3 ml syringe

Ethanol was administered intragastrically (i.g.) via a 12-cm length of polyethylene-50 tubing (PE-50 Clay Adams, Parsippany, NJ, USA) attached to a 3 ml syringe (Becton Dickinson, Rutherford, NJ, USA) with a 23-gauge needle. Ethanol doses of 0.5, 1.25, 2.5 and 3.25 g/kg resulted from the administration of a volume equivalent to 0.015 ml per gram of body weight of 4.2% 10.5%, 21%, or 27.3% v/v ethanol (Porta Hnos, Córdoba, Argentina) solutions, respectively. An equivalent volume of tap water was administered as vehicle (0.0 g/kg). All of the animals were gently intubated in approximately 5 s, and the solutions were then slowly delivered over 3–4 s into the stomach. The doses and mode of administration were selected based on previous studies [14 (link),16 (link)].

Upon mixing the silk-HRP hydrogel solution and before setting, a 3 mL syringe (Becton, Dickinson and Company, Franklin Lakes, New Jersey) equipped with either a 16 G or 21 G needle was used to extract the homogenously mixed solution from a 6-well plate. Prior to injection, silicone tubing (Dow Corning Corporation, Midland, MI) was prepared by rinsing, autoclaving and cutting the tubing into 20 cm long pieces. The syringe with the hydrogel solution was degassed and hydrogel solution was injected into 1 mm or 1.98 mm ID silicone tubing that was open at both ends (Figure 1A). Cast tubing was incubated at room temperature for 1 hour during gelation. Following gelation, the tubing was placed in an oven and incubated for 24 hours (1 mm) or 48 hours (1.98 mm) at 60 °C or room temperature (RT) (18–22° C) (Figure 1B). Upon dehydration, the fibers were removed from tubing using a 16 G needle (McMaster-Carr, Robinsville, NJ) and prepared for post-processing (Figure 1C). The 60 °C fibers were removed from tubing after 24 hours and the RT fibers required a week to dry prior to ejection.