Abstract: The present disclosure refers to a keratin-based substrate, comprising a keratin derivative and natural biopolymer, where the keratin derivative and natural biopolymer are crosslinked. The present disclosure also refers to a method of forming a keratin-based substrate, comprising (i) mixing a solution of keratin derivative with a solution of natural biopolymer; and (ii) drying the resulting solution of step (i) to obtain the keratin-based substrate. The present disclosure further relates to the use of the substrate as a plant growth medium or hydroponic support medium. In a preferred embodiment, a substrate comprising keratin intermediate filament protein and cellulose nanofibers is provided.