The Behavior Of Hepatoma Cells Controlled By Several Surface Chemistry Groups

Liver cancer is one of the most common malignant tumors in the world,which causes about 622,000 new cases every year as to seriously threaten human health.However,there is still lack of an effective method to treat liver cancer.Some research reported that the hepatoma(HepG2)cells fate was controlled by cellular microenvironment,which played a key role in growth,proliferation,invasion and metastasis of tumor cells.Therefore,the proliferation,invasion and metastasis of HepG2 cells could be regulated by making different cellular microenviroment.The Self-Assembled Monolayers(SAMs)is an effective method to modify the surface properties of biomaterials.The biomaterial surfaces with single or multiple chemical groups were prepared by self-assembled monolayers technology to control the chemical factors of the HepG2 cells microenvironment for investigating the influence of chemical groups on the adhesion,proliferation and apoptosis of the HepG2 cells.The mechanism of interaction between chemical groups and cancer cells was analyzed at molecular level in chemistry and at cell level in biology.This results provided a theoretical basis for designing biomaterials with specific cellular responses.The main contents are as follows:Firstly,the SAMs surfaces with different chemical groups(SAMs-CH3,SAMs-NH2 and SAMs-COOH)were prepared by modification of silicon surfaces using organosilane reagents.Subsequently the properties of SAMs surfaces were characterized by atomic force microscopy,Fourier transform infrared spectroscopy and contact angle measuring instruments.The results proved that SAMs surfaces with the same density and different terminal chemical groups were prepared successfully.These surfaces with different chemical groups expressed different hydrophilic and hydrophobic.The SAMS-CH3 surface had the largest contact angle value and was the most hydrophobic surface.The SAMs-NH2 surface was a moderately hydrophilic surface and the SAMs-COOH surface is the most hydrophilic surface.Secondly,SAMs surfaces with single chemical group were served as the biomaterial model to investigate the interaction between a single chemical group and HepG2 cells.The results indicated that different chemical groups have different effects on the behavior of HepG2 cells.The HepG2 cells adhered on the SAMs-CH3 surfaces poorly and exhibited a smaller round shape,which adhered on the SAMs-NH2 and SAMs-COOH surfaces with a more flattened morphology.Compared with other chemical surfaces,a lower rate of cell proliferation and a higher rate of cell apoptosis on the SAMs-CH3 surfaces were obtained.The results demonstrated that the-CH3 group could be the key factor to promote the apoptosis of HepG2 cells and inhibit the proliferation of HepG2 cells.Finally,composite SAMs-NH2/CH3 surfaces with different surface positive charge were prepared by adjusting the concentration of-NH2 group to investigate the influence of surface positive charge on the adhesion and proliferation of HepG2 cells.The results indicated that cell behavior was affected by surface charge combined with hydrophobicity and hydrophilicity,and the factors that played a leading role in cell behavior at different time periods were different.At the initial of the culture time(24h),cell behavior was mainly affected by surface chemistry.With the prolongation of culture time,the adhesion and proliferation behavior of cells was mainly regulated by surface positive charge.Especially,the proliferation rate of cells increased as the concentration of-NH2 groups increasing after 72h of culture.