Search

Dermoscopy refers to the examination of skin by use of a dermatoscope. These devices provide a practical, noninvasive, painless, and incredibly detailed view of the skin. When used in the hands of a trained clinician, dermoscopy significantly increases diagnostic accuracy. Although most known for its role in pigmented lesion assessment, dermoscopy use has expanded to include the evaluation of nonpigmented lesions, conditions of the hair (trichoscopy), infestations (entomodermatoscopy), nail disease (onychoscopy), and cutaneous inflammatory disease (inflammatoscopy). Studies suggest that dermoscopy is valuable as it increases sensitivity for skin cancer detection. This is especially important in the setting of melanoma as it accounts for most skin-cancerrelated deaths. Overall, utilization enhances diagnosis, prompts treatment, reduces morbidity and mortality, and increases healthcare cost-effectiveness. This article is written with the intent to inform dermatology nurse practitioners about this innovation. It may additionally serve as a useful resource for other advanced care providers who perform cutaneous assessment. Examples of such cliniciansmay include, but are not limited to, urgent care providers, pediatricians, dentists, podiatrists, and primary care providers. [ABSTRACT FROM AUTHOR]

Background: The observation of color is an integral part of the nursing assessment. However, the current understanding of individual skin qualities and pigmentation has not yet been integrated thoroughly into foundational assessment courses, clinical education, simulation, and textbooks. Evidence Acquisition: Literature is scarce regarding racial groups, skin color, and physical assessment for patients across the lifespan, but even more so for the neonatal population. Historically, many nursing textbooks did not provide visual pictures or observational assessment strategies for the assessment of the Black, Indigenous, and people of color (BIPOC) population. This is improving in some nursing textbooks; however, the descriptors of and visual differences and anticipated assessment findings for the BIPOC population are not comprehensive. Results: Evidence-based assessment findings, which may occur in newborns with varying skin tones/pigmentations, are presented. Implications for Practice and Research: The most essential step to having an accurate assessment is acknowledging the importance of color awareness. Color blindness, while thought to support inclusivity, only contributes to exclusion of one of the most important components of a person's being—their color. [ABSTRACT FROM AUTHOR]

Copyright of Biotechnologie, Agronomie, Societe et Environnement is the property of Les Presses Agronomiques de Gembloux and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The tobacco BY-2 cell line is one of the most utilized plant cell lines. After long-term culture, the cells turn brown to black, but the causal pigment is unknown. We successfully isolated a blackish-brown pigment from BY-2 cells cultured for 3 weeks. Morphological and spectroscopic analyses indicated that the pigment had similar features to a melanin-like substance reported previously. Furthermore, physicochemical analyses revealed that this pigment possessed most of the properties of melanin-like pigments. In addition, the high nitrogen content suggested that it differed from common plant melanins classified as allomelanins, suggesting a novel eumelanin-like pigment: "BY2-melanin". This is the first example showing that eumelanin-like pigments are produced in the cultures of plant cells for which the accumulation of melanin has not been reported. This tobacco BY-2 cell culture technique may represent a customizable and sustainable alternative to conventional melanin production platforms, with significant potential for industrial and pharmacological applications. [ABSTRACT FROM AUTHOR]

Background: Bletilla species are endangered terrestrial orchids used in natural skin care formulas in Asia for a long history. In order to explore the bioactivity potential of Bletilla species as a cosmetic ingredient in a sustainable resource manner, the callus of Bletilla formosana (Hayata) Schltr. was established and extracted by an eco-friendly supercritical fluid CO2 extraction (SFE-CO2) method. The intracellular reactive oxygen species (ROS) scavenging activity and antioxidation-related gene expression of the callus extract were evaluated in both Hs68 fibroblast cells and HaCaT keratinocytes. The melanogenesis-inhibitory effect was investigated in B16F10 melanoma cells and in an in vivo zebrafish model. Results: The calli of B. formosana were propagated for 10–15 generations with a consistent yellow friable appearance and then subjected to SFE-CO2 extraction to obtain a yellow pasty extract. Obvious intracellular ROS scavenging activity of the extract was detected in both Hs68 and HaCaT cells with 64.30 ± 8.27% and 32.50 ± 4.05% reduction at the concentration of 250 μg/mL. Moreover, marked expression levels of heme oxygenase-1 (HO-1) and (NAD(P)H) quinone oxidoreductase-1 (NQO1) genes were detected after 6-h and 24-h treatments. These results indicate the cellular antioxidative activity of B. formosana callus extract was probably activated via the nuclear factor erythroid 2-related factor 2 (Nrf2)/HO-1 signaling pathway. Melanogenesis-inhibitory effect of the extract was observed in α-MSH stimuli-inducing B16F10 cells with 28.46% inhibition of intracellular melanin content at the concentration of 50 μg/ml. The effect was confirmed with in vivo zebrafish embryos that showed a relative pigmentation density of 80.27 ± 7.98% at the concentration of 100 μg/mL without toxicity. Conclusion: Our results shed light on a sustainable utilization of Bletilla species as a potential ingredient for skin. [ABSTRACT FROM AUTHOR]

Objective: To compare and evaluate the clinical efficacy of diode laser and cryosurgery for treating melanin pigmentation of gingiva. Material and Methods: A total of twenty-five subjects with physiological gingival pigmentation on the facial aspect of both maxillary and mandibular anterior arches (50 sites), both male and female, with an average age ranging from 18-35 years, participated in the study. The sites were randomly divided into Group I: depigmentation by Laser and Group II: depigmentation by Cryosurgery. The following parameters were assessed for the evaluation of treatment results: Melanin Oral Pigmentation Index (PI), Visual Analogue Scale (VAS) for pain evaluation and Healing index (HI). The data collected was statistically evaluated. Results: On intergroup comparison, there was no statistical difference in the score from baseline (p>0.05); however, a statistically significant difference was seen at the end of 1 year (p<0.05). Moreover, 57- 60% of arches showed recurrence of pigmentation in the laser group whereas; only 12.7-17% recurrence was seen in the cryosurgery group at the end of the first year. Conclusion: Treatment of gingival hyperpigmentation with laser and cryosurgery shows a marked improvement of gingival pigmentation in both groups, but the cryosurgery depigmentation sites showed more sustainability. [ABSTRACT FROM AUTHOR]

Melanin, a macromolecule derived from the oxidative polymerization of phenolic compounds, possesses notable bioactive attributes and serves as a crucial biological safeguard against deleterious environmental factors. Melanin originates in Streptomyces and is known for its antioxidative properties. This study aimed to characterize and evaluate the antioxidant activity of melanin obtained from Streptomyces lasalocidi NTB 42. Based on 16 S rRNA identification, strain NTB 42 was identified as Streptomyces lasalocidi NTB 42 (OR710932). During melanin biosynthesis, S. lasalocidi NTB 42 had the highest tyrosinase activity on day 5 and the highest L-3,4-dihydroxyphenylalanine concentration on day 6. Melanin NTB 42 exhibited polymorphic and irregular morphology. Melanin NTB 42 characteristics were analyzed using the A 650 /A 500 ratio, UV–visible spectroscopy, Fourier transform infrared spectroscopy, high-performance liquid chromatography, dispersive X-ray spectroscopy, and thermal degradation products based on pyrolysis-gas chromatography-mass spectrometry were identified as eumelanin. The scavenging ability of NTB 42 melanin, as determined by the half maximal inhibitory concentration (IC 50), was 70.60 ± 0.40 μg/mL for 2,2-diphenyl-1-picrylhydrazyl and 176.76 ± 0.93 μg/mL for 2,2′-azino-bis(3-ethylbenzothiazolin-6-acid sulfonate radicals. The Fe-reducing power and total antioxidant capacity values were 114.05 ± 0.41 mg AAE/g melanin and 145.10 ± 0.56 mg AAE/g melanin, respectively. This study is the first attempt to characterize the antioxidant properties of eumelanin from S. lasalocidi NTB 42. The antioxidant ability of eumelanin NTB 42 against various free radicals shows promise for further development as an antioxidant. [Display omitted] • Streptomyces lasalocidi NTB 42 has never been reported to produce melanin. • Tyrosinase and L-DOPA play a role in the eumelanin formation process of NTB 42. • Melanin NTB 42 has unique characteristics and is classified as eumelanin. • Eumelanin NTB 42 can scavenge DPPH and ABTS radicals. • Eumelanin NTB 42 can potentially reduce the power of Fe3+ and Mo(VI). [ABSTRACT FROM AUTHOR]

