Kohei Kugo

Fibroblast attachment to Arg-Gly-Asp peptide-immobilized poly(γ-methyl L-glutamate)

The attachment of MRC-5 human fibroblasts was investigated on poly(γ-methyl L-glutamate) (PMLG), and upon cell adhesion peptides Arg-Gly-Asp-Ser (RGDS)- and Gly-Arg-Gly-Asp-Ser (GRGDS)-immobilized PMLG (RGDS-PMLG and GRGDS-PMLG). The peptides were immobilized by their N-terminal amine to activated PMLG surfaces. Prior to peptide immobilization, the aminolysis of PMLG surfaces was performed with hydrazine hydrate (HA), ethylenediamine (EDA), and hexamethylenediamine (HMDA) and was followed by the activation with hexamethylene diisocyanate. Surface characterization of these films was carried out by means of a Fourier transform IR (FT-IR) spectrometer equipped with an attenuated total reflectance (ATR) attachment. The amount of immobilized RGDS could be controlled by the reaction time of the aminolysis. The effects of HA, EDA, and HMDA as a spacer on the cell attachment were also investigated, and it was suggested that a longer spacer promoted the cell attachment via specific receptor-ligand interaction.

Effect of the molecular weight on the surface composition of polycarbonate/poly(ethylene terephthalate) blends by Fourier transform IR attenuated total reflectance spectroscopy

The surface structure of melt-mixed blends of bisphenol A polycarbonate (PC) and poly(ethylene terephthalate) (PET) was investigated by Fourier transform infrared attenuated total reflectance (FTIR ATR) spectroscopy. Based on the peak intensity of the aromatic carbonate band for PC and the aliphatic ester band for PET by using germanium and KRS-5 ATR crystals, the enrichment of the PET component in the surface layer of PC/PET blend films was observed. This surface enrichment of PET component was also enhanced by decreasing the PET molecular weight. The peak position of the aromatic carbonate band for PC shifted to higher frequencies with increasing PET weight fraction, while that of the aliphatic ester band for PET shifted to higher frequencies with increasing PC weight fraction. The peak shift for both PC and PET by using a germanium crystal was, however, relatively small. This means that a self-association state of each component is kept relatively well in the outer surface layer. Furthermore, the self-...

Estimation of the Secondary Structure of Fibronectin Adsorbed to Polystyrene and Deprotected Poly(ε-N-Benzyloxycarbonyl-L-Lysine) by FTIR ATR Spectroscopy

The secondary structure of fibronectin (FN) adsorbed to polymer surfaces were investigated in a quantitative manner using Fourier transform ir attenuated total reflectance (FTIR ATR) techniques. Polystyrene (PSt), poly(e-N-benzyloxycarbonyl-L-lysine) (PBCL), and 10 mol% deprotected PBCL (CLIO) were used as polymer substrates. The conformation of adsorbed FN was substrate dependent even though the comparable amount of FN adsorbed. The contents of the s-structure, a-helix, and random coil structure of FN on PSt at 10 min after the injection were 61%, 22%, and 17%, respectively. The β-structure content increased gradually and reached ca.70% after 180 min. In the case of CLIO, the content of the β-structure, a-helix, and random coil structure at 10 min were 47%, 43%, and 10%, respectively. The β-structure content increased as well as PSt and reached 65% after 180 min, while the a-helical content decreased to 26%. Deconvolved ir spectra in the amide II region showed that the s-structure content in FN increased upon adsorption to PSt and CLIO, but the secondary structure content changed depending on polymers.