Effect of bioactive glass crystallization on the conformation and bioactivity of adsorbed proteins

Abstract

Protein adsorption onto the surface of a biomaterial mediates cell adhesion and enhances tissue-implant integration. In a previous study, we demonstrated that crystallization of bioactive glass (BG) significantly increased the negative zeta potential and decreased serum protein adsorption onto the material surface. In this study, the conformation of protein adsorbed onto the surface of amorphous bioactive glass (ABG) and crystallized bioactive glass (CBG) was analyzed and correlated to bone marrow mesenchymal stem cell adhesion and spreading. ABG and CBG were immersed in three different protein solutions containing 10% fetal bovine serum, bovine serum albumin (BSA), and fibronectin (FN) for 4 h at 37 degrees C. Grazing angle Fourier transform infrared spectroscopy (GA-FTIR) demonstrated that the ratio of (amide I)/(amide II) functional groups of all proteins adsorbed onto ABG was greater than that for proteins adsorbed onto CBG. The Gaussian curve fitting analysis suggests that the significant expression of amide I, rich in charged and flexible unordered secondary structure of adsorbed FN, stimulated bone cell adhesion and spreading on the surface of ABG. CBG enforces protein conformation that exposes amide II, rich in neutral and stable beta-sheet structure and alpha-helix, which limited cell adhesion and spreading. Although ABG adsorbed significantly higher quantity of BSA than FN, GA-FTIR analyses showed that the ratio of amide I/amide II was significantly higher for adsorbed FN. Therefore, the intensity of amide I or amide II bands cannot be taken as a measure of the quantity of adsorbed protein.

Vitamin E blended Uhmwpe may have the potential to reduce bacterial adhesive ability

“…The ATR–FTIR bands in the spectra of control samples suspended in TSB cultural medium (Fig. 4) can be attributed to the absorptions of amide I and amide II groups,32–34 indicating adsorption of protein‐like substances on the polymer surface, most likely coming from media, which contained proteins, lipids, and oligosaccharides. The extent of the proteins adsorption was maximized in OX‐PE, whereas it was barely detectable in the other PEs tested.…”

Heat treatment of Na2O‐CaO‐P2O5‐SiO2 bioactive glasses: Densification processes and postsintering bioactivity

“…In fact several investigations on the 45S5 Bioglass ® and other bioactive glasses have proved that the development of chemically stable crystal phases may sensibly reduce the reaction kinetics of bone tissue integration 35–37. Moreover, recent contributions have suggested that the crystallization may inhibit the protein adsorption and even promote inappropriate protein conformations for cell adhesion 38, 39…”

Cell Resistant Peptidomimetic Poly (2‐ethyl‐2‐oxazoline) Coatings Developed by Low Pressure Inductively Excited Pulsed Plasma Polymerization for Biomedical Purpose

“…[34] Hence, we have performed the peak area analysis to demonstrate the effects of plasma power on the chemical composition of ppEtOz coatings. The Gaussian curve fitting process applied to amide I band (1 600-1 700 cm À1 ) to resolve the underlying bands of the ppEtOz coating spectrum (carrier gas flow rate was 5 sccm) which was obtained on coatings deposited at different effective plasma powers are reported in Figure 3a-d. A summary of the amide I band fit results is tabulated in Table 1.…”