Recombinant Supercharged Polypeptide Fusions for the Hydrophilic Finishing of PET Textiles

Textile processing has had a negative impact on the environment in past decades, e.g., due to the usage of toxic chemicals and high amounts of contaminated wastewater. Therefore, the demand for bio-based and eco-friendly textile processing has strongly increased in the past few years. Polyethylene terephthalate (PET) is the most commonly used polymer in the clothing and technical textile sectors due to its excellent chemical and physical properties (e.g., low weight while being mechanically durable). However, its intrinsic hydrophobicity requires harsh pretreatment and processing before being fully usable as a product in the field of clothing and sportswear. To overcome these issues, we present a protein-based finish that improves the hydrophilicity of PET fabrics, thus improving the comfortability and suitability of PET fibers in sportswear. Fusion proteins consisting of a material binding anchor peptide (AP) and a functional moiety consisting of supercharged unfolded polypeptides (SUPs) were genetically engineered. The protein was produced in an easy, one-step, and scalable recombinant expression. Functionalization of PET with the AP-SUP fusion protein was achieved through dip coating in aqueous solution at room temperature, offering an energy efficient and resource saving textile finishing process that is compatible with existing machinery in the textile finishing industry. We successfully demonstrated that our ultrathin AP-SUP finish hydrophilized the textile surface, improved moisture management, and remained on the PET surface after washing.