Department of Plastic and Reconstructive Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Zhizaoju Road 369, 200011 Shanghai, China; Department of Biomedicine, University Hospital Basel, University of Basel, Hebelstrasse 20, 4031 Basel, Switzerland; Department of Plastic, Reconstructive, Aesthetic, and Hand Surgery, University Hospital Basel, Basel, Switzerland.
Department of Biomedicine, University Hospital Basel, University of Basel, Hebelstrasse 20, 4031 Basel, Switzerland.
Acta Biomater. 2020 Jan 15;102:458-467. doi: 10.1016/j.actbio.2019.11.046. Epub 2019 Nov 26.
Engineering of materials consisting of hypertrophic cartilage, as physiological template for de novo bone formation through endochondral ossification (ECO), holds promise as a new class of biological bone substitutes. Here, we assessed the efficiency and reproducibility of bone formation induced by the combination of ceramic granules with fractionated human adipose tissue ("nanofat"), followed by in vitro priming to hypertrophic cartilage. Human nanofat was mixed with different volumetric ratios of ceramic granules (0.2-1 mm) and cultured to sequentially induce proliferation (3 weeks), chondrogenesis (4 weeks), and hypertrophy (2 weeks). The resulting engineered constructs were implanted ectopically in nude mouse. The presence of ceramic granules regulated tissue formation, both in vitro and in vivo. In particular, their dispersion in nanofat at a ratio of 1:16 led to significantly increased cell number and glycosaminoglycan accumulation in vitro, as well as amount and inter-donor reproducibility of bone formation in vivo. Our findings outline a strategy for efficient utilization of nanofat for bone regeneration in an autologous setting, which should now be tested at an orthotopic site. STATEMENT OF SIGNIFICANCE: In this study, we assessed the efficiency and reproducibility of bone formation by a combination of ceramic granules and fractionated human adipose tissue, also known as nanofat, in vitro primed into hypertrophic cartilage. The resulting engineered cartilaginous constructs, when implanted ectopically in nude mouse, resulted in bone and bone marrow formation, more reproducibly and strongly that nanofat alone. This project evaluates the impact of ceramic granules on the functionality and chondrogenic differentiation of mesenchymal progenitors inside their native adipose tissue niche and outlines a novel strategy for an efficient application of nanofat for bone regeneration in an autologous setting.
工程材料组成的肥大软骨，作为生理模板为从头骨形成通过软骨内骨化（ECO），有望作为一种新的生物骨替代物的类。在这里，我们评估了诱导骨形成的陶瓷颗粒与分馏人体脂肪组织（“纳米脂肪”）的组合的效率和可重复性，接着进行体外诱导肥大软骨。人纳米脂肪与陶瓷颗粒（0.2-1 毫米）的不同体积比混合，并培养顺序诱导增殖（3 周），软骨形成（4 周）和肥大（2 周）。所得的工程构建体异位植入裸鼠。陶瓷颗粒的存在调节组织形成，无论是在体外和体内。特别是，它们在纳米脂肪中的分散比为 1:16 导致细胞数量和糖胺聚糖积累显著增加，在体内也导致骨形成的量和供体间的可重复性增加。我们的研究结果概述了一种在自体环境中有效利用纳米脂肪进行骨再生的策略，现在应该在原位进行测试。意义声明：在这项研究中，我们评估了陶瓷颗粒和分馏人体脂肪组织（也称为纳米脂肪）的组合在体外诱导成肥大软骨后诱导骨形成的效率和可重复性。所得的工程软骨构建体异位植入裸鼠后导致骨和骨髓形成，比单独的纳米脂肪更可重复和更强。该项目评估了陶瓷颗粒对间充质祖细胞在其天然脂肪组织龛内的功能和软骨分化的影响，并概述了一种在自体环境中有效应用纳米脂肪进行骨再生的新策略。
