Inanc Bülend, Elcin A Eser, Elcin Y Murat
Tissue Engineering and Biomaterials Laboratory, Biotechnology Institute and Faculty of Science, Ankara University, Ankara, Turkey.
Tissue Eng. 2006 Feb;12(2):257-66. doi: 10.1089/ten.2006.12.257.
Human periodontal ligament fibroblasts (hPDLF) play a key role in the regeneration of periodontal compartment during guided tissue regeneration procedures. This property is attributed to the progenitor cell subsets residing in the area. The aim of this study was to investigate whether hPDLFs could undergo an osteogenic differentiation under two- and three-dimensional (2D and 3D) culture conditions upon osteogenic induction. hPDLFs were isolated from six healthy donors, cultured, and expanded according to standard protocols. Then, three osteogenic culture conditions (dexamethasone, ascorbic acid, and beta-glycerophosphate) were established: 1) 2D culture as single-cell monolayer, 2) 3D-static culture on mineralized poly(DL-lactic-co-glycolic acid) (PLGA) scaffold, and 3) 3D culture on mineralized PLGA scaffold inside the NASA-approved bioreactor stimulating microgravity conditions. After 21 days of osteogenic induction, the majority of monolayer cultures had undergone differentiation toward osteogenic lineage, as indicated by morphological changes, mineralization assay, and some phenotypical properties. However, immunohistochemistry revealed that the scaffold cultures expressed higher levels of osteogenic marker proteins compared with that of the monolayers. Secondly, hPDLF-PLGA constructs in bioreactor showed an increased expression of osteopontin and osteocalcin compared with that of static 3D culture after 21 days. Results indicate that human periodontal ligament contains a subpopulation of cells capable of undergoing osteogenic differentiation and presumably contributing to regeneration of bone defects in the adjacent area. Human PDLF-seeded mineralized PLGA scaffold in microgravity bioreactor may be used to support osteogenic differentiation in vitro. Thus, this system may offer new potential benefits as a tool for periodontal tissue engineering.
人牙周膜成纤维细胞（hPDLF）在引导组织再生过程中牙周组织再生中起关键作用。这一特性归因于该区域存在的祖细胞亚群。本研究的目的是调查hPDLF在成骨诱导下于二维和三维（2D和3D）培养条件下是否能发生成骨分化。从六名健康供体中分离hPDLF，按照标准方案进行培养和扩增。然后，建立三种成骨培养条件（地塞米松、抗坏血酸和β-甘油磷酸）：1）二维单细胞单层培养，2）在矿化聚（DL-乳酸-共-乙醇酸）（PLGA）支架上进行三维静态培养，3）在美国国家航空航天局（NASA）批准的模拟微重力条件的生物反应器内的矿化PLGA支架上进行三维培养。成骨诱导21天后，大多数单层培养物已向成骨谱系分化，形态变化、矿化测定和一些表型特性表明了这一点。然而，免疫组织化学显示，与单层培养相比，支架培养物中骨生成标记蛋白的表达水平更高。其次，生物反应器中的hPDLF-PLGA构建体在21天后与静态三维培养相比，骨桥蛋白和骨钙素的表达增加。结果表明，人牙周膜含有能够发生成骨分化并可能有助于相邻区域骨缺损再生的细胞亚群。在微重力生物反应器中接种人PDLF的矿化PLGA支架可用于支持体外成骨分化。因此，该系统作为牙周组织工程工具可能具有新的潜在益处。
