This study aimed to synthesize a star-shaped
micelle using 3-azido-2,2-bis(azidomethyl)propan-1-ol (
pentaerythritol triazide) core, as an initiator for the synthesis of three-arm
polylactic acid (PLA) block. Then, the ends of the PLA arms were converted to PLA
triazide followed by conjugation to the three
alkyne-PEG-maleamide through click reaction. The maleamide ends were available for coupling with sulfhydryl-modified
DNA aptamer against
epithelial cell adhesion molecule in order to offer targeted delivery of encapsulated drug,
camptothecin to the site of action. The successful synthesis of the star-shaped
polymers was confirmed via1HNMR. Hydrophobic anti-
cancer drug,
camptothecin was encapsulated into the
micelles core implementing
solvent switching method providing loading content (LC%) and encapsulation efficiency (EE%) of 3.7 ± 0.4 and 73.7 ± 8.2, respectively. The size of both non-targeted and aptamer-targeted
micelles was determined to be 154 and 192 nm, respectively with polydispersity index below 0.3. In vitro drug release evaluation at 37 °C, pH 7.4 showed a controlled release pattern for
camptothecin during 72 h. In vitro cytotoxicity of the prepared non-targeted and targeted
micelles was carried out on human colorectal
adenocarcinoma (HT29) and mouse colon
carcinoma (C26) as
EpCAM positive cell lines and Chinese hamster ovary (CHO) as
EpCAM negative cell line. The results verified significantly higher cytotoxicity of the targeted
micelles on HT29 and C26 cell lines, while no obvious difference was observed between targeted and non-targeted formulation on CHO cell line. The in vivo therapeutic efficiency investigation on BALB/c C26
tumor-bearing mice showed superior capability of the targeted formulation on
tumor suppression and survival rate of the treated mice. The developed platform exhibited excellent characteristics to diminish
camptothecin drawbacks and its adverse effects while considerably increasing its therapeutic index.