David H. Koch Center for Applied Research, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA; Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA.
Center for Infectious & Inflammatory Diseases, Institute of Bioscience and Technology, Texas A&M Health Science Center, 2121 Holcombe Blvd., Houston, TX 77030, USA.
Acta Biomater. 2014 Jul;10(7):3354-62. doi: 10.1016/j.actbio.2014.04.005. Epub 2014 Apr 13.
The major barriers to the clinical success of orthopedic and dental implants are poor integration of fixtures with bone tissue and biomaterial-associated infections. Although multifunctional device coatings have long been considered a promising strategy, their development is hindered by difficulties in integrating biocompatibility, anti-infective activity and antithrombotic properties within a single grafting agent. In this study, we used cell adhesion assays and confocal microscopy of primary murine osteoblasts and human osteoblast cell lines MG-63 and Saos-2 to demonstrate that a streptococcal collagen-like protein engineered to display the α1 and α2 integrin recognition sequences enhances osteoblast adhesion and spreading on titanium fixtures. By measuring calcium deposition and alkaline phosphatase activity, we also showed that selective activation of α2β1 integrin induces osteoblast differentiation, osteoid formation and mineralization. Moreover, cell adhesion assays and scanning electron microscopy of clinical isolates Staphylococcus aureus Philips and Staphylococcus epidermidis 9491 indicated that streptococcal collagen-mimetic proteins inhibit bacterial colonization and biofilm formation irrespective of their interaction with integrins. Given that streptococcal collagenous substrates neither interact with platelets nor trigger a strong immune response, this novel bioactive coating appears to have desirable multifaceted properties with promising translational applications.
骨科和牙科植入物临床成功的主要障碍是固定装置与骨组织和生物材料相关感染之间的整合不良。尽管多功能设备涂层长期以来一直被认为是一种很有前途的策略，但由于难以在单个接枝剂中整合生物相容性、抗感染活性和抗血栓形成特性，其发展受到阻碍。在这项研究中，我们使用细胞黏附实验和原代鼠成骨细胞以及人成骨细胞系 MG-63 和 Saos-2 的共聚焦显微镜，证明了一种经过工程改造的链球菌胶原样蛋白，该蛋白被设计为展示α1 和α2 整合素识别序列，可增强钛固定装置上成骨细胞的黏附和铺展。通过测量钙沉积和碱性磷酸酶活性，我们还表明，选择性激活α2β1 整合素可诱导成骨细胞分化、类骨质形成和矿化。此外，临床分离株金黄色葡萄球菌飞利浦和表皮葡萄球菌 9491 的细胞黏附实验和扫描电子显微镜表明，链球菌胶原模拟蛋白可抑制细菌定植和生物膜形成，而与整合素的相互作用无关。鉴于链球菌胶原性基质既不与血小板相互作用，也不会引发强烈的免疫反应，这种新型生物活性涂层似乎具有理想的多方面特性，具有有前景的转化应用。
