Metallic glass coating for improved needle tattooing performance in reducing trauma: analysis on porcine and pig skins

This paper reports coating tattoo needles with metallic glass (MG) to reduce skin trauma. Experiments on pork samples and live pigs showed beneficial effects of non-stick MG coatings. After 30 insertions into pork skin, significantly less tissue adhered to MG-coated needles than to uncoated needles. MG-coated needles reduced the spread of pigment across surrounding skin by up to 57%, producing narrower, denser tattoo lines that could benefit high-resolution tattooing. Histopathology in live pigs revealed severe trauma with bare needles, including immediate fluid secretions; wounds from coated needles closed within 2 h, whereas those from bare needles remained open for at least 2 h and showed inflammation after 3 days. At 5 days, skin punctured by coated needles was fully healed, while skin punctured by bare needles remained scabbed. MG-coated needles also improved tattoo quality by enhancing pigment retention, which appeared inversely proportional to needle-induced trauma.