E-Tattoos: Toward Functional but Imperceptible Interfacing with Human Skin.

The human body continuously emits physiological and psychological information from head to toe. Wearable electronics capable of noninvasively and accurately digitizing this information without compromising user comfort or mobility have the potential to revolutionize telemedicine, mobile health, and both human-machine or human-metaverse interactions. However, state-of-the-art wearable electronics face limitations regarding wearability and functionality due to the mechanical incompatibility between conventional rigid, planar electronics and soft, curvy human skin surfaces. E-Tattoos, a unique type of wearable electronics, are defined by their ultrathin and skin-soft characteristics, which enable noninvasive and comfortable lamination on human skin surfaces without causing obstruction or even mechanical perception. This review article offers an exhaustive exploration of e-tattoos, accounting for their materials, structures, manufacturing processes, properties, functionalities, applications, and remaining challenges. We begin by summarizing the properties of human skin and their effects on signal transmission across the e-tattoo-skin interface. Following this is a discussion of the materials, structural designs, manufacturing, and skin attachment processes of e-tattoos. We classify e-tattoo functionalities into electrical, mechanical, optical, thermal, and chemical sensing, as well as wound healing and other treatments. After discussing energy harvesting and storage capabilities, we outline strategies for the system integration of wireless e-tattoos. In the end, we offer personal perspectives on the remaining challenges and future opportunities in the field.

The amnesic shellfish poisoning toxin, domoic acid: The tattoo of the king scallop Pecten maximus.

Domoic acid (DA) is a potent neurotoxin produced by diatoms of the genus Pseudo-nitzschia and is responsible for Amnesic Shellfish Poisoning (ASP) in humans. Some fishery resources of high commercial value, such as the king scallop Pecten maximus, are frequently exposed to toxic Pseudo-nitzschia blooms and are capable of accumulating high amounts of DA, retaining it for months or even a few years. This poses a serious threat to public health and a continuous economical risk due to fishing closures of this resource in the affected areas. Recently, it was hypothesized that trapping of DA within autophagosomic-vesicles could be one reason explaining the long retention of the remaining toxin in P. maximus digestive gland. To test this idea, we follow the kinetics of the subcellular localization of DA in the digestive glands of P. maximus during (a) the contamination process - with sequential samplings of scallops reared in the field during 234 days and naturally exposed to blooms of DA-producing Pseudo-nitzschia australis, and (b) the decontamination process - where highly contaminated scallops were collected after a natural bloom of toxic P. australis and subjected to DA-depuration in the laboratory for 60 days. In the digestive gland, DA-depuration rate (0.001 day-1) was much slower than contamination kinetics. The subcellular analyses revealed a direct implication of early autophagy in DA sequestration throughout contamination (r = 0.8, P < 0.05), while the presence of DA-labeled residual bodies (late autophagy) appeared to be strongly and significantly related to slow DA-depuration (r = -0.5) resembling an analogous DA-tattooing in the digestive glands of P. maximus. This work provides new evidence about the potential physiological mechanisms involved in the long retention of DA in P. maximus and represents the baseline to explore procedures to accelerate decontamination in this species.

Elastofibromatous changes in giant cell fibroma and amalgam tattoo: Unusual findings in common oral lesions.

Several cases of elastofibromatous lesion affecting the oral mucosa have been reported. Clinically, these lesions may appear as small exophytic lesions or less often as white lesions. Therefore, fibrous hyperplasia and leukoplakia are not uncommonly considered in clinical differential diagnosis. Microscopically, elastic and fibrous connective tissue deposition is seen. Rarely, elastofibromatous changes can be detected when assessing intraoral lesions, including cysts, salivary gland neoplasms, and epithelial dysplasia. Here we report two oral lesions showing elastofibromatous changes, expanding their clinicopathological spectrum. The first case was a 46-year-old man with a history of asymptomatic nodular lesion on the palate 1 year ago, diagnosed as giant cell fibroma with elastofibromatous changes. The second case was a 79-year-old woman who presented a pigmented and mildly symptomatic lesion on the mandibular alveolar mucosa several months ago, diagnosed as amalgam tattoo associated with elastofibromatous changes.

Tattoo Pigment Biokinetics in vivo in a 28-Day Porcine Model: Elements Undergo Fast Distribution to Lymph Nodes and Reach Steady State after 7 Days.