This study aims to characterize and explore the biological effects of melanin derived from nigerseed (Guizotia abyssinica) hulls, which are inedible. Extracted melanin was selectively soluble in alkali and DMSO. The melanin extract demonstrated robust antioxidant and DPPH radical scavenging activities. It exhibited strong antibacterial effects against foodborne pathogens, as indicated by the zone of inhibition (in mm); Salmonella enterica (40.00 ± 0.00), Staphylococcus aureus (37.33 ± 1.15), Micrococcus luteus (31.67 ± 0.58), Klebsiella oxytoca (31.33 ± 1.15), Escherichia coli (30.33 ± 0.58), and Bacillus cereus (28.33 ± 1.15). For antifungal activity, melanin displayed selectivity, suggesting its potential as a targeted antifungal agent. This research highlights nigerseed byproducts as a cost-effective and promising source for melanin production, showcasing its potential in the pharmaceutical sector as a natural alternative to chemically derived drugs. [Display omitted] • FTIR spectral study revealed common signals in synthetic melanin and melanin from nigerseed hulls (NH). • Melanin from Nigerseed hulls exhibited significant antimicrobial activity against various microorganisms. • DPPH scavenging activity of NH melanin indicated a gradual increase in scavenging with higher melanin concentration. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the effects of phenolic acids (caffeic, ferulic, and coumaric acids) and flavones (luteolin and apigenin) on the proliferation and melanogenesis in murine melanoma B16-F10 cells. Methods: Cell proliferation was determined after 24 and 48 hours of incubation using MTT assay. The effects of these tested compounds on cell cycle progression were analyzed by flow cytometry. Moreover, the melanin content and tyrosinase activity were measured spectrophotometrically at 475 nm. Results: Luteolin and apigenin exhibited significant anti-proliferative activity against B16-F10 cells, while caffeic, ferulic, and coumaric acids induced slight inhibition after 24 and 48 hours of incubation. The tested compounds disturbed cell cycle progression of B16-F10, by a subsequent decrease in G1 and arrested cycle progression in either G1/S or G2/M phase. Furthermore, apigenin provoked an increase in melanin content of B16-F10 cells. In contrast, luteolin, caffeic, ferulic and coumaric acids induced a decrease in melanin content of B16-F10 cells by inhibiting tyrosinase activity. Conclusions: These active polyphenols may be used as skin whitening agents or natural tanning agents to treat skin pigmentation disorders. [ABSTRACT FROM AUTHOR]

Rhabdomyolysis-induced acute kidney injury (AKI) is closely related to toxic reactive oxygen species (ROS), apoptosis, and inflammation. Excessive activation of poly (ADP-ribose) polymerase-l (PARP-1) by ROS can cause mitochondrial dysfunction and release of the proapoptotic protein AIF, which triggers an intrinsic PARP-1-dependent cell death program. Considering these characteristics of rhabdomyolysis-induced AKI, we developed a targeting nanodrug delivery platform by loading PJ34 and coupling anti-GPR97 with melanin nanoparticles (GMP nanoparticles) that could realize photoacoustic self-monitoring and triple-collaborative treatment (antioxidant, antiapoptotic, and anti-inflammatory). The nanoparticles exhibited good dispersibility, solubility, and broad-spectrum ROS scavenging ability. In vitro experiments revealed high biocompatibility of the GMP nanoparticles and strong ability of scavenging multiple toxic ROS, antiapoptotic activity, and anti-inflammatory activity. Because melanin nanoparticles possess inherent photoacoustic (PA) imaging capability, they can not only serve as a drug carrier but also perform self-monitoring for real-time tracking of GMP biodistribution and renal uptake in a murine AKI model through PA imaging. In vivo experiments showed that the GMP nanoparticles could effectively reduce oxidative stress, apoptosis, and inflammatory response in mice with rhabdomyolysis-induced AKI, and the mechanism of alleviation was verified through western blot experiments. These results indicated that the nanoplatform could realize the targeted delivery and curative effect monitoring under the guidance of PA imaging, which is of great significance for the prevention and treatment of AKI. A targeting nanodrug delivery platform was developed by loading PJ34 and coupling anti-GPR97 with melanin nanoparticles (GMP nanoparticles) for photoacoustic self-monitoring and triple-collaborative treatment (antioxidant, antiapoptotic, and anti-inflammatory) of acute kidney injury (AKI). Further studies indicated that the Keap-1/Nrf2/HO-1 and PARP-1/AIF signaling pathways are involved in the therapeutic mechanisms to alleviate AKI. Immunohistochemical staining and routine blood test confirmed the anti-inflammatory performance of GMP nanoparticles. Compared to exogenous nanomaterials, we used endogenous melanin with broad ROS scavenging capacity as the nanocarrier and antioxidant, which not only overcomes the defects of high specificity, potential toxicity, low loading capacity, and high cost but also shows good biosafety and photoacoustic imaging performance in vivo. [Display omitted] [ABSTRACT FROM AUTHOR]

People of color are at a lower risk for developing skin cancer; however, melanoma skin cancer in this population is associated with a high mortality rate. Misconceptions regarding skin cancer risk often delay treatment, contributing to negative outcomes. These misconceptions were evident in a nurse-practitioner-led project that was conducted at a Division I University to improve sun safety in female collegiate athletes, with a lack of sun safety knowledge noted among Black participants. Nurses and nurse practitioners have a pivotal role in preventing skin cancer in people of color. This article summarizes the project's findings and current literature to clarify misconceptions regarding skin cancer in people of color, specifically in Black individuals. Clinical information is provided to guide nurses and nurse practitioners in promoting awareness and early detection of skin cancer. [ABSTRACT FROM AUTHOR]

Chloroquine is an important, and commonly prescribed, antimalarial drug which can lead to the development of retinopathy and potential blindness. This paper reports on the design and fabrication of a highly selective potentiometric sensor for chloroquine, demonstrating the first use of ionophore-doped ion-selective electrodes (ISEs) for its detection. Several molecules, with known affinity for chloroquine, were investigated as potential ionophores for the chloroquine ISE. Incorporating melanin as the ionophore resulted in a linear detection range of 10 mM to 2.4 μM and a limit of detection of 630 nM. Importantly, the melanin-doped ISE resulted in an increased selectivity by several orders of magnitude compared to an ionophore-free ISE. This added selectivity allowed for detection of chloroquine without interference from other commonly prescribed antimalarials, hydroxychloroquine and quinine that have similar molecular structures. To determine the applicability of the melanin-doped ISE, chloroquine was successfully measured in human urine samples, and the results of the sensor were validated using a High-Performance Liquid Chromatography (HPLC) protocol. To demonstrate the utility of the sensor, the components of the ISE were translated to a paper)based potentiometric device capable of detecting chloroquine between 10 mM and 100 μM, covering the biologically relevant range excreted in human urine. [ABSTRACT FROM AUTHOR]

