Department of Periodontology, Bernhard Gottlieb University Clinic of Dentistry, Medical University of Vienna, Austria.
Dent Mater. 2010 Nov;26(11):1043-51. doi: 10.1016/j.dental.2010.07.003. Epub 2010 Aug 21.
Osteogenesis on titanium (Ti) surfaces is a complex process involving cell-substrate and cell-cell interaction of osteoblasts and endothelial cells. The aim of this study was to investigate the osteogenic properties of Ti surfaces on osteoblasts in the presence of endothelial cells (ECs).
Osteoblast-like cells (MG63 cells) and human umbilical vein endothelial cells (HUVECs) were grown in cocultures on four kinds of Ti surfaces: acid-etched (A), coarse-grit-blasted and acid-etched (SLA), hydrophilic A (modA) and hydrophilic SLA (modSLA) surfaces. MG63 cells in single cultures served as controls. Cell ratios and cell types in cocultures were determined and isolated using flow cytometry. Cell numbers were obtained by direct cell counting. In MG63 cells, alkaline phosphatase (ALP) activity was determined and protein levels of osteocalcin (OC) and osteoprotegerin (OPG) were detected with enzyme-linked immunosorbant assay (ELISA). The mRNA levels of ALP, OC and OPG of sorted MG63 cells were determined with real time polymerase chain reaction (PCR).
MG63 cells proliferated in the presence of HUVECs, which showed higher cell numbers on Ti surfaces (A, SLA, modSLA) after 72h, and lower cell numbers on Ti surfaces (modA, SLA, modSLA) after 120h in comparison to single cultures. Protein and mRNA levels of ALP and OPG were higher in cocultures than in single cultures, while OC exhibited a lower expression. These three parameters were higher expressed on modA, SLA and modSLA surfaces compared to A surfaces.
Cocultures of osteoblasts and endothelial cells represent the most recently developed research model for investigating osteogenesis and angiogenesis which play both a major role in bone healing. This paper investigates for the first time the osteogenic properties of titanium surfaces used for dental implants with a coculture system with osteoblast-like cells and endothelial cells: (1) In cocultures with ECs (HUVECs) osteoblast-like cells (MG63 cells) show enhanced expression of early differentiation markers and osteogenic factors on Ti surfaces compared to single cultures of MG63 cells. (2) The differentiation and the expression of an osteogenic phenotype of osteoblast-like cells (MG63 cells) in coculture with ECs (HUVECs) is enhanced by both hydrophilicity and roughness of Ti surfaces.
钛（Ti）表面的成骨作用是一个复杂的过程，涉及成骨细胞和内皮细胞的细胞-基质和细胞-细胞相互作用。本研究的目的是研究成骨细胞在存在内皮细胞（ECs）的情况下在 Ti 表面的成骨特性。
成骨样细胞（MG63 细胞）和人脐静脉内皮细胞（HUVECs）在四种 Ti 表面上进行共培养：酸蚀（A）、粗砂喷砂酸蚀（SLA）、亲水 A（modA）和亲水 SLA（modSLA）表面。单培养的 MG63 细胞作为对照。使用流式细胞术确定和分离共培养物中的细胞比例和细胞类型。通过直接细胞计数获得细胞数量。在 MG63 细胞中，通过酶联免疫吸附试验（ELISA）测定碱性磷酸酶（ALP）活性和骨钙素（OC）和骨保护素（OPG）的蛋白水平。用实时聚合酶链反应（PCR）测定分选 MG63 细胞的 ALP、OC 和 OPG 的 mRNA 水平。
MG63 细胞在 HUVECs 的存在下增殖，与单培养相比，72h 后在 Ti 表面（A、SLA、modSLA）上的细胞数量更高，而 120h 后在 Ti 表面（modA、SLA、modSLA）上的细胞数量更低。与单培养相比，共培养物中的 ALP 和 OPG 的蛋白和 mRNA 水平更高，而 OC 的表达水平更低。与 A 表面相比，这三个参数在 modA、SLA 和 modSLA 表面上的表达更高。
成骨细胞和内皮细胞的共培养是研究成骨和血管生成的最新研究模型，这两者在骨愈合中都起着重要作用。本文首次用成骨样细胞和内皮细胞的共培养系统研究用于牙科植入物的钛表面的成骨特性：（1）在与 EC（HUVECs）共培养的情况下，成骨样细胞（MG63 细胞）在 Ti 表面上的早期分化标志物和成骨因子的表达增强与 MG63 细胞的单培养相比。（2）成骨样细胞（MG63 细胞）与 EC（HUVECs）共培养时，Ti 表面的亲水性和粗糙度增强了成骨细胞的分化和成骨表型的表达。
