LAUSR

In this study we describe the fabrication of a variety of open-cellular titanium alloy (Ti-6Al-4V) implants, both reticular mesh and foam structures, using electron beam melting (EBM). These structures allow for the elimination of stress shielding by adjusting the porosity (or density) to produce an elastic modulus (or stiffness) to match that of both soft (trabecular) and hard (cortical) bone, as well as allowing for bone cell ingrowth, increased cell density, and all-matrix interactions; the latter involving the interplay between bone morphogenetic protein (BMP-2) and osteoblast functions. The early formation and characterization of elementary vascular structures in an aqueous hydrogel matrix are illustrated. Preliminary results for both animal (sheep) and human trials for a number of EBM-fabricated, and often patient-specific Tialloy implants are also presented and summarized. The results, while preliminary, support the concept and development of successful, porous, engineered “living” implants.摘要本文采用电子束增材(EBM)制造技术制备了多种具有开放孔隙结构的多孔钛合金(Ti-6Al-4V)植入物, 包括网状和泡沫状结构. 该多孔钛合金植入物可以通过调节孔隙率(或密度)降低其弹性模量(或刚度)以减轻 “应力屏蔽” 效应, 实现与软(小梁)和硬(皮质)骨的弹性模量(或刚度)匹配; 同时还可以促进骨组织长入, 增加细胞密度和细胞外基质间的相互作用, 后者涉及骨形态发生蛋白(BMP-2)和成骨细胞功能之间的相互影响. 总结了在水性水凝胶基质中初级血管结构的早期形成和特征, 报道了EBM技术制备的个性化钛合金植体在动物(羊)和人体临床试验的初步结果. 本文结果为钛合金多孔材料作为组织工程“活性”植入物的应用可行性研究提供了有力支持.