An 11-year-old spayed female Miniature Schnauzer dog was presented with loss of a claw caused by a nail bed mass. Histopathological evaluation revealed that the mass comprised neoplastic squamous cells with abundant cytoplasmic melanin pigment. Immunohistochemically, the neoplastic cells were positive for cytokeratin and negative for vimentin and ionized calcium-binding adaptor molecule 1, supporting a diagnosis of pigmented squamous cell carcinoma. To our knowledge, this is the first report of subungual pigmented squamous cell carcinoma in animals. [ABSTRACT FROM AUTHOR]

The koi carp is an ornamental fish that was obtained through artificial selection from the common carp (Cyprinus carpio L.). The most economically important traits of koi are their beautiful skin patterns in bright colors. As seasonality is an important factor in the biology and ecology of fish, we thus assumed that seasonal changes are involved in regulating the formation of skin color and patterns of koi carp. The white, red, cyan, and black skin colors from four varieties of scaleless koi carp (Doitsu Shiromuji (W), Doitsu Kohaku (W R), Doitsu Showa Sanke (WRI), and Kumonryu (WI)) were evaluated using the CIELab color space (lightness, redness, and yellowness) in different seasons. Compared to winter, the yellowness of the white color in all koi varieties decreased in summer and autumn. The black skin color areas in WRI and WI koi increased in summer and autumn compared to winter. The yellowness of the red color decreased only in WRI koi, while no changes were observed in W R koi. Targeted metabolomics analysis revealed that the levels of the structural pigment guanine of all koi varieties showed significant seasonal variation. Of seven detected carotenoids, the zeaxanthin and tunaxanthin contents in W, WI, and WRI koi changed with the seasons, while none of the carotenoids in W R koi were altered. Of the seven potential regulatory metabolites, epinephrine, melatonin, and cyclic adenosine monophosphate (cAMP) in all four koi varieties showed the highest levels in winter. A correlation analysis suggested that the seasonal changes in white skin color occurred through the epinephrine-cAMP pathway; melanin-dependent and carotenoid-dependent skin color changes occurred through melatonin in koi carp. This study demonstrated the seasonal plasticity of skin color in koi carp regulated by melatonin and epinephrine, associating with variety and color specificity. [Display omitted] • Koi variety differences in seasonal skin color plasticity. • Components of seasonal variation in carotenoids are zeaxanthin and tunaxanthin. • Seasonality changes the red skin of koi through melatonin. • Seasonality changes the white skin of koi through epinephrine-cAMP pathway. [ABSTRACT FROM AUTHOR]

Reactive oxygen species (ROS) are oxygen-free radicals produced from the metabolic reactions in living organisms. ROS with moderate levels in cells are the cell signaling molecules involved in cellular proliferation, survival, differentiation, and gene expression. Nevertheless, it can cause oxidative damage through increased excessive ROS generation. Melanin, a natural pigment found in all biological kingdoms, is known to contribute to different biological processes and to protect organisms from adverse environmental conditions. Its antioxidant capacity has been broadly studied and demonstrated. This study aimed to find out how the melanin extracted from the cuttlefish Sepia pharaonis ink (MCI) affected the antioxidant activities of Clone-9 cells. The results showed that 300 and 500 μg/mL MCI decreased the intracellular ROS level by 89.8% and 78.6%, respectively. MCI could promote mitochondrial functions and the increase in mitochondrial membrane potential. Furthermore, the gene expression and activities of master antioxidant enzymes, namely SOD, CAT, and GPx, were also increased by at least 20% by MCI inducement. The mechanistic study found that this protective capacity is mediated by enhanced translocation of Nrf2 from the cytoplasm to the nucleus due to MCI induction of activation of the Nrf2 transcription factor. Our study might contribute to throwing light on the molecular mechanism of the MCI's cytoprotective capacity under oxidative stress conditions, which may provide a foundation for the application of MCI in both the pharmaceutical and food industries. This helps to build awareness about using cephalopod ink, which most processing industries and consumers throw away as a byproduct. [Display omitted] • Melanin extracted from the cuttlefish (Sepia pharaonis) ink (MCI) decreased the intracellular ROS level. • MCI elevated the mitochondrial membrane potential, thereby enhancing mitochondrial functions. • Through the Nrf2 pathway, MCI increased the expression of genes and activities of antioxidant enzymes (SOD, CAT, and GPx). • MCI could be applied as a new preservation strategy in the food industry or as a dietary supplement. [ABSTRACT FROM AUTHOR]

Body color is an important visual indicator of crustacean quality and plays a major role in consumer acceptability, perceived quality, and the market price of crustaceans. The freshwater prawn (Macrobrachium rosenbergii) has two distinct phenotypic variations, characterized by dark blue and light yellow body colors. However, the underlying mechanisms regulating the body color of M. rosenbergii remain unclear. In this study, the composition of shell color parameters and pigment cells of raw and cooked dark blue and light yellow M. rosenbergii was investigated and the mechanisms associated with body color were elucidated by transcriptome analysis. The results showed significant differences in the raw shells of the dark blue and light yellow M. rosenbergii (L : 26.20 ± 0.53 vs. 29.25 ± 0.45; a : −0.88 ± 0.19 vs. 0.35 ± 0.18; b : 1.73 ± 0.20 vs. 3.46 ± 0.37; dE : 70.33 ± 0.53 vs. 67.34 ± 0.45, respectively, p = 0.000) as well as the cooked shells (L : 58.14 ± 0.81 vs. 55.78 ± 0.55; a : 19.30 ± 0.56 vs. 16.42 ± 0.40; b : 23.60 ± 0.66 vs. 20.30 ± 0.40, respectively, p < 0.05). Transcriptome differential gene analysis obtained 39.02 Gb of raw data and 158,026 unigenes. Comprehensive searches of the SwissProt, Nr, KEGG, Pfam, and KOG databases resulted in successful annotations of 23,902 (33 %), 40,436 (25.59 %), 32,015 (20.26 %), 26,139 (16.54 %), and 22,155 (14.02 %) proteins, respectively. By KEGG pathway analysis, numerous differentially expressed genes were related to pigmentation-related pathways (MAPK signaling pathway, Wnt signaling pathway, melanin production, tyrosine metabolism, and cell-cell communication process). Candidate DEGs that may be involved in body color included apolipoprotein D, crustacyanin, cytochrome P450, and tyrosinase, as verified by quantitative real-time PCR. The results of this study provide useful references to further elucidate the molecular mechanisms of color formation of M. rosenbergii and other crustaceans. [Display omitted] • There is a significant difference in the color difference between dark blue and light yellow M. rosenbergii. • Dark blue M. rosenbergii has abundant blue pigment cells, light yellow M. rosenbergii shows only yellow and black pigments; • A considerable number of DEGs in the two colors were related to pigmentation-related pathways; [ABSTRACT FROM AUTHOR]

