The opportunity to obtain surfaces which are bioactive from both the inorganic and biological point of view represents an interesting solution in order to improve tissue integration of implants and bone regeneration. The aim of this research work is enzyme grafting onto bioactive glasses in order to promote also a biological bioactivity. Two kinds of glasses, with different compositions and degree of bioactivity were employed as substrates. Samples have been firstly washed to expose hydroxyls groups and then silanized with 3-amminopropyltriethoxysilane in order to introduce amino groups. Finally, samples have been grafted with the enzyme alkaline phosphatase (ALP). Both silanized and only washed samples have been grafted with ALP. Different washings were performed after functionalization in order to study bonding stability. Hydroxyls exposition and silanization have been verified by means of contact angle measurements. ALP grafting has been studied by means of XPS analysis. After the addition of the specific substrate, the ALP activity was evaluated by UV-Vis spectroscopy. XPS spectra revealed ALP presence onto surfaces of grafted samples by enrichment in carbon and nitrogen and a decrease in the constituents' characteristic of the substrate. Peaks characteristic for the enzyme can be evidenced by the detailed study of carbon region. Enzymatic activity tests showed that ALP maintains its activity after grafting and also that enzyme activity is reduced but maintained after different washings.
|Titolo:||Enzyme grafting to bioactive glasses|
|Settore Scientifico Disciplinare:||Settore CHIM/04 - Chimica Industriale|
|Data di pubblicazione:||2010|
|Tipologia:||Book Part (author)|
|Appare nelle tipologie:||03 - Contributo in volume|