Explore chapters and articles related to this topic
Fabrication of Artificial Melanin-Based Structural Color Materials through Biomimetic Design
Published in Akihiro Miyauchi, Masatsugu Shimomura, Biomimetics, 2023
Structural colors are often found in bright colors of insects, fish, plants and animals. Typical examples include the coloring of Morpho butterflies, jewel beetles, and peacock feathers. Melanin is a brown to black substance that is well known as a component of human hair and skin. It has the function of protecting skin from ultraviolet rays, plays an important role in the structural color of these organisms. The color of the blue Morpho butterfly wing is derived from the shelf structure with a melanin layer below the shelf structure [2]. The color of a jewel beetle's wings is a structural color derived from a multilayer film in which a melanin layer and a cuticle layer are alternately laminated [3]. Inside peacock feathers, rod-shaped melanin granules form a regular microstructure, causing beautiful structural colors [4]. The size of these microstructures is on the order of hundreds of nanometers. In general, when light hits these submicron-sized structures, the light appears white to the human eye due to light scattering. When part of the microstructure is formed by black melanin, it appears brighter to the human eye because the scattered light is absorbed and the structural color becomes more enhanced. In other words, in bright structural coloration in the natural world, melanin plays an important role in the construction of a fine structure and the suppression of scattered light.
Deep Learning-Computer Aided Melanoma Detection Using Transfer Learning
Published in P. Madhumathy, M. Vinoth Kumar, R. Umamaheswari, Machine Learning and IoT for Intelligent Systems and Smart Applications, 2021
Mohan Kumar S., T. Kumanan, T. R. Ganesh Babu, S. Poovizhi
The skin protects our body and shields us from the sun's heat, sunlight, any injury, and skin infection. However, excessive exposure of our skin to the UV rays from the sun leads to skin cancer. The fair-complexioned population has been more at risk of developing melanoma. Given diagnosis at an early stage improves the chances of proper treatment and cure which, otherwise, may be fatal, it's a matter of no little concern that each year close to 55,000 people are diagnosed with this type of cancer. The skin is the largest portion of the human body, and it protects the internal parts of the body from harmful UV radiation from the sun. Further, the human skin is made up of mostly three layers which are the dermis, the epidermis and the hypodermis [6]. Melanin as the skin coloring pigment is a main element of the skin and excessive production of this pigment may lead to skin cancer. Though occurrence of brown spots and normal growths on the skin are usually harmless and may be non-carcinogenic, still excessive exposure to UV rays may lead to uncontrolled multiplication of the skin cells which is a characteristic of melanoma. Those who have over 100 moles all over their body are at a higher risk [7,8]. The moles have to be observed for the ABCD signs or, the asymmetry, border, Color and Diameter.
An IoHT–Based Intelligent Skin Lesion Detection and Classification Model in Dermoscopic Images
Published in K. Shankar, Eswaran Perumal, Deepak Gupta, Artificial Intelligence for the Internet of Health Things, 2021
K. Shankar, Eswaran Perumal, Deepak Gupta
Advanced developments of the Internet of Health Things (IoHT) have significantly changed the healthcare sector. The IoHT devices are found to be useful in the medical field of developing, testing, and trials, and they are used in hospitals and homes. Recently, skin cancer has been considered a common disease all over the world. There are different types of cancers such as melanoma, basal cell carcinoma, squamous cell carcinoma, intraepithelial carcinoma, etc. The human skin is comprised of three cells: dermis, epidermis, and hypodermis. Initially, the epidermis contains melanocytes that produce imbalanced values. For instance, melanin is generated when there is ultraviolet (UV) exposure from the sun for a long period. Anomalous growth of melanocytes tends to lead to melanoma, which is a dangerous skin cancer [3]. Based on the study of the American Cancer Society, a greater number of new cases of melanoma are occurring, which increases the mortality rate [4]. Melanoma is said to be a malignant type of cancer that leads to maximum death when compared with other types of cancer [5]. Earlier prediction of cancer is more significant and tends to increase the lifespan of an individual [6]. Therefore, finding similarities between benign and malignant lesions is a more difficult process while detecting melanoma. It is difficult to identify melanoma with the human eye, even for medical experts.
