Multifunctional role of osteopontin in directing intrafibrillar mineralization of collagen and activation of osteoclasts

详细信息    查看全文

• 作者：Douglas E. Rodriguez ; Taili Thula-Mata ; Edgardo J. Toro ; Ya-Wen Yeh ; Carl Holt ; L. Shannon Holliday ; Laurie B. Gower
• 关键词：Osteoclast ; Biomineralization ; Bioresorption ; Bone graft ; Osteopontin
• 刊名：Acta Biomaterialia
• 出版年：January, 2014
• 年：2014
• 卷：10
• 期：1
• 页码：494-507
• 全文大小：4824 K

文摘

Mineralized collagen composites are of interest because they have the potential to provide a bone-like scaffold that stimulates the natural processes of resorption and remodeling. Working towards this goal, our group has previously shown that the nanostructure of bone can be reproduced using a polymer-induced liquid-precursor (PILP) process, which enables intrafibrillar mineralization of collagen with hydroxyapatite to be achieved. This prior work used polyaspartic acid (pASP), a simple mimic for acidic non-collagenous proteins, to generate nanodroplets/nanoparticles of an amorphous mineral precursor which can infiltrate the interstices of type-I collagen fibrils. In this study we show that osteopontin (OPN) can similarly serve as a process-directing agent for the intrafibrillar mineralization of collagen, even though OPN is generally considered a mineralization inhibitor. We also found that inclusion of OPN in the mineralization process promotes the interaction of mouse marrow-derived osteoclasts with PILP-remineralized bone that was previously demineralized, as measured by actin ring formation. While osteoclast activation occurred when pASP was used as the process-directing agent, using OPN resulted in a dramatic effect on osteoclast activation, presumably because of the inherent arginine-glycine-aspartate acid ligands of OPN. By capitalizing on the multifunctionality of OPN, these studies may lead the way to producing biomimetic bone substitutes with the capability of tailorable bioresorption rates.