5 fluorouracil

Chitosan-covered magnetic nanoparticles were utilized to expand the deliverance of 5-fluorouracil [4 (link)]. Chitosan (243 kDa, DA: 87%), 3,7-dimethyl-2,6-octadienal (95%), 5-fluorouracil (purity: 99%), and phosphate tampon solution with a pH of 7.4 were purchased from Aldrich Chemical Co Inc. and brought to the required standard quality. All other reagents were of analytical grade.

LCA (cat # L6250; Sigma-Aldrich, St. Louis, MI, USA) was dissolved in DMSO at a stock concentration of 100 mM. LCA was used at a concentration of 0.03 µM, corresponding to normal human serum concentration [7 (link), 47 , 48 (link)]. Non-treated cells received 0.001% DMSO in the medium as a vehicle. Glutathione (GSH; cat # G4251; Sigma-Aldrich) was used at a final concentration of 5 mM. Pegylated catalase (pegCAT; cat # C4963; Sigma-Aldrich) was used at a concentration of 500 U/ml. BA receptor antagonists (NF449 [95 (link)], CINPA1 [96 (link)], DY268 [97 (link)], and GSK2033 [98 (link)]) were acquired from Tocris Bioscience (Bristol, UK), and ketoconazole [99 (link)] was purchased from Sigma-Aldrich. NF449 (G_sα-selective antagonist; 5 µM) was used to inhibit TGR5 signaling. Nuclear receptor activation was inhibited using 5 µM CINPA1 (CAR antagonist), DY268 (FXR antagonist), and GSK2033 (LXR antagonist). PXR downstream signaling was inhibited using ketoconazole (5 μM). Chemotherapy drugs (irinotecan, paclitaxel, gemcitabine, 5-fluorouracil and oxaliplatin) were purchased from Sigma-Aldrich. Silencer Select siRNAs targeting TGR5 (GPBAR1-siRNA ID: s195791), VDR (NR1I1- siRNA ID: s14777), and FXR (NR1H4-siRNA ID: s19371), and the negative control siRNA #1 (cat # 4390843) were purchased from Thermo Fisher Scientific (Waltham, MA, USA) and used at a final concentration of 30 nM.

Polycaprolactone powder (MW 50000 Daltons; Tm = 58°C; PCL) was supplied by Polysciences Inc. The low molecular weight chitosan powder (deacetylation degree ≥ 75%; Tm = 102.5°C; CS) and the 5-Fluorouracil (MW 130.08 g/mol; sparingly soluble in water <1 mg/ml; ≥ 99% HPLC; Tm = 282°C; 5-FU) were purchased from Sigma-Aldrich.

Sulforaphane (Cayman Chemical, Ann Arbor, Michigan, United States) was purchased as a solution in ethanol with purity ≥ 98% and stored at −20 °C. Cisplatin (Cayman Chemical) was prepared in phosphate-buffered saline (PBS) to a 0.3 mg/ml stock and was kept protected from light at 4 °C. 5-Fluorouracil (Sigma Aldrich, St. Louis, Missouri, United States) was prepared in dimethyl sulfoxide (DMSO) to 50 mg/ml stock. The final concentrations of the solvents, either PBS or DMSO, in the working solution medium were 0.1% or less.