Center of Craniofacial Orthodontics, Department of Oral and Cranio-maxillofacial Science, Ninth People's Hospital Affiliated to Shanghai Jiao Tong University, School of Medicine, Shanghai 200011, China.
State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China.
Biomaterials. 2014 Oct;35(30):8514-27. doi: 10.1016/j.biomaterials.2014.06.028. Epub 2014 Jul 4.
Tissue engineering strategies to construct vascularized bone grafts potentially revolutionize the treatment of massive bone loss. The surface topography of the grafts plays critical roles on bone regeneration, while adipose derived stem cells (ASCs) are known for their capability to promote osteogenesis and angiogenesis when applied to bone defects. In the present study, the effects of hydroxyapatite (HAp) bioceramic scaffolds with nanosheet, nanorod, and micro-nano-hybrid (the hybrid of nanorod and microrod) surface topographies on attachment, proliferation and osteogenic differentiation, as well as the expression of angiogenic factors of rat ASCs were systematically investigated. The results showed that the HAp bioceramic scaffolds with the micro-/nano-topography surfaces significantly enhanced cell attachment and viability, alkaline phosphatase (ALP) activity, and mRNA expression levels of osteogenic markers and angiogenic factors of ASCs. More importantly, the biomimetic feature of the hierarchical micro-nano-hybrid surface topography showed the highest stimulatory effect. The activation in Akt signaling pathway was observed in ASCs cultured on HAp bioceramics with nanorod, and micro-nano-hybrid surface topographies. Moreover, these induction effects could be repressed by Akt signaling pathway inhibitor LY294002. Finally, the in vivo bone regeneration results of rat critical-sized calvarial defect models confirmed that the combination of the micro-nano-hybrid surface and ASCs could significantly enhance both osteogenesis and angiogenesis as compared with the control HAp bioceramic scaffold with traditional smooth surface. Our results suggest that HAp bioceramic scaffolds with micro-nano-hybrid surface can act as cell carrier for ASCs, and consequently combine with ASCs to construct vascularized tissue-engineered bone.
组织工程策略构建血管化骨移植物可能彻底改变治疗大段骨缺损的方法。移植物的表面形貌在骨再生中起着关键作用，而脂肪来源的干细胞（ASCs）因其在骨缺损应用中促进成骨和血管生成的能力而闻名。在本研究中，系统研究了具有纳米片、纳米棒和微纳混合（纳米棒和微棒的混合）表面形貌的羟基磷灰石（HAp）生物陶瓷支架对附着、增殖和成骨分化的影响，以及对大鼠 ASCs 血管生成因子表达的影响。结果表明，具有微/纳形貌表面的 HAp 生物陶瓷支架显著增强了细胞附着和活力、碱性磷酸酶（ALP）活性，以及 ASCs 成骨标志物和血管生成因子的 mRNA 表达水平。更重要的是，分层微纳混合形貌的仿生特征显示出最高的刺激效果。在纳米棒和微纳混合表面形貌的 HAp 生物陶瓷支架上培养的 ASCs 中观察到 Akt 信号通路的激活。此外，这些诱导作用可以被 Akt 信号通路抑制剂 LY294002 抑制。最后，大鼠临界尺寸颅骨缺损模型的体内骨再生结果证实，与传统光滑表面的对照 HAp 生物陶瓷支架相比，微纳混合表面与 ASCs 的结合可显著增强成骨和血管生成。我们的结果表明，具有微纳混合表面的 HAp 生物陶瓷支架可以作为 ASCs 的细胞载体，与 ASCs 结合构建血管化组织工程骨。
