Detection of anaerobic and aerobic bacteria from commercial tattoo and permanent makeup inks.

Tattooing and use of permanent makeup (PMU) have dramatically increased over the last decade, with a concomitant increase in ink-related infections. Studies have shown evidence that commercial tattoo and PMU inks are frequently contaminated with pathogenic microorganisms. Considering that tattoo inks are placed into the dermal layer of the skin where anaerobic bacteria can thrive and cause infections in low-oxygen environments, the prevalence of anaerobic and aerobic bacteria should be assessed in tattoo and PMU inks. In this study, we tested 75 tattoo and PMU inks using the analytical methods described in the FDA Bacteriological Analytical Manual Chapter 23 for the detection of both aerobic and anaerobic bacterial contamination, followed by 16S rRNA gene sequencing for microbial identification. Of 75 ink samples, we found 26 contaminated samples with 34 bacterial isolates taxonomically classified into 14 genera and 22 species. Among the 34 bacterial isolates, 19 were identified as possibly pathogenic bacterial strains. Two species, namely Cutibacterium acnes (four strains) and Staphylococcus epidermidis (two strains) were isolated under anaerobic conditions. Two possibly pathogenic bacterial strains, Staphylococcus saprophyticus and C. acnes, were isolated together from the same ink samples (n = 2), indicating that tattoo and PMU inks can contain both aerobic (S. saprophyticus) and anaerobic bacteria (C. acnes). No significant association was found between sterility claims on the ink label and the absence of bacterial contamination. The results indicate that tattoo and PMU inks can also contain anaerobic bacteria. IMPORTANCE: The rising popularity of tattooing and permanent makeup (PMU) has led to increased reports of ink-related infections. This study is the first to investigate the presence of both aerobic and anaerobic bacteria in commercial tattoo and PMU inks under aerobic and anaerobic conditions. Our findings reveal that unopened and sealed tattoo inks can harbor anaerobic bacteria, known to thrive in low-oxygen environments, such as the dermal layer of the skin, alongside aerobic bacteria. This suggests that contaminated tattoo inks could be a source of infection from both types of bacteria. The results emphasize the importance of monitoring these products for both aerobic and anaerobic bacteria, including possibly pathogenic microorganisms.

Tattoo inks: evaluation of cellular responses and analysis of some trace metals.

After tattoo application, inks remain in the skin, mostly in the dermal layer, and manufacturers use inks that have not been adequately evaluated for safety in tattoo production. In this study, the metal contents (Cd, Hg, Pb, and Cr) of tattoo inks available in the Turkish market were determined and the relationship between cell viability and inflammatory response of the detected metal levels was investigated. Nine tattoo inks (3 colors) from 3 different brands abbreviated as E, I, and W were examined. ICP-MS was used for element analysis. The viability of human keratinocyte cells was determined by the WST-1 assay following ink exposures at various dilutions. IL-18 levels were measured in cell culture supernatant by ELISA method following ink or metal (Cd, Cr, Hg, and Pb) exposures. The concentrations of trace elements were found in inks as follows: Cd, 0.0641-1.3857; Hg, 0.0204-0.2675; Pb, 0.8527-6.5981; Cr, 0.1731-45.3962 µg mL-1. It was observed that the levels of Pb and especially Cr in the samples exceeded the limit values. Tattoo inks reduced the cell viability in a dose- and color-dependent manner. IL-18 release was significantly increased in all groups except Cr and black ink of brand I treated cells (p < 0.05). Our results show that the metal contents of tattoo inks exceed Council of Europe Resolution values in some samples and some inks induce immune system activation (IL-18 secretion) and cytotoxic effects. It is thought that these findings may contribute to the toxic/adverse effects of tattoo inks commonly used.

Does corneal tattooing affect the conjunctival microbiota?

