The Development of Squid Ink Melanin Nanoparticles as a Multifunctional Colorant Anchored on Hair Fibers: Preparation, Physicochemical Characterization and Dyeing Performance

This study explores the use of discarded squid ink to create high-performance, bio-based hair colorants. Squid ink melanin nanoparticles (SIMNPs) were developed using ultrasound disruption and enzymatic hydrolysis, resulting in particles with improved solubility and reduced steric limitations. To enhance binding to hair, Fe(III) ions were used as supramolecular bridges. The dyeing process, optimized at pH 8.0, 45 °C, and 80 minutes, produced a stable deep black color that remained vibrant after 13 washes. Unlike traditional dyes, this method preserves hair's natural structure and offers UV protection. Safety evaluations showed no adverse effects, highlighting the potential of SIMNPs as a safe, sustainable alternative to conventional hair dyes.