Doxorubicin-loaded nanostructured lipid carriers functionalized with folic acid against MCF-7 breast cancer cell line

Doxorubicin (DOX) is used in chemotherapy for the treatment of breast cancer (BC), however with several side effects. Nanostructured lipid carriers (NLCs) were developed from a mixture of surfactants, thermoresponsive and cationic quaternary ammonium, such as pluronic F-127 (PF-127-FA) and cetrimonium bromide (CTAB), respectively, and functionalized with folic acid as a strategy to target BC cells. This research aimed to develop NLC functionalized with folic acid containing DOX, directing its activity against BC cells (MCF-7). The NLCs obtained by the fusion-emulsification technique with (NLC +) and without (NLC-) cetrimonium bromide were developed and characterized to verify the guarantee of cationic or anionic charge. The results of dynamic light scattering sizes and scanning electron microscopy varied between 124 and 180 nm and, spherical morphology. Polydispersity < 0.3, indicating low polydispersity. Zeta potential revealed values between 22 and 13.2 for NLC + and -12.2 and -17 for NLC-. The encapsulation efficiency was 79% and 102% for NLC + and NLC-, respectively. The release profile was 100% after 10 h for DOX-NLC, while commercial DOX ≤ 30 min. Cell viability demonstrates that NLC- has higher cytotoxicity (87%) compared to commercial DOX (54%) (46 µM). NLC + with or without DOX increases greater toxicity (~ 90%). It is possible to conclude that NLCs have characteristics that point them as a potential alternative for preclinical studies in vivo, to elucidate their toxicity and antitumor activities. Graphical Abstract As an alternative for the treatment of breast cancer, nanostructured lipid carriers containing doxorubicin functionalized with folic acid showed promising characteristics, such as high encapsulation index, high cytotoxicity to the target tissue and improved release when compared to commercial DOX.