𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Mechanism of calcium disilicide-induced calcification of crystalline silicon surfaces in simulated body fluid under zero bias

✍ Scribed by Vladimir V. Seregin; Jeffery L. Coffer


Book ID
102294235
Publisher
John Wiley and Sons
Year
2008
Tongue
English
Weight
378 KB
Volume
87A
Category
Article
ISSN
1549-3296

No coin nor oath required. For personal study only.

✦ Synopsis


Abstract

A dry‐etch spark ablation method was used to produce calcium disilicide (CaSi~2~/Si) layers on silicon surfaces, and their biomineralization under zero bias was followed by means of scanning electron microscopy, X‐ray energy dispersive analysis, and Raman spectroscopy. CaSi~2~/Si wafers are bioinert at 25°C and bioactive at 37°C. Mechanistic insights regarding biomineralization were derived from an analysis of film growth morphology and chemical composition after various soaking periods in standard simulated body fluid (SBF). Changes in CaSi~2~ calcification behavior as a function of reaction temperature and pH, SBF concentration, and various surface modification processes were also employed for this purpose. During CaSi~2~/Si calcification under zero bias, calcium phosphate (CaP) growth is strongly dependent on the structural degradation of CaSi~2~ grains. Surface silanol groups, initially present on the as‐prepared material, cannot induce CaP nucleation, which begins only upon delamination of CaSi~2~ layers. The calcium phosphate phases, which are present during various growth stages, possibly include a combination of Mg‐substituted whitlockite, monetite, and tricalcium phosphate. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008