Although metallic biomaterials find numerous biomedical applications, their inherent low bioactivity and poor osteointegration had been a great challenge for decades. Surface modification via silanization can serve as an attractive method for improving the aforementioned properties of such substrates. However, its effect on protein adsorption/conformation and subsequent cell adhesion and spreading has rarely been investigated. This work reports the in-depth study of the effect of Ti6Al4V surface functionalization on protein adsorption and cell behavior. We prepared self-assembled monolayers (SAMs) of five different surfaces (amine, octyl, mixed [1:1 ratio of amine:octyl], hybrid, and COOH). Synthesized surfaces were characterized by Fourier transform infrared-attenuated total reflection (FTIR-ATR) spectroscopy, contact angle goniometry, profilometry, and field emission scanning electron microscopy (FESEM). Quantification of adsorbed mass of bovine serum albumin (BSA) and fibronectin (FN) was determined on different surfaces along with secondary structure analysis. The adsorbed amount of BSA was found to increase with an increase in surface hydrophobicity with the maximum adsorption on the octyl surface while the reverse trend was detected for FN adsorption, having the maximum adsorbed mass on the COOH surface. The α-helix content of adsorbed BSA increased on amine and COOH surfaces while it decreased for other surfaces. Whereas increasing β-turn content of the adsorbed FN with the increase in the surface hydrophobicity was observed. In FN, RGD loops are located in the β-turn and consequently the increase in Δ adhered cells (%) was predominantly increased with the increasing Δ β-turn content (%). We found hybrid surfaces to be the most promising surface modifier due to maximum cell adhesion (%) and proliferation, larger nuclei area, and the least cell circularity. Bacterial density increased with the increasing hydrophobicity and was found maximum for the amine surface (θ = 63 ± 1°) which further decreased with the increasing hydrophobicity. Overall, modified surfaces (in particular hybrid surface) showed better protein adsorption and cell adhesion properties as compared to unmodified Ti6Al4V and can be potentially used for tissue engineering applications.

中文翻译：

---

通过自组装单层Ti6Al4V的表面功能化，以改善蛋白质吸附和成纤维细胞粘附

尽管金属生物材料在生物医学中得到了广泛的应用，但数十年来，其固有的低生物活性和不良的骨整合一直是一个巨大的挑战。经由硅烷化的表面改性可以用作改善此类基材的前述性能的有吸引力的方法。然而，很少研究其对蛋白质吸附/构象以及随后的细胞粘附和扩散的影响。这项工作报告了Ti6Al4V表面功能化对蛋白质吸附和细胞行为的影响的深入研究。我们准备了五个不同表面（胺，辛基，混合的[胺：辛基的1：1比例]，杂化和COOH）的自组装单层（SAMs）。合成表面的特征在于傅立叶变换红外衰减全反射（FTIR-ATR）光谱，接触角测角法，轮廓测定法和场发射扫描电子显微镜（FESEM）。牛血清白蛋白（BSA）和纤连蛋白（FN）的吸附量的定量是在不同的表面上进行的，并进行了二级结构分析。发现BSA的吸附量随着表面疏水性的增加而增加，在辛基表面上的吸附最大，而检测到FN吸附的相反趋势，在COOH表面上具有最大的吸附质量。胺和COOH表面吸附的BSA的α-螺旋含量增加，而其他表面则降低。然而，观察到随着表面疏水性的增加，吸附的FN的β-转角含量增加。在FN中 RGD环位于β-转弯处，因此，Δ粘附细胞（％）的增加主要随Δβ-转弯含量（％）的增加而增加。我们发现杂化表面由于最大的细胞粘附力（％）和增殖，更大的细胞核面积以及最小的细胞圆度而成为最有前途的表面改性剂。细菌密度随疏水性的增加而增加，并发现胺表面的最大值（θ= 63±1°）随疏水性的增加而进一步降低。总体而言，与未修饰的Ti6Al4V相比，修饰的表面（特别是杂化表面）显示出更好的蛋白质吸附和细胞粘附特性，可潜在地用于组织工程应用。我们发现杂化表面由于最大的细胞粘附力（％）和增殖，更大的细胞核面积以及最小的细胞圆度而成为最有前途的表面改性剂。细菌密度随疏水性的增加而增加，并发现胺表面的最大值（θ= 63±1°）随疏水性的增加而进一步降低。总体而言，与未修饰的Ti6Al4V相比，修饰的表面（特别是杂化表面）显示出更好的蛋白质吸附和细胞粘附特性，可潜在地用于组织工程应用。我们发现杂化表面由于最大的细胞粘附力（％）和增殖，更大的细胞核面积以及最小的细胞圆度而成为最有前途的表面改性剂。细菌密度随疏水性的增加而增加，并发现胺表面的最大值（θ= 63±1°）随疏水性的增加而进一步降低。总体而言，与未修饰的Ti6Al4V相比，修饰的表面（特别是杂化表面）显示出更好的蛋白质吸附和细胞粘附特性，可潜在地用于组织工程应用。