BEH.462/3. 962J Molecular Principles of Biomaterials Spring 2003 A second example, immobilized insulin( Ito) Ins-PSt 10 Amount of insulin (ug/well) (8N●(N (ns-PAA Fig. 2. Relative growth rate of mouse fibroblast STO cells in the presence of (A) native insulin,(4)Ins-POE (O)Ins-PAA, (O)Ins-PSt. Bars represent standard deviation. N=6. This data interestingly shows several biophysical effects o PEG-insulin not as good as free insulin Steric interference o PAA-insulin better than free insulin Multivalent o Surface-immobilized PAA-insulin better than all above Lack of internalization/signal downregulation? Issues faced in incorporation of cytokines in biomaterials: Protein stability (rugged, but not as good as peptides-may significant secondary structure to worry about Steric interference of tether/surface with receptor binding Growth factors that have been studied in biomaterials EGF Insulin(Y Ito) TGF阝(West) Lecture 4- Biological Recognition pt. 2 8 of 9BEH.462/3.962J Molecular Principles of Biomaterials Spring 2003 • A second example, immobilized insulin (Ito): ƒ This data interestingly shows several biophysical effects: o PEG-insulin not as good as free insulin ƒ Steric interference o PAA-insulin better than free insulin ƒ Multivalent o Surface-immobilized PAA-insulin better than all above ƒ Lack of internalization/signal downregulation? ƒ • Issues faced in incorporation of cytokines in biomaterials: ƒ Protein stability (rugged, but not as good as peptides- may significant secondary structure to worry about ƒ Steric interference of tether/surface with receptor binding • Growth factors that have been studied in biomaterials: ƒ EGF ƒ Insulin (Y. Ito) ƒ TGF-β (West) Lecture 4 – Biological Recognition pt. 2 8 of 9