Copyright of Arquivos de Neuro-Psiquiatria is the property of Thieme Medical Publishing Inc. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Melanins are tyrosine-derived pigments that are ubiquitous in animals, plants, and fungi. Melanins are often associated with black and brown pigmentation, which provide a variety of biological functions, such as mimicry, camouflage, thermoregulation, and UV protection. The synthetic pathway of melanin pigments has been extensively studied in vertebrates, but interestingly, it has become clear that the kinds of melanin pigments and genes involved in melanin biosynthesis differ significantly between insects and vertebrates. Dopamine melanin is the major melanin pigment in various insects. In insects, most of the melanin synthesis genes are highly conserved, but the yellow family genes and aaNAT family genes exhibit diversity in gene repertoire among diverse insect taxa. In this review, we introduce eight melanin synthesis genes involved in insect epidermal pigmentation: tyrosine hydroxylase (TH), dopa decarboxylase (DDC), aspartate 1-decarboxylase (ADC, black), N-ß-alanyldopamine synthase (NBADS, ebony), N-ß-alanyldopamine hydrolase (NBADH, tan), arylalkylamine N-acetyltransferase (aaNAT), multicopper oxidase 2 (MCO2, laccase2), and yellow. For each gene, we show the molecular phylogenetic tree based on the amino acid sequences of six representative insects, the fruit fly Drosophila melanogaster (Diptera), the silkworm Bombyx mori (Lepidoptera), the swallowtail butterfly Papilio xuthus (Lepidoptera), the red flour beetle Tribolium castaneum (Coleoptera), the honeybee Apis mellifera (Hymenoptera), and the blue-tailed damselfly Ischnura senegalensis (Odonata), which highlights the diversity of melanin synthesis genes among insects. We also introduce the current knowledge of the melanin synthesis gene that contribute to colour pattern formation in various insects. [ABSTRACT FROM AUTHOR]

Effective and noninvasive diagnosis and prompt treatment of early-stage hepatocellular carcinoma (HCC) are urgently needed to reduce its mortality rate. Herein, the integration of high-resolution diagnostic second near-infrared (NIR-II) photoacoustic computed tomography (PACT) and imaging-guided targeted photothermal ablation of orthotopic small HCC (SHCC) is presented for the first time, which was enabled by a plasmonic platinum (Pt)-doped polydopamine melanin-mimic nanoagent. As designed, an antibody-modified nanoagent (designated Pt@PDA-c) with a plasmonic blackbody-like NIR absorption and superior photothermal conversion efficiency (71.3%) selectively targeted and killed CXCR4-overexpressing HCC (HepG2) cells, which was validated in in vitro experiments. The targeted accumulation properties of Pt@PDA-c in vivo were previously recognized by demonstrating effective NIR-II PA imaging and photothermal ablation in a subcutaneous HCC mouse model. Subsequently, with real-time quantitative guidance by PACT for the accurate diagnosis of intraabdominal SHCC (approximately 4 mm depth), the effective and noninvasive photothermal ablation of SHCCs was successfully demonstrated in an orthotopic tumor-bearing mouse model without damaging adjacent liver tissues. These results show a great potential of NIR-II PACT-guided noninvasive photothermal therapy as an innovative phototheranostic approach and expand the biomedical applications of melanin-mimic materials. In this paper, we report the first diagnostic NIR-II photoacoustic computed tomography (PACT)-guided noninvasive photothermal ablation of small hepatocellular carcinoma (SHCC) located in deep tissues in orthotopic tumor-bearing mice; this process is empowered by a polydopamine-based melanin-mimic tumor-targeting nanoagent doped with plasmonic platinum that provides superior NIR-II (1064 nm) absorption and photothermal conversion efficiency of 71.3%. Following surface modification with anti-CXCR4 antibodies, the nanoagent (namely Pt@PDA-c) can selectively target CXCR4-overexpressed HepG2 carcinoma cells and tumor lesions, and serve as the theranostic agent for both NIR-II PACT-based diagnosis of orthotopic SHCC (diameter less than 5 mm) and efficient NIR-II PTT in vivo. This study may also extend the potential of melanin-derived blackbody materials for optical-biomedical and water distillation applications. [Display omitted] [ABSTRACT FROM AUTHOR]

Background: Hypoxia refers to the condition of low oxygen pressure in the atmosphere and characterization of response to hypoxia as a biological complex puzzle, is challenging. Previously, we carried out a comparative genomic study by whole genome resequencing of highland and lowland Iranian native chickens to identify genomic variants associated with hypoxia conditions. Based on our previous findings, we used chicken as a model and the identified hypoxia-associated genes were converted to human's orthologs genes to construct the informative gene network. The main goal of this study was to visualize the features of diseases due to hypoxia-associated genes by gene network analysis. Results: It was found that hypoxia-associated genes contained several gene networks of disorders such as Parkinson, Alzheimer, cardiomyopathy, drug toxicity, and cancers. We found that biological pathways are involved in mitochondrion dysfunctions including peroxynitrous acid production denoted in brain injuries. Lewy body and neuromelanin were reported as key symptoms in Parkinson disease. Furthermore, calmodulin, and amyloid precursor protein were detected as leader proteins in Alzheimer's diseases. Dexamethasone was reported as the candidate toxic drug under the hypoxia condition that implicates diabetes, osteoporosis, and neurotoxicity. Our results suggested DNA damages caused by the high doses of UV radiation in high-altitude conditions, were associated with breast cancer, ovarian cancer, and colorectal cancer. Conclusions: Our results showed that hypoxia-associated genes were enriched in several gene networks of disorders including Parkinson, Alzheimer, cardiomyopathy, drug toxicity, and different types of cancers. Furthermore, we suggested, UV radiation and low oxygen conditions in high-altitude regions may be responsible for the variety of human diseases. [ABSTRACT FROM AUTHOR]

An interdisciplinary review of the chemical literature that points to a unifying scenario for the origin of life, referred to as the Primordial Multifunctional organic Entity (PriME) scenario, is provided herein. In the PriME scenario it is suggested that the Insoluble Organic Matter (IOM) in carbonaceous chondrites, as well as interplanetary dust particles from meteorites and comets may have played an important role in the three most critical processes involved in the origin of life, namely 1) metabolism , via a) the provision and accumulation of molecules that are the building blocks of life, b) catalysis (e.g., by templation), and c) protection of developing life molecules against radiation by excited state deactivation; 2) compartmentalization , via adsorption of compounds on the exposed organic surfaces in fractured meteorites, and 3) replication , via deaggregation, desorption and related physical phenomena. This scenario is based on the hitherto overlooked structural and physicochemical similarities between the IOM and the dark, insoluble, multifunctional melanin polymers found in bacteria and fungi and associated with the ability of these microorganisms to survive extreme conditions, including ionizing radiation. The underlying conceptual link between these two materials is strengthened by the fact that primary precursors of bacterial and fungal melanins (collectively referred to herein as allomelanins) are hydroxylated aromatic compounds like homogentisic acid and 1,8-dihydroxynaphthalene, and that similar hydroxylated aromatic compounds, including hydroxynaphthalenes, figure prominently among possible components of the organic materials on dust grains and ices in the interstellar matter, and may be involved in the formation of IOM in meteorites. Inspired by this rationale, a vis-à-vis review of the properties of IOM from various chondrites and non-nitrogenous allomelanin pigments from bacteria and fungi is provided herein. The unrecognized similarities between these materials may pave the way for a novel scenario at the origin of life, in which IOM-related complex organic polymers delivered to the early Earth are proposed to serve as PriME and were preserved and transformed in those primitive forms of life that shared the ability to synthesize melanin polymers playing an important role in the critical processes underlying the establishment of terrestrial eukaryotes. • The IOM in chondrites is remarkably similar to the allomelanins in microorganisms. • Allomelanins can promote phenomena and processes of astrobiological relevance. • Being similar to allomelanins, IOM may have played a role in the origin of life. [ABSTRACT FROM AUTHOR]

