Striking Effect of Polymer End-Group on C₆₀ Nanoparticle Formation by High Shear Vibrational Milling with Alkyne-Functionalized Poly(2-oxazoline)s

Buckminsterfullerene (C₆₀) has a large potential for biomedical applications. However, the main challenge for the realization of its biomedical application potential is to overcome its extremely low water solubility. One approach is the coformulation with biocompatible water-soluble polymers, such as poly­(2-oxazoline)­s (PAOx), to form water-soluble C₆₀ nanoparticles (NPs). However, uniform and defined NPs have only been obtained via a thin film hydration method or using cyclodextrin-functionalized PAOx. Here, we report the mechanochemical preparation of defined and stable C₆₀:PAOx NPs by the introduction of a simple alkyne group as a polymer end-group. The presence of this alkyne bond is proven to be crucial in the mechanochemical synthesis of stable, defined sub-100 nm C₆₀:PAOx NPs, with high C₆₀ content up to 8.9 wt %.