Fracture incidence increases with ageing and other contingencies. However, the strategy of accelerating fracture repair in clinical therapeutics remain a huge challenge due to its complexity and a long-lasting period. The emergence of nano-based drug delivery systems provides a highly efficient, targeted and controllable drug release at the diseased site. Thus far, fairly limited studies have been carried out using nanomedicines for the bone repair applications. Perfluorocarbon (PFC), FDA-approved clinical drug, is received increasing attention in nanomedicine due to its favorable chemical and biologic inertness, great biocompatibility, high oxygen affinity and serum-resistant capability. In the premise, the purpose of the current study is to prepare nano-sized PFC materials and to evaluate their advisable effects on promoting bone fracture repair. Our data unveiled that nano-PFC significantly enhanced the fracture repair in the rabbit model with radial fractures, as evidenced by increased soft callus formation, collagen synthesis and accumulation of beneficial cytokines (e.g., vascular endothelial growth factor (VEGF), matrix metalloprotein 9 (MMP-9) and osteocalcin). Mechanistic studies unraveled that nano-PFC functioned to target osteoblasts by stimulating their differentiation and activities in bone formation, leading to accelerated bone remodeling in the fractured zones. Otherwise, osteoclasts were not affected upon nano-PFC treatment, ruling out the potential target of nano-PFC on osteoclasts and their progenitors. These results suggest that nano-PFC provides a potential perspective for selectively targeting osteoblast cell and facilitating callus generation. This study opens up a new avenue for nano-PFC as a promising agent in therapeutics to shorten healing time in treating bone fracture.

中文翻译：

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纳米级全氟化碳通过选择性激活成骨细胞分化和功能来加速骨折愈合。


骨折发生率随着年龄的增长和其他意外事件而增加。然而，由于其复杂性和持续时间长，加速骨折修复的策略在临床治疗中仍然是一个巨大的挑战。纳米药物递送系统的出现为病变部位提供了高效、靶向和可控的药物释放。迄今为止，使用纳米药物进行骨修复应用的研究相当有限。全氟化碳（PFC）作为FDA批准的临床药物，因其良好的化学和生物惰性、良好的生物相容性、高氧亲和力和抗血清能力而在纳米医学领域受到越来越多的关注。在此前提下，本研究的目的是制备纳米PFC材料并评价其促进骨折修复的效果。我们的数据表明，纳米 PFC 显着增强了兔桡骨骨折模型的骨折修复，软愈伤组织形成增加、胶原蛋白合成和有益细胞因子（例如血管内皮生长因子 (VEGF)、基质金属蛋白 9）的积累增加证明了这一点。 MMP-9) 和骨钙素)。机理研究表明，纳米 PFC 通过刺激成骨细胞的分化和骨形成活动来靶向成骨细胞，从而加速骨折区域的骨重塑。否则，破骨细胞不会受到纳米 PFC 治疗的影响，排除了纳米 PFC 对破骨细胞及其祖细胞的潜在靶点。这些结果表明纳米 PFC 为选择性靶向成骨细胞和促进愈伤组织生成提供了潜在的前景。 这项研究为纳米 PFC 作为一种有前途的治疗药物开辟了一条新途径，可缩短骨折治疗的愈合时间。