Triphenyltin (TPT) is a typical persistent organic pollutant whose occurrence in coral reef ecosystems may threaten the survival of reef fishes. In this study, a brightly colored representative reef fish, Amphiprion ocellaris was used to explore the effects of TPT at environmental levels (1, 10, and 100 ng/L) on skin pigment synthesis. After the fish were exposed to TPT for 60 days, the skin became darker, owing to an increase in the relative area of black stripes, a decrease in orange color values while an increase in brown color values, and an increase in the number of melanocytes in the orange part of the skin tissues. To explore the mechanisms by which TPT induces darker body coloration, the enzymatic activity and gene expression levels of the members of melanocortin system that affect melanin synthesis were evaluated. Leptin levels and lepr expression were found to be increased after TPT exposure, which likely contributed to the increase found in pomc expression and α-melanocyte-stimulating hormone (α-MSH) levels. Then Tyr activity and mc1r , tyr , tyrp1 , mitf , and dct were upregulated, ultimately increasing melanin levels. Importantly, RT-qPCR results were consistent with the transcriptome analysis of trends in lepr and pomc expression. Because the orange color values decreased, pterin levels and the pteridine metabolic pathway were also evaluated. The results showed that TPT induced BH 4 levels and spr , xdh , and gch1 expression associated with pteridine synthesis decreased, ultimately decreasing the colored pterin content (sepiapterin). We conclude that TPT exposure interferes with the melanocortin system and pteridine metabolic pathway to increase melanin and decrease colored pterin levels, leading to darker body coloration in A. ocellaris. Given the importance of body coloration for the survival and reproduction of reef fishes, studies on the effects of pollutants (others alongside TPT) on body coloration are of high priority. [Display omitted] • The changes of body coloration were studied in Amphiprion ocellaris as a model. • Triphenyltin exposure induced darker body coloration. • Triphenyltin interfered with the melanocortin system and pteridine metabolic pathway. • Coral reef ecosystems and reef fishes deserved more attention and protection. [ABSTRACT FROM AUTHOR]

Marine bivalves are economically important and exhibit a remarkable diversity in shell color. The Pacific oyster Crassostrea gigas stands out as an important economic species, with the successful development of four distinct color strains through selective breeding. While previous studies have shed light on the genetic mechanism underlying color segregation, the precise molecular regulatory mechanisms responsible for shell coloration in oysters remains elusive. In this study, we confirmed that the golden phenotype is primarily attributed to pheomelanin by histological and ultrastructural observations. Additionally, we conducted a comparative transcriptome analysis of the black and golden shell color oysters to explore the potential genes and pathways contributing to the golden phenotype in C. gigas. Our results revealed a significant increase in differentially expressed genes in the golden phenotype associated with pathways such as glutathione metabolism, and calcium signaling pathway, suggesting a potential role in the synthesis of pheomelanin. Of particular note, we highlighted the potential role of two-pore channel 2 (TPC2) in modulating tyrosinase activity and melanosomal pH, ultimately determining the shade of pigmentation. Our study in this work provided a preliminary exploration of the mechanism, shedding light on the melanosome microenvironment and shell color. [Display omitted] • The golden phenotype is primarily attributed to pheomelanin. • The ratio of eumelanin to pheomelanin is determined by tyrosinase activity and the availability of cysteine in melanosomes. • Melanosomal pH influences the internal environment of melanosomes, subsequently affecting melanogenesis. [ABSTRACT FROM AUTHOR]

Fish body color changes play vital roles in adapting to ecological light environment and influencing market value. However, the initial mechanisms governing the changes remain unknown. Here, we scrutinized the impact of light spectrum on turbot (Scophthalmus maximus) body coloration, exposing them to red, blue, and full light spectra from embryo to 90 days post hatch. Transcriptome and quantitative real-time PCR (qRT-PCR) analyses were employed to elucidate underlying biological processes. The results showed that red light induced dimorphism in turbot juvenile skin pigmentation: some exhibited black coloration (Red_Black_Surface, RBS), while others displayed lighter skin (Red_White_Bottom, R_W_B), with red light leading to reduced skin lightness (L *) and body weight, particularly in RBS group. Transcriptomic and qRT-PCR analyses showcased upregulated gene expressions related to melanin synthesis in RBS individuals, notably tyrosinase (tyr), tyrosinase-related protein 1 (tyrp1), and dopachrome tautomerase (dct), alongside solute carrier family 24 member 5 (slc24a5) and oculocutaneous albinism type II (oca2) as pivotal regulators. Nervous system emerged as a critical mediator in spectral environment-driven color regulation. N-methyl d -aspartate (NMDA) glutamate receptor , and calcium signaling pathway emerged as pivotal links intertwining spectral conditions, neural signal transduction, and color regulation. The individual differences in NMDA glutamate receptor expression and subsequent neural excitability seemed responsible for dichromatic body coloration in red light-expose juveniles. This study provides new insights into the comprehending of fish adaptation to environment and methods for fish body color regulation and could potentially help enhance the economic benefit of fish farming industry. [Display omitted] • Red light caused dimorphism in skin pigmentation of turbot juvenile. • Juveniles with black skin under red light showed upregulated tyrosine metabolism. • Slc24a5 and oca2 were vital genes accounting for tyrosine metabolism regulation. • Neural signaling pathway mediates the regulation of body color by light spectrum. • NMDA glutamate receptor accounted for dichromatic body color under red light. [ABSTRACT FROM AUTHOR]

In this study, we revealed that melanin biomaterial extracted from squid ink-sacs could effectively remove both gram-positive and gram-negative bacteria from water. A solid/liquid ratio of 25 mg/mL, melanin was able to remove 82% and 63% of E. coli and V. vulcificus, respectively; and, at any tested solid/liquid ratios of 5, 15, or 25 mg/mL, melanin could eliminate almost all B.cereus and S.aureus. FTIR analysis showed differences in chemical properties on surfaces of melanin in cases of with and without bacterial adsorptions. Besides, melanin nanoparticle (200 nm in size) at a concentration of 2 mg/mL had an antibacterial activity with antibacterial diameters of 17, 15, 12 and 14 for E.coli, V. vulfinicus, S. aureus and B.cereus, respectively. More interestingly, melanin nanoparticles could enhance killing ability of X-ray on SKMEL28 cell about 20%. Conlusively, we suggested that melanin biomaterial could be applied in different fields in biology depending on its existing forms. [ABSTRACT FROM AUTHOR]

