A great variety of powder metallurgy techniques can produce biomimetic porous titanium structures with similar mechanical properties to host bone tissue. In this work, loose sintering and space holder techniques, two frequently used metallurgical techniques, are compared to evaluate the influences of porosity (content, size, morphology and wall roughness), mechanical properties (stiffness and yield strength) and in-vitro cellular responses (adhesion and proliferation of myoblasts and osteoblasts). These comparisons are made to achieve the best balance between biomechanical and bifunctional behavior of a partial porous implant for cortical bone replacement. Cell adhesion (filopodia presence) and spreading were promoted on both porous surfaces and fully dense substrates (non-porous control surfaces). Porous scaffold samples designed using 50 vol.% NaCl space holder technique had an improved bioactive response over those obtained with the loose sintering technique due to higher roughness and scaffold pore diameter. However, the presence of large and heterogeneous pores compromises the mechanical reliability of the implant. Considering both scenarios, the substrates obtained with 40 vol.% NH₄HCO₃ and pore size ranges between 100 and 200 μm provide a balanced optimization of size and strength to promote in-vitro osseointegration.

中文翻译：

---

多孔钛样品上的体外骨细胞行为：疏松烧结和空间保持器技术对孔隙率的影响

多种粉末冶金技术可以生产出具有类似机械特性的仿生多孔钛结构，以承载骨骼组织。在这项工作中，比较了两种常用的冶金技术—松散烧结和空间保持器技术，以评估孔隙率（含量，尺寸，形态和壁面粗糙度），机械性能（刚度和屈服强度）和体外细胞反应的影响（成肌细胞和成骨细胞的粘附和增殖）。进行这些比较是为了在用于骨皮质置换的部分多孔植入物的生物力学和双功能行为之间达到最佳平衡。在多孔表面和完全致密的基质（无孔对照表面）上都促进了细胞粘附（存在丝虫足）和扩散。使用50 vol。由于较高的粗糙度和支架孔直径，％NaCl太空保持器技术的生物活性响应比采用松散烧结技术获得的生物活性响应更高。但是，大而异质的孔的存在损害了植入物的机械可靠性。考虑到这两种情况，获得的基材含40％（体积）NH₄ HCO ₃和孔径范围在100到200μm之间的颗粒提供了平衡的尺寸和强度优化，以促进体外骨整合。