Sb 12l shaking water bath

The gelation time was determined using the ball drop method [37 ]. First, to ensure homogeneity, 2.25, 2.5, and 3.0 wt% alginate solutions were added to test tubes and placed in a shaking water bath at 37 °C (SB-12L Shaking Water Bath, Benchmark Scientific, Inc., Sayreville, NH, USA) for 50 rpm before the experiment was conducted. In the manufactured compressed sprayer (Figure 7), 2.25, 2.5, and 3.0 wt% alginate solutions and 3.0 wt% CaCl₂ solution were placed, respectively, and directly sprayed onto a steel square tray to check the gelation retention time. A steel square tray was judged to be in a gelled state when it was tilted at an angle of 30 degrees and stopped or remained within about 1.0 cm, depending on whether it was flowing. To determine the gelation time, pH 7.4 phosphate-buffered saline (PBS, Thermo Fisher Scientific Inc., Waltham, MA, USA) was sprayed at 30 min intervals to confirm whether the gel was maintained in a wet surface condition, and it was defined as the time from the moment of spraying to the gelation point.
To analyze the sprayed gelation stability according to the viscosity of the manufactured material, the gelation strength and retention time were measured on a Peltier adjusted to 25 °C using a rheometer (HAAKE™ MARS™, Thermo Fisher Scientific, Karlsruhe, Germany), and all measurements were repeated thrice.