Stable biofunctionalization of hydroxyapatite (HA) surfaces by HA-binding/osteogenic modular peptides for inducing osteogenic differentiation of mesenchymal stem cells.
Stable biofunctionalization of hydroxyapatite (HA) surfaces by HA-binding/osteogenic modular peptides for inducing osteogenic differentiation of mesenchymal stem cells.
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DOI：
10.1039/c4bm00164h
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发表时间：
2014
影响因子：
6.6
通讯作者：
Mao C
中科院分区：
文献类型：
--
作者：
Polini A;Wang J;Bai H;Zhu Y;Tomsia AP;Mao C
羟基磷灰石(HA)是骨矿物的主要成分，用于涂层金属植入物和人工骨移植中的支架材料时，具有良好的导骨性。为了给这种材料提供骨诱导能力，以促进更快的骨再生，我们展示了一种简单的方法来功能化HA植入物表面，并通过使用HA结合的模块化多肽来丰富它们的骨诱导特性。模块多肽被设计成两个结构域的组合，一个是HA结合的多肽基序，另一个是来源于成骨生长多肽(OGP)或骨形态计量蛋白7(BMP-7)的成骨多肽基序。为了确定最好的HA结合肽，比较了几种源自天然骨细胞外基质蛋白(骨唾液蛋白、骨结素、骨钙素和唾液凝集素)的天然多肽与HA的结合活性，揭示了浓度依赖和孵育时间依赖的行为。我们发现Poly-E七聚体(E7)是最好的HA结合肽，并因此将其与第二个成骨多肽结构域结合创建了骨诱导模块多肽。通过结合/释放表征，我们发现第二个成骨多肽结构域的加入并没有改变模块多肽的结合轮廓，并且只引起了它们的释放动力学的微小变化。将间充质干细胞(MSCs)培养在含有模块多肽的HA基质上，研究细胞在基础培养液(即不含任何成骨补充剂)中的黏附、增殖和分化。基因表达数据清楚地表明，在模块化多肽存在的情况下，MSCs致力于分化为成骨细胞。在所研究的所有模块多肽中，E7 BMP-7模块多肽功能化的HA间盘诱导MSCs成骨分化的能力最强。这些模块多肽可以很容易地通过其组成的HA结合基序来功能化HA植入物，使成骨多肽基序从表面突出以诱导成骨。我们的工作为研制新的生物活性HA涂层和植入物开辟了一条新的途径，用于骨和牙齿修复。
Hydroxyapatite (HA), the principal component of bone mineral, shows osteoconductive properties when employed for coating metal implants as well as scaffold materials in synthetic bone grafts. With the goal of providing this material with osteoinductive capabilities to promote faster bone regeneration, we show an easy approach to functionalize HA implant surfaces and enrich them with osteoinductive properties by the use of HA-binding modular peptides. The modular peptides are designed as a combination of two domains, an HA-binding peptide motif and an osteogenic peptide motif derived from the osteogenic growth peptide (OGP) or bone morphometric protein 7 (BMP-7). To identify the best HA-binding peptide, several nature-inspired peptides derived from natural bone extracellular matrix proteins (bone sialoprotein, osteonectin, osteocalcin, and salivarin statherin) were compared for HA-binding activity, revealing concentration-dependent and incubation-time-dependent behaviours. We discovered that a Poly-E heptamer (E7) is the best HA-binding peptide, and thus combined it with a second osteogenic peptidic domain to create an osteoinductive modular peptide. After binding/release characterization, we found that the addition of the second osteogenic peptide domain did not change the binding profile of the modular peptides and caused only a slight change in their release kinetics. Mesenchymal stem cells (MSCs) were cultured on the HA substrates functionalized with modular peptides, and cell adhesion, proliferation, and differentiation in a basal medium (i.e., without any osteogenic supplements) were investigated. Gene expression data clearly showed that MSCs were committed to differentiate into osteoblasts in the presence of the modular peptides. HA discs functionalized with the E7 BMP-7 modular peptide showed the best capability in inducing the osteogenic differentiation of MSCs among all modular peptides studied. The modular peptides can easily be used to functionalize the HA implants through its constituent HA-binding motif, leaving the osteogenic peptide motif protruding from the surface for inducing osteogenesis. Our work opens up a new approach to the formulation of new bioactive HA coatings and implants for bone and dental repair.