Coating with hydroxyapatite (HAP) presents a mainstream strategy for rendering bioinert titanium implants bioactive. However, the low porosity of pure HAP coatings does not allow for the infiltration of the surface of the metallic implant with the host cells. Polymeric scaffolds do enable this osseointegration effect, but their bonding onto titanium presents a challenge because of the disparity in hydrophilicity. Here, we demonstrate the inability of a composite scaffold composed of carbonated HAP (CHAP) nanoparticles interspersed within electrospun ε-polycaprolactone (PCL) nanofibers to bind onto titanium. To solve this challenge, an intermediate layer of graphene nanosheets was deposited in a pulsed laser deposition process, which facilitated the bonding of the scaffold. The duration of the deposition of graphene (0, 5, 10, 15, and 20 min) and the thickness of its mesolayer affected numerous physical and chemical properties of the material, including the surface atomic proportion of carbon bonds, the orientation and interlinking of the polymeric nanofibers, and the surface roughness, which increased in direct proportion with the thickness of the graphene mesolayer. Because the polymeric scaffold did not adhere onto the surface of pure titanium, no cells were detected growing on it in vitro. In contrast, human fibroblasts adhered, spread, and proliferated well on all the substrates sputtered with both graphene and the composite scaffold. The orientations of cytoskeletal filopodia and lamellipodia were largely determined by the topographic orientation of the nanofibers and the geometry of the surface pores, attesting to the important effects that the presence of a scaffold has on the cellular behavior. The protection of titanium from corrosion in the simulated body fluid (SBF) was enhanced by coating with graphene and the composite scaffold, with the most superior resistance to the attack of the corrosive ions being exhibited by the substrate subjected to the shortest duration of the graphene deposition because of the highest atomic ratio of C–C to C–O bonds detected in it. Overall, some properties of titanium, such as roughness and wettability, were improved monotonously with an increase in the thickness of the graphene mesolayer, while others, such as cell viability and resistance to corrosion, required optimization, given that they were diminished at higher graphene mesolayer thicknesses. Nevertheless, every physical and chemical property of titanium analyzed was significantly improved by coating with graphene and the composite scaffold. This type of multilayer design evidently holds a great promise in the design of biomaterials for implants in orthopedics and tissue engineering.

中文翻译：

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将羟基磷灰石涂层的钛植入物向前推进两个步骤：使用石墨烯中间层和羟基磷灰石增强的聚合物支架进行表面改性

羟基磷灰石（HAP）涂层是使生物惰性钛植入物具有生物活性的主流策略。但是，纯HAP涂层的低孔隙率不允许宿主细胞渗透金属植入物的表面。聚合物支架确实能够实现这种骨整合作用，但是由于亲水性的差异，它们在钛上的键合提出了挑战。在这里，我们证明了由碳酸盐化的HAP（CHAP）纳米颗粒组成的复合支架无法散布在电纺ε-聚己内酯（PCL）纳米纤维中以结合到钛上。为了解决该挑战，在脉冲激光沉积过程中沉积了石墨烯纳米片的中间层，这促进了支架的结合。石墨烯的沉积时间（0、5、10、15 20分钟）和它的中间层的厚度影响了材料的许多物理和化学特性，包括碳键的表面原子比例，聚合物纳米纤维的取向和交联以及表面粗糙度，它们与材料的成比例成正比增加。石墨烯中间层的厚度。由于聚合物支架没有粘附在纯钛表面上，因此未检测到细胞生长体外。相比之下，人类成纤维细胞在石墨烯和复合支架溅射的所有基材上均能很好地粘附，扩散和增殖。细胞骨架丝状伪足和片状脂质体的取向很大程度上取决于纳米纤维的形貌取向和表面孔的几何形状，证明了支架的存在对细胞行为具有重要影响。通过涂覆石墨烯和复合支架，增强了钛对模拟体液（SBF）的腐蚀防护，在石墨烯的最短持续时间内，基材表现出了最强的抗腐蚀性离子的能力由于在其中检测到的C–C与C–O键的原子比最高，因此沉积。总体而言，钛的某些特性 石墨烯中间层厚度的增加单调改善了粗糙度和润湿性等特性，而当石墨烯中间层厚度增加时，其可行性和耐腐蚀性等其他方面则需​​要进行优化。尽管如此，通过涂覆石墨烯和复合支架可以显着改善所分析的钛的每个物理和化学性质。这种类型的多层设计显然在骨科和组织工程中用于植入物的生物材料设计中具有广阔的前景。通过涂覆石墨烯和复合支架可以显着改善所分析钛的所有物理和化学性质。这种类型的多层设计显然在骨科和组织工程中用于植入物的生物材料设计中具有广阔的前景。通过涂覆石墨烯和复合支架可以显着改善所分析钛的所有物理和化学性质。这种类型的多层设计显然在骨科和组织工程中用于植入物的生物材料设计中具有广阔的前景。