Mechanical and in vitro investigation of a porous PEEK foam for medical device implants
Mechanical and in vitro investigation of a porous PEEK foam for medical device implants
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DOI：
10.5301/jabfm.2012.9771
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发表时间：
2013-01-01
影响因子：
2.5
通讯作者：
Jarman-Smith, Marcus
中科院分区：
文献类型：
--
作者：
Landy, Bonnie C.;VanGordon, Samuel B.;Jarman-Smith, Marcus
目的：植入级聚醚醚酮 (PEEK-OPTIMA (R)) 是一种高性能热塑性塑料，自 1999 年推出以来一直用于脊柱融合器等植入装置。本文研究了一种新的多孔 PEEK 版本。方法：采用工业规模相关方法制造多孔 PEEK，即与致孔剂填料复合、挤出，然后在超临界温度和压力下用水萃取。机械性能根据ISO标准进行评估。在多孔 PEEK 样品上培养骨髓基质细胞，并通过总 DNA、碱性磷酸酶活性、骨桥蛋白、钙和细胞形态来评估体外细胞相容性，以指示增殖、分化和矿化阶段。对 21 天的细胞培养物和培养基浸泡的样品进行静态评估，并在椎间融合笼 (ASTM F2077) 的医疗设备应用特定环境中动态评估抗压强度。 结果：制造产生的生物材料具有类似 50% 的孔隙率和 100 微米的平均孔径。多孔PEEK被发现具有：拉伸强度（14.5MPa）、断裂应变（3.5%）、冲击强度（3.6 kJ/m(2)）、弯曲强度（21.6MPa）和弯曲模量（0.8GPa）。细胞外矿化基质的产生发生在培养阶段的早期，表明分化的首选表面。 SEM 图像显示多边形细胞形态支持分化的成骨细胞样表型。 EDS 分析检测到的碳、磷和钙水平与增殖和分化阶段的测定结果一致。结论：之前对 PEEK 生物材料的细胞相容性和钙化的观察结果可以应用于这种新型多孔形式的 PEEK 生物材料。这有助于多孔 PEEK 为需要降低模量和/或增加表面组织向内生长的植入装置提供更多设计选择。
Purpose: Implantable-grade polyetheretherketone (PEEK-OPTIMA (R)) is a high-performance thermoplastic that has been used in implant devices such as spinal-fusion cages since its introduction in 1999. Here, a new porous PEEK version was investigated.Methods: Porous PEEK was fabricated using industrial scale relevant methods of compounding with porogen filler, extrusion, and subsequent extraction with water at supercritical temperatures and pressures. Mechanical properties were assessed according to ISO standards. Marrow stromal cells were cultured on porous PEEK samples and in vitro cytocompatibility was assessed by total DNA, alkaline phosphatase activity, osteopontin, calcium, and cell morphology to indicate stages of proliferation, differentiation, and mineralization. Compressive strength was assessed statically on 21 day cell cultures and media-soaked samples and dynamically within a medical device application specific context for interbody fusion cages (ASTM F2077).Results: Manufacturing resulted in a biomaterial with similar to 50% porosity and a mean pore size of 100 microns. The porous PEEK was found to have: tensile strength (14.5MPa), strain at break (3.5%), impact strength (3.6 kJ/m(2)), flexural strength (21.6MPa), and flexural modulus (0.8GPa). Production of extracellular mineralized matrix occurred very early in the culture period, indicating a preferred surface for differentiation. SEM images revealed polygonal cell morphology supporting a differentiated osteoblastic-like phenotype. EDS analysis detected levels of carbon, phosphorus, and calcium coinciding with assay results for the proliferation and differentiation stages.Conclusion: Previous observations of cytocompatibility and calcification on the PEEK biomaterial could be carried through to this new porous form of the PEEK biomaterial. This helps porous PEEK to potentially offer more design options for implant devices requiring reduced modulus and/or increased tissue ingrowth aspects at the surface.