Poly(2-ethyl-2-oxazoline)–IR780 conjugate nanoparticles for breast cancer phototherapy - Supplementary dataset

Aims: To address the limitations of IR780 by preparing hydrophilic polymer–IR780 conjugates and to
employ these conjugates in the assembly of nanoparticles (NPs) intended for cancer photothermal
therapy. Materials & methods: The cyclohexenyl ring of IR780 was conjugated for the first time with
thiol-terminated poly(2-ethyl-2-oxazoline) (PEtOx). This novel poly(2-ethyl-2-oxazoline)-IR780 (PEtOx-
IR) conjugate was combined with D-α-tocopheryl succinate (TOS), leading to the assembly of mixed
NPs (PEtOx-IR/TOS NPs). Results: PEtOx-IR/TOS NPs displayed optimal colloidal stability as well as
cytocompatibility in healthy cells at doses within the therapeutic range. In turn, the combination of
PEtOx-IR/TOS NPs and near-infrared light reduced heterotypic breast cancer spheroid viability to just 15%.
Conclusion: PEtOx-IR/TOS NPs are promising agents for breast cancer photothermal therapy.