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Journal of Nanobiotechnology Sep 2023Excessive and prolonged ultraviolet radiation (UVR) exposure causes photodamage, photoaging, and photocarcinogenesis in human skin. Therefore, safe and effective sun...
Excessive and prolonged ultraviolet radiation (UVR) exposure causes photodamage, photoaging, and photocarcinogenesis in human skin. Therefore, safe and effective sun protection is one of the most fundamental requirements. Living organisms tend to evolve various natural photoprotective mechanisms to avoid photodamage. Among them, melanin is the main functional component of the photoprotective system of human skin. Polydopamine (PDA) is synthesized as a mimic of natural melanin, however, its photoprotective efficiency and mechanism in protecting against skin damage and photoaging remain unclear. In this study, the novel sunscreen products based on melanin-inspired PDA nanoparticles (NPs) are rationally designed and prepared. We validate that PDA NPs sunscreen exhibits superior effects on photoprotection, which is achieved by the obstruction of epidermal hyperplasia, protection of the skin barrier, and resolution of inflammation. In addition, we find that PDA NPs are efficiently intake by keratinocytes, exhibiting robust ROS scavenging and DNA protection ability with minimal cytotoxicity. Intriguingly, PDA sunscreen has an influence on maintaining homeostasis of the dermis, displaying an anti-photoaging property. Taken together, the biocompatibility and full photoprotective properties of PDA sunscreen display superior performance to those of commercial sunscreen. This work provides new insights into the development of a melanin-mimicking material for sunscreens.
Topics: Humans; Sunscreening Agents; Ultraviolet Rays; Antioxidants; Melanins; Skin; Anti-Inflammatory Agents
PubMed: 37775761
DOI: 10.1186/s12951-023-02107-7 -
Archives of Microbiology Aug 2023Melanin is an amorphous polymer made of heterogeneous functional groups synthesized by diverse organisms including fungi, bacteria, animals, and plants. It was widely... (Review)
Review
Melanin is an amorphous polymer made of heterogeneous functional groups synthesized by diverse organisms including fungi, bacteria, animals, and plants. It was widely acknowledged for its biological processes and its key role in the protection of organisms from environmental stress. Recently, melanin clutches attention in the field of nanobiotechnology, drug delivery, organic semiconductors and bioelectronics, environmental bioremediation, photoprotection, etc., Furthermore, melanin from natural sources like microbial community shows antimicrobial, fighting cancer, radical scavenging, cosmeceuticals, and many therapeutic areas as well. Though the multipotentiality nature of melanin has been put forth, real-world applications still flag fall behind, which might be anticipated to the inadequate and high price essence of natural melanin. However, current bioprocess technologies have paved for the large-scale or industrial production of microbial melanin, which could help in the replacement of synthetic melanin. Thus, this review emphasizes the various sources for melanin, i.e., types-based on its pathways and its chemical structures, functional efficiency, physical properties, and conventional and modern methods of both extraction and characterization. Moreover, an outlook on how it works in the field of medicine, bioremediation, and other related areas provides perspectives on the complete exploitation of melanin in practical applications of medicine and the environment.
