Chen Junde, Li Jianying, Li Yushuang, Wu Sijia
Technical Innovation Center for Utilization of Marine Biological Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China.
Food Chem X. 2024 Jan 16;21:101138. doi: 10.1016/j.fochx.2024.101138. eCollection 2024 Mar 30.
Collagen electrospun fibers are promising materials for food packaging and tissue engineering. The conventional electrospinning of collagen, however, is usually carried out by dissolving it in organic reagents, which are toxic. In this study, collagen/pullulan (COL/PUL) ultra-thin fibers were prepared by electrospinning using acetic acid as a solvent. Compared to the conventional preparation method, the proposed method is safe and does not produce toxic solvent residues. The introduction of PUL increased the degree of molecular entanglement in the solution, so the viscosity of the COL/PUL electrospun solution increased from 0.50 ± 0.01 Pa∙s to 4.40 ± 0.08 Pa∙s, and the electrical conductivity decreased from 1954.00 ± 1.00 mS/cm to 1372.33 ± 0.58 mS/cm. Scanning electron microscopy analysis confirmed that PUL improved the spinnability of COL, and smooth, defect-free COL/PUL ultra-thin fibers with diameters of 215.32 ± 40.56 nm and 240.97 ± 53.93 nm were successfully prepared at a viscosity of greater than 1.18 Pa∙s. As the proportion of PUL increased, intramolecular hydrogen bonds became the dominant interaction between COL and PUL. The intermolecular hydrogen bonding content decreased from 52.05 % to 36.45 %, and the intramolecular hydrogen bonding content increased from 46.11 % to 62.95 %. The COL was gradually unfolded, the content of α-helices decreased from 33.57 % to 25.91 % and the random coils increased from 34.22 % to 40.09 %. More than 36 % of the triple helix fraction of COL was retained by the COL/PUL ultra-thin fibers, whereas only 16 % of the triple helix fraction of COL was retained by the COL nanofibers prepared with 2.2.2-trifluoroethanol. These results could serve as a reference for the development of green food COL-based fibers.
胶原静电纺丝纤维是用于食品包装和组织工程的有前景的材料。然而，传统的胶原静电纺丝通常是通过将其溶解在有毒的有机试剂中进行的。在本研究中，以醋酸为溶剂，通过静电纺丝制备了胶原/普鲁兰多糖（COL/PUL）超细纤维。与传统制备方法相比，该方法安全且不会产生有毒溶剂残留。PUL的引入增加了溶液中的分子缠结程度，因此COL/PUL静电纺丝溶液的粘度从0.50±0.01 Pa∙s增加到4.40±0.08 Pa∙s，电导率从1954.00±1.00 mS/cm降低到1372.33±0.58 mS/cm。扫描电子显微镜分析证实，PUL提高了COL的可纺性，在粘度大于1.18 Pa∙s时成功制备了直径为215.32±40.56 nm和240.97±53.93 nm的光滑、无缺陷的COL/PUL超细纤维。随着PUL比例的增加，分子内氢键成为COL与PUL之间的主要相互作用。分子间氢键含量从52.05%降至36.45%，分子内氢键含量从46.11%增至62.95%。COL逐渐展开，α-螺旋含量从33.57%降至25.91%，无规卷曲从34.22%增至40.09%。COL/PUL超细纤维保留了超过36%的COL三螺旋部分，而用2,2,2-三氟乙醇制备的COL纳米纤维仅保留了16%的COL三螺旋部分。这些结果可为基于COL的绿色食品纤维的开发提供参考。
