Thermodynamics & Kinetic of Plasma Protein Adsorption onto Poly(L-lactide)/Poly(L-lysine) Mixtures.

• Main Authors: Ting-Chu Hsu, 許廷竹
• Other Authors: David Shiaw-guang Hu
• Format: Others
• Language: zh-TW
• Published: 2001
• Online Access: http://ndltd.ncl.edu.tw/handle/70280033265357357993

碩士 === 國立臺灣科技大學 === 纖維及高分子工程系 === 89 === Abstract(Part I) This work investigated the adsorption of bovine serum albumin onto the poly(L-lysine)(PLL)/poly(L-lactide)(PLLA) blends with the UV-VIS spectroscopy to measure the protein concentration in the solution. The influence of van der waals forces and electrostatic forces between the protein and polymers as determined by the protein size and ionic composition of polymers, on the adsorption equilibrium constant Ke was also studied. Experiments find that the protein adsorption onto the polymer surface increases with protein concentration in bulk and the PLL content. Theoretical analysis with the DLVO theory and molecular theory of adsorption show that the protein size increases the van der waals interaction energy and the adsorption equilibrium constant Ke. Also the ionic composition in polymers increases the total interaction energy and the Ke values. Numerical computation indicats the slight increase of Ke with the ionic strength. Abstract(Part II) This work investigated the adsorption of fibrinogen onto the poly(L-lysine)(PLL)/poly(L-lactide)(PLLA) blends with the UV-VIS spectroscopy to measure the protein concentration. Experiments find that the equilibrium constant protein adsorption onto the polymer surface increases with the fibrinogen concentration in solution and PLL content in blends. The limiting adsorption rate constnt(kapp) under the adsorption control(or equilibrium adsorption) was taken from the adsorption data. Also the diffusion-adsorption equation was numerically analyzed with the Crank-Nicolson finite-difference method. The fibrinogen adsorption data were used to find the real adsorption rate constant(k). It is found that kapp was overestimated with a fator of several hundrads. The simulation indicates that the fractional coverage increases with the ratio of adsorption rate to molecular diffusion and that of protein amount in bulk to saturated adsorption. Moreover, k and kapp increase with PLL content in blends. In conjunction with results from part I, it is shown that the adsorption amount and equilibrium constant of fibrinogen is higher than that of BSA. This is caused by the effects of protein size and the ionic change on protein,of which the former plays more significant rote. It is also obserable that the higher equilibrium adsorption corresponds to the higher rate on the polymer surface.