The average particle diameter, particle size distribution, and surface charge were determined by dynamic light scattering (DLS) technique using a Zetasizer Nano ZS (Malvern, UK).23 (link) The morphology and size of the particles were observed using JEM-1010 transmission electron microscopy (JEOL, Tokyo, Japan). The encapsulation capacity of LPNs was determined by measuring the concentrations of CBP and PTX using a C-18 reverse-phase high-performance liquid chromatography (RP-HPLC) (Beckman Coulter, Brea, CA) at a flow rate of 1 mL/min.24 (link) Tert-butyl methyl ether (5 mL) was added to the LPNs suspension and vortex for 1 min to extract the drugs and then redissolved in acetonitrile:water (10:90) solution. The solution (1 mL) was injected into the C-18 column, and CPT and PTX were detected at 227 nm after different retention times. The amounts of CBP and PTX were quantified by HPLC. The encapsulation efficiency (EE) was determined as: (Amount of entrapped drug/amount of total drug) × 100%.