Novel thymoquinone lipidic core nanocapsules with anisamide-polymethacrylate shell for colon cancer cells overexpressing sigma receptors.

The biggest challenge in colorectal cancer therapy is to avoid intestinal drug absorption before reaching the colon, while focusing on tumor specific delivery with high local concentration and minimal toxicity. In our work, thymoquinone (TQ)-loaded polymeric nanocapsules were prepared using the nanoprecipitation technique using Eudragit S100 as polymeric shell. Conjugation of anisamide as a targeting ligand for sigma receptors overexpressed by colon cancer cells to Eudragit S100 was carried out via carbodiimide coupling reaction, and was confirmed by thin layer chromatography and 1H-NMR. TQ nanocapsules were characterized for particle size, surface morphology, zeta potential, entrapment efficiency % (EE%), in vitro drug release and physical stability. A cytotoxicity study on three colon cancer cell lines (HT-29, HCT-116, Caco-2) was performed. Results revealed that the polymeric nanocapsules were successfully prepared, and the in vitro characterization showed a suitable size, zeta potential, EE% and physical stability. TQ exhibited a delayed release pattern from the nanocapsules in vitro. Anisamide-targeted TQ nanocapsules showed higher cytotoxicity against HT-29 cells overexpressing sigma receptors compared to their non-targeted counterparts and free TQ after incubation for 48 h, hence delineating anisamide as a promising ligand for active colon cancer targeting.

Cancer nanotheranostics: A review of the role of conjugated ligands for overexpressed receptors.

Cancer treatment using chemotherapy has many drawbacks because of its non-specificity, in which the chemotherapeutic agent attacks both normal and cancerous cells, leading to severe damage to the normal cells, especially rapidly proliferating ones. Cancer targeting enables the drug to kill only tumor cells without adversely affecting healthy tissues, which leads to the improvement of the patient's well-being. Nanoparticles offer several advantages in drug delivery such as enhancing the solubility of hydrophobic drugs, sustaining their release and prolonging their circulation time. The ability of nanoparticles to specifically target tumor cells makes them a useful delivery system for anticancer agents. The type of the delivery system and formulation additives used can also improve the delivery of the anticancer agent. This review highlights some of the most highly sought receptors to be targeted in selective cancer treatment. It also reports some of the recent advances in cancer targeting using drug-loaded ligand-conjugated nanocarriers.