Preparation Of Polyurethane /keratin Nanofibers And Their Properties

Keratin is a natural protein derived from hair, wool, horns, hooves or nails, with characteristics of non-immunogenic, biocompatible, biodegradable and so on. Keratin has an important application in tissue engineering scaffolds, drug delivery and other areas. Recently, foreign researchers have carried out a lot of wool keratin biomaterials based on fundamental research and application development, such as keratin nanofiber material, keratin membrane materials. However, the researchers found that keratin nanofibers are mechanically weak, so we always use keratin composite with other polymer materials to strengthen the mechanical properties.Due to the above problems, we present the first fabrication of wool based polyurethane/keratin nanofibers by electrospinning. We first tried two methods to extract keratin, include reduction and oxidation process. These two types of keratin material called kerateine and keratose. We studied microstructure of different ratios keratin/polyurethane nanofibers, physical and chemical properties of nanofiber and their influence to cell compatibility. Observed under SEM found that the higher the keratin contents, nanofiber diameter became more fine; the contact angle test found that the higher protein contents, nanofiber’s hydrophilicity is higher, the smaller the contact angle is. Their mechanical properties of material study found that keratin contents is higher, the mechanical properties is worse. Therefore, the addition of PU effectively improve the mechanical properties of nanofiber; FTIR study shows protein material components did not happen chemical reaction; XRD study found that, protein and PU composite membrane does not exist crystal structure; The higher protein contents, the greater the porosity, and kerateine nanofiber porosity higher than that of keratose. Cell proliferation experiment study found that the polyurethane/keratin composite nanofibers membrane can effectively increase the speed of cell proliferation, and SEM observation showed that cells on the composite nanofibers can growth in good condition.In addition, in view of kerateine and keratose are soluble in water, we respectively using 75% alcohol solution and 25% glutaraldehyde steam crosslinking methods for keratin modification. The results show that the modified keratin secondary conformation changed, thermal degradation performance has no obvious change. FTIR spectra analysis found that alcohol solution immerse and glutaraldehyde crosslinking effectively change the secondary conformation of keratin; Thermogravimetric curve can be seen that thermal degradation of keratin must be changed; Finally, through the study of keratin degradation experiment we found that glutaraldehyde steam crosslinking prompt kerateine successful with good water insoluble.