Pollution by fossil-based plastics is a rapidly growing concern in need of urgent solutions. Bioplastics have been proposed as alternatives, however, their properties limit application. In this thesis, we improved the properties of the bioplastic polylactic acid (PLA) by adding chitin nanocrystals derived from seafood waste. This addition enhanced mechanical and barrier properties without risk to food safety and without affecting the biodegradability of PLA. Additionally, chitin nanocrystals can induce functionality, such as antioxidant activity, to the material. We delved into the envisioned life cycle of this bio-nanocomposite material and highlighted potential improvements from a sustainability point of view. In brief, we anticipate a future in which bio-nanocomposite materials play a pivotal role in creating environmentally friendly food packaging solutions that increase shelf-life.