Construction of anticancer drug incorporated aptamer-functionalized cationic β-lactoglobulin: induction of cell cycle arrest and apoptosis in colorectal cancer

Nanoscale drug delivery systems that are both multifunctional and targeted have been developed using proteins as a basis, thanks to their attractive biomacromolecule properties. A novel nanocarrier, aptamer (AS1411)-conjugated beta-lactoglobulin/poly-l-lysine (BLG/Ap/PL) nanoparticles, was developed in this study. To this unique formulation, the as-prepared nanocarrier blends the distinctive features of an aptamer as a chemotherapeutic targeting agent with those of protein nanocarriers. By loading cabazitaxel (CTX) onto the nanocarriers, the therapeutic potential of BLG/Ap/PL could be demonstrated. The CTX-loaded BLG/Ap/PL (CTX@BLG/Ap/PL) showed a regulated drug release profile in an acidic milieu, which could improve therapeutic efficacy in cancer cells and have a high drug encapsulation efficacy of up to 93%. However, compared to free CTX, CTX@BLG/Ap/PL killed colorectal HCT116 cancer cells with a higher efficacy at 24 and 48 h. Further investigation confirms the apoptosis by acridine orange and ethidium bromide (AO/EB), and DAPI staining confirms the morphological changes, chromatin condensation, and membrane blebbing in the treated cell through flow cytometry displayed the release of higher percentages of apoptosis. Cell cycle analysis revealed that CTX@BLG/Ap/PL induced sub-G1 and G2/M phase (apoptosis) at 24 and 48 h. Annexin V/propidium iodide (PI) flow cytometry analysis confirmed that CTX@BLG/Ap/PL induces apoptosis in HCT116 cells. Overall, this study proved that CTX@BLG/Ap/PL had several advantages over free chemotherapeutic drugs and showed promise as a solution to the clinical problems associated with targeted antitumor drug delivery systems.