Review and comparative analysis of keratin biocomposites with composites based on collagen

Keratin and collagen are ones of the most abundant proteins which can be used in a variety of biomedical application due to their biocompatibility and biodegradability. Even though, keratin and collagen biomaterials are very high potential for tissue engineering applications. But, the major disadvantages of the natural biomolecules are their poor mechanical properties. Therefore it must be modified or combined with synthetic polymers. More of the synthetic polymers have good mechanical properties and thermal stability and numerous studies of biocomposites based on collagen or keratin and synthetic polymers are performed. The polyurethanes (PUs) are considered the most promising class of synthetic polymers for in vivo studies, and fulfill all the criteria for application to medical practice. Keratin biomaterials have many various advantages over conventional biomolecules, including unique chemical properties due to the high content of sulfur in their structure, high biocompatibility, having aptitude to intracellular recognition and tendency to self-configure. There have been a lot of studies for the composites based on the keratin and one of the following synthetic polymers: poly(ethylene-oxide) (PEO), polyamide (PA6); poly(vinyl alcohol) (PVA), poly(methylmethacrylate) (PMMA), poly(L-lactic acid) (PLLA), etc., with the application in tissue engineering and drug delivery, in the form of gels, sponges, foams, films, fibers, mats and others. In the literature, however, no investigations for the composites based keratin/polyurethane for biomedical applications.