Targeted co-delivery of curcumin and doxorubicin by citric acid functionalized Poly (ε-caprolactone) based micelle in...

This study aimed to design an effective targeted combination of doxorubicin (Dox)-Curcumin (Cur) delivery system to eradicate the MDA-MB231 cell line. A novel biodegradable poly ε-Caprolactone-co-maleic anhydride-graft-citric acid copolymer micelle (PCL-co-P(MA-g-CA)) was synthesized through thiolen radical copolymerization and ring-opening polymerization. The unique micelle structure allowed simultaneous loading of hydrophilic Dox and hydrophobic Cur with a loading efficiency of above 98 % for each drug. The physicochemical characterization of copolymeric micelle was analyzed by ¹HNMR, ¹³CNMR, FTIR, DSC, CMC, DLS and SEM. The in vitro cytotoxicity was assessed by MTT assay, cell cycle analysis, annexin V-FITC apoptosis, qRT-PCR and western blot. The final obtained micelles with critical micelle concentration (CMC) of 0.5 μg/mL, and particle size and surface charge was 60 nm and -14.1 mV, respectively. Beside the fast uptake of designed micelle, Dox@Cur loaded micelle showed a synergistic effect with the combination index (CI) value of below 1. Our results revealed that this novel engineered combinatorial micelle induced apoptosis (96 %) which was proved by annexin V and cell cycle. qRT-PCR and western blot assays demonstrated involvement of intrinsic apoptosis pathways in the genetic and protein levels. Finally, the penetration of Dox@Cur loaded micelle was evaluated by 3D in vitro tumor formation. Our findings showed the penetration behavior of micelles is in a concentration-dependent manner. In conclusion, combinational therapy by using Dox and Cur nano-formulation has boosted the cytotoxicity in MDA-MB231 cells by promoting the apoptotic response.