Development and Characterization of Curcumin-Loaded TPGS/F127/P123 Polymeric Micelles as a Potential Therapy for Colorectal Cancer

Colorectal cancer (CRC) is the third most prominent cancer worldwide, and the second leading cause of cancer death. Poor outcomes and limitations of current treatments fuel the search for new therapeutic options. Curcumin (CUR) is often presented as a safer alternative for cancer treatment with a staggering number of molecular targets involved in tumor initiation, promotion, and progression. Despite being promising, its therapeutic potential is hindered due to its hydrophobic nature. Hence, the ongoing development of optimal delivery strategies based on nanotechnology, such as polymeric micelles (PMs), to overcome issues in CUR solubilization and delivery to tumor cells. In this sense, this study aimed to optimize the development and stability of CUR-loaded P123:F127:TPGS PMs (PFT:CUR) based on the thin-film approach and evaluate their therapeutic potential in CRC. Overall, the results revealed that the solubility of CUR was improved when room temperature was used to hydrate the film. The PFT-CUR hydrated at room temperature presents an average hydrodynamic diameter of 15.9 ± 0.3 nm with a polydispersity index (PDI) of 0.251 ± 0.103 and a zeta potential of -1.5 ± 1.9 mV, and a 35.083 ± 1.144 encapsulation efficiency (EE%) and 3.217 ± 0.091 drug loading (DL%) were observed. To ensure the stability of the optimized PFT-CUR nanosystems, different lyophilization protocols were tested, the use of 1% of glycine (GLY) being the most promising protocol. Regarding the critical micellar concentration (CMC), it was shown that the cryoprotectant and the lyophilization process could impact it, with an increase from 0.064 mg/mL to 0.119 mg/mL. In vitro results showed greater cytotoxic effects when CUR was encapsulated compared to its free form, yet further analysis revealed the heightened cytotoxicity could be attributed to the system itself. Despite challenges, the developed CUR-loaded PM shows potential as an effective therapeutic agent for CRC. Nonetheless, the system must undergo refinements to enhance drug entrapment as well as improve overall stability.