Amphiphilic carboxylated cellulose-g-poly(l-lactide) copolymer nanoparticles for oleanolic acid delivery

Carboxylated cellulose nanocrystals (CCNs), as one of nanocellulose are promising hydrophilic biomass materials for drug delivery. In this work, a series of amphiphilic carboxylated cellulose-graft-Poly(L-lactide) (CC-g-PLLA) copolymers were synthesized via ring-opening polymerization (ROP) method. The copolymers were characterized by ¹H-NMR, FT-IR, WXRD and TGA, and their solubility in organic solvents was improved. Then, these amphiphilic copolymers were self-assembled into nanoparticles for delivery of anticancer drug oleanolic acid (OA). The copolymer (DS_PLLA 2.03) nanoparticles displayed the smallest size (196.82 ± 9.14 nm) and the highest drug loading efficiency (24.76 ± 0.58%). The nanoparticles exhibited a spherical shape, well water solubility of OA (16.9 mg/mL) and a prolonged drug release (120 h). In vitro and In vivo study indicated that the nanoparticles maintained cytotoxicity to 4T1 cells and MCF-7 cells and displayed high antitumor efficiency. The amphiphilic CC-g-PLLA copolymer nanoparticles provide a novel platform for drug delivery.