Candida albicans is a harmless commensal resident in the human gut and a prevalent opportunistic pathogen. A key part of its commensalism and pathogenesis is its ability to switch between different morphological forms, including white‐to‐opaque switching. The Wor1 protein was previously identified as a master regulator of white‐to‐opaque switching in mating type locus (MTL) homozygous cells. The mechanisms by which the dark color of the opaque colonies is controlled and the pimpled surface of opaque cells is formed remain unknown. Candida albicans produces melanin pigment in vitro and during infection. However, the molecular mechanism underlying the regulation of melanin production is unclear. In this study, we demonstrated that ferroxidases (Fets) function as pigment multicopper oxidases and regulate the production of dark‐pigmented melanin in opaque cells. The FET genes presented distinct regulation patterns in response to different extracellular stimuli. In YPD (1% yeast extract, 2% peptone and 2% dextrose)‐rich medium, four of the five FET genes were up‐regulated by Wor1, especially at the human body temperature of 37 °C. In minimal medium with low ammonium concentrations, all five FET genes were up‐regulated by Wor1. However, at high ammonium concentrations, some FET genes were down‐regulated by Wor1. Wor1‐up‐regulated Fets contributed to dark pigment formation in opaque colonies, but not to the elongated shape of these opaque cells. Increased melanin externalization was associated with the pimpled surface of the opaque cells. Melanized C. albicans cells were more resistant to fungal clearance. Deletion of the five FET genes completely blocked melanin production in opaque cells and resulted in the generation of white elongated 'opaque' cells. In addition, the up‐regulated Fets are important for defense against oxidant attacks. The functional diversity of Fets may reflect the multiple strategies of C. albicans to rapidly adapt to diverse host niches. [ABSTRACT FROM AUTHOR]

111 NANOTECHNOLOGY & FINISHING UV Drotective,inisning on cottoniallric using melanin nanoilarticles Mahesh H Joshi, AshwiniA Patil and RavindraVAdivarekar Institute of Chemical Technology, Matunga (E), Mumbai, India rv.adivarekar@ictmumbai.edu.in elanin is a high molecular weight compound produced by oxidation of L-tyrosine as the primary precursor in the melanocytes n-' I present at the base of the hair. For this study, dimethylol- 4 (SEM) and 3D laser scanning Idihydroxyethylene urea (DMDHEU), UV-Visible spectroscopy microscopy glutaraldehyde and glyoxal were The absorption spectrum of melanin Melanin nanoparticles were dried, selected14. Effect of washing UV protection factor (UPF) i.e., the DMDHU, glutaraldehyde, glyoxal etc on UPF ratings was studied till 10 Asian Dyer• February- March 2021 • 26 NANOTECHNOLOGY & FINISHING washing cycles using a launder-0-meter UV irradiance calculated for unprotected Table 1: Classification scheme for (AATCC 1993). [Extracted from the article]

Albino mutants (white coat and red eyes) of tanuki (Nyctereutes procyonoides viverrinus) have been repeatedly found in the Central Alps area of Japan. We recently reported that an albino tanuki from Iida, a city in this area, lacks the third exon of the TYR gene encoding tyrosinase, which is essential for melanin synthesis. The absence of this exon was due to the chromosomal deletion of a complex structure. In the present study, we analyzed TYR of another albino tanuki that was found in Matsusaka, a city located outside the mountainous area. In this animal, the third exon was also lost, and the loss was due to a deletion in which the structure was identical to that of the Iida mutant. Our results indicate, in consideration of the complex structure of the deletion, that the two albino animals inherited a single deletion that arose in their common ancestor. Iida and Matsusaka are approximately 170 km apart. This is, to our knowledge, the first report of an albino mutant gene that is widely distributed in mammalian natural populations. As the origin of this mutation is not known, the distance covered by the mutant gene remains unclear. If we assume that the mutation occurred halfway between Iida and Matsusaka, we can predict the migration distance to be approximately 85 km; however, if the mutation occurred at any other place, a longer distance would be predicted. Natural selection against albino tanuki may be relaxed because of a recent increase in food resources and refuge in urban areas. [ABSTRACT FROM AUTHOR]

Pear juice concentrate prepared by boiling Japanese pear (Pyrus pyrifolia Nakai cv. Nijisseiki) juice can significantly inhibit the activity of tyrosinase, a key enzyme in melanin synthesis in human skin. Using the ethanol extract of pear juice concentrate, we homogeneously purified an active compound that was identified as 5-hydroxymethyl-2-furaldehyde (5-HMF) through 1H- and 13C-NMR and mass spectroscopy. We observed that 5-HMF inhibited the monophenolase and diphenolase activities of mushroom tyrosinase as a mixed-type inhibitor (Ki values of 3.81 and 3.70 mmol/L, respectively). In B16 mouse melanoma cells, treatment with 170 µmol/L of 5-HMF significantly reduced α-melanocyte-stimulated melanin synthesis by suppressing the cyclic adenosine monophosphate-dependent signaling pathway involved in melanogenesis. The results of our study indicated that 5-HMF can be potentially used as a skin-lightening agent in the cosmetic industry. Abbreviations: AC: adenylate cyclase; CREB: cAMP response element-binding protein; dhFAME: S-(−)-10,11-Dihydroxyfarnesoic acid methyl ester; DMEM: dulbecco′s modified eagle medium; l-DOPA: 3-(3,4-Dihydroxyphenyl)- l-alanine; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; HEPES: 4-(2-Hydroxyethyl)-1-piperazine ethane sulfonic acid; 5-HMF: 5-Hydroxymethyl-2-furaldehyde; MITF: microphthalmia-associated transcription factor; α-MSH: α-Melanocyte-stimulating hormone; PKA: protein kinase A; PVDF: polyvinylidene difluoride; SDS: sodium dodecyl sulfate; TRP1: tyrosinase-related protein 1; TRP2: tyrosinase-related protein 2 5-Hydroxymethyl-2-furaldehyde can act as a tyrosinase and/or melanogenesis inhibitor, which can be used as a skin-lightening agent in the cosmetic industry. [ABSTRACT FROM AUTHOR]

Skin cancer is the most prevalent cancer in the United States. Contributing factors include phenotypic exposure to ultraviolet radiation, lack of protective measures, and using high-risk behaviors. Protective measures (sunblock/protective clothing) are not popular with college-aged individuals, whereas tanning bed use is highly prevalent. The purpose of this study was to describe phenotypic risk factors for skin cancer, application of sunscreen, and tanning bed use in college students. A convenience sample of 673 students (55% male) completed a descriptive survey during winter, spring, and summer months. Researchers collected information about phenotypic risk factors using the Fitzpatrick Skin Scale, use of sunscreen, previous tanning bed use, and gender. Furthermore, 9.5% of college-aged individuals reported using sunscreen. Sunscreen use varied by season (p =.009) but not by skin type. Women reported higher sunscreen use (p =.0001). In addition, 12.6% disclosed a history of tanning bed use (M = 1.2). Male participants were more likely to use tanning beds during winter months (p =.015). Skin type did not influence tanning bed use. College-aged individuals are not sufficiently protecting themselves from the sun. More attention is needed to help melano-compromised individuals, especially men, understand how risk factors influence the development of skin cancer. [ABSTRACT FROM AUTHOR]

