In vitro bioactivity and dissolution of Ca2(SiO3)(OH)2 and β-Ca2SiO4 fibers

In this paper, needlelike and dispersible hillebrandite (Ca-2(SiO3)(OH)(2)) and beta-dicalcium silicate (beta-Ca2SiO4) fibers, 1.0-1.5 mum in diameter and 15-25 mum in length were prepared by a modified hydrothermal method. In vitro bioactivity and dissolution of the two types of fibers were evaluated by soaking in the simulated body fluid (SBF) for various periods. Hydroxyapatite-like aggregates appeared on the fibers after soaking for 7 days, and uniform lathlike agglomerates with typical morphology of hydroxyapatite (HAp) formed after 14 days. It was observed that the fibers after soaking still kept stability in fibrous morphology with an aspect ratio in the range of 6-9. The Ca-2(SiO3)(OH)(2) and beta-Ca2SiO4 fibers dissolved about 30.91 and 30.42%, respectively, within 14 days. The two types of fibers exhibited certain desirable characteristics including bioactivity, degradability and stability in morphology, and they are promising candidates as reinforcement reagents to develop novel bioactive composites for biomedical applications. (C) 2004 Elsevier Ltd. All rights reserved.