BACKGROUND: Polydimethylsiloxane (PDMS) is widely used in the basic research on cell biology because of its good biocompatibility and ability to be processed at the micro/nano level. However, cell culture on PDMS has been generally compromised by its strong hydrophobicity.OBJECTIVE: To perform a comparative investigation on the influences of different surface modifications as well as stiffness of PDMS on cellular behaviors.METHODS: PDMS films with varying stiffnesses were subjected to various surface modifications, including serum incubation, type I collagen deposition and air plasma treatment. Bovine articular chondrocytes were seeded on PDMS films and cell adhesion, proliferation and matrix production were characterized using F-actin staining, cell counting kit-8,microscopic examination, Sirius red/Safranin-O staining and quantitative determination of glycosaminoglycans,respectively.RESULTS AND CONCLUSION: Serum incubation, type I collagen deposition and air plasma treatment were all found to promote adhesion and proliferation of bovine articular chondrocytes from the results of F-actin staining and cell prolifereration curve, with air plasma treatment the best. Total amount of glycosaminoglycans (GAG) secretion was only increased by air plasma treatment and GAG/DNA was decreased by all modifications. Stiffness also played roles in cell adhesion, proliferation and GAG production, which was found to be dependent on surface modifications. This study would provide guidance for applying PDMS in cell culture.