The adsorption of collagen on spin-coated poly(lactic acid) (PLA) surface was investigated using quartz crystal microbalance (QCM).The effects of concentration (0~9.25 g/mL) and temperature (10~50℃) on adsorption were studied.The results show that:with the increasing concentration of collagen

the adsorption amount and initial adsorption rate on spincoated PLA surface increases correspondingly.Langmuir model and Freundlich model were applied for data fitting.The isotherm equations q=1169(0.99c/1+0.99c) and q=610c(1/3.79) were obtained.It is found that Langmuir model described experiments better than the Freundlich model.The kinetic experimental data were correlated with the Lagergren pseudofirst order kinetic model and the Lagergren pseudo-second order kinetic model.It is shown that under low concentrations the Lagergren pseudofirst order kinetic model fits the results better and the Lagergren pseudosecond order kinetic fits the results better under high concentrations.It means that the diffusion process is the ratecontrolling step under low concentration and the interaction between collagen and PLA surface is the ratecontrolling step under high concentrations.The AFM images show that the collagen adsorbed on PLA surface formed meshlike structure.The adsorption was significantly influenced by temperature changes in the adsorption buffer

indicating that the collagen is a kind of temperaturesensitive material.The results also indicate that collagen denaturalizes gradually with increasing temperature in the range (10~40℃).The adsorption quantity drops sharply when the temperature approaches (40~45℃)

40℃ is the denaturizing temperature of collagen under present experimental conditions.