Page 35 - An Introduction to Laser Tattoo Removal

Chapter 2 – Fundamentals of Laser Tattoo Removal v1.0
These fibroblasts/macrophages are the reason why tattoo ink remains in the dermis for long periods. The ink particles aggregate together inside these cells, and remain there, unless disturbed.
This is an important issue. The ink which is injected into the skin may be composed of a colloid of individual particles with a size range from 10nm up to 100nm. The ‘delivery’ liquid is usually water, glycerine, propylene, witch hazel and alcohol, but this is quickly removed by the skin, leaving trillions of tiny ink particles.
Figure 12 – Histological Section of an Amateur Tattoo (x150, H&E stain)
The individual ink particles are attracted to each other through electrostatic forces (which are quite weak!) to form aggregates. Subsequently, they are absorbed by fibroblasts, where the same forces create even larger aggregates. These aggregates may be up to a few microns across (see figure 12 – 1 micron = 1000 nanometres).
The final result, after a period of time, is a mass of dermal fibroblasts and macrophages, each containing many, many aggregates of tiny ink particles surrounded by tissue water (potentially thousands of particles in each cell). This combination of ink particles and tissue water inside individual fibroblast/macrophage cells becomes very important when discussing the physical mechanisms behind laser tattoo removal.
In an amateur tattoo the ink particles have a much wider range of sizes and tend to be more distributed throughout the dermis.
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Chapter 2 LEVEL A Laser Tattoo Removal
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