Biodegradable materials based on silk fibroin and keratin
Biodegradable materials based on silk fibroin and keratin
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DOI：
10.1021/bm7012789
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发表时间：
2008-04-01
影响因子：
6.2
通讯作者：
Cavaco-Paulo, Artur
中科院分区：
文献类型：
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作者：
Vasconcelos, Andreia;Freddi, Giuliano;Cavaco-Paulo, Artur
羊毛和丝绸被溶解并用于制备混纺薄膜。提出了两种体系：(1)丝素蛋白与角蛋白水溶液共混膜；(2)丝素蛋白与角蛋白溶于甲酸。水溶液纯膜的FTIR光谱表明，角蛋白二级结构主要由a-螺旋结构和随机螺旋结构组成。纯SF的红外光谱特征是薄膜普遍具有无定形结构（随机线圈结构）。甲酸铸造的纯角蛋白膜显示出β -片的数量增加和角蛋白结构紊乱。SF溶解在甲酸中的FTIR模式是具有普遍的β -片结构的薄膜的特征，β -片晶体嵌入在无定形基体中。共混物的热行为证实了FTIR结果。纯角蛋白的DSC曲线为典型的非晶态角蛋白，纯角蛋白的DSC曲线为水体系a-螺旋的特征熔化峰。由于甲酸能诱导SF结晶并增加角蛋白上β -片结构的数量，在甲酸铸造的薄膜中不再观察到这些模式。从FTIR分析和DSC曲线得到的SF/角蛋白系统的不同参数的非线性趋势表明，当蛋白质混合时，它们不遵循添加剂规则，而是能够建立分子间相互作用。可降解高分子生物材料是医疗应用的首选材料。通过胰蛋白酶体外酶培养研究了SF/角蛋白系统的降解行为。水浇铸的SF/角蛋白膜的生物降解速度比甲酸浇铸的慢。所获得的重量减轻是混合物中角蛋白含量的函数。本研究鼓励进一步研究本文提出的基质类型，以应用于组织工程支架或作为控释药物递送载体。
Wool and silk were dissolved and used for the preparation of blended films. Two systems are proposed: (1) blend films of silk fibroin and keratin aqueous solutions and (2) silk fibroin-and keratin dissolved in formic acid. The FTIR spectra of pure films cast from aqueous solutions indicated that the keratin secondary structure mainly consists of a-helix and random coil conformations. The IR spectrum of pure SF is characteristic of films with prevalently amorphous structure (random coil conformation). Pure keratin film cast from formic acid shows an increase in the amount of beta-sheet and disordered keratin structures. The FTIR pattern of SF dissolved in formic acid is characteristic of films with prevalently beta-sheet conformations with beta-sheet crystallites embedded in an amorphous' matrix. The thermal behavior of the blends confirmed the FTIR results. DSC curve of pure SF is typical of amorphous SF and the curve of pure keratin show the characteristic melting peak of a-helices for the aqueous system. These patterns are no longer observed in the films cast from formic acid due to the ability of formic acid to induce crystallization of SF and to increase the amount of beta-sheet structures on keratin. The nonlinear trend of the different parameters obtained from FTIR analysis and DSC curves of both SF/keratin systems indicate that when proteins are mixed they do not follow additives rules but are able to establish intermolecular interactions. Degradable polymeric biomaterials are preferred candidates for medical applications. It was investigated the degradation behavior of both SF/keratin systems by in vitro enzymatic incubation with trypsin. The SF/keratin films cast from water underwent a slower biological degradation than the films cast from formic acid. The weight loss obtained is a function of the amount of keratin in the blend. This study encourages the further investigation of the type of matrices presented here to be applied whether in scaffolds for tissue engineering or as controlled release drug delivery vehicles.