Tyrosinase is an important enzyme in controlling the formation of melanin in melanosome, and plays a key role in the pigmentation of hair and skin. The abnormal expression or activation of tyrosinase is associated with several diseases such as albinism, vitiligo, melanoma and Parkinson disease. Excessive deposition of melanin could cause diseases such as freckles and brown spots in the human body, and it is also closely related to browning of fruits and vegetables and insect molting. Detecting and inhibiting the activity of tyrosinase is of extraordinary value in the progress of diagnosis and treatment of these diseases. Therefore, many selective optical detection probes and small molecular inhibitors have been developed, and have made significant contributions to the basic and clinical research on these diseases. In this paper, the detection and inhibition of tyrosinase and their application in whitening products are reviewed, with special emphasis on development of fluorescent probes and inhibitors. Hopefully, this review will help design more efficient and sensitive tyrosinase probes and inhibitors, as well as shed light on novel treatment of diseases such as melanoma. Image 1 • The abnormal expression or activation of tyrosinase is the pathogenesis of several diseases such as albinism, vitiligo, and melanoma. • Detecting and inhibiting tyrosinase activity is of great value in the diagnosis and treatment of these diseases. • The detection/inhibition of tyrosinase and its application in whitening products are reviewed, with special emphasis on probes/inhibitors. [ABSTRACT FROM AUTHOR]

Melanin metabolism disorders may cause severe impacts on the psychological and social activities of patients. Different from the other two steps of melanin metabolism, namely synthesis and transport, little has been known about the mechanism of melanin degradation. Isoimperatorin (ISO) suppressed the activity of tyrosinase, an essential enzyme in melanin biosynthesis, hence, we investigated the effects and mechanism of ISO in melanin reduction. ISO stimulation significantly reduces the melanin contents and PMEL 17 protein levels; meanwhile, the activity and the protein levels of two critical lysosomal enzymes, Cathepsin B and Cathepsin D, can be significantly increased by ISO treatment. MiR-3619 inhibited the expression of CSTB and CSTD, therefore affecting ISO-induced degradation of melanin. In summary, ISO reduces the melanin content via miR-3619/CSTB and miR-3619/CSTD axes. ISO could be a potent skin-whitening agent, which needs further in vivo and clinical investigation. ISO reduces the melanin content and increase lysosomal enzye activity via miR-3619/CSTB and miR-3619/CSTD axes. [ABSTRACT FROM AUTHOR]

Owing to antibiotic abuse and the subsequent development of antibiotic resistance, bacterial infection has become one of the most persistent unresolved problems. New antibacterial agents, especially those that are environmental-friendly, are urgently needed. Melanin extracted by filtration centrifugation and acid and proteolytic hydrolysis was characterized using UV, FTIR, TEM, and XPS. Photothermal conversion was calculated, and the bacteriostatic effects, in vitro and in vivo , were assessed by plate counting and ratios (%) of wound areas. Natural melanin hydrolyzed by trypsin had good photothermal conversion effects, which resulted in superior bacteriostatic activities. The extracted melanin along with laser NIR irradiation at 808 nm promoted the healing of wounds infected by drug-resistant bacteria in vivo and was biocompatible according to toxicity tests in vivo and in vitro. The present findings indicated a safe and efficient method of developing natural antibacterial agents. [ABSTRACT FROM AUTHOR]

Melanin is a biopolymer of easy and cheap availability that can be found among the living organisms and excels for its biocompatibility and biodegradability properties, along with scavenging abilities, metal chelation and electronic conductance. This biomaterial can act as a nanocarrier or agent itself to be used in diverse biomedical applications, such as imaging, controlled drug release, bioengineering and bioelectronics, antioxidant applications and theranostics. In this review, the melanin source and structure, its physicochemical properties, melanin-like polymers as well as the differences among those will be elucidated. The focus will be the discussion of the current approaches that apply melanin nanoparticles (MNPs) and melanin-like nanoparticles (MLNPs) in the biomedical field, to which promising capabilities have been attributed, regarding optoelectronic, photoconductivity and photoacoustic. The use of these nanoparticles, in the last 10 years, in topics as drug delivery or theranostics will be detailed and the major achievements will be discussed. Overall, we anticipate that melanin can drive us toward a new paradigm in medical diagnostics and treatments, since applying melanin features possibly its use as a theranostics nanocarrier agent, not only for diagnostics, but also for photothermal therapy and controlled drug release through chemotherapy. We present here a timely and opportune review article focusing the significant potential of melanin nanoparticles in biomedical applications, which will be discussed thoroughly. This biomaterial presents multiple capabilities that may be taken into consideration towards cancer theranostics, expecting a high future impact in the nanosized-platforms design and performance. Image, graphical abstract [ABSTRACT FROM AUTHOR]

Kuji amber is fossilized tree resin of the Late Cretaceous in Japan. In this study, new biological activities of ethanol extract of Kuji amber (EtOH ext.) and supercritical carbon dioxide fluid extract of Kuji amber (scCO2 ext.) were examined. Both EtOH ext. and scCO2 ext. inhibited melanin production in B16 mouse melanoma cells and promoted collagen production in human skin fibroblast SF-TY cells. The scCO2 ext. had more potent activity than that of EtOH ext. and may depend on the efficiency of the extraction. The main new biologically active compound in Kuji amber, kujigamberol had no activities against melanin production, however, it promoted collagen production at low concentrations. A biologically active compound having a different structure, spirolactone norditerpenoid, showed both the inhibition activity against melanin production and the promotion activity of collagen production in a dose dependent manner. EtOH ext. and scCO2 ext., which include both kujigamberol and spirolactone norditerpenoid, have not only anti-allergy activity, but also inhibit melanin production and promote collagen production. The extracts of Kuji amber had inhibition activity of melanin production and promotion activity of collagen activity, with almost the same activity as β-arbutin and L-ascorbic acid. Biologically active compounds were idetified as spirolactone norditerpenoid and kujigamberol. [ABSTRACT FROM AUTHOR]

Esthetics has become a significant aspect of dentistry and clinicians are faced with achieving acceptable gingival esthetics as well as addressing biological and functional problems. The gingiva is the most commonly affected intraoral tissue that is responsible for a displeasing appearance. Melanin pigmentation often occurs in the gingiva as a result of an abnormal deposition of melanin, due to which the gums may appear black, but the principles, techniques, and management of the problems associated with gingival melanin pigmentation are still not fully established. Depigmentation procedures such as scalpel surgery, gingivectomy with free gingival autografting, electrosurgery, cryosurgery, abrasion with diamond bur, Nd:YAG laser, semiconductor diode laser, and CO2 laser have been employed for removal of melanin pigmentation. The following case report describes three different surgical depigmentation techniques: scalpel blade surgery, abrasion with diamond bur, and semiconductor diode laser. The diode laser is a solid-state semiconductor laser that typically uses a combination of Gallium (Ga), Arsenide (Ar), and other elements, such as aluminium (Al) and indium (In) to change electrical energy into light energy. Better results were achieved with semiconductor diode laser than conventional scalpel blade and abrasion with bur. [ABSTRACT FROM AUTHOR]

Melanin, a nonhemoglobin-derived brown pigment, is the most common of the endogenous pigments and is produced by melanocytes present in the basal layer of the epithelium. Although melanin pigmentation of the gingiva is completely benign and does not present a medical problem, complaints of 'black gums' are common, particularly in patients having a very high smile line (gummy smile). Gingival hyperpigmentation is caused by excessive deposition of melanin located in the basal and suprabasal cell layers of the epithelium. Various depigmentation techniques have been employed, such as scalpel surgery, gingivectomy, gingivectomy with free gingival autografting, cryosurgery, electrosurgery, chemical agents such as 90% phenol and 95% alcohol, abrasion with diamond burs, Nd:YAG laser, semiconductor diode laser, and CO2 laser. The present case series describes two simple and effective surgical depigmentation techniques - scalpel blade surgery and semiconductor diode laser surgery - for gingival depigmentation, which have produced good results with patient satisfaction. The diode laser is a solid-state semiconductor laser that typically uses a combination of Gallium (Ga), Arsenide (Ar), and other elements, such as Aluminum (Al) and Indium (In), to change electrical energy into light energy. In this report, better results were achieved with semiconductor diode laser than conventional scalpel blade surgery. [ABSTRACT FROM AUTHOR]

