Poly(tetrahydrofuran) (PTHF) with a weight-average molar mass (Mw) of 650 g mol -1 (PTHF 650) was acquired from BASF (Germany), under the brand name PolyTHF®. Betulin (98%) was purchased from NST-Chemicals (USA). PHO was kindly bioproduced and supplied by the University of Dublin in the frame of MIX-UP Project (Horizon 2020 research and innovation program under grant agreement No 870294). PHO was bioproduced according to the protocol given by Cerrone et al. .