Penicillin streptomycin antibiotics ps

The compounds 4,5-Benzoindotricarbocyanine (indocyanine green; ICG; C₄₃H₄₇N₂NaO₆S₂; MW = 775 g∙mol⁻¹) and 4′-demethylepipodophyllotoxin-9-(4,6-o-ethylidene-b-d-glucopyranoside) (etoposide; VP-16; C₂₉H₃₂O₁₃; MW = 588.6 g∙mol⁻¹) were purchased from Sigma-Aldrich (Sigma-Aldrich Canada Ltd., Oakville, ON, Canada) and used without any further purification. Stock solution of 5 mM ICG was prepared in ultrapure water (Barnstead Nanopure, Thermo Scientific, Dubuque, IA, USA) and stored in dark at −20 °C. Stock solution of 50 mM VP-16 was made in dimethyl sulfoxide (DMSO) and stored at −20 °C.
The human non-small-cell lung cancer cell line (A549, ATCC#: CCL-185™) was obtained from American Type Culture Collection (ATCC, Manassas, VA, USA). Nutrient mixture F12 Ham Kaighn’s modification (F12K), trypsin-EDTA (0.5 g/L porcine trypsin and 0.2 g/L EDTA $·4$ Na in Hank’s Balanced Salt Solution with phenol red), and penicillin streptomycin antibiotics (PS) were purchased from Sigma-Aldrich (Sigma-Aldrich Canada Ltd., Oakville, ON, Canada), and fetal bovine serum (FBS) was purchased from Hyclone Laboratories (Logan, UT, USA). A549 cells were cultivated in F12K supplemented with 10% FBS, 100 units/mL penicillin G and 100 μg/mL streptomycin. The cell culture was kept at 37 °C in a humidified atmosphere containing 5% CO₂.

Human umbilical vein endothelial cells (HUVECs) (ATCC, Rockville, MD, USA) were cultured in a complete culture medium made of Dulbecco’s modified Eagle’s medium (DMEM, Gibco), 10% hypoxanthine-aminopterin-thymidine (HAT, Gibco), 10% fetal bovine serum (FBS, Gibco), and 1% penicillin-streptomycin antibiotics (PS, Sigma-Aldrich) [33 (link)]. After the cells covered the culture flask (80% confluency), cell subculture was performed. Cells were detached using 0.025% trypsin treatment for 2 min. Trypsin then was neutralized by the complete culture medium (containing FBS). The dissociated cell suspension was centrifuged at 1200 rpm at 4 °C for 5 min. The supernatant was removed, and the pellet was cultured again. Passage IV cells were used for 3D bioprinting.