Bone Biology and Implant Therapy Laboratory, Department of Prosthodontics, University of North Carolina at Chapel Hill, 330 Brauer Hall, CB #7450, Chapel Hill, NC 27599, USA.
Bone. 2011 Sep;49(3):463-72. doi: 10.1016/j.bone.2011.04.019. Epub 2011 Apr 27.
Collagen-dependent microstructure and physicochemical properties of newly formed bone around implant surfaces represent key determinants of implant biomechanics. This study investigated the effects of implant surface topography on collagen biosynthesis of adherent human mesenchymal stem cells (hMSCs). hMSCs were grown for 0 to 42 days on titanium disks (20.0 × 1.0 mm) with smooth or rough surfaces. Cell attachment and spreading were evaluated by incubating cells with Texas-Red-conjugated phalloidin antibody. Quantitative real-time PCR was used to measure the mRNA levels of Col1α1 and collagen modifying genes including prolyl hydroxylases (PHs), lysyl oxidases (LOXs) and lysyl hydroxylases (LHs). Osteogenesis was assessed at the level of osteoblast specific gene expression and alizarin red staining for mineralization. Cell layer-associated matrix and collagen content were determined by amino acid analysis. At 4h, 100% cells were flattened on both surfaces, however the cells on smooth surface had a fibroblast-like shape, while cells on rough surface lacked any defined long axis. PH, LH, and most LOX mRNA levels were greater in hMSCs grown on rough surfaces for 3 days. The mineralized area was greater for rough surface at 28 and 42 days. The collagen content (percent total protein) was also greater at rough surface compared to smooth surface at 28 (36% versus 26%) and 42 days (46% versus 29%), respectively (p<.05). In a cell culture model, rough surface topography positively modulates collagen biosynthesis and accumulation and the expression of genes associated with collagen cross-linking in adherent hMSC. The altered biosynthesis of the collagen-rich ECM adjacent to endosseous implants may influence the biomechanical properties of osseointegrated endosseous implants.
种植体表面周围新形成骨的胶原依赖性微观结构和理化特性是影响种植体生物力学的关键决定因素。本研究探讨了种植体表面形貌对贴壁人骨髓间充质干细胞（hMSC）胶原生物合成的影响。将 hMSC 在具有光滑或粗糙表面的钛盘（20.0×1.0mm）上培养 0 至 42 天。通过用 Texas-Red 缀合的鬼笔环肽抗体孵育细胞来评估细胞附着和扩散。使用定量实时 PCR 测量 Col1α1 和胶原修饰基因（包括脯氨酰羟化酶（PH）、赖氨酰氧化酶（LOX）和赖氨酰羟化酶（LH））的 mRNA 水平。通过成骨细胞特异性基因表达和茜素红染色评估矿化。通过氨基酸分析测定细胞层相关基质和胶原含量。在 4 小时时，两种表面上的细胞均 100%变平，但光滑表面上的细胞呈成纤维细胞样形状，而粗糙表面上的细胞没有任何明确的长轴。在培养 3 天时，在粗糙表面上培养的 hMSC 中 PH、LH 和大多数 LOX 的 mRNA 水平更高。在 28 天和 42 天时，粗糙表面的矿化面积更大。与光滑表面相比，在 28 天（36%对 26%）和 42 天（46%对 29%）时，粗糙表面的胶原含量（总蛋白的百分比）也更高（p<.05）。在细胞培养模型中，粗糙表面形貌可正向调节贴壁 hMSC 中胶原生物合成和积累以及与胶原交联相关基因的表达。骨内种植体周围富含胶原的细胞外基质的生物合成改变可能会影响骨整合种植体的生物力学特性。