PURPOSE: This study aimed to investigate the effects of commercial tattoo inks used in corneal tattooing on conjunctival microbiota. METHOD: This prospective case control study consisted of 125 participants divided in the following three groups: 35 patients with corneal tattoos, 40 patients with corneal leukoma, and 50 healthy subjects. Corneal tattooing was performed in all the cases in this study using a tattoo pen machine and commercial tattoo ink. A total of 500 cultures were taken from 250 eyes of 125 individuals on chocolate and sheep blood agar. Bacteriological samples were taken from the inferior eyelid conjunctiva using a sterile cotton swab. Without any contact elsewhere, the swabs were smeared on bedside chocolate agars and 5% sheep blood agar. RESULTS: In tattooed eyes, bacterial growth was detected in 42.9% of the chocolate and sheep blood agar samples. In other healthy eyes of patients with corneal tattoos, 54.5% bacterial growth on chocolate agar and 57.1% on sheep blood agar were detected. No statistical difference was detected in the conjunctival microbiota of chocolate and sheep blood agar (p = 0.254, p = 0.134, respectively) in the tattooed eyes compared to the other eye of the individual. No statistically significant difference was found in terms of bacterial growth in tattooed, leukoma, or healthy eyes on chocolate and sheep blood agar (p = 0.408, p = 0.349). The growth rate of Staphylococcus epidermidis decreased by 33.3% (from 12 to 8) on chocolate agar in 35 tattooed eyes, and it decreased by 28.5% (from 14 to 10) on sheep blood agar, while gram-negative bacteria Brevundimonas diminuta, Acinetobacter lwoffii, and Psychrobacter faecalis were detected in three patients. CONCLUSION: Corneal tattooing using commercial dye does not affect conjunctival microbiota. In the past 3 years, 120 patients have been tattooed with commercial tattoo ink in Istanbul Medeniyet University Göztepe Training and Research Hospital. No complications related to infection were found in the 3-year follow-up. The gram-negative bacteria detected in the healthy control group and tattooed eyes were bacteria found on normal skin or in the respiratory tract. Although some gram-negative bacteria do not cause infection, careful eye examination, follow-up, and culture are required in suspicious cases.

Hypersensitivity to permanent tattoos: Literature summary and comprehensive review of patch tested tattoo patients 1997-2022.

We outline constituents of tattoo and permanent make-up ink with regard to inflammatory tattoo reactions and population-based confounders. The comprehensive review of patch-tested tattoo patients between 1997 and 2022 shows that tattoo allergy cannot be reliably diagnosed via patch testing with today's knowledge. Weak penetration and slow haptenization of pigments, unavailability of pigments as test allergens and a lack of knowledge concerning relevant epitopes hamper the diagnosis of tattoo allergy. Patch testing p-phenylenediamine and disperse (textile) dyes is not able to close this gap. Sensitization to metals was associated with all types of tattoo complications, although often not clinically relevant for the tattoo reaction. Binders and industrial biocides are frequently missing on ink declarations and should be patch tested. The pigment carbon black (C.I. 77266) is no skin sensitizer. Patch tests with culprit inks were usually positive with cheap ink products for non-professional use or with professionally used inks in patients with eczematous reactions characterized by papules and infiltration. Tape stripping before patch testing and patch test readings on Day 8 or 10 may improve the diagnostic quality. The meaningfulness of the categorical EU-wide ban of Pigment Green 7 and Pigment Blue 15:3 is not substantiated by the presented data.

Quantification of preservatives in tattoo and permanent make-up inks in the frame of the new requirements under the REACH Regulation.

BACKGROUND: According to the REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals) restriction, tattoo and permanent make-up (PMU) inks placed on the European Union market after January 4, 2022, shall not contain methylisothiazolinone, benzisothiazolinone (BIT), octylisothiazolinone (OIT), or other skin sensitizers in concentrations of 10 mg/kg or higher and phenoxyethanol (PE) or other eye irritants or damaging substances in concentrations of 100 mg/kg or higher. In addition, preservatives and other substances enlisted in Annex II to Cosmetic Product Regulation shall not be present in concentrations of 0.5 mg/kg or higher. OBJECTIVES: This study aims to quantify 14 preservatives in 99 tattoo and 39 PMU inks from the Italian market and presents a comparison with concentration limits set by the REACH restriction. METHODS: Inks were analysed by applying validated analytical methods based on liquid chromatography techniques. RESULTS: About 24.0%, 15.2% and 1.5% of the overall samples contained BIT, PE and OIT, respectively, at concentrations exceeding REACH concentration limits. The number of noncompliant tattoo inks (49.5%) would be significantly greater than that of the PMU inks (17.9%). CONCLUSIONS: About 40.6% of the samples would be noncompliant with the restriction for the presence of preservatives above the permitted level. Additional concentration limits will apply to skin sensitizing preservatives for proper labelling of inks under CLP (Classification, Labelling and Packaging) Regulation.

