da Silva Batista Beatriz, da Silva Luzeli Moreira, de Menezes Alan Silva, Barbosa Corrêa Luana, Cruz Rosas Elaine, Santos-Oliveira Ralph, Mendes Fernando, Macêdo Ana Angélica M, Rebelo Alencar Luciana M
Federal University of Maranhão, Campus Avançado, Maranhão, Center for Social Sciences, Health and Technology, Imperatriz, Brazil.
Federal University of Maranhão, Department of Physics, Laboratory of Biophysics and Nanosystems, Campus Bacanga, São Luís, Maranhão, Brazil.
J Biomed Mater Res B Appl Biomater. 2023 Jun;111(6):1247-1258. doi: 10.1002/jbm.b.35229. Epub 2023 Feb 14.
The development of bioactivity in bioinert metallic alloys is a field of interest aiming to improve some aspects of these materials for implant applications. New Co Cr W Ta alloys with different Ta concentrations (x = 0, 2, 4, 6, and 9% w/w) were synthesized in the work reported here. The alloys were characterized by x-ray diffraction, volumetric density, Vickers microhardness, atomic force microscopy, scanning electron microscopy (SEM), and energy-dispersion x-ray spectroscopy (EDS). Bioactivity properties were evaluated by in vitro tests with simulated body fluid (SBF). In vivo assays were performed to assess biocompatibility. The influence of surface thermochemical treatment and Ta insertion on the bioactive properties of the alloys was investigated. The results showed that the alloy structure comprises εCo and αCo phases, with cobalt as a matrix with Cr, W, and Ta as a solid solution. TaCo phase is observed in the alloys with 4, 6, and 9% w/w of Ta, and its amount increase as Ta concentration increases. Volumetric density is reduced (from 8.78 ± 0.06 to 8.56 ± 0.09 g/cm ) as Ta concentration increases (from 0% to 9% w/w) mainly due to the lower density of the tantalum compared to the tungsten metal. On the other hand, the TaCo phase contributes to the increase of Vickers's hardness by ~17.6% for the alloy with 9% Ta (394.7 ± 8.1 HV) compared with Co Cr W (336 ± 5 HV). The topographic analysis showed increased roughness and adhesion due to the nucleation of Ta O and Ca Ta O crystals after surface thermochemical treatment. The roughness and adhesion increase from 16.9 ± 0.6 nm and 8.3 ± 1.8 nN (untreated surface) to 255.7 ± 17.7 nm and 24.1 ± 12.6 nN (treated surface), respectively, for the Co Cr Ta alloy. These results suggest that thermochemical treatment provides surface conditions favorable to hydroxyapatite (HA) nucleation. The SEM and EDS data showed the nucleation of spongy structures, consistent with HA, composed mainly of Ca and P, indicating that oxides tantalum promoted a bioactive response on the sample's surface. The biological assay corroborated the alloy's safety and applicability, highlighting its potential in biomedical application since no harmful effects were observed.
生物惰性金属合金生物活性的发展是一个备受关注的领域，旨在改进这些材料在植入应用方面的某些性能。在本文报道的工作中合成了具有不同钽浓度（x = 0、2、4、6和9% w/w）的新型钴铬钨钽合金。通过X射线衍射、体积密度、维氏显微硬度、原子力显微镜、扫描电子显微镜（SEM）和能量色散X射线光谱（EDS）对合金进行了表征。通过模拟体液（SBF）体外试验评估生物活性性能。进行体内试验以评估生物相容性。研究了表面热化学处理和钽的掺入对合金生物活性性能的影响。结果表明，合金结构由εCo和αCo相组成，以钴为基体，铬、钨和钽为固溶体。在钽含量为4%、6%和9% w/w的合金中观察到TaCo相，其含量随钽浓度的增加而增加。随着钽浓度从0%增加到9% w/w，体积密度降低（从8.78±0.06降至8.56±0.09 g/cm³），这主要是由于钽的密度低于钨金属。另一方面，与钴铬钨合金（336±5 HV）相比，含9%钽的合金（394.7±8.1 HV）中TaCo相使维氏硬度提高了约17.6%。形貌分析表明，表面热化学处理后由于Ta₂O₅和Ca₂Ta₂O₆晶体的成核，粗糙度和附着力增加。对于钴铬钽合金，粗糙度和附着力分别从未处理表面的16.9±0.6 nm和8.3±1.8 nN增加到处理表面的255.7±17.7 nm和24.1±12.6 nN。这些结果表明，热化学处理提供了有利于羟基磷灰石（HA）成核的表面条件。SEM和EDS数据显示了海绵状结构的成核，与主要由钙和磷组成的HA一致，表明钽氧化物促进了样品表面的生物活性响应。生物学试验证实了合金的安全性和适用性，突出了其在生物医学应用中的潜力，因为未观察到有害影响。
