Department of Prosthodontics, Institute of Clinical Dentistry, Faculty for Dentistry, University of Oslo, PO box 1109, 0317, Blindern, Oslo, Norway.
Department of Biomaterials, Institute of Clinical Dentistry, Faculty for Dentistry, University of Oslo, Oslo, Norway.
Clin Oral Investig. 2023 Sep;27(9):5073-5082. doi: 10.1007/s00784-023-05128-6. Epub 2023 Jul 6.
The influence of radiation backscatter from titanium on DNA damage and migration capacity of human osteoblasts (OBs) and mesenchymal stem cells (MSCs) may be critical for the osseointegration of dental implants placed prior to radiotherapy. In order to evaluate effects of radiation backscatter, the immediate DNA damage and migration capacity of OBs and MSCs cultured on titanium or plastic were compared after exposure to ionizing irradiation.
Human OBs and MSCs were seeded on machined titanium, moderately rough fluoride-modified titanium, or tissue culture polystyrene, and irradiated with nominal doses of 2, 6, 10, or 14 Gy. Comet assay was performed immediately after irradiation, while a scratch wound healing assay was initiated 24 h post-irradiation. Fluorescent live cell imaging documented the migration.
DNA damage increased with higher dose and with backscatter from titanium, and MSCs were significantly more affected than OBs. All doses of radiation accelerated the cell migration on plastic, while only the highest dose of 10 Gy inhibited the migration of both cell types on titanium.
High doses (10 Gy) of radiation inhibited the migration capacity of both cell types on titanium, whereas lower doses (2 and 6 Gy) did not affect the migration of either OBs or MSCs.
Fractionated doses of 2 Gy/day, as distributed in conventional radiotherapy, appear not to cause severe DNA damage or disturb the migration of OBs or MSCs during osseointegration of dental implants.
钛的辐射背散射对人成骨细胞（OBs）和间充质干细胞（MSCs）的 DNA 损伤和迁移能力的影响，对于放射治疗前植入的牙科种植体的骨整合可能至关重要。为了评估辐射背散射的影响，在暴露于电离辐射后，比较了培养在钛或塑料上的 OBs 和 MSCs 的即刻 DNA 损伤和迁移能力。
将人 OBs 和 MSCs 接种在机械加工的钛、中等粗糙度氟化钛或组织培养聚苯乙烯上，并给予标称剂量为 2、6、10 或 14 Gy 的照射。照射后立即进行彗星试验，照射后 24 小时开始划痕愈合试验。荧光活细胞成像记录迁移情况。
DNA 损伤随剂量增加和钛的背散射而增加，MSCs 的损伤明显大于 OBs。所有剂量的辐射均加速了塑料上的细胞迁移，而只有最高剂量 10 Gy 抑制了两种细胞类型在钛上的迁移。
高剂量（10 Gy）的辐射抑制了两种细胞类型在钛上的迁移能力，而低剂量（2 和 6 Gy）则不影响 OBs 或 MSCs 的迁移。
常规放射治疗中分布的 2 Gy/天的分次剂量似乎不会导致严重的 DNA 损伤，也不会在牙科种植体的骨整合过程中干扰 OBs 或 MSCs 的迁移。
