Collagen is one of the most important biomaterials for biomedical applications due to its excellent biocompatibility. To produce mechanically and biologically stable collagen multifilament yarns for biomimetic implants, a wet-spinning process has been developed. This method utilizes the intrinsic self-assembly and fibrillogenesis of collagen, which are essential for mechanical stability and elasticity. The process is strongly influenced by pH, osmotic pressure and temperature, and precise control over these parameters, particularly pH and salt concentration, enhances fiber properties, process stability, and scalability, facilitating industrial production. The developed structural protein processing method, using collagen as a model protein, is transferable to other structural proteins such as keratin and silk. These materials offer high biocompatibility, broad availability, and biodegradability, making them promising candidates for sustainable biomaterials in both biomedical and technical applications. Additionally, the environmental sustainability of the spinning process is significantly improved by eliminating toxic chemicals. This enables the eco-friendly production of high-performance biomaterials with a reduced environmental footprint.