Apostrand elisa apoptosis kit

Apoptosis was assessed using the Apostrand Elisa apoptosis kit (Enzo, Switzerland). This kit assays the sensitivity of DNA in apoptotic cells to formamide denaturation, and this was performed with the aid of a monoclonal antibody to single strand DNA. Approximately 5000 cells were seeded in each well of a 96 well plate. After 24 h, different concentrations of SFCP microparticles were added to each well. The cells were incubated with 10, 25, 50, 100, and 200 µg/mL SFCP microparticles for 24, 48, and 72 h, respectively. Cells were cultured in carboplatin (100 µg/mL) as the positive control, whilst only culture media were added as the negative control. The absorbance at 450 nm was recorded with the aid of a microplate reader and the IC₅₀ was calculated with the aid of the graphpad prism statistical tool version 8.

The cocoons of the silk fibroin from the Bombyx mori silk worms were obtained from North Cyprus. The Apostrand Elisa apoptosis kit (Enzo, Switzerland), MCF-7 breast cancer cells (ATCC® HTB-22™, Manassas, Virginia, US), 10% fetal bovine serum (FBS Thermofisher, Grand island, Newyork, US), 1% penicillin/streptomycin (Thermofisher, Grand island, US), insulin in DMEM/F12 (Thermofisher US), carboplatin (C₆H₁₂N₂O₄Pt, Sigma Aldrich, Schnelldorf, Germany), sodium carbonate (Na₂CO₃, Sigma Aldrich, Germany), calcium chloride (CaCl₂, Sigma Aldrich, Germany), ethanol (C₂H₅OH, Sigma Aldrich, Germany), and dialysis membrane (cut off MW 12,400) with a full average diameter of 16 mm, a flat width of 25 mm, and a capacity of 60 mL/ft were purchased from Sigma Aldrich, Germany. All other reagents were of analytical grade and also purchased from Sigma Aldrich, Germany.