In vivo animal study

All of the animal experiments were approved by the National Defense Medical Center’s Institutional Animal Care and Use Committee (Certificate no. IACUC-16-280) in accordance with the ethics standards of the responsible committee. The mice were grouped and housed in polypropylene cages (n = 5 per cage). The vivarium was maintained on a 12 h light:12 h dark cycle, at room temperature (22 ± 1 °C) under relative humidity level of 50 ± 5% with food (laboratory rodent diet, labdiet 5001, USA) and water ad libitum.

Seven-week-old mice (C57BL6/J, male) were used in the subcutaneous injection studies. At the beginning of the experiments, the mice were weighted (avg. 23.8 g/mice) and underwent hair removal in the dorsal area. Anesthesia was performed via intraperitoneal (IP) injection with 40–80 μL of Zoletil 50 to reduce pain. The durability and anti-adhesion performance of the needles was evaluated by performing 20 hypodermic injections on each mouse. The ten mice used in this study were divided into two groups: (1) control group: hypodermic injections administered using bare 23 G needles, (2) experiment group: hypodermic injections were administered using TFMG-coated 23 G needles.