Alternative bone regeneration strategies that do not rely on harvested tissue or exogenous growth factors are needed. One of the major challenges in tissue reconstruction is recreating the bone tissue microenvironment using the appropriate combination of cells, scaffold, and stimulation to direct differentiation. This study presents a bone regeneration formulation that involves the use of human adipose-derived mesenchymal stem cells (hASCs) and a three-dimensional (3D) hydrogel scaffold based on self-assembled RADA16 peptides containing superparamagnetic iron oxide nanoparticles (NPs). Although superparamagnetic NPs could be used as stimulus to manipulate the cell proliferation and differentiation, in this paper their use is explored for assisting osteogenic differentiation of hASCs in conjunction with direct stimulation by extremely low-frequency pulsed electromagnetic fields (pEMFs). Cellular morphology, proliferation, and viability, as well as alkaline phosphatase activity, calcium deposition, and osteogenic capacity were monitored for cells cultured up to 21 days in the 3D construct. The results show that the pEMFs and NPs do not have any negative effect on cell viability, but instead distinctly induced early differentiation of hASCs to an osteoblastic phenotype, when compared with cells without biophysical stimulation. This effect is attributed to synergy between the pEMFs and NPs, which may have stimulated mechanotransduction pathways, which, in turn activated biochemical signals between cells to differentiate or proliferate. This approach may offer a safe and effective option for the treatment of non-union bone fractures. Bioelectromagnetics. © 2020 The Authors. Bioelectromagnetics published by Wiley Periodicals, Inc.

中文翻译：

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脉冲电磁场​​对使用 3D 磁性支架的人类间充质干细胞的影响。

需要不依赖于收获的组织或外源性生长因子的替代骨再生策略。组织重建的主要挑战之一是使用细胞、支架和刺激的适当组合来重建骨组织微环境以指导分化。本研究提出了一种骨再生配方，该配方涉及使用人类脂肪来源的间充质干细胞 (hASC) 和基于含有超顺磁性氧化铁纳米颗粒 (NPs) 的自组装 RADA16 肽的三维 (3D) 水凝胶支架。尽管超顺磁性 NPs 可以用作刺激细胞增殖和分化，在本文中，它们在极低频脉冲电磁场​​ (pEMF) 的直接刺激中用于辅助 hASC 的成骨分化。监测在 3D 构建体中培养长达 21 天的细胞的细胞形态、增殖和活力，以及碱性磷酸酶活性、钙沉积和成骨能力。结果表明，与没有生物物理刺激的细胞相比，pEMFs和NPs对细胞活力没有任何负面影响，而是明显诱导hASCs早期分化为成骨细胞表型。这种效应归因于 pEMF 和 NP 之间的协同作用，这可能刺激了机械转导途径，进而激活细胞之间的生化信号以分化或增殖。这种方法可能为不愈合骨折的治疗提供一种安全有效的选择。生物电磁学。© 2020 作者。Wiley Periodicals, Inc. 出版的生物电磁学