The ideal bone implant would effectively prevent aseptic as well as septic loosening by minimizing stress shielding, maximizing bone ingrowth, and preventing implant-associated infections. Here, a novel gradient-pore-size titanium scaffold was designed and manufactured to address these requirements. The scaffold features a larger pore size (900 μm) on the top surface, gradually decreasing to small sizes (600 μm to 300 μm) towards the center, creating a gradient structure. To enhance its functionality, the additively manufactured scaffolds were biofunctionalized using simple chemical and heat treatments so as to incorporate calcium and iodine ions throughout the surface. This unique combination of varying pore sizes with a biofunctional surface provides highly desirable mechanical properties, bioactivity, and notably, long-lasting antibacterial activity. The target mechanical aspects, including low elastic modulus, high compression, compression-shear, and fatigue strength, were effectively achieved. Furthermore, the biofunctional surface exhibits remarkable in vitro bioactivity and potent antibacterial activity, even under conditions specifically altered to be favorable for bacterial growth. More importantly, the integration of small pores alongside larger ones ensures a sustained high release of iodine, resulting in antimicrobial activity that persisted for over three months, with full eradication of the bacteria. Taken together, this gradient structure exhibits obvious superiority in combining most of the desired properties, making it an ideal candidate for orthopedic and dental implant applications.

中文翻译：

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具有梯度孔释放碘离子的钛支架的机械、生物活性和持久抗菌性能

理想的骨植入物可以通过最小化应力屏蔽、最大化骨向内生长和预防植入物相关感染来有效防止无菌性和脓毒性松动。在这里，设计和制造了一种新型梯度孔径钛支架来满足这些要求。该支架的顶面孔径较大（900μm），向中心逐渐减小到较小尺寸（600μm至300μm），形成梯度结构。为了增强其功能，使用简单的化学和热处理对增材制造的支架进行生物功能化，以便在整个表面掺入钙和碘离子。这种不同孔径与生物功能表面的独特组合提供了非常理想的机械性能、生物活性，尤其是持久的抗菌活性。有效实现了低弹性模量、高压缩、压缩剪切和疲劳强度等机械方面的目标。此外，即使在专门改变为有利于细菌生长的条件下，生物功能表面也表现出显着的体外生物活性和有效的抗菌活性。更重要的是，小孔与大孔的结合确保了碘的持续高释放，从而使抗菌活性持续超过三个月，并完全消灭细菌。总而言之，这种梯度结构在结合大多数所需特性方面表现出明显的优越性，使其成为骨科和牙科植入应用的理想选择。