Assessment of cytotoxicity and sensitization potential of intradermally injected tattoo inks in reconstructed human skin.

BACKGROUND: The number of people within the European population having at least one tattoo has increased notably, and with it the number of tattoo-associated clinical complications. Despite this, safety information and testing regarding tattoo inks remain limited. OBJECTIVE: To assess cytotoxicity and sensitization potential of 16 tattoo inks after intradermal injection into reconstructed human skin (RHS). METHODS: Commercially available tattoo inks were injected intradermally into RHS (reconstructed epidermis on a fibroblast-populated collagen hydrogel) using a permanent makeup device. RHS biopsies, tissue sections, and culture medium were assessed for cytotoxicity (thiazolyl blue tetrazolium bromide assay [MTT assay]), detrimental histological changes (haematoxylin and eosin staining), and the presence of inflammatory and sensitization cytokines (interleukin [IL]-1α, IL-8, IL-18; enzyme-linked immunosorbent assay). RESULTS: Varying degrees of reduced metabolic activity and histopathological cytotoxic effects were observed in RHS after ink injection. Five inks showed significantly reduced metabolic activity and enhanced sensitization potential compared with negative controls. DISCUSSION: Using the RHS model system, four tattoo inks were identified as highly cytotoxic and classified as potential sensitizers, suggesting that allergic contact dermatitis could emerge in individuals carrying these inks. These results indicate that an RHS-based assessment of cytotoxicity and sensitization potential by intradermal tattoo ink injection is a useful analytical tool to determine ink-induced deleterious effects.

Phylogenetically diverse bacteria isolated from tattoo inks, an azo dye-rich environment, decolorize a wide range of azo dyes.

PURPOSE: There has been an interest in the microbial azo dye degradation as an optional method for the treatment of azo dye-containing wastes. Tattoo ink is an extremely unique azo dye-rich environment, which have never been explored in terms of microorganisms capable of degrading azo dyes. Previously, we isolated 81 phylogenetically diverse bacteria, belonging to 18 genera and 52 species, contaminated in tattoo inks. In this study, we investigated if these bacteria, which can survive in the azo dye-rich environment, have an ability to degrade azo dyes. METHODS: We conducted a two-step azo dye degradation (or decolorization) assay. In step 1, a high-throughput degradability assay was done for 79 bacterial isolates using Methyl Red and Orange II. In step 2, a further degradation assay was done for 10 selected bacteria with a representative of 11 azo dyes, including 3 commercial tattoo ink azo dyes. Degradation of azo dyes were calculated from measuring optical absorbance of soluble dyes at specific wavelengths. RESULTS: The initial high-throughput azo dye assay (step 1) showed that 79 isolates had a complete or partial degradation of azo dyes; > 90% of Methyl Red and Orange II were degraded within 24 h, by 74 and 20 isolates, respectively. A further evaluation of azo dye degradability for 10 selected isolates in step 2 showed that the isolates, belonging to Bacillus, Brevibacillus, Paenibacillus, and Pseudomonas, exhibited an excellent decolorization ability for a wide range of azo dyes. CONCLUSIONS: This study showed that phylogenetically diverse bacteria, isolated from azo dye-rich tattoo inks, is able to degrade a diverse range of azo dyes, including 3 azo dyes used in commercial tattoo inks. Some of the strains would be good candidates for future studies to provide a systematic understanding of azo dye degradation mechanisms.

Tattooist-Associated Tattoo Complications: "Overworked Tattoo," "Pigment Overload" and Infections Producing Early and Late Adverse Events.

