Department of Instructive Biomaterials Engineering, MERLN Institute for Technology-Inspired Regenerative Medicine, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands.
Biomater Sci. 2021 Mar 10;9(5):1754-1766. doi: 10.1039/d0bm01494j.
Calcium phosphates (CaPs) in the form of hydroxyapatite (HA) have been extensively studied in the context of bone regeneration due to their chemical similarity to natural bone mineral. While HA is known to promote osteogenic differentiation, the structural properties of the ceramic have been shown to affect the extent of this effect; several studies have suggested that nanostructured HA can improve the bioactivity. However, the role shape plays in the osteogenic potential is more elusive. Here we studied the effect of HA nanoparticle shape on the ability to induce osteogenesis in human mesenchymal stromal cells (hMSCs) by developing nanoparticle films using needle-, rice- and spherical-shaped HA. We showed that the HA films made from all three shapes of nanoparticles induced increased levels of osteogenic markers (i.e. runt-related transcription factor 2 (RUNX2), bone morphogenetic protein 2 (BMP2), alkaline phosphatase (ALP), osteopontin (OPN), osteocalcin (OCN) on protein and gene level in comparison to hMSCs cultured on cover glass slides. Furthermore, their expression levels and profiles differed significantly as a function of nanoparticle shape. We also showed that nanoparticle films were more efficient in inducing osteogenic gene expression in hMSCs compared to adding nanoparticles to hMSCs in culture media. Finally, we demonstrated that hMSC morphology upon adhesion to the HA nanoparticle films is dependent on nanoparticle shape, with hMSCs exhibiting a more spread morphology on needle-shaped nanoparticle films compared to hMSCs seeded on rice- and spherical-shaped nanoparticle films. Our data suggests that HA nanoparticle films are efficient in inducing hMSC osteogenesis in basic cell culture conditions and that nanoparticle shape plays a vital role in cell adhesion and morphology and extent of induction of osteogenic differentiation.
钙磷酸盐（CaPs）以羟基磷灰石（HA）的形式在骨再生的背景下得到了广泛的研究，因为它们在化学上与天然骨矿物质相似。虽然 HA 被认为可以促进成骨分化，但陶瓷的结构特性已被证明会影响这种效果的程度；有几项研究表明，纳米结构的 HA 可以提高生物活性。然而，形状在成骨潜力中的作用更加难以捉摸。在这里，我们通过使用针状、稻状和球形 HA 开发纳米粒子薄膜，研究了 HA 纳米粒子形状对诱导人间充质基质细胞（hMSC）成骨能力的影响。我们表明，与 hMSC 在盖玻片上培养相比，所有三种形状的纳米粒子制成的 HA 薄膜在蛋白和基因水平上均诱导了更高水平的成骨标志物（即 runt 相关转录因子 2（RUNX2）、骨形态发生蛋白 2（BMP2）、碱性磷酸酶（ALP）、骨桥蛋白（OPN）、骨钙素（OCN））的表达。此外，它们的表达水平和谱因纳米粒子形状的不同而有显著差异。我们还表明，与在培养基中向 hMSC 添加纳米粒子相比，纳米粒子薄膜在诱导 hMSC 成骨基因表达方面更有效。最后，我们证明了 hMSC 在粘附到 HA 纳米粒子薄膜时的形态取决于纳米粒子的形状，与在稻状和球形纳米粒子薄膜上接种的 hMSC 相比，hMSC 在针状纳米粒子薄膜上表现出更伸展的形态。我们的数据表明，在基本细胞培养条件下，HA 纳米粒子薄膜能够有效地诱导 hMSC 成骨，并且纳米粒子形状在细胞粘附和形态以及诱导成骨分化的程度方面起着至关重要的作用。
