Francesco Santarelli

Modern tattoos cause high concentrations of hazardous pigments in skin

Background:  Modern tattoo colourants frequently consist of azo pigments that not only contain multiple impurities but also are originally produced for car paint and the dyeing of consumer goods.

Tattooing of skin results in transportation and light-induced decomposition of tattoo pigments – a first quantification in vivo using a mouse model

Abstract:  Millions of people are tattooed with inks that contain azo pigments. The pigments contained in tattoo inks are manufactured for other uses with no established history of safe use in humans and are injected into the skin at high densities (2.5 mg/cm2). Tattoo pigments disseminate after tattooing throughout the human body and although some may photodecompose at the injection site by solar or laser light exposure, the extent of transport or photodecomposition under in vivo conditions remains currently unknown. We investigated the transport and photodecomposition of the widely used tattoo Pigment Red 22 (PR 22) following tattooing into SKH‐1 mice. The pigment was extracted quantitatively at different times after tattooing. One day after tattooing, the pigment concentration was 186 μg/cm2 skin. After 42 days, the amount of PR 22 in the skin has decreased by about 32% of the initial value. Exposure of the tattooed skin, 42 days after tattooing, to laser light reduced the amount of PR 22 by about 51% as compared to skin not exposed to laser light. A part of this reduction is as a result of photodecomposition of PR 22 as shown by the detection of corresponding hazardous aromatic amines. Irradiation with solar radiation simulator for 32 days caused a pigment reduction of about 60% and we again assume pigment decomposition in the skin. This study is the first quantitative estimate of the amount of tattoo pigments transported from the skin into the body or decomposed by solar or laser radiation.

Tattoo inks contain polycyclic aromatic hydrocarbons that additionally generate deleterious singlet oxygen

Please cite this paper as: Tattoo inks contain polycyclic aromatic hydrocarbons that additionally generate deleterious singlet oxygen. Experimental Dermatology 2010; 19: e275–e281.

Fluorescence induction of protoporphyrin IX by a new 5‐aminolevulinic acid nanoemulsion used for photodynamic therapy in a full‐thickness ex vivo skin model

Please cite this paper as: Fluorescence induction of protoporphyrin IX by a new 5‐aminolevulinic acid nanoemulsion used for photodynamic therapy in a full‐thickness ex vivo skin model. Experimental Dermatology 2010; 19: e302–e305.

2D luminescence imaging of physiological wound oxygenation

Abstract:  In cutaneous wound healing, the role of oxygen in vivo is poorly understood. We studied wound surface pO2 during physiological wound healing in humans. Split‐thickness skin graft donor sites (n = 12) served as standardized wound models. Wound surface pO2 was measured at 1, 6 and 14 days after split‐skin harvesting using two‐dimensional luminescence lifetime imaging (2D‐LLI) of palladium(II)‐meso‐tetraphenyl‐tetrabenzoporphyrin (Pd‐TPTBP) in polystyrene‐co‐acrylonitrile (PSAN) particles on transparent foils. In another experiment, we removed the stratum corneum (SC) on the volar forearm (n = 10) by tape strippings to study the impact of the SC on the epidermal oxygen barrier. Split‐skin donor site pO2 significantly decreased during the time course of physiological healing. Regional differences in pO2 within donor site wounds were visualized for the first time in literature. No difference was found in pO2 before and after SC removal, showing that the SC is not a major constituent of the epidermal oxygen barrier.

Black tattoo inks are a source of problematic substances such as dibutyl phthalate.

Background. Tattooing has recently become increasingly popular. Using tiny needles, tattooists place the tattoo ink in the dermis along with numerous unknown ingredients. Most tattoos consist of black inks, which are predominantly composed of soot products (carbon black with polycyclic aromatic hydrocarbons).

A helpful technology--the luminescence detection of singlet oxygen to investigate photodynamic inactivation of bacteria (PDIB).

Photodynamic inactivation of bacteria (PDIB) is considered a new approach for the struggle against multiresistant bacteria. To achieve a sufficient level of bacteria killing, the photosensitizer must attach to and/or penetrate the bacteria and generate a sufficiently high amount of singlet oxygen. To optimize PDIB, the direct detection and quantification of singlet oxygen in bacteria is a helpful tool. Singlet-oxygen luminescence is a very weak signal, in particular in living bacteria. We first performed experiments in aqueous photosensitizer solution to optimize the luminescence system. We eliminated non-singlet-oxygen photons, which is important for the quantification of singlet oxygen and its rise and decay rates. This procedure is even more important when the laser excitation beam is scattered by bacteria (diameter 1 microm). In suspensions with both Gram-positive and Gram-negative bacteria we then clearly detected singlet oxygen by its luminescence and determined the respective rise and decay times. The decay times should provide an indication of localization of singlet oxygen and hence of the photosensitizer even in small bacteria.

The decrease of pigment concentration in red tattooed skin years after tattooing

Background  Tattooing entails the injection of high amounts of colourants into skin. Excepting black inks, red azo pigments are the most frequent colourant used. Part of the pigment is transported away via lymphatic system. Another part can be decomposed in skin, which might be responsible for many known adverse skin reactions.

Black Tattoos Entail Substantial Uptake of Genotoxicpolycyclic Aromatic Hydrocarbons (PAH) in Human Skin and Regional Lymph Nodes

Hundreds of millions of people worldwide have tattoos, which predominantly contain black inks consisting of soot products like Carbon Black or polycyclic aromatic hydrocarbons (PAH). We recently found up to 200 μg/g of PAH in commercial black inks. After skin tattooing, a substantial part of the ink and PAH should be transported to other anatomical sites like the regional lymph nodes. To allow a first estimation of health risk, we aimed to extract and quantify the amount of PAH in black tattooed skin and the regional lymph nodes of pre-existing tattoos. Firstly, we established an extraction method by using HPLC – DAD technology that enables the quantification of PAH concentrations in human tissue. After that, 16 specimens of human tattooed skin and corresponding regional lymph nodes were included in the study. All skin specimen and lymph nodes appeared deep black. The specimens were digested and tested for 20 different PAH at the same time.PAH were found in twelve of the 16 tattooed skin specimens and in eleven regional lymph nodes. The PAH concentration ranged from 0.1–0.6 μg/cm2 in the tattooed skin and 0.1–11.8 μg/g in the lymph nodes. Two major conclusions can be drawn from the present results. Firstly, PAH in black inks stay partially in skin or can be found in the regional lymph nodes. Secondly, the major part of tattooed PAH had disappeared from skin or might be found in other organs than skin and lymph nodes. Thus, beside inhalation and ingestion, tattooing has proven to be an additional, direct and effective route of PAH uptake into the human body.