Guillot-Ferriols Maria, Costa Carlos M, Correia Daniela M, Rodríguez-Hernández José Carlos, Tsimbouri Penelope M, Lanceros-Méndez Senentxu, Dalby Matthew J, Gómez Ribelles José Luis, Gallego-Ferrer Gloria
Center for Biomaterials and Tissue Engineering (CBIT), Universitat Politècnica de València, Valencia 46022, Spain.
Biomedical Research Networking Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Valencia 46022, Spain.
ACS Appl Polym Mater. 2024 Nov 6;6(22):13710-13722. doi: 10.1021/acsapm.4c02485. eCollection 2024 Nov 22.
Physical cues have been shown to be effective in inducing osteogenic differentiation of mesenchymal stem cells (MSCs). Here, we propose piezoelectric stimulation as a potential osteogenic cue mimicking the electroactive properties of bone's extracellular matrix. When combined with a magnetostrictive component, piezoelectric polymers can be used for MSC stimulation by applying an external magnetic field. The deformation of the magnetostrictive component produces a deformation in the polymer matrix, generating a change in the surface charge that induces an electric field that can be transmitted to the cells. Cell adhesion, cytoskeleton changes, and metabolomics are the first evidence of MSC osteoblastogenesis and can be used to study initial MSC response to this kind of stimulation. In the current study, poly(vinylidene) fluoride (PVDF) piezoelectric films with and without cobalt ferrite oxide (CFO) crystallized from the melt in the presence of the ionic liquid 1-butyl-3-methyl-imidazolium chloride ([Bmim][Cl]) were produced. [Bmim][Cl] allowed the production of the β-phase, the most electroactive phase, even without CFO. After ionic liquid removal, PVDF and PVDF-CFO films presented high percentages of the β-phase and similar crystalline content. Incorporating CFO nanoparticles was effective, allowing the electromechanical stimulation of MSCs by applying a magnetic field with a bioreactor. Before stimulation, the initial response of MSCs was characterized in static conditions, showing that the produced films were biocompatible and noncytotoxic, allowing MSC adhesion and proliferation in the short term. Stimulation experiments revealed that MSCs electromechanically stimulated for 3 days in PVDF-CFO supports showed longer focal adhesions and decreased vimentin cytoskeletal density, both signals of early osteogenic differentiation. Furthermore, they rearranged their energy metabolism toward an osteogenic phenotype after 7 days of culture under the same stimulation. The results prove that MSCs respond to electromechanical stimulation by osteogenic differentiation.
物理线索已被证明在诱导间充质干细胞（MSC）的成骨分化方面是有效的。在此，我们提出压电刺激作为一种潜在的成骨线索，可模拟骨细胞外基质的电活性特性。当与磁致伸缩组件结合时，压电聚合物可通过施加外部磁场用于刺激MSC。磁致伸缩组件的变形会在聚合物基质中产生变形，从而产生表面电荷变化，进而诱导可传递给细胞的电场。细胞黏附、细胞骨架变化和代谢组学是MSC向成骨细胞分化的首要证据，可用于研究MSC对这种刺激的初始反应。在当前研究中，制备了在离子液体1-丁基-3-甲基咪唑氯盐（[Bmim][Cl]）存在下从熔体中结晶的含和不含钴铁氧体氧化物（CFO）的聚偏二氟乙烯（PVDF）压电薄膜。即使没有CFO，[Bmim][Cl]也能促使生成最具电活性的β相。去除离子液体后，PVDF和PVDF-CFO薄膜呈现出高比例的β相和相似的结晶含量。掺入CFO纳米颗粒是有效的，通过生物反应器施加磁场可对MSC进行机电刺激。在刺激之前，在静态条件下对MSC的初始反应进行了表征，结果表明所制备的薄膜具有生物相容性且无细胞毒性，可在短期内使MSC黏附并增殖。刺激实验表明，在PVDF-CFO支架中进行3天机电刺激的MSC显示出更长的黏着斑以及波形蛋白细胞骨架密度降低，这两者都是早期成骨分化的信号。此外，在相同刺激下培养7天后，它们将能量代谢重排为成骨表型。结果证明MSC通过成骨分化对机电刺激作出反应。
