Advanced technological processes for recycling of waste keratin biomass and development of novel keratin based functional bio-products

The main objective of the project is to develop sustainable integrated process for the production of functional medical devices and materials (wound dressings, dermal and epidermal substitutes for the use in skin wound healing) from natural building blocks isolated from waste biomass. New advanced circular processes, which primarily address problematic material streams (feathers, wool) that are produced in considerable amounts and are currently not utilised though being rich in valuable polymer keratin will be established. A protein keratin has an extraordinary commercial potential for bio‐based medical applications, including for wound healing, bio‐films prevention, medical membranes and filters, bone grafting, injectable gels, and drug delivery. However, until now there are only very few applications based on recycled keratin owing to harmful, expensive, nonreusable, time-consuming and difficult to handle technologies for recycling of keratin from biomasses. Moreover, by using existing conventional technologies, keratin is mostly extracted in low yields, with limited solubility, purity and with decreased molecular weights, which significantly limits its wider use. The bioactivity and biocompatibility of keratin are namely greatly reduced by decreasing the molecular weight, besides it is difficult to form nanofibers when the molecular weight is too low. In the project, an innovative integrated process will be developed that will consist of several stages: i) isolation of keratin from feathers and wool waste, ii) copolymerization of isolated keratin with other functional bio-polymers, and iii) preparation of nanofibrous structures. In the isolation step for the extraction of keratin new suistainable technology using sub- critical water, i.e. hydrothermal process, which will preserve the molecular weight and functionality of keratin will be developed. In the next step the isolated keratin will be copolymerized with biopolymers under conditions suitable for the preparation of colloidal solutions / suspensions of applicable viscosities. In the last step, the nanofibrous structures will be prepared from isolated keratin and keratin-based copolymers, as well as with addition of natural polyphenols by needleless electrospinning to produce advanced generation of medical devices with excellent antibacterial and antioxidant properties. To provide an optimal platform for the development of innovative medical devices and materials, qualitative and quantitative correlations between fiber characteristics (size/diameter, morphology, bioactivity) and the processing parameters (for all processes, from hydrothermal process, copolymerization and electrospinning) will be studied. Finally, a multicriteria optimization analysis of technologies in each processing step while considering economics, environmental impacts, energy consumption, investments and product quality will be performed and integrated process flow sheet will be designed. The project shows high transdisciplinary and complementary approach in the areas of Chemical engineering, Textile engineering and Environmental engineering. It will significantly contribute to the: - bio-waste reduction, strengthening “zero waste” concepts and establishing new advanced circular economy concepts; - environmental engineering through the development of green technologies for recycling of bio-waste and production of new functional bio-materials for smart medical devices; - new knowledge in the field of bio-polymers and bio-composites and their processability, that is crucial for successful conversion of wastes into uniform, soluble, easily processable, and safe keratin-enriched feedstock, that could be exploited for conversion into a number of high-value bio-materials and bio-products; - it will open new possible areas of application of developed bio-polymers and bio-composites (e.g. in medicine, pharmaceutical, cosmetic, textile, plastic and packaging industries).