Thula Taili T, Svedlund Felicia, Rodriguez Douglas E, Podschun Jacob, Pendi Laura, Gower Laurie B
Department of Materials Science & Engineering, University of Florida, Gainesville, FL 32611, USA.
Polymers (Basel). 2011;3(1):10-35. doi: 10.3390/polym3010010.
The nanostructure of bone has been replicated using a polymer-induced liquid-precursor (PILP) mineralization process. This polymer-mediated crystallization process yields intrafibrillar mineralization of collagen with uniaxially-oriented hydroxyapatite crystals. The process-directing agent, an anionic polymer which we propose mimics the acidic non-collagenous proteins associated with bone formation, sequesters calcium and phosphate ions to form amorphous precursor droplets that can infiltrate the interstices of collagen fibrils. In search of a polymeric agent that produces the highest mineral content in the shortest time, we have studied the influence of various acidic polymers on the in vitro mineralization of collagen scaffolds via the PILP process. Among the polymers investigated were poly-L aspartic acid (PASP), poly-L-glutamic acid (PGLU), polyvinylphosphonic acid (PVPA), and polyacrylic acid (PAA). Our data indicate that PASP and the combination of PGLU/PASP formed stable mineralization solutions, and yielded nano-structured composites with the highest mineral content. Such studies contribute to our goal of preparing biomimetic bone graft substitutes with composition and structure that mimic bone.
利用聚合物诱导液相前驱体（PILP）矿化过程复制了骨的纳米结构。这种聚合物介导的结晶过程产生了具有单轴取向羟基磷灰石晶体的胶原纤维内矿化。该过程导向剂是一种阴离子聚合物，我们认为它模拟了与骨形成相关的酸性非胶原蛋白，螯合钙和磷酸根离子以形成无定形前驱体液滴，这些液滴可以渗透到胶原纤维的间隙中。为了寻找能在最短时间内产生最高矿物质含量的聚合物试剂，我们研究了各种酸性聚合物通过PILP过程对胶原支架体外矿化的影响。所研究的聚合物包括聚-L-天冬氨酸（PASP）、聚-L-谷氨酸（PGLU）、聚乙烯基膦酸（PVPA）和聚丙烯酸（PAA）。我们的数据表明，PASP以及PGLU/PASP组合形成了稳定的矿化溶液，并产生了矿物质含量最高的纳米结构复合材料。此类研究有助于我们制备具有模仿骨的组成和结构的仿生骨移植替代物这一目标的实现。