BACKGROUND: Tattooist-related technical failures of tattooing were hitherto unstudied and related to clinical complications. Tattooing requires talent, training and experience. Amateurism is a challenge in popular tattoo industry with no formal education and certification of the tattooists. OBJECTIVE: To study technical tattoo failures causing disease in a consecutive hospital material of tattoo complications. MATERIAL: 574 patients with 702 tattoo complications referred to the "Tattoo Clinic" (a subspecialised dermatological clinic) were enrolled. Patients were examined clinically and classified with respect to the cause of complication. RESULTS: 147 (21%) tattooist and tattoo studio-related complications were recorded, i.e. excessive pigment installed in the dermis with "pigment overload" in 64 (9%), tattoo "needle trauma" with "overworked tattoos" in 43 (6%), contaminated ink causing infection in 20 (3%), and other sources of infections related to tattooing in 20 (3%). Pain and discomfort were particularly common as well as long-term complications including scarring induced by "needle trauma." "Pigment overload" with black pigment carried a special risk of granulomatous inflammation and sarcoid granuloma and was observed in 12/35 (34%) of punch biopsies taken from tattoos with "pigment overload." Keratoacanthoma associated with trauma was observed in 1 case. 82% of complications were related to professional tattooists working in a tattoo studio and 18% to amateurs. CONCLUSION: Technical failures of tattooing are associated with medical tattoo complications. "Needle trauma" with major skin damage, e.g. "overworked tattoo," and installation of excessive pigment, e.g. "pigment overload," and (re)use of contaminated tattoo ink bottles are identified failures calling for preventive intervention.

Quantification of cutaneous allergic reactions using 3D optical imaging: A feasibility study.

BACKGROUND: User-independent quantitative measures of cutaneous allergic reactions can help the physicians manage and evaluate the treatment of cutaneous allergic reactions. In this paper, we present and validate a method to quantify the elevation, volume and area of cutaneous allergic reactions to red tattoos. METHODS: The skin surface of allergic tattoo reactions was imaged using an optical 3D scanner. The in-house developed analysis tool measured the elevation, volume and area of the lesions, compared to a reference surface. This reference surface was created by 3D interpolation of the skin after manual removal of the lesions. The error of the interpolation tool was validated using a digital arm model. The error of our optical scanner was determined using a 3D printed lesion phantom. The clinical feasibility of the method was tested in 83 lesions in 17 patients. RESULTS: The method showed clear potential to assess skin elevation, volume change and area of an allergic reaction. The validation measurements revealed that the error due to interpolation increases for larger interpolation areas and largely determined the error in the clinical measurements. Lesions with a width ≥4 mm and an elevation ≥0.4 mm could be measured with an error below 26%. Patient measurements showed that lesions up to 600 mm2 could be measured accurately, and elevation and volume changes could be assessed at follow-up. CONCLUSION: Quantification of cutaneous allergic reactions to red tattoos using 3D optical scanning is feasible and may objectify skin elevation and improve management of the allergic reaction.

Microbial contamination of tattoo and permanent makeup inks marketed in the US: a follow-up study.

In a 2018 survey, U.S. Food and Drug Administration (FDA) identified microbial contamination in 42 (49%) of 85 unopened tattoo and permanent makeup (PMU) inks purchased from 13 manufacturers in the US between November 2015 and April 2016. To confirm the results of our previous survey, we evaluated the level of microbial contamination in an additional 27 samples from 10 manufacturers from September 2017 to December 2017, including 21 unopened tattoo and PMU inks which were selected based on our previous survey results and 6 ink diluents that were not previously analysed. Aerobic plate count and enrichment culture methods from the FDA's Bacteriological Analytical Manual revealed 11 (52%) out of 21 inks, from six manufacturers, were contaminated with micro-organisms, with contamination levels up to 3·6 × 108  CFU per gram, consistent with our previous survey results. We identified 25 bacterial strains belonging to nine genera and 19 species. Strains of Bacillus sp. (11 strains, 44%) were dominant, followed by Paenibacillus sp. (5 strains, 20%). Clinically relevant strains, such as Kocuria rhizophila and Oligella ureolytica, were also identified, as similar to the findings in our previous survey. No microbial contamination was detected in any of the six ink diluents.

Microbiological survey of commercial tattoo and permanent makeup inks available in the United States.