Topics: Animals; Melanins; Biopolymers; Anti-Infective Agents; Biodegradation, Environmental; Bacteria
PubMed: 37580645
DOI: 10.1007/s00203-023-03642-5 -
Physiology and Molecular Biology of... May 2024Reducing protochlorophyllide (Pchlide) to chlorophyllide (Chlide) is a major regulatory step in the chlorophyll biosynthesis pathway. This reaction is catalyzed by... (Review)
Review
Reducing protochlorophyllide (Pchlide) to chlorophyllide (Chlide) is a major regulatory step in the chlorophyll biosynthesis pathway. This reaction is catalyzed by light-dependent protochlorophyllide oxidoreductase (LPOR) in oxygenic phototrophs, particularly angiosperms. LPOR-NADPH and Pchlide form a ternary complex to be efficiently photo-transformed to synthesize Chlide and, subsequently, chlorophyll during the transition from skotomorphogenesis to photomorphogenesis. Besides lipids, carotenoids and poly-cis xanthophylls influence the formation of the photoactive LPOR complexes and the PLBs. The crystal structure of LPOR reveals evolutionarily conserved cysteine residues implicated in the Pchlide binding and catalysis around the active site. Different isoforms of LPOR viz PORA, PORB, and PORC expressed at different stages of chloroplast development play a photoprotective role by quickly transforming the photosensitive Pchlide to Chlide. Non-photo-transformed Pchlide acts as a photosensitizer to generate singlet oxygen that causes oxidative stress and cell death. Therefore, different isoforms of LPOR have evolved and differentially expressed during plant development to protect plants from photodamage and thus play a pivotal role during photomorphogenesis. This review brings out the salient features of LPOR structure, structure-function relationships, and ultra-fast photo transformation of Pchlide to Chlide by oligomeric and polymeric forms of LPOR.
PubMed: 38846463
DOI: 10.1007/s12298-024-01454-5 -
Experimental Dermatology Jan 2024Excessive exposure to ultraviolet (UV) light leads to acute and chronic UV damage and is the main risk factor for the development of skin cancer. In most countries with...
Excessive exposure to ultraviolet (UV) light leads to acute and chronic UV damage and is the main risk factor for the development of skin cancer. In most countries with western lifestyle, the topical application of sunscreens on UV-exposed skin areas is by far the most frequently used preventive measure against sunburn. Further than preventing sunburns, increasing numbers of consumers are appreciating sunscreens with a medium- to high-level sun protective factor (SPF) as basis for sustainable-skin ageing or skin cancer prevention programs. However, recent investigations indicate that clinically significant DNA damages as well as a lasting impairment of cutaneous immunosurveillance already occur far below the standard of one minimal erythema dose (MED) sunburn level, which contributes to the current discussion of the clinical value of high-protective SPF values. Ex vivo investigations on human skin showed that the application of SPF30 reduces DNA damage for a day long sun exposure (24 MED) drastically by about 53% but is significantly surpassed by SPF100 reducing DNA damage by approx. 73%. Further analysis on different SPF protection levels in UV-exposed cell culture assays focusing on IL-18, cell vitality and cis/trans-urocanic acid support these findings. Whereas SPF30 and SPF50 sunscreens already offer a solid UVB cover for most indications, our results indicate that SPF100 provides significant additional protection against mutagenic (non-apoptotic-) DNA damage and functional impairment of the cutaneous immunosurveillance and therefore qualifies as an optimized sunscreen for specifically vulnerable patient groups such as immunosuppressed patients, or skin cancer patients.
Topics: Humans; Sunburn; Sunscreening Agents; Skin; Ultraviolet Rays; Skin Neoplasms
PubMed: 38284193
DOI: 10.1111/exd.15002 -
Journal of Clinical Medicine Dec 2023Electromagnetic radiation, notably visible light (VL), has complicated effects on human skin, particularly pigmentation, which have been largely overlooked. In this... (Review)
Review
Electromagnetic radiation, notably visible light (VL), has complicated effects on human skin, particularly pigmentation, which have been largely overlooked. In this review, we discuss the photobiological mechanisms, pathological effects, clinical applications and therapeutic strategies of VL at varying wavelengths on melanocyte biology and skin pigmentary disorders. Different VL wavelengths may impose positive or negative effects, depending on their interactions with specific chromophores, photoaging, ROS production, circadian rhythm and other photon-mediated reactions. Further in vivo and in vitro studies are required to establish the pathologic mechanisms and application principles of VL in pigmentary disorders, as well as optimal photoprotection with coverage against VL wavelengths.
PubMed: 38068540
DOI: 10.3390/jcm12237488 -
Journal of Drugs in Dermatology : JDD Nov 2023Oral tetracyclines (TCNs) are commonly prescribed for acne, but they have been shown to increase the risk of hyperpigmentation, particularly in the setting of sun...
