TPGS and CS-Surface-Modified DPPC Liposomes Coloaded with Docetaxel and 5-Fluorouracil: A Potential Avenue for Enhanced Colorectal Cancer Therapy

Colorectal cancer (CRC) continues to be a foremost human health concern globally, with chemotherapy being the cornerstone of the therapy. However, conventional chemotherapy is often hampered by nonspecific targeting, limited efficiency, drug resistance, and undesirable adverse effects. 5-Fluorouracil (5-FU), the primary agent for CRC treatment, has a short duration of action and causes systemic toxicity. Docetaxel (DTX), another chemotherapeutic agent, has shown potential in CRC therapy, but its use is also hindered by poor targeting and resistance. Therefore, advanced drug delivery carriers can enhance their therapeutic efficacy. This combination offers a synergistic effect by targeting multiple pathways concurrently. This study aimed to design and assess dipalmitoylphosphatidylcholine (DPPC) liposomes (LPs) coloaded with DTX and 5-FU, surface-modified with d-α-tocopheryl poly(ethylene glycol) succinate (TPGS-LPs) and chitosan (CS-LPs), as a dual-drug delivery for CRC therapy. Various LPs based on TPGS and CS, containing 5-FU and DTX, were successfully prepared and characterized by dynamic light scattering (DLS), and their entrapment efficiencies (EE%) were determined. The optimized formulations, DTX-TPGS-LPs, 5-FU-TPGS-LPs, and DTX/5-FU-TPGS-LPs, were subjected to in vitro release, cytotoxicity, and apoptosis studies using HT-116 cell lines. The LPs were successfully produced, with sizes ranging from 117.3 ± 2.7 to 205.6 ± 2.3 nm, and achieved EE% over 70% for DTX and 20% for 5-FU. The selected formulations, including DTX-TPGS-LPs, 5-FU-TPGS-LPs, and DTX/5-FU-TPGS-LPs, exhibited spherical morphology and controlled release profiles. Among these, the DTX/5-FU-TPGS-LPs formulation exhibited enhanced cytotoxicity and effectively induced apoptosis in HT-116 cells. These results highlight the potential of DTX/5-FU-TPGS-LPs as an effective dual-drug delivery system for CRC treatment; however, further optimization is required to balance its efficacy and toxicity for clinical application.