Sterilization of PAN/Gelatin Nanofibrous Mats for Cell Growth

Nanofi brous mats can be used as a substrate for eukaryotic cell growth in biotechnology, tissue engineering, etc. Several adherent cells (e.g. human fibroblasts) have been shown to grow well on fine fibres. For most applications, it is necessary to sterilize nanofibrous mats before adding the cells. Another possibility would be the addition of antibiotics and antimycotics to the cell culture medium to prevent microbial infection. However, antibiotics are disadvantageous since they might promote the growth of resistant bacteria in possible future medical applications of nanofibrous mats. Possible sterilization techniques include autoclaving, UV-sterilization, ozone treatment, heat sterilization and other techniques which usually necessitate more expensive equipment, such as gamma irradiation. Systematic examinations of the infl uence of different sterilization techniques on the cell growth on nanofibrous mats have not yet been reported in the literature. Here, we report on the first experimental investigations of the effect of sterilization with different methods on the properties of polyacrylonitrile (PAN)/gelatine nanofibrous mats, and the resulting growth and adhesion of Chinese hamster ovary cells. While all techniques under investigation yielded sterile nanofibrous mats, autoclaving and heat sterilization change the PAN/gelatine fibre morphology. Ozone, on the other hand, modifies the pH value of the culture medium and partly impedes cell adhesion. UV sterilization also suggests a chemical modification of the nanofibrous mat. Unexpectedly, heat sterilization resulted in the highest amount of adherent Chinese hamster ovary cells grown on PAN/gelatine nanofibrous mats in spite of gelatine melting.