Fiorani Andrea, Gualandi Chiara, Panseri Silvia, Montesi Monica, Marcacci Maurilio, Focarete Maria Letizia, Bigi Adriana
Department of Chemistry ''G. Ciamician'' and National Consortium of Materials Science and Technology (INSTM, Bologna RU), University of Bologna, Bologna, Italy.
J Mater Sci Mater Med. 2014 Oct;25(10):2313-21. doi: 10.1007/s10856-014-5196-2. Epub 2014 Mar 25.
Collagen electrospun scaffolds well reproduce the structure of the extracellular matrix (ECM) of natural tissues by coupling high biomimetism of the biological material with the fibrous morphology of the protein. Structural properties of collagen electrospun fibers are still a debated subject and there are conflicting reports in the literature addressing the presence of ultrastructure of collagen in electrospun fibers. In this work collagen type I was successfully electrospun from two different solvents, trifluoroethanol (TFE) and dilute acetic acid (AcOH). Characterization of collagen fibers was performed by means of SEM, ATR-IR, Circular Dichroism and WAXD. We demonstrated that collagen fibers contained a very low amount of triple helix with respect to pristine collagen (18 and 16% in fibers electrospun from AcOH and TFE, respectively) and that triple helix denaturation occurred during polymer dissolution. Collagen scaffolds were crosslinked by using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC), a commonly employed crosslinker for electrospun collagen, and 1,4-butanediol diglycidyl ether (BDDGE), that was tested for the first time in this work as crosslinking agent for collagen in the form of electrospun fibers. We demonstrated that BDDGE successfully crosslinked collagen and preserved at the same time the scaffold fibrous morphology, while scaffolds crosslinked with EDC completely lost their porous structure. Mesenchymal stem cell experiments demonstrated that collagen scaffolds crosslinked with BDDGE are biocompatible and support cell attachment.
通过将生物材料的高仿生特性与蛋白质的纤维形态相结合，电纺胶原蛋白支架能够很好地重现天然组织细胞外基质（ECM）的结构。胶原蛋白电纺纤维的结构特性仍是一个有争议的话题，文献中关于电纺纤维中胶原蛋白超微结构的存在存在相互矛盾的报道。在这项工作中，成功地从两种不同的溶剂，即三氟乙醇（TFE）和稀醋酸（AcOH）中电纺出了I型胶原蛋白。通过扫描电子显微镜（SEM）、衰减全反射红外光谱（ATR-IR）、圆二色性（CD）和广角X射线衍射（WAXD）对胶原蛋白纤维进行了表征。我们证明，相对于原始胶原蛋白，胶原蛋白纤维中三螺旋的含量非常低（分别从AcOH和TFE电纺的纤维中为18%和16%），并且在聚合物溶解过程中发生了三螺旋变性。胶原蛋白支架通过使用1-乙基-3-（3-二甲基氨基丙基）碳二亚胺（EDC，一种常用于电纺胶原蛋白的交联剂）和1,4-丁二醇二缩水甘油醚（BDDGE，在这项工作中首次作为电纺纤维形式的胶原蛋白交联剂进行测试）进行交联。我们证明，BDDGE成功地交联了胶原蛋白，同时保留了支架的纤维形态，而用EDC交联的支架则完全失去了其多孔结构。间充质干细胞实验表明，用BDDGE交联的胶原蛋白支架具有生物相容性并支持细胞附着。
