Abstract: ObjectiveTo study the relationship between endocy tosis of human lung adenocarcinoma cell line SPC-A1 modified by ox idized Glutathione(GSSG)and culture conditions including culture temperature,time and concentration.MethodThe uptake of GSSG-modified Fe₃O₄ nanoparticles by SPC-A1 cell was observed by transmission electron microscopy (TEM)and Prussian blue staining.The extracellular adhesion or intracellular uptake of GSSG-modified Fe₃O₄ nanoparticles were measured by atom absorb spectrum(AAS).ResultsTEM results indicated that GSSG-modified Fe₃O₄ nanoparticles adhered on the membrane of SPC-A1 cell after being cultured at 4℃ for 1 h or 24 h,but SPC-Al cell could took up nanoparticles particles after cultured at 37℃ for 1 h.Prussian blue staining indicated that SPC-Al cells containing GSSG-modified Fe₃O₄ nanoparticles were much more with the pro longation of culture time or the increase of concentration.AAS analysis indicated that the extracellular adhesion of GSSG-modified magnetic particles was depended on culture time and concentration.The uptake amount of GSSG-modiied Fe₃O₄ nanoparticles by SPC-A1 cell was saturated after 24 h when the nanoparticles in low concentration(0.1 mg/ml or 0.4 mg/ml),the uptake was saturated after 72 h when the nano particles in high concentration(0.7 mg/ml or 1.0 mg/ml).The maximal amount per SPC-A1 cell could reach 160 pg.ConclusionThe uptake of GSSG-modified Fe₃O₄ nanoparticles by SPC-A1 cell is energy needed.It depends on the concentration of nanopar ticles and saturates at certain time.