Department of Polymer Engineering and Color Technology, Amirkabir University of Technology , Tehran, Iran.
ACS Appl Mater Interfaces. 2014 Jan 8;6(1):72-82. doi: 10.1021/am404500c. Epub 2013 Dec 26.
Nanofibrous scaffolds with specific modifications have shown promising potential for bone tissue engineering applications. In the present study, poly(ether sulfone) (PES) and sulfonated PES (SPES) nanofibers were fabricated via electrospinning. Calcium ions were then incorporated in SPES by immersion in a Ca(OH)2 solution. The calcium-ion-exchanged SPES (Ca-SPES), PES, and SPES nanofibers were characterized and then evaluated for their osteogenic capacity: both in vitro using stem cell culture and in vivo after subcutaneous implantation in mice. After 7 days of immersion in simulated body fluid, the formation of an apatite layer was only observed on Ca-SPES nanofibers. According to the MTT results, an increasing stem cell population was detected on all scaffolds during the period of study. Using real-time reverse transcriptase-polymerase chain reaction, alkaline phosphatase activity, and calcium content assays, it was demonstrated that the osteogenic differentiation of stem cells was higher on Ca-SPES scaffolds in comparison with PES and SPES nanofibers. Interestingly, Ca-SPES scaffolds were shown to induce ectopic bone formation after 12 weeks of subcutaneous implantation in mice. This was confirmed by mineralization and the production of collagen fibers using van Kossa and Masson's trichrome staining, respectively. Taken together, it was demonstrated that the incorporation of calcium ions into the ion-exchange nanofibrous scaffolds not only gives them the ability to enhance osteogenic differentiation of stem cells in vitro but also to induce ectopic bone formation in vivo.
具有特定修饰的纳米纤维支架在骨组织工程应用中显示出了巨大的潜力。在本研究中，通过静电纺丝制备了聚醚砜（PES）和磺化聚醚砜（SPES）纳米纤维。然后，通过将 SPES 浸入 Ca(OH)2 溶液中，将钙离子掺入 SPES 中。对钙离子交换 SPES（Ca-SPES）、PES 和 SPES 纳米纤维进行了表征，并评估了它们的成骨能力：体外使用干细胞培养，体内通过皮下植入小鼠后进行评估。在模拟体液中浸泡 7 天后，仅在 Ca-SPES 纳米纤维上观察到形成了磷灰石层。根据 MTT 结果，在研究期间，所有支架上的干细胞群体都在增加。通过实时逆转录-聚合酶链反应、碱性磷酸酶活性和钙含量测定，证明与 PES 和 SPES 纳米纤维相比，Ca-SPES 支架上的干细胞成骨分化更高。有趣的是，Ca-SPES 支架在皮下植入小鼠 12 周后被证明能诱导异位骨形成。通过 van Kossa 和 Masson 三色染色分别对矿化和胶原纤维的产生进行证实。综上所述，研究结果表明，将钙离子掺入离子交换纳米纤维支架中不仅赋予了它们增强体外干细胞成骨分化的能力，而且还能在体内诱导异位骨形成。
