The Study Of The Dao-sensitizing And Radio-protection Effect For Ion-heavy Radiation Of Nano Chitosan

Objective:To investigate radio-sensitization effect and radio-protective effect of nano-chitosan.Methods:The MTT assay was used to measure cell proliferation of human oral epidermoid carcinoma KB cell line. Inhibition ratio of ion-heavy for human oral epidermoid carcinoma KB cell had been calculated by variance of optical density. The sensitivity of human oral epidermoid carcinoma KB cell for6+C12irradiation had been analyzed by inhibition ratio with or without treatment with nano-chitosan.The cell proliferation of mouse osteoblast MC3T3-E1cell line had been measured by MTT assay. Infrared spectroscopy was used to analyze functional group of nano-chitosan after irradiation. The antitumor effect of nano-chitosan after irradiation had been measured by MTT assay.Results:Proliferation of human oral epidermoid carcinoma cell line KB was weakly inhibited by nano-chitosan alone in a concentration-dependent manner ranging from125-1500mg/L. Proliferation of human oral epidermoid carcinoma cell line KB was inhibited by C irradiation alone. Otherwise, radio activation had been observed in low-dose C irradiation. The radio activation disappeared after treatment with nano-chitosan and optimization dose was ranging from500mg/L to1000mg/L. Proliferation of mouse osteoblast cell line MC3T3-E1was weakly inhibited by nano-chitosan alone, but inhibition ration was obviously correlation with treatment time and dose. The inhibition ration of nano-chitosan had changed negatively ranging from500to1000mg/L after24h,48h or72h. Proliferation of mouse osteoblast cell line MC3T3-E1had been inhibited by nano-chitosan ranging from1000to1500mg/L after72h. Proliferation of mouse osteoblast cell line MC3T3-E1had been inhibited by C ion heavy irradiation ranging from1Gy to4Gy. The proliferation of MC3T3-E1was weakly slowed down by irradiation1Gy to2Gy and significant slowed down by irradiation in4Gy. The suppressing effect was not disappearing until72h after irradiation. The survival rate was improved after treated with nano-chitosan compared with irradiation alone. The optimization dose of radiation protection was ranging from500mg/L to1000mg/L. The antitumor effect of nano-chitosan after irradiated with different dose C ion heavy had obviously promoted to5to10times. The promotion effect was not positively correlated with irradiation dose and optimization dose of radiation degradation was1000Gy.Conclusion:The inhibition ration of nano-chitosan alone was weakly for human oral epidermoid carcinoma cell line KB. Pretreatment by nano-chitosan could improve sensitivity of KB cell for C irradiation. The optimization dose of radio sensitization was ranging from500mg/L to1000mg/L. The nano-chitosan could protect mouse osteoblast cell line MC3T3-E1from irradiation damage by ion heavy. The optimization dose of radio protection was below to1000mg/L. The ion heavy induced the degradation and improve the antitumor acitivity of nano-chitosan. The optimization dose of radio degradation was1000Gy.