INTRODUCTION: Pigments of tattoo inks may over time migrate to other parts of the body. Inks kinetics are still poorly understood and little studied. The aim of this first study was to investigate the kinetics of tattoo inks pigment in tattooed porcine skin, which is closer to human skin than mouse skin studied in the past. METHODS: Three animals were tattooed on the inner thigh and one animal served as untreated control. Skin biopsies were taken on days 7, 14, and 28 after tattooing. Animals were sacrificed on day 28 and homogenate samples of the liver, spleen, kidney, and brain, as well the local lymph nodes were prepared. All samples were analyzed for ink components using inductively coupled plasma-mass spectrometry. The ink itself was characterized by dynamic light scattering and matrix-assisted laser desorption-ionization mass analysis. RESULTS: Titanium (212 g/kg), copper (6 mg/kg), aluminum (1 mg/kg), zirconium (1 mg/kg), and chromium (3 mg/kg) were found in the ink. Significant deposits of ink elements were detected in the tattooed skin when compared to non-tattooed skin from the same animal (mean ± standard deviation: titanium 240 ± 81 mg/kg, copper 95 ± 39 mg/kg, aluminum 115 ± 63 mg/kg, zirconium 23 ± 12 mg/kg, and chromium 1.0 ± 0.2 mg/kg; p < 0.05). Lymph node concentrations of titanium, copper, aluminum, zirconium, and chromium were 42 ± 2 mg/kg, 69 ± 25 mg/kg, 49 ± 18 mg/kg, 0.3 ± 0.2 mg/kg, 0.5 ± 0.2 mg/kg, respectively. CONCLUSION: Deposits in skin were unchanged from days 7-28 indicating no redistribution or elimination. No significant deposits of ink elements were found in the liver, spleen, kidney, and brain. In conclusion, our findings confirmed distribution of elements from tattoos to regional lymph nodes, but neither to excretory organs, e.g., liver and kidney, nor to spleen and brain. Thus systemic internal organ exposure was not found.

"Tattoo Characteristics and Testing for Body Dysmorphic Disorder: An Internet-based Self-questionnaire Survey of 4,809 Individuals with Tattoos".

Tattoos have become very popular worldwide in recent years. The aim of this study was to analyse a group of people interested in having tattoos, and screen them for body image disturbances. This cross-sectional self-administered internet-based survey included 4,809 individuals interesting in having tattoos. The majority of the study population were female (79.1%). The survey was conducted using a self-created questionnaire and the Body Dysmorphic Disorder Questionnaire - Dermatology version. Most tattoos in the study group were located on the forearms and hands (28.1%). The most popular motifs were plants (17.5%) and animals (16.9%). Out of 4,809 individuals, 19.9% had problems with acceptance of some parts of their body and 9.8% were screened for body dysmorphic disorder with the Body Dysmorphic Disorder Questionnaire - Dermatology version. Four percent of individuals reported that tattoos helped to improve their own perception of the appearance of their body by distracting attention from the other problems. Limitations of this study include possible participant selection bias and the overrepresentation of women. In conclusion, clinicians may expect to see more patients with tattoos and, of these, approximately 10% may be screened for body dysmorphic disorder.

What's in My Ink: An Analysis of Commercial Tattoo Ink on the US Market.

As tattoos continue to rise in popularity, the demand for tattoo ink has surged. Historically, tattoo inks have been underregulated in the US market. This study analyzes inks from nine different brands that are common in the United States, ranging from major to small manufacturers. Out of 54 inks, 45 contained unlisted additives and/or pigments. Major, unlisted adulterants include poly(ethylene glycol), propylene glycol, and higher alkanes. Many of the adulterants pose possible allergic or other health risks. Taken together, the results from this study highlight the potential for a significant issue around inaccurate tattoo ink labeling in the United States.

Retrospective clinical evaluation of Q-switched Nd:YAG laser safety and efficacy in tattoo removal: A new perspective on the Kirby-Desai scale.

BACKGROUND: With nearly 50% of the population in the United States, Italy, and Sweden tattooed with at least one tattoo, the demand for its removal has risen by 32% since 2011. Traditional removal methods, such as Q-switched (QS) laser-based tattoo removal, can be lengthy, requiring up to 20 sessions. AIM: This study presents a retrospective clinical evaluation of seven short-pulsed QS, dual-wavelength Nd:YAG laser, as an efficient alternative, that can potentially reduce the number of sessions needed as calculated by a founded scale. METHODS: The QS modality delivers high-intensity pulses in four wavelengths, ideal for removing multicolored tattoos, of which two were used. We studied 11 patients who underwent 3-8 treatments (average 5.09) every 2-3 months. Each tattoo was assessed using the Kirby-Desai scale, considering the following factors: location, Fitzpatrick skin type, ink amount, layering, scarring, tissue changes, and tattoo color. Follow-ups were conducted after 6 months and at 4-5 years following last session. RESULTS: The long-term follow-up presented a significantly higher tattoo removal efficiency than the short-term follow-up (p < 0.001), indicating a sustained process of ink breakdown and elimination. Notably, the actual number of treatments were significantly lower than that predicted by the Kirby-Desai scale (average 5.09 vs. 9.9, p < 0.001). No severe adverse events were reported. CONCLUSIONS: In conclusion, the QS Nd:YAG laser offers a safe and effective alternative for tattoo removal, requiring fewer treatments than initially expected.