Adhesive hydrogel patches have received great recognitions in wound healing applications. Structural manipulation and functional enhancement are current trends aiming to achieve better curative effect. Herein, adhesive microparticles (AMPs) were prepared via microfluidic electrospray as novel patch for would healing. The AMPs were composed of chitosan oligosaccharide-polyacrylic acid (CSO-PAA) hydrogel matrix embedded with natural melanin nanoparticles. The AMPs exhibited excellent wet adhesion ability, and their particulate structure made them easily adaptable to irregular wound sites. Additionally, the incorporated melanin nanoparticles endowed the AMPs with reactive oxygen species-scavenging and photothermal conversion capacities. Based on these features, the AMPs were employed to close the fractured wound and promote wound healing in vivo , especially under near-infrared irradiation. Therefore, we believe that the multifunctional AMPs are promising adhesive patch for wound management, and potential applications can be expected in battlefield nursing, postoperative management, and household healthcare. [Display omitted] • Adhesive microparticles were prepared via microfluidic electrospray as novel patch for would healing. • The adhesive microparticles exhibited excellent wet adhesion ability and shape-fitting performance to irregular wounds. • The incorporated melanin particles endowed the adhesive microparticles with antioxidant property and photothermal effect. [ABSTRACT FROM AUTHOR]

The present study was carried out to examine the removal of melanin pigmentation from human gingival surfaces using the Er:YAG laser. The results were compared to those obtained using the Nd:YAG laser. Two laser devices, an Er:YAG laser (SMART2940D) and an Nd:YAG laser (A10) (developed by DEKA, Florence, Italy) were used for laser treatment. The parameters of the Er:YAG laser were 5 Hz and 100 mJ, applied for 230 μs using a contact tip under water mist and a noncontact tip without water mist. The Nd:YAG laser was applied at 10 Hz and 100 mJ for 300 μs with Chinese black ink. In all cases, melanin pigmentation could be removed without local anesthesia. Melanin pigmentation removed by Er:YAG laser with or without water mist induced slight bleeding. Neither postoperative pain nor swelling were observed. Compared with the Nd:YAG laser, the Er:YAG laser showed no tendency for melanin pigmentation recurrence after 36 months. In addition, the color of the gingival surface lased by the Er:YAG laser was changed to pink. Comparison with the Nd:YAG laser revealed that the Er:YAG laser is useful in the removal of human gingival melanin pigmentation. [ABSTRACT FROM AUTHOR]

Purpose: Melanin hyperpigmented gingiva is an esthetic problem in many individuals, particularly if the hyperpigmentation is on the facial aspect of gingiva and visible during smile and speech, especially in patients with gummy smiles. Gingival depigmentation has been carried out using surgical, chemical, electrosurgical, and cryosurgical procedures. The two cases presented here show the successful depigmentation using an Er,Cr:YSGG laser, and a short follow-up period (6 months) for repigmentation results. Materials and Methods: An Er,Cr:YSGG hydrokinetic system laser set at 20 Hz, 1.75 W to 1.5W, with 20% to 40% air and 12% to 5% water spray was used for removal of pigmented gingiva in 2 patients. The pigmented areas were treated in noncontact mode, and both cases were completed during one appointment. Results: Even though both cases were performed without any anesthesia, no intra-operative or postoperative pain or discomfort appeared. After 24 h, the lased gingiva was partly covered with a thin layer of fibrin, which exfoliated during the first week following treatment. The ablated wound healed almost completely in 1 week. Conclusion: These results pointed out that YSGG laser is a good and safe choice for removal of pigmented gingiva without local anesthesia. The postoperative period is comfortable for the patient and healing is fast and good. No repigmentation occurred in either patient after 6 months. [ABSTRACT FROM AUTHOR]

Purpose: People with moderate to severe gingival or mucosal pigmentation usually demand treatment for esthetic reasons and/or anxiety about appearance. The present study clinically evaluates the effectiveness of CO2 laser to eliminate abnormal deposition of melanin in the oral tissues. Materials and Methods: In this study, 28 different melanin pigmented mucosal sites of 17 patients were depigmented with CO2 laser. Results: The treated areas appeared normal within 2 to 3 weeks after performing one-step laser surgery and in all but one case remained depigmented during the follow-up period of 5 years. Conclusion: The CO2 laser appears to have a place in the treatment of melanin pigmented tissues and offers a reliable and a satisfying result for both surgeons and patients. [ABSTRACT FROM AUTHOR]

To minimize side effects and increase drug efficacy, a novel strategies are needed to facilitate rapid drug release at the lesion site. In this study, a nanovesicle composed of phospholipids including melanin, poly(N-isopropylacrylamide-co-acrylamide) (PNIPAM) and 5-fluorouracil (5-FU) is suggested for thermoresponsive drug release by near-infrared (NIR) laser irradiation. The novel aspect of the nanovesicles is the use of melanin, which has excellent biocompatibility. The nanovesicle was 180.4 ± 1.6 nm in size and stable for 1 week. After exposure to NIR laser, the temperature of the nanovesicle solution was increased above 51°C by the photothermal effect of melanin. The rate of 5-FU release from the nanovesicle was increased by about 14% for 12 h, following exposure to the laser irradiation compared with no such exposure. The drug release rate was increased depending on the amount of PNIPAM. Consequently, the nanovesicle has a potential application in NIR laser-responsive drug release. [ABSTRACT FROM AUTHOR]

Background: Vitamin D deficiency is fast emerging as a global pandemic. In South Africa few studies have been conducted to determine the vitamin D status of the healthy population. Methods: This prospective study with an analytical component investigated vitamin D status of healthy undergraduate students at two time points (winter and summer) at Stellenbosch University. Serum 25(OH)D was determined, anthropometric measurements taken and dietary vitamin D intake estimated (food-frequency questionnaire). Skin tone was determined (Fitzpatrick skin type classification), and a skin reflectometry device used to measure dermal melanin content. Results: Results of 242 students indicated a mean serum 25(OH)D of 63.80 ± 41.35 ng/ml and a high prevalence of vitamin D sufficiency (88%). Significantly more females experienced suboptimal vitamin D levels than males (18 vs. 5%; p < 0.01). Participants with lighter skin tones had higher levels of 25(OH)D than those with darker skin tones (chi-square = 24.02; p = 0.02). The majority (60.74%) had a normal BMI, although there was no significant relationship between BMI and serum 25(OH)D (Spearman's r = –0.11; p = 0.09). Total mean dietary vitamin D intake was 7.99 ± 13.81 mcg, with 87.2% having inadequate intake (< 15 mcg). The relationship between total vitamin D intake and serum 25(OH)D was found to be significant in winter (p < 0.001) and summer (p = 0.01). Serum vitamin D levels were significantly higher in the winter phase (p < 0.001). Conclusions: A low prevalence of vitamin D deficiency was found amongst healthy young adults, despite low dietary vitamin D intakes. Significant relationships were found between serum 25(OH)D and gender, skin tone and vitamin D intake. Further studies need to be conducted, especially in high-risk groups, before results are applied to the greater South African public. [ABSTRACT FROM AUTHOR]