Polyphosphazene/nano-hydroxyapatite composite microsphere scaffolds for bone tissue engineering
Polyphosphazene/nano-hydroxyapatite composite microsphere scaffolds for bone tissue engineering
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DOI：
10.1021/bm800031t
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发表时间：
2008-07-01
影响因子：
6.2
通讯作者：
Laurencin, Cato T.
中科院分区：
文献类型：
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作者：
Nukavarapu, Syam P.;Kumbar, Sangamesh G.;Laurencin, Cato T.
氨基酸酯聚磷腈的无毒、中性降解产物使其成为体内骨科应用的理想候选物。寻求新的骨相容性材料的承重组织工程应用，使我们调查机械能力的氨基酸酯取代的聚磷腈。在这项研究中，我们合成了三个可生物降解的聚磷腈取代侧基，即亮氨酸，缬氨酸，苯丙氨酸乙酯。在这些聚合物中，苯丙氨酸乙酯取代的聚磷腈显示出最高的玻璃化转变温度（41.6 ° C），因此被选择作为用于形成具有100 nm尺寸的羟基磷灰石（nHAp）的复合微球的候选材料。采用动态溶剂烧结法将制备的复合微球烧结成三维多孔支架。复合微球支架显示出46-81 MPa的压缩模量，平均孔径在86-145 μ m的范围内。三维聚磷腈-nHAp复合微球支架具有良好的成骨细胞粘附、增殖和碱性磷酸酶表达，是骨组织工程应用的潜在候选者。
The nontoxic, neutral degradation products of amino acid ester polyphosphazenes make them ideal candidates for in vivo orthopedic applications. The quest for new osteocompatible materials for load bearing tissue engineering applications has led us to investigate mechanically competent amino acid ester substituted polyphosphazenes. In this study, we have synthesized three biodegradable polyphosphazenes substituted with side groups, namely, leucine, valine, and phenylalanine ethyl esters. Of these polymers, the phenylalanine ethyl ester substituted polyphosphazene showed the highest glass transition temperature (41.6 degrees C) and, hence, was chosen as a candidate material for forming composite microspheres with 100 nm sized hydroxyapatite (nHAp). The fabricated composite microspheres were sintered into a three-dimensional (3-D) porous scaffold by adopting a dynamic solvent sintering approach. The composite microsphere scaffolds showed compressive moduli of 46-81 MPa with mean pore diameters in the range of 86-145 mu m. The 3-D polyphosphazene-nHAp composite microsphere scaffolds showed good osteoblast cell adhesion, proliferation, and alkaline phosphatase expression and are potential suitors for bone tissue engineering applications.