The Effects Of Air Cold Atmospheric Plasma On Cellular Early Attachment, Proliferation And Migration On Pure Titanium Surfaces

Objective:Cold plasma has been studied for several fields of medicine,for example,pathogen inactivation and implant functionalization.However,its clinical application is limited as the effects of plasma treatment cannot be maintained for a long time.Air cold atmospheric plasma（CAP）is cost-efficient and convenient for clinical application compared to other work gas atmospheric plasma.In this study,we studied the effects of air cold atmospheric plasma on property of pure titanium surface and initial cellular attachment,proliferation and migration of osteoblasts.Methods:In this study,the behavior of MC3T3-E1 cells on titanium discs was analyzed after treatment with air CAP.The characteristics of the titanium surfaces before and after the air CAP treatment were analyzed by a field emission scanning electron microscope（SEM）,atomic force microscope（AFM）,X-ray photoemission spectroscopy（XPS）and contact angle measurements.The morphologies of cells attached to the titanium surfaces were observed by SEM and fluorescence microscope at 2,8 and 24 h after seeding.The gene and protein expression levels of integrinβ1,α2 andα5 were examined by RT-PCR and Western-Blot after incubating2,8 and 24 h,respectively.The abilities of cell proliferation and migration were studied by MTT assay and migration assay,respectively.Results:The relative content percentage of TiO₂ and Ti-OH increased,and the relative content percentage of C decreased.The air CAP made the titanium surfaces more hydrophilic,but the effect can not maintain for a long time.The roughness of titanium surfaces with and without air CAP were 30.6±9.00 nm and 27.66±3.68nm,respectively.There was no obvious difference（p>0.05）.The MC3T3-E1 cells adhered to the untreated surface were fusiform,whereas the cells covered a larger surface area on the air CAP-treated surface at 2 h.The gene and protein expression levels of integrinβ1,α2,andα5 in cells on the surfaces treated by air CAP were upregulated in the early stage compared to those untreated.And the air CAP-treated titanium surfaces enhanced cell proliferation and migration with more developed cellular network.Conclusion:Air CAP treatment is a potential surface modifying method that can enhance the initial cellular attachment,proliferation and migration.Since the effects of plasma treatment cannot be maintained for a long time,it is expected that implants treated by air CAP immediately before implantation could improve the successful rate of implants.