Gabbai-Armelin P R, Souza M T, Kido H W, Tim C R, Bossini P S, Magri A M P, Fernandes K R, Pastor F A C, Zanotto E D, Parizotto N A, Peitl O, Renno A C M
Federal University of São Carlos (UFSCar), Rodovia Washington Luís (SP-310), km 235, São Carlos, SP, Brazil,
J Mater Sci Mater Med. 2015 May;26(5):177. doi: 10.1007/s10856-015-5516-1. Epub 2015 Apr 17.
Researchers have investigated several therapeutic approaches to treat non-union fractures. Among these, bioactive glasses and glass ceramics have been widely used as grafts. This class of biomaterial has the ability to integrate with living bone. Nevertheless, bioglass and bioactive materials have been used mainly as powder and blocks, compromising the filling of irregular bone defects. Considering this matter, our research group has developed a new bioactive glass composition that can originate malleable fibers, which can offer a more suitable material to be used as bone graft substitutes. Thus, the aim of this study was to assess the morphological structure (via scanning electron microscope) of these fibers upon incubation in phosphate buffered saline (PBS) after 1, 7 and 14 days and, also, evaluate the in vivo tissue response to the new biomaterial using implantation in rat tibial defects. The histopathological, immunohistochemistry and biomechanical analyzes after 15, 30 and 60 days of implantation were performed to investigate the effects of the material on bone repair. The PBS incubation indicated that the fibers of the glassy scaffold degraded over time. The histological analysis revealed a progressive degradation of the material with increasing implantation time and also its substitution by granulation tissue and woven bone. Histomorphometry showed a higher amount of newly formed bone area in the control group (CG) compared to the biomaterial group (BG) 15 days post-surgery. After 30 and 60 days, CG and BG showed a similar amount of newly formed bone. The novel biomaterial enhanced the expression of RUNX-2 and RANK-L, and also improved the mechanical properties of the tibial callus at day 15 after surgery. These results indicated a promising use of the new biomaterial for bone engineering. However, further long-term studies should be carried out to provide additional information concerning the material degradation in the later stages and the bone regeneration induced by the fibrous material.
研究人员已经研究了几种治疗骨折不愈合的治疗方法。其中，生物活性玻璃和玻璃陶瓷已被广泛用作移植物。这类生物材料具有与活骨结合的能力。然而，生物玻璃和生物活性材料主要以粉末和块状形式使用，这不利于填充不规则的骨缺损。考虑到这一问题，我们的研究小组开发了一种新的生物活性玻璃组合物，它可以形成可延展的纤维，这可以提供一种更适合用作骨移植替代物的材料。因此，本研究的目的是通过扫描电子显微镜评估这些纤维在磷酸盐缓冲盐水（PBS）中孵育1、7和14天后的形态结构，并通过将其植入大鼠胫骨缺损来评估体内组织对这种新型生物材料的反应。在植入15、30和60天后进行组织病理学、免疫组织化学和生物力学分析，以研究该材料对骨修复的影响。PBS孵育表明玻璃支架的纤维随时间降解。组织学分析显示，随着植入时间的增加，材料逐渐降解，同时被肉芽组织和编织骨替代。组织形态计量学显示，术后15天，与生物材料组（BG）相比，对照组（CG）新形成的骨面积更多。30天和60天后，CG和BG新形成的骨量相似。这种新型生物材料增强了RUNX-2和RANK-L的表达，并且在术后15天时还改善了胫骨骨痂的力学性能。这些结果表明这种新型生物材料在骨工程方面具有广阔的应用前景。然而，应该进行进一步的长期研究，以提供有关该材料后期降解以及纤维材料诱导的骨再生的更多信息。