AIMS: Tattooing and use of permanent makeup (PMU) has dramatically increased over the last decade, with a concomitant increase in ink-related infections. The aim of this study was to determine whether micro-organisms are present, and if so, the number and their identification in the commercial tattoo and PMU inks available in the United States. METHODS AND RESULTS: We surveyed 85 unopened tattoo and PMU inks, purchased from 13 companies. We incubated 100 µl of ink samples on trypticase soy agar plates for bacterial growth, 7H10 Middlebrook medium for mycobacterial growth, and Sabouraud dextrose medium for fungal growth. In total, 42 inks were contaminated with micro-organisms (49%). Thirty-three inks were contaminated with bacteria, 2 inks with fungi, and 7 inks had both bacterial and fungal growth. Mycobacteria were not detected in any of the examined tattoo and PMU inks. In 26 inks, microbial concentrations ranged between 101 and 103 CFU per ml, but higher counts (>103 CFU per ml) were recorded in 16 inks. We identified 83 bacteria by their 16S rDNA sequences, including 20 genera and 49 species. Strains of Bacillus spp. (53%) were dominant, followed by Lysinibacillus fusiformis (7%) and Pseudomonas aeruginosa (5%). Thirty-four (41%) possibly clinically relevant strains were identified, including P. aeruginosa, Dermacoccus barathri and Roseomonas mucosa, some of which have been previously reported to be associated with human skin infections. CONCLUSIONS: The results indicate that commercial tattoo and PMU inks on the US market surveyed in this study contain a wide range of micro-organisms, including pathogenic bacteria. SIGNIFICANCE AND IMPACT OF THE STUDY: Microbial contaminants in tattoo and PMU inks are an emerging safety concern for public health. This study provides evidence that microbial contamination of tattoo and PMU inks available in the United States is more common than previously thought and highlights the importance of monitoring these products for potentially pathogenic micro-organisms.

Comparison of the skin sensitization potential of 3 red and 2 black tattoo inks using interleukin-18 as a biomarker in a reconstructed human skin model.

BACKGROUND: During the last decade, the number of people with ≥1 tattoo has increased noticeably within the European population. Despite this, limited safety information is available for tattoo inks. OBJECTIVES: To test the skin sensitization potential of 5 tattoo inks in vitro by using reconstructed human skin (RHS) and the contact sensitization biomarker interleukin (IL)-18. METHODS: Two red and 3 black tattoo inks, 1 additive (Hamamelis virginiana extract) and 1 irritant control (lactic acid) were tested. The culture medium of RHS (reconstructed epidermis on a fibroblast-populated collagen hydrogel) was supplemented with test substances in a dose-dependent manner for 24 hours, after which cytotoxicity (histology; thiazolyl blue tetrazolium bromide assay) and skin sensitization potential (IL-18 secretion; enzyme-linked immunosorbent assay) were assessed. RESULTS: All but 1 ink showed cytotoxicity. Notably, 1 red ink and 1 black ink were able to cause an inflammatory response, indicated by substantial release of IL-18, suggesting that these inks may be contact sensitizers. CONCLUSIONS: The in vitro RHS model showed that 4 tattoo inks were cytotoxic and 2 were able to cause an inflammatory IL-18 response, indicating that an individual may develop allergic contact dermatitis when exposed to these tattoo inks, as they contain contact sensitizers.

Cutaneous Tattoo Ink as a Mimicker of Endometriosis-Like Lesions on Diagnostic Laparoscopy.

This paper presents the case of a 28-year-old with a history of chronic pelvic pain suspicious of endometriosis. She underwent a diagnostic laparoscopy and biopsy of lesions along the posterior cul-de-sac and right sidewall near the external iliac artery. Histopathological examination revealed no evidence of endometriosis but did comment on benign lymph node tissue with tattoo-like pigment. These findings correspond to the patient's tattoos located along the lower extremities. It is suspected there was cutaneous tattoo ink migration causing intra-abdominal lymphadenopathy, which visually mimicked endometriosis on diagnostic laparoscopy. Surgeons should become familiar with and recognize this phenomenon, as it can be misleading in the setting of endometriosis and diagnostic laparoscopy. Surgeons undertaking these cases must be able to identify and safely excise abnormal-appearing lesions in many different locations to prevent a missed or delayed diagnosis of endometriosis.

