Faculty of Pharmacy, University of Ljubljana, Ljubljana, Slovenia.
Eur J Pharm Biopharm. 2013 Jun;84(2):401-11. doi: 10.1016/j.ejpb.2012.09.009. Epub 2012 Oct 22.
Despite a lot of intensive research in the field of polymer nanofibers as wound-healing and tissue-regeneration materials, the behavior of cells in contact with nanofibers in vitro as well as in vivo is still not well understood. However, this knowledge is crucial for the design of nanofibrillar materials that are suitable for biomedical applications. Therefore, in this study, we present the preparation of poly(vinyl alcohol) (PVA) nanofibers from a physico-chemically characterized polymer solution by electrospinning together with a stabilization method to preserve the morphology of the nanofibers in aqueous conditions. An investigation of the effects of a nanofibrillar scaffold on the growth of human keratinocytes showed that randomly oriented PVA nanofibers delay the keratinocytes' adhesion but improve their strength, greatly alter their morphology, increase their metabolic activity, and limit their mobility. We have shown that due to the small interfiber pores, the whole cells are unable to penetrate into nanofibrillar network efficiently. However, flexible cell parts can penetrate into the nanofibrillar network, whereas the cell nuclei stay on the surface of electrospun scaffold. Additional reason for poor cell mobility is random orientation of nanofibers, which does not provide continuous routes for successful cell infiltration. Therefore, nanofibrillar support with nanosized interfiber pores could potentially be used to enable an efficient cell proliferation and accelerate surface-wound healing, but not for three-dimensional tissue regeneration. Finally, we showed that aligned nanofibers can successfully direct the migration and proliferation of cells, which is a crucial property of nanomaterials for the successful regeneration of tissues with a highly organized structure.
尽管在聚合物纳米纤维作为伤口愈合和组织再生材料的领域进行了大量的深入研究，但细胞在体外和体内与纳米纤维接触的行为仍然没有得到很好的理解。然而，这种知识对于设计适合生物医学应用的纳米纤维材料至关重要。因此，在本研究中，我们通过静电纺丝制备了具有物理化学特性的聚合物溶液的聚（乙烯醇）（PVA）纳米纤维，并提出了一种稳定化方法，以在水介质中保持纳米纤维的形态。研究表明，纳米纤维支架对人角质形成细胞生长的影响表明，随机取向的 PVA 纳米纤维延迟了角质形成细胞的黏附，但增强了其强度，极大地改变了其形态，增加了其代谢活性，并限制了其迁移。我们已经表明，由于纤维间的小孔较小，整个细胞无法有效地穿透到纳米纤维网络中。然而，细胞的柔性部分可以穿透到纳米纤维网络中，而细胞核则留在静电纺丝支架的表面。细胞迁移能力差的另一个原因是纳米纤维的随机取向，它不能为细胞成功渗透提供连续的途径。因此，具有纳米级纤维间孔的纳米纤维支架有可能用于促进细胞的有效增殖和加速表面伤口愈合，但不适用于三维组织再生。最后，我们表明，取向纳米纤维可以成功地引导细胞的迁移和增殖，这是纳米材料成功再生具有高度组织化结构的组织的关键特性。
