Evaluation of the biocompatibility of S-phase layers on medical grade austenitic stainless steels

S-phase surface layers were formed in AISI 316LVM (ASTM F138) and High-N (ASTM F1586) medical grade austenitic stainless steels by plasma surface alloying with nitrogen (at 430 C), carbon (at 500 C) and both carbon and nitrogen (at 430 C). The presence of the S-phase was confirmed by microscopy, hardness testing, depth-profile analysis of chemical composition and X-ray Diffraction. Attachment and proliferation of mouse osteoblast MC3T3-E1 cells were tested on S-phase and untreated controls and the results demonstrated that all the S-phase layers formed were biocompatible under the conditions used. Cells adhered equally well to all samples but proliferation was enhanced on the treated materials.peer-reviewe