Incarcerated Ink: A Case of Mycobacterium chelonae.

A 30-year-old African American male presented with pain and swelling of the right foot one month after receiving a tattoo on this foot in prison. During his admission for presumed cellulitis, he developed a rash on his contralateral (left) leg, which had been tattooed 10 months prior. A biopsy of the contralateral (left) leg showed acute, chronic, and granulomatous inflammation with a differential diagnosis including infection. His overall condition and both legs worsened, prompting biopsy and tissue culture of the right ankle and foot. Pathology of the right foot showed a granulomatous reaction. Culture grew Mycobacterium chelonae. This case highlights the importance of considering infectious etiologies for rashes appearing within tattoos and represents the importance of a full investigation to obtain the correct diagnosis.

Recalls of tattoo and permanent makeup inks in the United States and a follow-up microbiological survey of inks with a previous recall history.

In this study, we collected voluntary recall records of tattoo and permanent makeup ink from the U.S. Food and Drug Administration (US FDA) Enforcement Report Database. The recall records contain information, such as recall date, manufacturer, ink color, reason for recall, and the microorganisms detected from the ink samples. Between 2003 and 2021, a total of 15 voluntary tattoo ink recalls occurred in the U.S. market, involving over 200 tattoo inks marketed by 13 manufacturers and one distributor. Fourteen recalls were due to microbial contamination, and one recall was due to allergic reaction. As follow-up, a microbiological survey of 28 tattoo inks of new batches from seven manufacturers having products that were previously recalled was conducted. Aerobic plate count (APC) and enrichment culture methods based on the FDA's Bacteriological Analytical Manual (BAM) were used to detect microbial contamination. The results revealed that six out of 28 tattoo inks were contaminated with bacteria and were produced by two manufacturers. The level of microbial contamination was less than 250 CFU/g in three of the tattoo inks and between 1 × 103 and 1 × 105 CFU/g in the other three inks. Eleven bacterial isolates were identified, including spore-forming Bacillus-related species and potentially pathogenic species. Overall, this study shows that some tattoo ink products produced by manufacturers with a recall history continue to be contaminated with microorganisms. This highlights the need for ongoing monitoring and quality control of such products.

In vitro analysis of catalase and superoxide dismutase mimetic properties of blue tattoo ink.

Tattoo inks are comprised of different combinations of bioactive chemicals with combined biological effects that are insufficiently explored. Tattoos have been associated with oxidative stress; however, a recent N-of-1 study suggested that blue tattoos may be associated with suppressed local skin oxidative stress. The present study aimed to explore the attributes of the blue tattoo ink (BTI) that may explain its possible effects on redox homeostasis, namely the catalase (CAT) and superoxide dismutase (SOD)-mimetic properties that have been reported for copper(II) phthalocyanine (CuPC)-the main BTI constituent. Intenze™ Persian blue (PB) BTI has been used in the experiment. CAT and SOD-mimetic properties of PB and its pigment-enriched fractions were analyzed using the carbonato-cobaltate (III) formation-derived H2O2 dissociation and 1,2,3-trihydroxybenzene autoxidation rate assays utilizing simple buffers and biochemical matrix of normal skin tissue as chemical reaction environments. CuPC-based tattoo ink PB and both its blue and white pigment-enriched fractions demonstrate CAT and SOD-mimetic properties in vitro with effect sizes demonstrating a substantial dependence on the biochemical environment. PB constituents act as inhibitors of CAT but potentiate its activity in the biochemical matrix of the skin. CuPC-based BTI can mimic antioxidant enzymes, however chemical constituents other than CuPC (e.g. the photoreactive TiO2) seem to be at least partially responsible for the BTI redox-modulating properties.

Color Biophysics and the Human Color Perception in Relation to Pigments and Tattooed Skin.

