A somewhat recent paper from 2019 highlighting halloysite’s potential in biomedicine. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6628522/ And here another pointing to its use in biocompatible implants etc. https://www.sigmaaldrich.com/US/en/technical-documents/technical-article/materials-science-and-engineering/drug-delivery/nanoclay-halloysite-nanotubes