Celastrol (Figure 1A) was purchased from the Shanghai Institute of Materia Medica, Chinese Academy of Sciences (Shanghai, People’s Republic of China). The preparation of CNMs was performed as previously described.11 (link) Briefly, PEG-b-PCL (2,000:1,000, Mw/Mn =1.18, JCS Biopolytech, Toronto, Canada; 10 mg) and Celastrol (2 mg) were mixed in chloroform (2 mL) and subsequently added drop-wise to deionized water (20 mL) under ultrasonic agitation using a Type 60 Sonic Dismembrator (Fisher Scientific, Pittsburgh, PA, USA). The organic solvent was then removed through vacuum distillation using a rotary evaporator to enable micelle formation. The samples were further concentrated and washed three times using a Millipore Centrifugal Filter Device (MW cutoff: 10,000 Da; Millipore, Billerica, MA, USA) to remove free Celastrol dissolved in the micelle solution, followed by filtration with a syringe filter (pore size: 0.22 µm) to eliminate large polymers or Celastrol aggregates. A schematic illustration of Celastrol-loaded micelle formation is shown in Figure 1. The blank micelles were prepared using the same preparation conditions and procedure.