The use of nanoscale materials provides a promising opportunity for advancement in different applications, most especially for coatings and wearable technology. Biological and nanoscale composites nanostructured coatings are a promising approach for fabricating thin films with enhanced corrosion resistance, durability and self-cleaning, amongst others. Their applications have been demonstrated to prolong the lifespan and performance of surfaces, offering a sustainable approach for multifunctional applications. Additionally, the application of bionanocomposites for wearable textiles presents a unique opportunity to achieve durability, comfort, breathability, conductivity and a moisture-wicking effect besides their excellent biocompatibility. These properties expand the applications of bio-nanocomposite materials in rehabilitation, sports, fashion and healthcare. Despite the wide applications, their safety in humans and the environment is not well understood, hence the need for a critical assessment of the safety and consumer acceptance of bionanocomposite-based nanostructured coatings and wearable textiles, consistent with the UNDP SDGs. In this chapter, we discuss the different types of bionanocomposites used for nanostructured coatings and wearable textile applications, properties and mechanisms for enhancing the performance and functionality of surfaces and wearable textiles. We further discuss the possible safety issues with the application of bionanocomposite materials to understand the regulatory, scalability, user experience and integration issues in textile electronics. The chapter finally concludes with some insights into promising areas for future wearable e-textile applications and nanostructured coatings for limited environmental impact.