In vivo bone response to 3D periodic hydroxyapatite scaffolds assembled by direct ink writing
In vivo bone response to 3D periodic hydroxyapatite scaffolds assembled by direct ink writing
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DOI：
10.1002/jbm.a.31329
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发表时间：
2007-12-01
影响因子：
4.9
通讯作者：
Ricci, John L.
中科院分区：
文献类型：
--
作者：
Simon, Joshua L.;Michna, Sarah;Ricci, John L.
研究了三维周期性羟基磷灰石（HA）支架的体内骨反应。两组的HA支架（11 mm直径X 3.5 mm厚）通过浓缩HA墨水的直接写入组装来制造。支架由周期性排列成四个象限的圆柱形杆组成，杆之间的间隔距离不同。在第一组中，HA棒（直径250 μ m）被图案化以产生孔道，其面积尺寸在象限1中为250 × 250 μ m（2），在象限2和4中为250 × 500 μ m（2），在象限3中为500 × 500 μ m（2）。在第二组中，HA棒（直径400 μ m）被图案化以产生矿石通道，其面积尺寸为500 × 500 μ m（2）象限1、500 × 750 μ m（2）象限2和4以及750 × 750 μ m（2）象限3。每组支架通过在1200 ℃下烧结而部分致密化，然后双侧植入到睾丸成熟的新西兰白色兔的环钻缺损中。在第8周和第16周时，使用微型计算机断层扫描、组织学和扫描电子显微镜评价其组织反应。新的骨小梁在这些图案化的3D HA支架内快速有效地穿过相当长的距离。我们的观察结果表明，HA棒首先涂覆一层新骨，然后通过涂覆区域的向外和向内径向生长进行后续支架填充。由微孔HA棒组成的3D周期性支架的直写组装体排列以产生与骨小梁尺寸匹配的大孔，这可能代表骨修复和置换结构的最佳策略。(C)2007 Wiley Periodicals，Inc.
The in vivo bone response of 3D periodic hydroxyapatite (HA) scaffolds is investigated. Two groups. of HA scaffolds (11 mm diameter X 3.5 mm thick) are fabricated by direct-write assembly of a concentrated HA ink. The scaffolds consist of cylindrical rods periodically arranged into four quadrants with varying separation distances between rods. In the first group, HA rods (250 mu m in diameter) are patterned to create pore channels, whose areal dimensions are 250 X 250 mu m(2) in quadrant 1, 250 X 500 mu m(2) in quadrants 2 and 4, and 500 x 500 mu m(2) in quadrant 3. In the second group, HA rods (400 mu m in diameter) are patterned to create ore channels, whose areal dimensions of 500 x 500 mu m(2) quadrant 1, 500 x 750 mu m(2) in quadrants 2 and 4, and 750 x 750 mu m(2) in quadrant 3. Each group of scaffolds is partially densified by sintering at 1200 degrees C prior to being implanted bilaterally in trephine defects of skeletally mature New Zealand White rabbits. Their tissue response is evaluated at 8 and 16 weeks using micro-computed tomography, histology, and scanning electron microscopy. New trabecular bone is conducted rapidly and efficiently across substantial distances within these patterned 3D HA scaffolds. Our observations suggest that HA rods are first coated with a layer of new bone followed by subsequent scaffold infilling via outward and inward radial growth of the coated regions. Direct-write assembly of 3D periodic scaffolds composed of micro-porous HA rods arrayed to produce macro-pores that are size-matched to trabecular bone may represent an optimal strategy for bone repair and replacement structures. (C) 2007 Wiley Periodicals, Inc.