Perception of skin color in the natural state, or with tattoo pigment installed in the dermis is highly complex and includes both optical requisites and eye and brain functions connected to advanced cognitive and psychological functions. Permanent makeup (PMU) is miniaturized tattooing on critical anatomical location aiming at fulfilment of a person's esthetic ideal. It is a special challenge since a satisfactory outcome depends on perfectionated technique and very critical selection of pigments. The eye can be compared to a digital camera, and the center of central vision in the brain to a computer and color integrator. Color perception is the end product of a complicated brain function. The background theory of color physics and perception is reviewed with emphasis on aspects related to changed skin color created by pigment installed in the dermis with the purpose to tattoo eyebrows, eyeliners, lips, and other locations. The delicate dosing of pigment relative to the natural skin tone is highlighted. The review is relevant for all aspects of PMU including medical tattooing, e.g., areola tattooing after breast cancer surgery. A detailed guidance to PMU artists and medical tattooists on selection and use of tattoo inks and pigments is provided. The guidance is also relevant to laser surgeons and technicians performing tattoo removal.

Determination of the Phototoxicity Potential of Commercially Available Tattoo Inks Using the 3T3-neutral Red Uptake Phototoxicity Test

Objectives: Tattooing is an ancient practice and its popularity has been increasing in the recent years. After tattooing, complications may occur related to compose tattoo inks. In this study, the phototoxicity potential of the blue, red and black colors of the most commonly used three different commercially-available tattoo ink brands have been examined by performing in vitro 3T3-neutral red uptake (NRU) phototoxicity test. Materials and Methods: In the study, the phototoxicity of serial diluted concentrations of tattoo inks were evaluated with in vitro 3T3-NRU phototoxicity test method according to OECD guide 432. The data obtained from the NRU test result were uploaded to Phototox software (version 2.0) and the phototoxicity potentials of tattoo inks were determined via the calculation of the mean photo effect (MPE) and photo irritation factor (PIF) values. Results: The red, black and blue colors of three different commercially available tattoo inks did not cause a cytotoxic activity on BALB/c 3T3 cells with 3T3-NRU test. The IC50 values could not be determined +ultraviolet (UV) and -UV conditions. PIF values could not be calculated and MPE values were <0.1, which predicts the absence of phototoxic effect for all of the tested tattoo inks. Conclusion: All tested inks were evaluated as non-phototoxic according to the results of MPE values calculated using Phototox software. However, test results should be verified by other phototoxicity test methods to obtain a comprehensive evaluation of phototoxic complications of different tattoo inks.

The effect of a color tattoo on the local skin redox regulatory network: an N-of-1 study.

Biomedical aspects of tattooing have been extensively discussed in literature, however pathophysiological effects of tattoo inks in the human body are still unexplored. Oxidative stress is considered responsible for the adverse effects of tattooing, however no experimental evidence for tattoo ink-related oxidative stress in the human body currently exists. The aim was to examine the effect of a blue tattoo on skin redox regulatory network (RRN) parameters in a single human subject. Skin surface oxidation-reduction potential (ORP) was analyzed with a PH60F flat probe. Interstitial and intracellular fluid enriched capillary blood from the tattoo and the control area was extracted and analyzed with I2/KI-stabilized microORP, nitrocellulose redox permanganometry (NRP), carbonato-cobaltate (III) formation-derived H2O2 dissociation rate assay, 1,2,3-trihydroxybenzene autoxidation assay, thiobarbituric reactive substances (TBARS) assay and 5,5,'-dithio-bis-(2-nitrobenzoic acid) (DTNB)-based determination of free thiol content in low molecular weight and protein precipitate fractions. Surface ORP analysis revealed a greater antioxidant capacity of tattooed skin in comparison with the control (CTR). Capillary blood analysis confirmed greater reductive capacity in the tattoo sample both by microORP (-4.33 mV vs CTR) and NRP (+10.8%). Hydrogen peroxide dissociation rate (+11.8%), and protein sulfhydryl content (+8.5%) were increased, and lipid peroxidation (-15%) was reduced in the tattoo sample in comparison with the CTR. In this N-of-1 study, RRN of tattooed skin was shifted toward a more reductive state with all parameters indicating reduced levels of oxidative stress in comparison with nontattooed skin. The local antioxidant effect of copper(II) phthalocyanine provides one possible explanation of the observed effects.