Bagno Andrea, Piovan Alessandro, Dettin Monica, Chiarion Alessia, Brun Paola, Gambaretto Roberta, Fontana Giovanni, Di Bello Carlo, Palù Giorgio, Castagliuolo Ignazio
Department of Chemical Process Engineering, University of Padova, via Marzolo 9, 35131, Padova, Italy.
Bone. 2007 Mar;40(3):693-9. doi: 10.1016/j.bone.2006.10.007. Epub 2006 Dec 4.
Biomaterials to be used for the production of endosseous devices in dental, orthopedic and maxillo-facial applications, might be designed to support, guide and enhance osteoblast adhesion. Cell recruitment onto biomaterial surface is a fundamental step within the complex process responsible for implant osseointegration; this process involves several proteins from the extra cellular matrix (ECM), cytoskeleton and cell membrane. A new strategy to improve endosseous implant integration is based on preparing biomimetic surfaces able to present adhesive factors to cells. Osteoblast adhesion takes place by at least two different mechanisms: the most investigated one implies the interaction with RGD sequences via cell-membrane integrin receptors; a further mechanism concerns the interaction between cell-membrane heparan sulfate proteoglycans and heparin-binding sites of ECM proteins. In the present study two different biomimetic surfaces were obtained by covalently grafting two adhesive peptides on oxidized titanium substrates after silanization: an RGD-containing peptide and a peptide mapped on human vitronectin. The two sequences are known to act via different adhesive mechanisms. The amount of human osteoblasts adhered onto peptide-enriched or not enriched titanium oxidized surfaces and the strength of cell binding were estimated, thus comparing the capacity of the bioactive substrates in promoting cell adhesion.
用于牙科、整形外科和颌面应用中骨内植入装置生产的生物材料，可能被设计用于支持、引导和增强成骨细胞黏附。细胞在生物材料表面的募集是负责植入体骨整合的复杂过程中的一个基本步骤；这个过程涉及细胞外基质（ECM）、细胞骨架和细胞膜中的几种蛋白质。一种改善骨内植入体整合的新策略是基于制备能够向细胞呈现黏附因子的仿生表面。成骨细胞黏附至少通过两种不同机制发生：研究最多的一种机制是通过细胞膜整合素受体与RGD序列相互作用；另一种机制涉及细胞膜硫酸乙酰肝素蛋白聚糖与ECM蛋白的肝素结合位点之间的相互作用。在本研究中，通过在硅烷化后的氧化钛基底上共价接枝两种黏附肽，获得了两种不同的仿生表面：一种含RGD的肽和一种定位在人玻连蛋白上的肽。已知这两种序列通过不同的黏附机制起作用。估计了黏附在富含肽或未富含肽的氧化钛表面上的人成骨细胞数量以及细胞结合强度，从而比较了生物活性底物促进细胞黏附的能力。
