State Key Laboratory for Mechanical Behavior of Materials, Xi’an Jiaotong University, Xi’an 710049, People’s Republic of China.
Nanotechnology. 2011 Jul 8;22(27):275603. doi: 10.1088/0957-4484/22/27/275603. Epub 2011 May 20.
We report here, for the first time, a novel multi-scaled hybrid orthopedic implant material consisting of a macroporous Ti scaffold, whose macropores' walls have a microporous titania layer which is fully covered with nanofibers of Sr-doped hydroxyapatite (Sr-HA). The microporous titania layer is formed on and within the Ti scaffold by micro-arc oxidation, which firmly binds to the Ti substrate and contains Ca2+, Sr2+ and PO4(3-) ions. It is then hydrothermally treated to form Sr-HA nanofibers. During the hydrothermal treatment, Sr-HA nanoprisms nucleate from Ca0.5Sr0.5TiO3 pre-formed on the TiO2 and grow in length to nanofibers at the expense of Ca2+, Sr2+ and PO4(3-) ions that migrate from the TiO2. These Sr-HA nanofibers construct a network structure similar to the hierarchical organization of bone extracellular matrix (ECM), and the resulting nanofibrous surface displays a firm adhesion to substrate, superhydrophilicity and apatite-inducing ability. The induced apatite prefers to nucleate on the basal-faceted surfaces of Sr-HA nanofibers. The nanofiber-walled scaffold has a great potential for load-bearing orthotopic use.
我们首次报道了一种新型的多尺度混合骨科植入材料，由大孔 Ti 支架组成，其大孔壁具有微孔氧化钛层，完全覆盖 Sr 掺杂羟基磷灰石（Sr-HA）纳米纤维。微孔氧化钛层通过微弧氧化形成于 Ti 支架上并存在于 Ti 支架内，与 Ti 基底结合牢固，并含有 Ca2+、Sr2+和 PO4(3-)离子。然后对其进行水热处理以形成 Sr-HA 纳米纤维。在水热处理过程中，Sr-HA 纳米棒从预先形成于 TiO2 上的 Ca0.5Sr0.5TiO3 成核，并在长度上生长为纳米纤维，Ca2+、Sr2+和 PO4(3-)离子则从 TiO2 中迁移出来。这些 Sr-HA 纳米纤维构建了类似于骨细胞外基质（ECM）的分级组织的网络结构，并且所得的纳米纤维表面显示出对基底的牢固附着性、超亲水性和诱导磷灰石的能力。诱导的磷灰石优先在 Sr-HA 纳米纤维的基面成核。纳米纤维壁支架具有用于承重原位使用的巨大潜力。