Tattooing to reconstruct Nipple-Areola Complex after oncological breast surgery: a scoping review.

PURPOSE: The dermopigmentation of the Nipple-Areola Complex (NAC) is a safe non-surgical reconstruction technique that can restore psychophysical integrity, representing the final step after oncological surgery. This scoping review aims to identify and synthesize the literature focused on medical tattooing for NAC reconstruction in women who underwent breast reconstruction after cancer surgery. Competence and training, outcomes and organizational aspects were assessed as specific outcomes. METHODS: The Joanna Briggs Institute (JBI) methodology for scoping reviews was followed. MEDLINE, Embase, Cochrane Library, Clinical Key, Scopus and Cinahl databases were consulted. After title (N = 54) and abstract (N = 39) screening and full-text review (N = 18), articles that met eligibility criteria were analyzed, critically apprised and narratively synthesized. RESULTS: 13 articles were analysed, with full texts (N = 11) and only abstract (N = 2). The overall quality of the literature (N observational studies = 11; N pilot experimental studies = 2) is weak. Nurses were the professionals mostly involved (N = 6), then medical staff (N = 4) and tattoo artists (N = 2). The professional training is poorly described in 6 papers. The most frequently assessed outcome was the satisfaction rate (N = 8). One study explored aspects of quality of life with a validated questionnaire. The management of these services resulted variable. Nurse-led services were implemented in 2 studies. CONCLUSION: Despite methodological weaknesses, NAC tattooing research is relevant because it helps women redefine their identity after demolitive cancer treatments. Further research on processes and outcomes is needed.

Compliance of blood donors in Germany with non-sexual deferral criteria.

BACKGROUND AND OBJECTIVES: In addition to mandatory testing of blood donations, the deferral of donors in the case of various sexual and non-sexual risk exposures ensures the safety of blood products in Germany. The study aimed to quantify non-disclosure of non-sexual risk exposures, as no data are available so far. MATERIALS AND METHODS: We conducted an anonymous online survey among whole-blood donors with successful donations between January and March 2020. Data on travel to countries with endemic malaria, recent mild or febrile infections, tattoos or piercings and drug use were collected. We analysed non-compliance in relation to donor demographics by multivariable analyses. RESULTS: Altogether, 5.4% of the donors were non-compliant. Non-disclosure was highest for mild infection with 3.3% of donors, followed by febrile infections (1.4%), travel to malaria endemic countries (0.7%) and body modifications (0.5%). Intravenous drug use was negligible in our study population. Age was a predictor for all investigated risks, with higher prevalence in younger age groups. Prevalence ratios for non-disclosure of body modifications and mild infection were higher in females than males. Donation in blood establishments with mobile services was associated with higher non-disclosure of mild infections. CONCLUSION: The considerable degree of non-compliance in some donor groups reflects the prevalence of risk factors in the underlying population (e.g., body modification) as well as probable tendency to socially desirable responding. Donor education should not focus exclusively on sexual risk behaviour, as undisclosed non-sexual exposures may bear risks for recipients and donors.

Tattoo-induced allergic contact dermatitis presents diagnostic challenge as a cellulitis mimic.

Allergic contact dermatitis (ACD) is a prevalent condition associated with numerous potential allergen exposures. Tattoo ink is variable and may contain allergens that can be overlooked in patient education and diagnosis. We present a 27-year-old female with ACD following a new tattoo. The patient was repeatedly misdiagnosed with cellulitis by three different clinicians and treated with multiple antibiotics without improvement. The correct diagnosis was eventually made in the emergency department (ED). Although the patient was aware of her allergies to nickel and cobalt from patch testing, she was not aware of the potential for tattoo ink to contain these allergens because prior tattoos had not provoked an allergic reaction. Consequently, the appropriate care was delayed by a month, resulting in significant morbidity. This case demonstrates the potential for ACD to present similarly to cellulitis in an ED setting and the need for clinical vigilance in diagnosis of ACD. It also highlights the importance of detailed patient education on potential allergen sources particularly in the context of tattooing, which is performed with unregulated and variable ink products.

Macrophage-like rapid uptake and toxicity of tattoo ink in human monocytes.

