Experience with tattoos that fade over time, and have blurred lines and colors without definition may make you rethink getting permanent ink. So, why are tattoos permanent? Let’s dive into the details.
The Immune System
Innate immunity is the first line of defense against infections. It recognizes foreign substances (germs) and swiftly destroys them. It also remembers encountered germs to respond quickly in future encounters. Immunity involves white blood cells called phagocytes and lymphocytes. Phagocytes swallow and digest harmful organisms, while lymphocytes create antibodies to fight off microbes. Some immune cells reside in the blood, while others work in tissues to combat infections.
Macrophages
Researchers studied mice to understand how tattoos work. They believe tattoo ink particles are trapped in immune cells called macrophages on the skin’s surface. Macrophages patrol the body and consume potential threats through a process called phagocytosis. The pigment particles in tattoos are too large to be broken down, so they remain inside the macrophages. When old macrophages die, new ones take up the pigment, ensuring the tattoo remains embedded in the skin for a long time.
Fibroblasts
Macrophages arrive at the damaged site to eliminate invaders and foreign materials. However, they can only consume tattoo ink in the dermis, not elsewhere in the body. As macrophages die off, they release ink particles which are then taken up by new macrophages. This capture-release and recapture process ensures the longevity of the tattoo.
The Dermis
The dermis is the layer beneath the epidermis and hypodermis. It contains various structures like blood vessels, nerves, glands, and collagen fibers. The dermis comprises connective tissue, including collagen and elastic fibers, creating a sturdy matrix for the skin.