Comparison of the effectiveness of textiles containing metal nanoparticle and metal-organic frameworks for protection against ultraviolet radiation: a systematic review and meta-analysis
Published in The Journal of The Textile Institute, 2022
Hadiseh Rabiei, Majid Montazer, Somayeh Farhang Dehghan, Shokooh Sadat Khaloo, Saeed Yousefinejad, Soheil Hassanipour, Amir Sharifi
Five percent of the sunlight radiated on earth consists of ultraviolent radiations (UVR) (visible light 50% and infrared (IR) radiations include 45%) (Ranjan Das, 2010). Human skin is the widest part of the body that can be exposed to sunlight. The high wavelength UVR (320–400 nm, UV-A) deforms melanin precursors in the skin and leads to pigment destruction. Furthermore, it can infiltrate to deeper levels of skin, and cause premature aging, wrinkle, and impairing the skin’s stretching ability. Shorter wavelengths (290 nm–320 nm) or higher energy ultraviolet (UV-B) rays penetrate to a depth of a few millimeters, forming a relatively stable pigment in the cells of the outer layer of the skin. This can lead to chronic acute reactions and injuries such as redness of the skin (erythema) or sunburn. The UVR with the lowest wavelength (10–290 nm, UV-C) can damage the human skin immensely, yet this type is filtered by the ozone layer and does not reach the surface (Palacin, 1997; Ranjan Das, 2010).
Bioactivities and phenolic composition of Limonium boitardii Maire and L. cercinense Brullo & Erben (Plumbaginaceae): two Tunisian strict endemic plants
Published in International Journal of Environmental Health Research, 2022
Ons Sefi, Soumaya Bourgou, Wided Megdiche-Ksouri, Mohamed Libiad, Abdelmajid Khabbach, Mohamed El Haissoufi, Fatima Lamchouri, Nikos Krigas, Zeineb Ghrabi-Gammar
Melanins, the main pigments primarily responsible in the skin and hair pigmentation, are produced by melanocytes through melanogenesis. Melanogenesis and skin pigmentation are the most important photoprotective factors in response to the damaging solar ultraviolet radiation inducing skin photocarcinogenesis. The increased melanin synthesis of these pigments occurs in many types of skin disorders, including Acanthosis nigricans, Cervical Poikiloderma, melasma, Periorbital hyperpigmentation, Lentigines and increased skin cancer risk. Tyrosinase enzyme possesses an essential role in the melanogenesis process since it catalyzes the hydroxylation of L-tyrosine to 3,4-dihydroxyphenylalanine (L-DOPA) and the oxidation of L-DOPA to dopaquinone. These reactions are considered rate-limiting steps for the melanin biosynthesis pathway, and therefore, for the production of skin pigments in melanocytes. Consequently, controlling the activity of this enzyme by tyrosinase inhibitors is an essential endeavor for treating pigmentary disorders in mammals. The mushroom tyrosinase inhibition biological assay is commonly used to investigate the whitening potential of natural extracts (Promden et al. 2018).
Eco-friendly preparation, characterization, evaluation of anti-melanogenesis/antioxidant effect and in vitro/in vivo safety profile of kojic acid loaded niosome as skin lightener preparation
Published in Journal of Biomaterials Science, Polymer Edition, 2023
Majid Saeedi, Katayoun Morteza-Semnani, Jafar Akbari, Seyyed Mobin Rahimnia, Amirhossein Babaei, Mohammad Eghbali, Alireza Sanaee, Seyyed Mohammad Hassan Hashemi, Mahmoud Omidi
Murine B16F10 melanoma cells were obtained from the National Cell Bank Pasteur Institute of Iran (Tehran, Iran). The cells were plated in a 12-well plate and allowed to grow for 24 h in RPMI medium supplemented with 10% fetal bovine serum (Gibco, USA), 100 units/mL of penicillin, and 0.1 mg/mL of streptomycin. After 24 h, the cells were treated with free kojic acid, plain niosome, and kojisome 6 at concentrations of 1000, 500, 250, 125, 62.5, and 31.25 µM and incubated for 24 h. The cells were then dissolved in 100 μL of 2 M NaOH solution for 30 min at 100 °C. The melanin content was measured by the absorption at 405 nm using a Microplate Reader (BioTek, Winooski, USA) and compared with that of the control.