Topical Imiquimod as an Adjuvant to Laser Removal of Mature Tattoos in an Animal Model

The effect of the perfluorodecalin patch on particle emission and skin temperature during laser-induced tattoo removal

Laser-based procedures for tattoo removals are popular due to high efficacy and a relatively moderate insult. However, it often requires multiple sessions to achieve a satisfactory effect. The perfluorodecalin (PFD) patch utilizes an optical clearing agent to speed up the removal process and may decrease skin insult and harmful particles emission during treatment. This study assessed in pigs the effect of the PFD patch in connection with laser treatment of skin with and without tattoos to determine whether the PFD patch provides benefit in lowering thermal skin insult and particle emission during treatment. Skin temperature measured by infrared thermometer during laser treatment or shortly thereafter showed a significant (approximately 40%) decrease with the PFD patch in sites with tattoos. For laser-treated sites without tattoos, there was a significant decrease of particles observed with the PFD patch. In laser-treated sites with tattoos, a strong trend was seen (approximately a twofold decrease) but did not reach statistical significance due to high variability. The present data show that the PFD patch limits the increase in skin temperature produced with laser during treatment. Moreover, it decreases the emission of particles in sites without tattoos and is suggestive of a similar effect in sites with tattoos.

Quantitative Monitoring of Tattoo Contrast Variations after 755-nm Laser Treatments in In Vivo Tattoo Models

Laser lights have been used by dermatologists for tattoo removal through photothermal interactions. However, most clinical studies used a visual scoring method to evaluate the tattoo removal process less objectively, leading to unnecessary treatments. This study aimed to develop a simple and quantitative imaging method to monitor the degree of tattoo removal in in vivo skin models. Sprague Dawley rat models were tattooed with four different concentrations of black inks. Laser treatment was performed weekly on the tattoos using a wavelength of 755 nm over six weeks. Images of non-treated and treated samples were captured using the same method after each treatment. The intensities of the tattoos were measured to estimate the contrast for quantitative comparison. The results demonstrated that the proposed monitoring method quantified the variations in tattoo contrast after the laser treatment. Histological analysis validated the significant removal of tattoo inks, no thermal injury to adjacent tissue, and uniform remodeling of epidermal and dermal layers after multiple treatments. This study demonstrated the potential of the quantitative monitoring technique in assessing the degree of clearance level objectively during laser treatments in clinics.

Tattoo removal with ingenol mebutate

An increasing number of people are getting tattoos; however, many regret the decision and seek their removal. Lasers are currently the most commonly used method for tattoo removal; however, treatment can be lengthy, costly, and sometimes ineffective, especially for certain colors. Ingenol mebutate is a licensed topical treatment for actinic keratoses. Here, we demonstrate that two applications of 0.1% ingenol mebutate can efficiently and consistently remove 2-week-old tattoos from SKH/hr hairless mice. Treatment was associated with relocation of tattoo microspheres from the dermis into the posttreatment eschar. The skin lesion resolved about 20 days after treatment initiation, with some cicatrix formation evident. The implications for using ingenol mebutate for tattoo removal in humans are discussed.

Deformable Nanovesicles Synthesized through an Adaptable Microfluidic Platform for Enhanced Localized Transdermal Drug Delivery

Phospholipid-based deformable nanovesicles (DNVs) that have flexibility in shape offer an adaptable and facile method to encapsulate diverse classes of therapeutics and facilitate localized transdermal delivery while minimizing systemic exposure. Here we report the use of a microfluidic reactor for the synthesis of DNVs and show that alteration of input parameters such as flow speeds as well as molar and flow rate ratios increases entrapment efficiency of drugs and allows fine-tuning of DNV size, elasticity, and surface charge. To determine the ability of DNV-encapsulated drug to be delivered transdermally to a local site, we synthesized, characterized, and tested DNVs carrying the fluorescently labeled hydrophilic bisphosphonate drug AF-647 zoledronate (AF647-Zol). AF647-Zol DNVs were lyophilized, resuspended, and applied topically as a paste to the calvarial skin of mice. High-resolution fluorescent imaging and confocal microscopy revealed significant increase of encapsulated payload delivery to the target tissue-cranial bone-by DNVs as compared to nondeformable nanovesicles (NVs) or aqueous drug solutions. Interestingly, NV delivery was not superior to aqueous drug solution. Our studies show that microfluidic reactor-synthesized DNVs can be produced in good yield, with high encapsulation efficiency, reproducibility, and stability after storage, and represent a useful vehicle for localized transdermal drug delivery.

Topical imiquimod in conjunction with Nd:YAG laser for tattoo removal

The purpose of this study is to evaluate the efficacy of tattoo removal using topical imiquimod 5% cream in conjunction with the 1,064-nm Nd:YAG laser. This procedure for tattoo removal will be compared to laser treatment alone, which is the standard for cosmetic removal of tattoos. Previous studies have linked partial tattoo removal to imiquimod application in a guinea pig model.

METHODS

This was a small-sized, double-blinded, placebo-controlled trial with patients with Fitzpatrick skin types I-IV (light skin) who were 18-65 years of age. The patients were required to have had two tattoos of similar age and dark blue or black in color in areas that can be covered by clothing. There were four visits in total, with laser treatment and photography being performed on the first visit. Laser settings were with 1,064-nm Nd:YAG with a 10-ns pulse, 3-mm spot size, and 4 J of energy, a standard laser used for tattoo removal. During the second visit, tattoos were randomized and chosen to receive either the laser-imiquimod treatment course or laser-vehicle cream treatment. The patients returned 1 month after the completion of cream application (week #10) and 2 months after the completion of treatment with cream (week #14) for final evaluation and photographing.

RESULTS

Three patients were enrolled in this study. All of them are Fitzpatrick skin type IV. All of the patients were compliant with the drug application and have good tolerability with only mild pruritus without changing of vascularity or pigmentation. None of the patients had ulceration or scar development during the cream application.

CONCLUSIONS

imiquimod plus laser therapy demonstrated a more favorable outcome when evaluated by the investigators or subjects. The mean scores for tattoo clearance from baseline to 2 months after completion of treatment with 5% imiquimod cream versus placebo cream were 4.3 versus 2.7 as rated by investigators and 4.7 versus 2.3 as rated by subjects. No textural changes were observed after therapy and were not shown to be different between the two groups. Further large-scale studies are important in developing a role for the use of imiqumod in laser-assisted tattoo removal.

Tattoo removal

Tattoos have been a part of costume, expression, and identification in various cultures for centuries. Although tattoos have become more popular in western culture, many people regret their tattoos in later years. In this situation, it is important to be aware of the mechanisms of tattoo removal methods available, as well as their potential short- and long-term effects. Among the myriad of options available, laser tattoo removal is the current treatment of choice, given its safety and efficacy.