Macrophages play a critical role for the persistence of tattoo ink in human skin. However, a comparison to other skin-resident and blood circulating immune cells and a profound analysis of REACH-compliant tattoo ink are unmet medical needs. We hence characterized the size distribution of ink particles using physicochemical methods. We studied the uptake of tattoo ink by key human skin cells and blood-derived immune cells using optical and electron microscopy as well as flow cytometry. Scanning electron microscopy of ink revealed its crystalline structure, and a tendency towards aggregations was indicated by size changes upon diluting it. Flow cytometric analyses of skin and immune cells after incubation with tattoo ink demonstrated an increase in cellular granularity upon uptake and red ink additionally evoked fluorescent signals. Human macrophages were most potent in internalizing ink in full thickness 3D skin models. Macrophage cultures demonstrated that the ink did not lead to elevated inflammatory mediators, and showed no indications for toxicity, even after nice days. Strikingly, monocytes were most efficient in ink uptake, but displayed reduced viability, whereas granulocytes and lymphocytes showed only temporary ink uptake with flow cytometric signals declining after 1 day. Mechanistic studies on ink retention by corticosteroids or dexpanthenol in macrophage cultures demonstrated that these compounds do not lead to ink excretion, but even slightly increase the ink load in macrophages. The highly motile monocytes, precursors of macrophages, may play an underrated role for tattoo ink translocation from dermal blood vessels into internal organs.

Prospective Evaluation of the Clinical Benefits of a Novel Tattoo-less Workflow for Nonspine Bone Stereotactic Body Radiation Therapy: Integrating Surface-Guidance With Triggered Imaging Reduces Treatment Time and Eliminates the Need for Tattoos.

PURPOSE: Oligometastatic disease has expanded the indications for nonspine bone stereotactic body radiation therapy (NSB SBRT). We investigated whether optical surface monitoring systems (OSMS) could enable tattoo-less setup and substitute for 2-dimensional/3-dimensional or cone beam computed tomography (CBCT)-based mid-imaging in NSB SBRT. METHODS AND MATERIALS: OSMS was incorporated in parallel with an existing workflow using pretreatment CBCT and 2-dimensional/3-dimensional kV/kV mid-imaging beginning November 2019. The ability of OSMS to detect out-of-tolerance (>2 mm/>2°) and commanded couch shifts was analyzed. A workflow incorporating OSMS reference captures, CBCT for pretreatment verification, and OSMS/triggered imaging (TI) for intrafraction monitoring was developed for rib/sternum SBRT beginning November 2021 and all NSB SBRT beginning February 2022. Treatment time and CBCT-related radiation dose between the OSMS and the non-OSMS intrafraction monitoring group was analyzed pre- and post-OSMS/TI workflow adoption. All fractions were analyzed through statistical process control with use of an XmR chart of treatment time per quarter from February 2019 to February 2023. Special cause rules were based on Institute for Healthcare Improvement criteria. RESULTS: From February 2019 to February 2023, 1993 NSB SBRT fractions were delivered, including 234 rib, 109 sternum, 214 ilium, and 682 multisite. Over 20 commanded shifts, OSMS could detect 2-mm shifts to within 0.4 mm 67% of the time and 0.8 mm 95% of the time. All NSB SBRT sites showed significant reductions in treatment time, including the greatest improvement in rib total treatment (21.6-13.4 minutes; P = 1.16 × 10-17) and beam time (7.9-3.2 minutes; P = 7.32 × 10-27). Significant reductions in CBCT-related radiation were also observed for several NSB sites. These process improvements were associated with OSMS adoption. CONCLUSIONS: Adoption of a novel NSB SBRT workflow incorporating OSMS/TI for bone intrafraction motion monitoring reduced treatment time and CBCT-related radiation exposure while also allowing for more continuous intrafraction motion monitoring for NSB SBRT. OSMS/TI enabled the transition to a tattoo-less workflow.

Indocyanine Green Tattooing During Colonoscopy as a Guide to Laparoscopic Colorectal Cancer Surgery: A Literature Review.

BACKGROUND: Endoscopic tattooing of colorectal lesions has been performed employing several markers. The indocyanine green (ICG) that uses near infrared fluorescence technology, has been recently adopted in laparoscopic colorectal cancer surgery. This study aims to systematically review the international literature to validate the ICG in laparoscopic colorectal surgery, in order to include the ICG in the therapeutic protocol. METHODS: Following AMSTAR 2 criteria, we performed a systematic review to evaluate the use of green indocyanine as a marker for preoperative endoscopic tattooing and for lymph nodes mapping. The study selection was conducted using the PubMed database from January 1989 to July 2022. RESULTS: We identified 25 eligible studies. 13 based on fluorescent tumor localization in laparoscopic colorectal surgery using ICG while 12 of them reported the lymphatic road mapping and sentinel node identification by ICG using a near-infrared camera system. One study analyzed both topics. CONCLUSIONS: In laparoscopic colorectal cancer surgery indocyanine green can be used to localize fluorescent tumors and mapping fluorescence lymph node. The use of ICG appears to be a valid and safe technique that helps the surgeon to achieve a better oncological radicality. However, the protocols need to be clarified by further studies.