BACKGROUND
Oral tetracyclines (TCNs) are commonly prescribed for acne, but they have been shown to increase the risk of hyperpigmentation, particularly in the setting of sun exposure.
OBJECTIVE
We evaluated seasonal trends in TCN-associated hyperpigmentation incidence in addition to Google search trends for hyperpigmentation-related terms.
METHODS
We performed a retrospective review of acne patients seen at Massachusetts General Brigham and Women’s Hospital between 1992 and 2022. We calculated the incidence of new hyperpigmentation diagnoses for each drug cohort. We also analyzed search volume of hyperpigmentation-related terms extracted from Google Trends.
RESULTS
Seasonal differences in new hyperpigmentation diagnoses were identified among acne patients prescribed doxycycline (P=0.016), with peak incidence in April. In the control group of patients who had never received a TCN, diagnoses peaked in May. There were no significant seasonal differences among patients prescribed minocycline (P=0.885). There was greater search volume for hyperpigmentation-related terms in spring and summer compared to fall and winter (P<0.001). Limitations of this study include its retrospective nature and reliance on prescription and diagnosis coding data.
CONCLUSIONS
Our findings support the seasonal periodicity of acne-related hyperpigmentation, underscoring the importance of photoprotection counseling for patients with acne. Additionally, doxycycline may be associated with an earlier onset of hyperpigmentation, suggesting a potential benefit of considering minocycline or other alternatives to doxycycline. J Drugs Dermatol. 2023;22(11):e9-e11 doi:10.36849/JDD.7409e.
Topics: Humans; Female; Seasons; Doxycycline; Minocycline; Retrospective Studies; Tetracycline; Anti-Bacterial Agents; Acne Vulgaris; Hyperpigmentation
PubMed: 37943268
DOI: 10.36849/JDD.7409 -
Critical Reviews in Biotechnology Feb 2024Cyanobacteria safeguard their photosynthetic machinery from oxidative damage caused by adverse environmental factors such as high-intensity light. Together with many... (Review)
Review
Cyanobacteria safeguard their photosynthetic machinery from oxidative damage caused by adverse environmental factors such as high-intensity light. Together with many photoprotective compounds, they contain myxoxanthophylls, a rare group of glycosidic carotenoids containing a high number of conjugated double bonds. These carotenoids have been shown to: have strong photoprotective effects, contribute to the integrity of the thylakoid membrane, and upregulate in cyanobacteria under a variety of stress conditions. However, their metabolic potential has not been fully utilized in the stress biology of cyanobacteria and the pharmaceutical industry due to a lack of mechanistic understanding and their insufficient biosynthesis. This review summarizes current knowledge on: biological function, genetic regulation, biotechnological production, and pharmaceutical potential of myxoxanthophyll, with a focus on strain engineering and parameter optimization strategies for increasing their cellular content. The summarized knowledge can be utilized in cyanobacterial metabolic engineering to improve the stress tolerance of useful strains and enhance the commercial-scale synthesis of myxoxanthophyll for pharmaceutical uses.
Topics: Cyanobacteria; Carotenoids; Photosynthesis; Biotechnology; Pharmaceutical Preparations
PubMed: 36137567
DOI: 10.1080/07388551.2022.2117682 -
Journal of Translational Medicine Apr 2024Melanocytes are dendritic cells localized in skin, eyes, hair follicles, ears, heart and central nervous system. They are characterized by the presence of melanosomes... (Review)
Review
Melanocytes are dendritic cells localized in skin, eyes, hair follicles, ears, heart and central nervous system. They are characterized by the presence of melanosomes enriched in melanin which are responsible for skin, eye and hair pigmentation. They also have different functions in photoprotection, immunity and sound perception. Melanocyte dysfunction can cause pigmentary disorders, hearing and vision impairments or increased cancer susceptibility. This review focuses on the role of melanocytes in homeostasis and disease, before discussing their potential in regenerative medicine applications, such as for disease modeling, drug testing or therapy development using stem cell technologies, tissue engineering and extracellular vesicles.
