Kleanthis was born in Thessaloniki, Greece, where he studied and obtained his undergraduate degree in Food Science. He also holds an MSc degree in Food Safety with a specialization in Toxicology. Having studied in Greece, the Netherlands and the UK, he then moved to Switzerland to join AMI's BioNanomaterials group as a PhD student. He is working on a National Research Project entitled “Biomedical Nanoparticles as Immune Modulators”, which belongs to the NRP-64 Program, funded by the Swiss National Science Foundation. His work focuses on nanoparticle–human immune cell interactions.