Tris hydroxymethylaminomethane acs reagent

The assessment of in vitro degradation of scaffolds was carried out by immersing 0.05 g of scaffold in 10 mL of buffer solution (Tris–HCl). The buffer solution was prepared according to EN ISO 10,993–14:2001. The Tris–HCl solution was prepared by dissolving tris-hydroxymethylaminomethane (ACS reagent, ≥ 99.8%, Sigma-Aldrich, Spain) in water (grade 2) with buffering at pH 7.4 ± 0.1 by 1 mol/L hydrochloric acid (ACS reagent, 37%, Sigma-Aldrich, Spain) at 37 °C. The bioactivity of the samples was studied in simulated body fluid (SBF) at 37 °C, 120 rpm by immersing 0.05 g of scaffold in 10 mL of SBF. Simulated body fluid (SBF) was prepared as described by Kokubo and Takadama^{37 (link)}. For degradation and bioactivity test six samples were collected after 2, 6, 72, 168, 336 and 672 h soaking at 37 °C and 120 rpm, respectively. At each time point, the samples were taken out, rinsed with deionized water and dried in an oven at 120 °C for 24 h. The element concentrations in the immersion solution at different time were analyzed by inductively coupled plasma-mass spectroscopy (ICP-MS 7700x, Agilent, US).

Standards of mycotoxins (AFB₁, ZEA and DON), carbonate–bicarbonate buffer glutaraldehyde solution (Grade II, 25%), glycine, tris (hydroxymethyl) amino-methane (ACS reagent, 99.8 + %) and sodium chloride (ACS reagent,  ≥ 99.0%) were purchased from Sigma–Aldrich (St. Louis, Missouri, USA). Skim milk (BD, Difco™ skim milk, Sparks, NV, USA), Tween 20 (molecular biology grade, Applichem, Darmstadt, Germany), SureBlue™ TMB Microwell peroxidase substrate (1-component) (KPL, Gaithersburg, MA, USA), sulfuric acid (Applichem, 95%–98% pure NF grade, Darmstadt, Germany), pyridine (Wako, Osaka, Japan), methanol (MeOH) (Merck, Darmstadt, Germany) and bovine serum albumin (BSA) (Fluka, St. Louis, USA) were purchased from the mentioned companies. The Micro BCA™ Protein Assay Kit (Thermo Scientific, Rockford, IL, USA) and commercial ELISA Kit for AFB₁, ZEA and DON 2/3 (8335) (NEOGEN, Lansing, MI, USA) were used for protein and mycotoxin determination. Immunoaffinity columns for AFB₁ (NEOGEN, Glasgow, UK) and ZEA (R-BIOPHARM RHÔNE LTD, Glasgow, Scotland) were used to purify mycotoxin from a liquid solution. HPLC-grade acetonitrile (ACN), MeOH and water were purchased from J. T. Baker Inc. (Phillipsburg, NJ, USA). Phosphate-buffered saline (PBS) buffer was purchased from Biosesang Inc. (Seongnam, Republic of Korea).