Frosch K-H, Barvencik F, Lohmann C H, Viereck V, Siggelkow H, Breme J, Dresing K, Stürmer K M
Department of Traumatology, Plastic and Reconstructive Surgery, Georg August University, Göttingen, Germany.
Cells Tissues Organs. 2002;170(4):214-27. doi: 10.1159/000047925.
The goal of this study was to characterize growth, mineralization and bone formation of osteoblast-like cells in titanium pore channels of defined diameter. Titanium implants with continuous drill channels of diameters of 300, 400, 500, 600 and 1,000 microm were inserted into human osteoblast-like cell cultures. The ingrowth of the cells into the drill channels was investigated by transmitted-light microscopy and scanning electron microscopy. Immunofluorescence and histological analysis of 15-channel sections of each diameter were used to investigate the growth behavior and the matrix protein patterns. Mineralization was evidenced by Alizarin red staining and high-resolution microradiography. The ingrowth of human osteoblast-like cells in the drill channels occurred in a sequence of four characteristic stages. In stage 1, osteoblast precursor cells adhered to the wall of the channel and migrated three-dimensionally into the channel by forming foot-like protoplasmic processes. For all 15 sample drill channels that were investigated, the cell ingrowth over 20 days amounted on average to 793 microm (+/- 179) into 600-microm-diameter channels, where they migrated significantly faster than in all the other channels. In stage 2, approximately on day 5-7, the osteoblast-like cells began to anchor on the substrate wall by matrix proteins and to build up a dense network of matrix proteins in the drill channel. The mineralization of the extracellular matrix, while depending on cell stimulation, was initiated in stage 3, on average after 4 weeks. In drill channels of a diameter of 1,000 microm the cell growth was incomplete and no mineralization was found by radiological assessment. Starting in week 6, in the drill channels of diameters ranging from 300 to 600 microm, the network of extracellular matrix proteins and osteoblast-like cells began to form an osteon-like structure. Neither the highly developed migration behavior of osteoblastic cells nor the reorganization from a fiber-like matrix to a lamellar structure have so far been described for cell cultures.
本研究的目的是表征成骨样细胞在特定直径钛孔道中的生长、矿化和骨形成情况。将直径为300、400、500、600和1000微米的连续钻孔通道的钛植入物插入人成骨样细胞培养物中。通过透射光显微镜和扫描电子显微镜研究细胞向钻孔通道内的生长情况。对每个直径的15个通道切片进行免疫荧光和组织学分析，以研究生长行为和基质蛋白模式。通过茜素红染色和高分辨率微放射摄影证实矿化情况。人成骨样细胞在钻孔通道内的生长按四个特征阶段依次发生。在第1阶段，成骨前体细胞附着在通道壁上，并通过形成足状原生质突起向通道内三维迁移。在所研究的所有15个样本钻孔通道中，20天内细胞向600微米直径通道内的生长平均达793微米（±179），其迁移速度明显快于所有其他通道。在第2阶段，大约在第5 - 7天，成骨样细胞开始通过基质蛋白锚定在基质壁上，并在钻孔通道内建立密集的基质蛋白网络。细胞外基质的矿化虽然取决于细胞刺激，但在第3阶段平均4周后开始。在直径为1000微米的钻孔通道中，细胞生长不完全，放射学评估未发现矿化。从第6周开始，在直径为300至600微米的钻孔通道中，细胞外基质蛋白和成骨样细胞网络开始形成类骨单位结构。迄今为止，在细胞培养中尚未描述过成骨细胞高度发达的迁移行为以及从纤维状基质到层状结构的重组情况。
