Li Xu-Ran, Deng Qing-Song, He Shu-Hang, Liu Po-Lin, Gao Yuan, Wei Zhan-Ying, Zhang Chang-Ru, Wang Fei, Zhu Tong-He, Dawes Helen, Rui Bi-Yu, Tao Shi-Cong, Guo Shang-Chun
Department of Orthopedic Surgery, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, 600 Yishan Road, Shanghai, 200233, China.
School of Medicine, Shanghai Jiao Tong University, 227 South Chongqing Road, Shanghai, 200025, China.
J Nanobiotechnology. 2024 Dec 19;22(1):764. doi: 10.1186/s12951-024-02977-5.
Bone defect healing is a multi-factorial process involving the inflammatory microenvironment, bone regeneration and the formation of blood vessels, and remains a great challenge in clinical practice. Combined use of three-dimensional (3D)-printed scaffolds and bioactive factors is an emerging strategy for the treatment of bone defects. Scaffolds can be printed using 3D cryogenic printing technology to create a microarchitecture similar to trabecular bone. Melatonin (MT) has attracted attention in recent years as an excellent factor for promoting cell viability and tissue repair. In this study, porous scaffolds were prepared by cryogenic printing with poly(lactic-co-glycolic acid) and ultralong hydroxyapatite nanowires. The hierarchical pore size distribution of the scaffolds was evaluated by scanning electron microscopy (SEM) and micro-computed tomography (micro-CT). Sleep-inspired small extracellular vesicles (MT-sEVs) were then obtained from MT-stimulated cells and 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-poly(ethylene glycol)-inorganic pyrophosphate (DSPE-PEG-PPi) was used to modify the membrane of MT-sEVs to obtain PPi-MT-sEVs. RNA sequencing was performed to explore the potential mechanisms. The results demonstrated that PPi-MT-sEVs not only enhanced cell proliferation, migration and angiogenesis, but also regulated the osteogenic/adipogenic fate determination and M1/M2 macrophage polarization switch in vitro. PPi-MT-sEVs were used to coat scaffolds, enabled by the capacity of PPi to bind to hydroxyapatite, and computational simulations were used to analyze the interfacial bonding of PPi and hydroxyapatite. The macrophage phenotype-modulating and osteogenesis-angiogenesis coupling effects were evaluated in vivo. In summary, this study suggests that the combination of hierarchical porous scaffolds and PPi-MT-sEVs could be a promising candidate for the clinical treatment of bone defects.
骨缺损修复是一个多因素过程，涉及炎症微环境、骨再生和血管形成，在临床实践中仍然是一个巨大挑战。三维（3D）打印支架与生物活性因子的联合应用是治疗骨缺损的一种新兴策略。可以使用3D低温打印技术打印支架，以创建类似于松质骨的微结构。褪黑素（MT）近年来作为促进细胞活力和组织修复的优秀因子而受到关注。在本研究中，采用聚乳酸-羟基乙酸共聚物和超长羟基磷灰石纳米线通过低温打印制备多孔支架。通过扫描电子显微镜（SEM）和微计算机断层扫描（micro-CT）评估支架的分级孔径分布。然后从MT刺激的细胞中获得受睡眠启发的小细胞外囊泡（MT-sEVs），并使用1,2-二硬脂酰-sn-甘油-3-磷酸乙醇胺-聚（乙二醇）-无机焦磷酸（DSPE-PEG-PPi）修饰MT-sEVs的膜以获得PPi-MT-sEVs。进行RNA测序以探索潜在机制。结果表明，PPi-MT-sEVs不仅增强了细胞增殖、迁移和血管生成，还在体外调节了成骨/成脂命运决定和M1/M2巨噬细胞极化转换。PPi-MT-sEVs用于包被支架，这得益于PPi与羟基磷灰石结合的能力，并使用计算模拟分析PPi与羟基磷灰石的界面结合。在体内评估巨噬细胞表型调节和成骨-血管生成耦合效应。总之，本研究表明分级多孔支架与PPi-MT-sEVs的组合可能是骨缺损临床治疗的一个有前景的候选方案。
