Center for Fundamental Science, Kaohsiung Medical University, Kaohsiung, Taiwan.
Department of Biomedical Engineering, National Cheng Kung University, Tainan, Taiwan.
J Formos Med Assoc. 2023 Jul;122(7):584-592. doi: 10.1016/j.jfma.2023.01.009. Epub 2023 Jan 31.
BACKGROUND/PURPOSE: Due to the general application of in vitro test, cell culture is generally selected to evaluate the cytocompatibility of devices and materials. The choice of test condition should depend on the probable site and clinical application. The oxygen content of human body could be estimated around 5%∼12%, and the oxygen level of healing bone fracture range from 0.8%∼3.8%%. However, materials for bone implant are traditionally evaluated under laboratory normoxia condition (21% O) in vitro. The aim was to study the effect of oxygen level on osteoblast upon high stiffness titanium with different roughness.
After sandblasted and acid-etched (SLA) process, we create titanium surfaces with four different roughness. The differentiation and proliferation of MC3T3-E1 osteoblast cultured on SLA-treated specimens were evaluated in designed chamber with oxygen level of 1%, 5%, 10%, 21%.
By scanning electron microscopy, all samples had sub-micro pit inside the micro-holes upon SLA-treated Ti disk surface. The decrease of oxygen level from 21% to 5% promoted osteoblast growth of SLA-treated specimens, but 1% O delayed cell proliferation. The surface roughness of specimens influenced osteoblast cell differentiation. The differentiation and proliferation ability of the cells upon SLA-treated specimens is proportional to oxygen level.
Our results demonstrated that 5% O will easily discriminate osteoblasts responses on different SLA-treated specimens. These results suggest that hypoxia (5% O) environment is better model for biological evaluation of bone-related materials.
背景/目的：由于体外测试的广泛应用，通常选择细胞培养来评估器械和材料的细胞相容性。测试条件的选择应取决于可能的部位和临床应用。人体的氧含量估计在 5%∼12%之间，而愈合骨折的氧水平范围在 0.8%∼3.8%之间。然而，传统上用于骨植入的材料在体外是在实验室常氧条件（21% O）下进行评估的。目的是研究氧水平对高硬度钛不同粗糙度表面上成骨细胞的影响。
经过喷砂酸蚀（SLA）处理后，我们在钛表面制造了具有四种不同粗糙度的 SLA 处理样本。在设计的腔室内，评估了氧水平分别为 1%、5%、10%和 21%时，MC3T3-E1 成骨细胞在 SLA 处理样本上的分化和增殖情况。
通过扫描电子显微镜观察，所有 SLA 处理的 Ti 盘表面微孔内均有亚微米级的凹坑。从 21%降至 5%的氧水平促进了 SLA 处理样本中成骨细胞的生长，但 1% O 则延迟了细胞增殖。样品表面粗糙度影响成骨细胞的分化。SLA 处理样本上细胞的分化和增殖能力与氧水平成正比。
我们的结果表明，5% O 可轻松区分不同 SLA 处理样本中成骨细胞的反应。这些结果表明，低氧（5% O）环境更适合骨相关材料的生物学评估。
