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.
botiss biomaterials GmbH, Ullsteinstrasse 108, 12109 Berlin, Germany.
Acta Biomater. 2018 Oct 1;79:158-167. doi: 10.1016/j.actbio.2018.08.034. Epub 2018 Aug 30.
A novel regenerative approach to Guided Bone Regeneration (GBR) in dental surgery is based on the development of biodegradable and volume stable barrier membranes made of metallic magnesium. Currently used volume stable barrier membranes are made of titanium-reinforced PTFE or titanium-reinforced collagen membranes, both, however, are accompanied by a high incidence of wound dehiscence resulting in membrane exposure, which leads to an increased infection risk. An exposed membrane could also occur directly after insertion due to insufficient soft tissue coverage of the membrane. In both cases, fast wound margin regeneration is required. As a first step of soft-tissue regeneration, gingival fibroblasts need to migrate over the barrier membrane and close the dehiscent wound. Based on this aim, this study investigated the migration behaviour of human gingival fibroblasts on a magnesium surface. Major experimental challenges such as formation of hydrogen bubbles due to initial magnesium corrosion and non-transparent material surfaces have been addressed to allow cell adhesion and to follow cell migration. The designed scratch-based cell migration assay involved vital fluorescent cell staining on a pre-corroded magnesium membrane to simulate invivo wound dehiscence. The assay has been used to compare cell migration on pre-corroded magnesium to titanium surfaces and tissue culture plastic as control substrates. First results of this assay showed that human gingival fibroblasts migrate slower on pre-corroded magnesium compared to plastic and titanium. However, the scratch was finally closed on all materials. Compared to titanium surfaces and tissue culture plastic, the surface roughness and the surface free energy (SFE) could not explain slower cell migration on magnesium surfaces. Immunohistological investigations of cellular structure revealed, that magnesium ions increased focal adhesion at concentration of additionally 75 mM MgCl in cell culture medium. The use of our designed cell migration assay has shown that ionic medium alterations due to magnesium corrosion has a higher impact on the cell migration rate than surface alterations.
The design of a migration assay on non-transparent magnesium surfaces will add the option to study cell response to surface modifications, coatings and the corrosion process itself under life view conditions.
一种新型的牙科学引导骨再生（GBR）再生方法基于开发由可生物降解和体积稳定的镁基屏障膜。目前使用的体积稳定的屏障膜是由钛增强聚四氟乙烯或钛增强胶原膜制成的，但两者都伴随着很高的创口裂开发生率，导致膜暴露，从而增加感染风险。由于膜的软组织覆盖不足，暴露的膜也可能直接在插入后发生。在这两种情况下，都需要快速的伤口边缘再生。作为软组织再生的第一步，牙龈成纤维细胞需要迁移到屏障膜上并封闭裂开的伤口。基于这一目标，本研究调查了人牙龈成纤维细胞在镁表面上的迁移行为。为了允许细胞黏附并跟踪细胞迁移，解决了由于初始镁腐蚀形成的氢气泡和非透明材料表面等主要实验挑战。设计的划痕细胞迁移实验涉及在预腐蚀镁膜上进行荧光细胞染色，以模拟体内创口裂开。该实验已被用于比较预腐蚀镁与钛表面和组织培养塑料作为对照底物上的细胞迁移。该实验的初步结果表明，与塑料和钛相比，人牙龈成纤维细胞在预腐蚀镁上的迁移速度较慢。然而，划痕最终在所有材料上都被封闭。与钛表面和组织培养塑料相比，表面粗糙度和表面自由能（SFE）并不能解释镁表面上细胞迁移速度较慢的原因。细胞结构的免疫组织学研究表明，镁离子在细胞培养液中浓度增加到 75mM MgCl 时会增加焦点附着。使用我们设计的细胞迁移实验表明，由于镁腐蚀导致的离子介质变化对细胞迁移率的影响大于表面变化。
在非透明镁表面上设计迁移实验将增加在生命视角条件下研究表面改性、涂层和腐蚀过程本身对细胞反应的选择。
