Sustainable products and materials, VTT, Technical Research Centre of Finland, Tietotie 2, FI-02044 Espoo, Finland.
School of Chemical Engineering, Department of Bioproducts and Biosystems, Aalto University, 02150 Espoo, Finland.
Langmuir. 2022 Aug 16;38(32):9917-9927. doi: 10.1021/acs.langmuir.2c01140. Epub 2022 Aug 5.
Keratin is a potential raw material to meet the growing demand for bio-based materials with special properties. Keratin can be obtained from feathers, a by-product from the poultry industry. One approach for keratin valorization is to use the protein to improve the properties of already existing cellulose and lignin-based materials to meet the requirements for replacing fossil-based plastics. To ensure a successful combination of keratin with lignocellulosic building blocks, keratin must have an affinity to these substrates. Hence, we used quartz crystal microbalance with a dissipation monitoring (QCM-D) technique to get a detailed understanding of the adsorption of keratin peptides onto lignocellulosic substrates and how the morphology of the substrate, pH, ionic strength, and keratin properties affected the adsorption. Keratin was fractionated from feathers with a scalable and environmentally friendly deep eutectic solvent process. The keratin fraction used in the adsorption studies consisted of different sized keratin peptides (about 1-4 kDa), which had adopted a random coil conformation as observed by circular dichroism (CD). Measuring keratin adsorption to different lignocellulosic substrates by QCM-D revealed a significant affinity of keratin peptides for lignin, both as smooth films and in the form of nanoparticles but only a weak interaction between cellulose and keratin. Systematic evaluation of the effect of surface, media, and protein properties enabled us to obtain a deeper understanding of the driving force for adsorption. Both the structure and size of the keratin peptides appeared to play an important role in its adsorption. The keratin-lignin combination is an attractive option for advanced material applications. For improved adsorption on cellulose, modifications of either keratin or cellulose would be required.
角蛋白是一种有潜力的原料，可以满足对具有特殊性能的生物基材料不断增长的需求。角蛋白可以从羽毛中获得，这是家禽业的一种副产品。角蛋白增值的一种方法是利用该蛋白质来改善已经存在的纤维素和木质素基材料的性能，以满足替代基于化石的塑料的要求。为了确保角蛋白与木质纤维素建筑模块成功结合，角蛋白必须对这些基质具有亲和力。因此，我们使用石英晶体微天平（QCM-D）技术来详细了解角蛋白肽在木质纤维素基质上的吸附情况，以及基质的形态、pH 值、离子强度和角蛋白性质如何影响吸附。角蛋白是通过一种可扩展且环保的深共晶溶剂工艺从羽毛中分离出来的。用于吸附研究的角蛋白部分由不同大小的角蛋白肽（约 1-4 kDa）组成，这些肽已经采用了无规卷曲构象，如圆二色性（CD）所观察到的。通过 QCM-D 测量角蛋白对不同木质纤维素基质的吸附，发现角蛋白肽对木质素具有显著的亲和力，无论是作为光滑薄膜还是纳米颗粒形式，但纤维素与角蛋白之间只有较弱的相互作用。系统地评估表面、介质和蛋白质性质的影响，使我们能够更深入地了解吸附的驱动力。角蛋白肽的结构和大小似乎都对角蛋白的吸附起着重要作用。角蛋白-木质素的组合是高级材料应用的一个有吸引力的选择。为了在纤维素上提高吸附，需要对角蛋白或纤维素进行修饰。
