culture plates containing the extracellular matrix constructs; cell culture chamber maintained a temperature of 37±0.5°C and 5% CO2|
|Setup||Helmholtz coils were each constructed of 10 AWG copper magnet wire with an inner diameter of 95.5 cm and a coil height of 6.2 cm; field with <1% deviation in field strength over an area of 25.4 cm in diameter|
|Sham exposure||A sham exposure was conducted.|
|magnetic flux density||1.2 mT||-||measured||-||-|
Cell populations in magnetic field exposed cultures with and without co-exposure to 20 nm gold nanoparticles appeared to show denser coverage of the matrix surfaces compared to sham-exposed cultures in microscopical analysis. Cell viability was significantly reduced in cultures with 20 nm particles after the first 3 days compared to the crosslinked group, regardless of the concentration and exposure to the magnetic field. In cultures exposed to the magnetic field, as well as in cultures with 100 nm particles alone, a significant higher cell proliferation could be found from day 3-10 compared to sham-exposed cultures and the crosslinked group, respectively. The daily exposure duration (0.5, 1 or 2 h) had no significant effect on cell proliferation.
The authors conclude that an in vitro exposure of murine fibroblasts to a 60 Hz magnetic field as well as to 100 nm gold nanoparticles can enhance cell proliferation. However, a co-exposure does not show any synergistic effects. Further studies with stronger magnetic fields and/or larger nanoparticles could provide other results, though.