Topics: Regenerative Medicine; Melanocytes; Pigmentation; Melanins; Hair Follicle
PubMed: 38589876
DOI: 10.1186/s12967-024-05113-x -
Photodermatology, Photoimmunology &... Jan 2024In this article, we review and discuss the photoprotection behavior of Asians based on the literature, along with a subanalysis of an original online survey, and make... (Review)
Review
Awareness of sun exposure risks and photoprotection for preventing pigmentary disorders in Asian populations: Survey results from three Asian countries and expert panel recommendations.
BACKGROUND
In this article, we review and discuss the photoprotection behavior of Asians based on the literature, along with a subanalysis of an original online survey, and make recommendations to optimize photoprotection for Asian populations to prevent photoaging and pigmentary disorders.
METHODS
An international panel of eight dermatologists from Asia (China, Korea, Japan, Singapore, Indonesia, and Vietnam) met to discuss sunscreen photoprotection for Asian patients. Additionally, a subanalysis of an online survey by 3000 respondents from three Asian countries (China, Indonesia, and Japan) investigated general public awareness and attitudes to sun exposure.
RESULTS
A pre-meeting survey of the eight experts from Asia showed key concerns of Asian patients consulting dermatologists are pigmentary disorders, especially actinic/senile lentigo, post-inflammatory hyperpigmentation, melasma, vitiligo, and Hori's nevus. The survey subanalysis of participants from China, Indonesia, and Japan with predominantly Fitzpatrick skin types (FST) II to IV revealed that they are particularly concerned about sun exposure causing photoaging and pigmentary disorders. Most of the respondents indicated they have limited knowledge on sunlight radiation and appropriate sunscreen protection factors. Only 22%, 13%, and 3% for China, Indonesia, and Japan, respectively, systematically use multiple protective measures (using sunscreen, avoiding midday sun, staying in the shade, wearing a hat, protective clothing, and sunglasses) when exposed to the sun.
CONCLUSIONS
Further education is needed for Asian populations on the importance of comprehensive daily photoprotection, including broad-spectrum sunscreen, with high UVA and visible light protection, to reduce and prevent photoaging and pigmentary disorders.
Topics: Humans; Sunscreening Agents; Skin Neoplasms; Sunlight; Photosensitivity Disorders; Surveys and Questionnaires; Asia; Lentigo
PubMed: 38059515
DOI: 10.1111/phpp.12932 -
International Journal of Molecular... Feb 2024Photoaging (PA) is considered a silent disease affecting millions of people globally and is defined as skin damage due to prolonged exposure to ultraviolet radiation... (Review)
Review
Photoaging (PA) is considered a silent disease affecting millions of people globally and is defined as skin damage due to prolonged exposure to ultraviolet radiation (UVR) from the sun. Physiologically, the skin is in a state of renewal and synthesis of components of the extracellular matrix (ECM). However, exposure to UVR affects the production of the ECM, and the functioning and response of skin cells to UVR begins to change, thus expressing clinical and phenotypic characteristics of PA. The primary mechanisms involved in PA are direct damage to the DNA of skin cells, increases in oxidative stress, the activation of cell signaling pathways responsible for the loss of skin integrity, and cytotoxicity. The medical and scientific community has been researching new therapeutic tools that counteract PA, considering that the damage caused by UVR exceeds the antioxidant defense mechanisms of the skin. Thus, in recent years, certain nutraceuticals and phytochemicals have been found to exhibit potential antioxidant and photoprotective effects. Therefore, the main objective of this review is to elucidate the molecular bases of PA and the latest pharmaceutical industry findings on antioxidant treatment against the progression of PA.
Topics: Humans; Antioxidants; Ultraviolet Rays; Skin Aging; Skin; Oxidative Stress
PubMed: 38397077
DOI: 10.3390/ijms25042403