CELL-ADHESION CONTROL BY ION-IMPLANTATION INTO EXTRACELLULAR-MATRIX

Cell adhesion control of polymer surfaces by ion implantation into pol ymers and extra-cellular matrix has been studied by means of in vitro adhesion measurements of the carcinoma of the cervix (HeLa cell). The specimens used were polystyrene (PS), oxygen plasma treated polystyren e (PS-0), extra-cellular matrix (Collagen: Type I) coated polystyrene (PS-C), and gelatin coated polystyrene (PS-G). Ne+, Na+, and Ar+ impla ntations were performed with a fluence of 1 X 10(15) ionS/cm2 at energ ies of 50, 100 and 150 keV. The chemical and physical structures of io n implanted specimens have been investigated by Fourier transform infr ared spectroscopy (FT-IR-ATR), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. Ion implanted PS demonstrated a dramatic impro vement of adhesion of HeLa cell. HeLa cell adhered only to ion implant ed circular domains of a diameter about 0.1 mm on PS. By contrast, ion implanted PS-C, PS-G and PS-0 domains inhibited the cell adhesion. Th ese phenomena were observed on Ne+, Na+, and Ar+ implanted specimens a t energies of 50, 100, and 150 keV. lob implantation broke the origina l chemical bonds to form new radicals such as [GRAPHICS] = O condensed rings, C-C, C-O and OH radical. Ion implanted PS had a large amount o f new radicals compared with_that of PS-C, PS-G and PS-0. lob implanta tion broke NH and NH 3 bonds originating from amino acid in PS-C and P S-G. OH and[GRAPHICS] = O caused by oxygen treatment in PS-0 were also destroyed by ion implantation. It is concluded that cell adhesion to ion implanted PS was caused by carbon structure and new radicals induc ed by ion implantation. The inhibition of HeLa cell adhesion on PS-C, PS-G and PS-0 was caused by the destruction of cell adhesion propertie s of amino acid, OH and [GRAPHICS] = O by radiation effects.