Jaiswal Devina, James Roshan, Shelke Namdev B, Harmon Matthew D, Brown Justin L, Hussain Fazle, Kumbar Sangamesh G
J Biomed Nanotechnol. 2015 Nov;11(11):2067-80. doi: 10.1166/jbn.2015.2100.
Electrospinning of water-soluble polymers and retaining their mechanical strength and bioactivity remain challenging. Volatile organic solvent soluble polymers and their derivatives are preferred for fabricating electrospun nanofibers. We report the synthesis and characterization of 2-nitrobenzyl-gelatin (N-Gelatin)--a novel gelatin Schiff base derivative--and the resulting electrospun nanofiber matrices. The 2-nitrobenzyl group is a photoactivatable-caged compound and can be cleaved from the gelatin nanofiber matrices following UV exposure. Such hydrophobic modification allowed the fabrication of gelatin and blend nanofibers with poly(caprolactone) (PCL) having significantly improved tensile properties. Neat gelatin and their PCL blend nanofiber matrices showed a modulus of 9.08 ± 1.5 MPa and 27.61 ± 4.3 MPa, respectively while the modified gelatin and their blends showed 15.63 ± 2.8 MPa and 24.47 ± 8.7 MPa, respectively. The characteristic infrared spectroscopy band for gelatin Schiff base derivative at 1560 cm(-1) disappeared following exposure to UV light indicating the regeneration of free NH2 group and gelatin. These nanofiber matrices supported cell attachment and proliferation with a well spread morphology as evidenced through cell proliferation assay and microscopic techniques. Modified gelatin fiber matrices showed a 73% enhanced cell attachment and proliferation rate compared to pure gelatin. This polymer modification methodology may offer a promising way to fabricate electrospun nanofiber matrices using a variety of proteins and peptides without loss of bioactivity and mechanical strength.
水溶性聚合物的静电纺丝并保持其机械强度和生物活性仍然具有挑战性。挥发性有机溶剂可溶性聚合物及其衍生物是制备静电纺纳米纤维的优选材料。我们报道了2-硝基苄基-明胶（N-明胶）——一种新型明胶席夫碱衍生物——的合成与表征以及由此得到的静电纺纳米纤维基质。2-硝基苄基是一种光可活化的笼形化合物，在紫外线照射后可从明胶纳米纤维基质上裂解下来。这种疏水改性使得能够制备出具有显著改善拉伸性能的明胶与聚己内酯（PCL）的共混纳米纤维。纯明胶及其PCL共混纳米纤维基质的模量分别为9.08±1.5兆帕和27.61±4.3兆帕，而改性明胶及其共混物的模量分别为15.63±2.8兆帕和24.47±8.7兆帕。明胶席夫碱衍生物在1560厘米-1处的特征红外光谱带在紫外线照射后消失，表明游离氨基和明胶得以再生。通过细胞增殖试验和显微镜技术证明，这些纳米纤维基质支持细胞附着和增殖，细胞形态良好且铺展。与纯明胶相比，改性明胶纤维基质的细胞附着和增殖率提高了73%。这种聚合物改性方法可能为使用多种蛋白质和肽制备静电纺纳米纤维基质提供一种有前景的方法，同时不会损失生物活性和机械强度。
