Investigation of cytocompatibility of surface-treated cellulose nitrate films by using plasma immersion ion implantation

The alpha-particle sensitive colorless cellulose nitrate films (commercially available as LR 115 films from DOSIRAD, France) have been proposed as cell-culture substrates for alpha-particle radiobiological experiments. Cytocompatibility of the substrate is a key factor to the success of such experiments. The present work aims to investigate the cytocompatibility of surface-treated cellulose nitrate films by using plasma immersion ion implantation-deposition. The films were placed in a vacuum chamber, into which nitrogen gas was continuously bled and where the pressure was kept at 2 × 10^{- 3} Torr. Implantation was carried out by igniting the nitrogen plasma at 100 W radio-frequency and applying high bias voltage in pulse with 20 μs pulse width and 50 Hz (with 20 kV or no voltage). HeLa cervix cancer cells were then cultured on both the plasma-treated and untreated cellulose nitrate films. Our tests showed that the plasma-treated films are in general more cytologically compatible.