Pattabhi Sudhakara Rao, Lehaf Ali M, Schlenoff Joseph B, Keller Thomas C S
Department of Biological Science, Florida State University, Tallahassee, Florida, 32306.
J Biomed Mater Res A. 2015 May;103(5):1818-27. doi: 10.1002/jbm.a.35322. Epub 2014 Sep 18.
Polyelectrolyte multilayer (PEMU) coatings built layer by layer with alternating pairs of polyelectrolytes can be tuned to improve cell interactions with surfaces and may be useful as biocompatible coatings to improve fixation between implants and tissues. Here, we show that human mesenchymal stromal cells (hMSCs) induced with bone differentiation medium (BDM) to become osteoblasts biomineralize crosslinked PEMUs built with the polycation poly(allylamine hydrochloride) (PAH) and the polyanion poly(acrylic acid) (PAA). Degrees of hMSC osteoblast differentiation and surface biomineralization on the smooth PAH-terminated PEMUs (PAH-PEMUs) and microstructured PAA-terminated PEMUs (PAA-PEMUs) reflect differences in cell-deposited extracellular matrix (ECM). BDM-induced hMSCs expressed higher levels of the early osteoblast differentiation marker alkaline phosphatase and collagen 1 (COL1) sooner on PAA-PEMUs than on PAH-PEMUs. Cells on both types of PEMUs proceeded to express the later stage osteoblast differentiation marker bone sialoprotein (BSP), but the BDM-induced cells organized a more amorphous Collagen I and denser BSP localization on PAA-PEMUs than on PAH-PEMUs. These ECM properties correlated with greater biomineralization on the PAA-PEMUs than on PAH-PEMUs. Together, these results confirm the suitability of PAH/PAA PEMUs as a substrate for hMSC osteogenesis and highlight the importance of substrate effects on ECM organization and BSP presentation on biomineralization.
通过交替排列的聚电解质对逐层构建的聚电解质多层（PEMU）涂层可以进行调整，以改善细胞与表面的相互作用，并且可用作生物相容性涂层，以改善植入物与组织之间的固定。在此，我们表明，用骨分化培养基（BDM）诱导人骨髓间充质基质细胞（hMSC）成为成骨细胞后，会对由聚阳离子聚（烯丙胺盐酸盐）（PAH）和聚阴离子聚（丙烯酸）（PAA）构建的交联PEMU进行生物矿化。在光滑的PAH端接的PEMU（PAH-PEMU）和微结构化的PAA端接的PEMU（PAA-PEMU）上，hMSC成骨细胞分化程度和表面生物矿化反映了细胞沉积的细胞外基质（ECM）的差异。BDM诱导的hMSC在PAA-PEMU上比在PAH-PEMU上更早地表达更高水平的早期成骨细胞分化标志物碱性磷酸酶和胶原蛋白1（COL1）。两种类型PEMU上的细胞都继续表达后期成骨细胞分化标志物骨唾液蛋白（BSP），但BDM诱导的细胞在PAA-PEMU上比在PAH-PEMU上组织了更无定形的胶原蛋白I和更密集的BSP定位。这些ECM特性与PAA-PEMU上比PAH-PEMU上更大的生物矿化相关。总之，这些结果证实了PAH/PAA PEMU作为hMSC成骨作用底物的适用性，并突出了底物效应在ECM组织和生物矿化中BSP呈现方面的重要性。
