Julius Wolff Institute, Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany; Berlin Brandenburger Center of Regenerative Therapies, Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany; Department of Prosthodontics, Charité-Universitätsmedizin Berlin, Assmannhauser Strasse 4-6, 14197 Berlin, Germany.
Botiss GmbH, Ullsteinstrasse 108, 12109 Berlin, Germany.
Acta Biomater. 2019 Oct 15;98:186-195. doi: 10.1016/j.actbio.2019.07.022. Epub 2019 Jul 26.
Volume stable barrier membranes made of magnesium are very promising in Guided Bone Regeneration (GBR) to treat periodontal bone defects in dentistry due to their excellent biocompatibility and biodegradability. During the degradation process the cells are exposed to the alteration of various parameters, so called physical cues, involving surface alterations due to the formed corrosion layer and medium alterations arising from the dissolved corrosion products. Cell migration of human gingival fibroblasts (HGF), as a crucial parameter for optimal healing process in GBR, has been investigated on magnesium membranes and revealed that medium alterations by dissolved corrosion products have a higher impact on cell migration than surface alterations. However, the effect of each altered medium parameter on cell migration has not been adequately studied, but their roles are crucial to explain the slower migration rate on magnesium surfaces compared to titanium and tissue culture plastic surfaces. Our study investigates the single effect of Mg, Ca, H and increased osmolality as well as the effect of magnesium extracts, which contain a dynamic mixture of previous parameters on cell migration, proliferation and viability of HGF. We showed that at 75 mM Mg concentration and at 0 mM Ca, respectively, the cell migration rate is greatly reduced. In complex magnesium extract media, we found that a temporarily increased ratio of Mg to Ca conditioned a slow HGF migration rate. Based on these findings and the characterization of supernatants from HGF migration assays on Mg membranes, we propose, that the slower migration rate of HGF can be explained by the altered ratio of Mg to Ca, caused by increasing concentrations of Mg and decreasing concentrations of Ca in the vicinity of the corroding Mg implant, combined with a constantly increased molecular hydrogen concentration in the supernatant. These results are cell type specific and should be checked carefully, if necessary, for Mg implant performance. STATEMENT OF SIGNIFICANCE: The study is providing a systematic approach to explain the main effects of extract medium parameters (physical cues) such as magnesium or calcium ion concentration, osmolality and dissolved molecular hydrogen and CO in cell culture media modified by co-incubating with corroding magnesium implants on the migration rate of human gingival fibroblasts (HGF). This study uncovers for the first time the combinatory effect of slightly increased molecular hydrogen and the change in Mg/Ca ratio on HGF cell migration.
由于其出色的生物相容性和可降解性，由镁制成的体积稳定的屏障膜在引导骨再生（GBR）中治疗牙周骨缺损方面非常有前景。在降解过程中，细胞会受到各种参数变化的影响，这些参数被称为物理线索，包括由于形成的腐蚀层而导致的表面变化以及由于溶解的腐蚀产物而引起的介质变化。人牙龈成纤维细胞（HGF）的细胞迁移，作为 GBR 中最佳愈合过程的关键参数，已经在镁膜上进行了研究，结果表明，溶解的腐蚀产物引起的介质变化对细胞迁移的影响大于表面变化。然而，每个改变的介质参数对细胞迁移的影响尚未得到充分研究，但其作用对于解释与钛和组织培养塑料表面相比，镁表面上较慢的迁移率至关重要。我们的研究调查了镁、钙、氢和渗透压升高以及镁提取物对细胞迁移、增殖和 HGF 活力的单一影响，镁提取物包含以前参数的动态混合物。我们表明，在 75mM Mg 浓度和 0mM Ca 浓度下，细胞迁移率大大降低。在复杂的镁提取物介质中，我们发现 Mg 与 Ca 的比例暂时增加会导致 HGF 迁移率缓慢。基于这些发现以及 HGF 在镁膜上迁移测定的上清液的特性，我们提出，HGF 迁移率较慢的原因可以解释为腐蚀镁植入物附近 Mg 浓度增加和 Ca 浓度降低导致的 Mg 与 Ca 的比例改变，以及上清液中分子氢浓度的持续增加。这些结果是细胞类型特异性的，如果有必要，应仔细检查镁植入物的性能。
该研究提供了一种系统的方法来解释提取介质参数（物理线索）的主要影响，例如镁或钙离子浓度、渗透压和溶解的分子氢和 CO 在细胞培养基中的变化，这些变化是通过与腐蚀镁植入物共孵育来改变的，对人牙龈成纤维细胞（HGF）的迁移率的影响。这项研究首次揭示了分子氢的轻微增加和 Mg/Ca 比率变化对 HGF 细胞迁移的组合效应。
