Bone tissue has an astonishing self-healing capacity yet only for non-critical size defects (<6 mm) and clinical intervention is needed for critical-size defects and beyond that along with non-union bone fractures and bone defects larger than critical size represent a major healthcare problem. Autografts are, still, being used as preferred to treat large bone defects. Mostly, due to the presence of living differentiated and progenitor cells, its osteogenic, osteoinductive and osteoconductive properties that allow osteogenesis, vascularization, and provide structural support. Bone tissue engineering strategies have been proposed to overcome the limited supply of grafts. Complete and successful bone regeneration can be influenced by several factors namely: the age of the patient, health, gender and is expected that the ideal scaffold for bone regeneration combines factors such as bioactivity and osteoinductivity. The commercially available products have as their main function the replacement of bone. Moreover, scaffolds still present limitations including poor osteointegration and limited vascularization. The introduction of pores in scaffolds are being used to promote the osteointegration as it allows cell and vessel infiltration. Moreover, combinations with growth factors or coatings have been explored as they can improve the osteoconductive and osteoinductive properties of the scaffold. This review focuses on the bone defects treatments and on the research of scaffolds for bone regeneration. Moreover, it summarizes the latest progress in the development of coatings used in bone tissue engineering. Despite the interesting advances which include the development of hybrid scaffolds, there are still important challenges that need to be addressed in order to fasten translation of scaffolds into the clinical scenario. Finally, we must reflect on the main challenges for bone tissue regeneration. There is a need to achieve a proper mechanical properties to bear the load of movements; have a scaffolds with a structure that fit the bone anatomy.

中文翻译：

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用于骨骼再生的脚手架和涂层。

骨组织具有惊人的自我修复能力，但仅对非关键尺寸的缺损（<6 mm）有效，对于关键尺寸的缺损需要进行临床干预，除此之外，还需要进行临床干预，包括不愈合的骨折和大于临界尺寸的骨缺损一个重大的医疗保健问题。自体移植仍被用作治疗大骨缺损的首选方法。通常，由于存在活的分化和祖细胞，其成骨性，骨诱导性和骨传导性允许成骨，血管形成并提供结构支持。已经提出了骨组织工程策略来克服移植物的有限供应。能否成功完成骨骼再生取决于几个因素，例如：患者的年龄，健康状况，性别，并期望理想的骨骼再生支架结合了生物活性和骨诱导性等因素。市售产品具有代替骨的主要功能。此外，支架仍存在局限性，包括不良的骨整合和有限的血管形成。在支架中引入孔被用于促进骨整合，因为它允许细胞和血管浸润。此外，已经探索了与生长因子或涂层的组合，因为它们可以改善支架的骨传导性和骨诱导性。这篇综述着重于骨缺损的治疗以及骨再生支架的研究。此外，它总结了在骨组织工程中使用的涂料开发的最新进展。尽管包括混合支架的开发在内的令人感兴趣的进步，但是仍然需要解决重要的挑战，以将支架转换成临床情况。最后，我们必须反思骨组织再生的主要挑战。需要获得适当的机械性能以承受运动负荷。有一个与骨骼解剖结构相适应的支架。