Skin Photosensitivity Research Articles

Skin Photosensitivity is Associated with 25-Hydroxyvitamin D and BMD but not Fractures Independent of Melanin Density in Older Caucasian Adults.

Whether skin photosensitivity modulates sun exposure behaviours, consequent vitamin D status and skeletal health outcomes independently of constitutive pigmentation have not been systematically investigated. 1072 community-dwelling adults aged 50-80years had skin photosensitivity quantified by questionnaire and melanin density by spectrophotometry. Bone mineral density (BMD), falls risk and 25-hydroxyvitamin D (25OHD) were measured using DXA, short form physiological profile assessment and radioimmunoassay, respectively. Sun exposure and symptomatic fractures were assessed by questionnaire. Participants were followed up at 2.5 (n = 879), 5 (n = 767) and 10 (n = 571) years. Higher resistance to sunburn and greater ability to tan were associated with reduced sun protection behaviours (RR 0.87, p < 0.001 & RR 0.88, p < 0.001), higher lifetime discretionary sun exposure in summer (RR 1.05, p = 0.001 & RR 1.07, p = 0.001) and winter (RR 1.07, p = 0.001 & RR 1.08, p = 0.02) and fewer lifetime sunburns (RR 0.86, p < 0.001 & RR 0.91, p = 0.001). Higher resistance to sunburn was associated with lower total body (β = - 0.006, p = 0.047) and femoral neck (β = - 0.006, p = 0.038) BMD, but paradoxically, fewer prevalent fractures (RR 0.94, p = 0.042). Greater ability to tan was associated with higher 25OHD (β = 1.43, p = 0.04), lumbar spine (β = 0.014, p = 0.046) and total body (β = 0.013, p = 0.006) BMD, but not fracture or falls risk. These associations were independent of constitutive melanin density. Cutaneous photosensitivity was associated with sun exposure behaviours, cutaneous sequelae and, consequently, 25OHD and BMD in older Caucasian adults independent of constitutive melanin density. There was no consistent association with fracture outcomes, suggesting environmental factors are at least as important.

Improved photodynamic anticancer activity and mechanisms of a promising zinc(II) phthalocyanine-quinoline conjugate photosensitizer in vitro and in vivo.

Since the discovery of photodynamic therapy, scientists have constantly been searching for more effective and ideal photosensitizers (PSs). As part of our ongoing interest in the development of more potent photosensitizers, quinoline-8-yloxy-substituted zinc(II) phthalocyanine (ZnPc-Q1) has been identified as a promising photosensitizers in tumor cells. This study aims to explore the photodynamic mechanism and in vivo photodynamic efficacy of ZnPc-Q1, and further evaluate its potential in clinical photodynamic therapy application. The single crystal structure of ZnPc-Q1 enables the easy control of clinical quality standards. In comparison with Photofrin, ZnPc-Q1 exhibits considerably higher in vitro anticancer activity by dual dose-related mechanisms (antiproliferative and apoptosis). In addition, the in vivo results demonstrate that ZnPc-Q1 exhibits significant tumor regression with less skin photosensitivity by both direct killing and apoptosis anticancer mechanisms. In conclusion, ZnPc-Q1 can be considered to be a promising ideal PS for clinical application owing to its defined chemical structure without phthalocyanine isomerization, good absorption of tissue-penetrating red light, improved photodynamic therapy efficacy, and reduced skin phototoxicity.

Minimal Erythema Dose: Correlation with Fitzpatrick Skin Type and Concordance Between Methods of Erythema Assessment in a Patient Sample in Colombia

Background and objectiveThe minimal erythema dose (MED), an essential measurement in studies of skin photosensitivity, requires establishing MED values for specific populations, given genetic variation. Different ways to assess erythema are also relevant. We aimed to determine MED values in a sample of Colombian patients and correlations between MED and Fitzpatrick skin type. We also studied concordance correlation between MEDs and two alternative ways to assess erythema. Patients and methodsCross-sectional study of 113 individuals in Bogotá, Colombia. We used a solar simulator to measure UV-A radiation and combined UV-A and UV-B (UVA+UVB) radiation, for MED calculation. Narrowband UV-B (NBUVB) radiation was measured in a phototherapy cabin. Erythema was assessed visually and with a Mexameter MX 18 device. ResultsThe median MEDs of UVA+UVB radiation were 22mJ/cm2 for Fitzpatrick skin types I and II, and 33 and 43mJ/cm2, respectively, for skin types III and IV. The MEDs of UV-A radiation were 22, 42, 86, and 100J/cm2 for skin types I, II, III, and IV, respectively. The MEDs of NBUVB radiation were 390, 550, 770, and 885mJ/cm2 for the 4 skin types. The correlation between MEDs and skin types ranged from 0.5 to 0.69. Lin's concordance correlation coefficients between visual and Mexameter assessments of erythema were greater than 0.8 in all cases. ConclusionThis study allowed us to understand MED values for UV-A, UVA+UVB, and NBUVB according to different skin types in the Colombian population. Concordance correlation coefficients between the different methods of erythema assessment were very good. Correlations between MEDs and skin types were moderate to good.

Uso etnomedicinal, fitoquímica y actividad biológica de la planta andina Buddleja incana Ruiz &amp; Pav. (Scrophulariaceae)

Background: Buddleja incana Ruiz &amp; Pav. (Scrophulariaceae) is an ancestral medicinal plant from the Andes of South America used in traditional medicine since the Inca culture, but currently little studied in its chemical components. The objective of this review is to gather all the scientific information on this plant for the purpose of its use in alternative medicine and at the same time stimulate its study in research groups in the Andean countries.Materials and methods: Various electronic search engines and specialized reference tools such as Google, Google Scholar, Scopus, Web of Science, publication sites and electronic databases (Pubmed, Springer, Wiley and Science Direct) were used.Results: Phytochemical studies have found the following chemical components: flavonoids, steroids, saponins, leucoanthocyanidins, triterpenes, phenols, tannins, reducing sugars, coumarins, alkaloids, terpenes and verbascosides. This plant is used to treat various diseases and pathological conditions, having shown anti-inflammatory, antineoplastic, antispasmodic, antibacterial, antifungal and febrifuge effects, in the following conditions: wounds, neuralgia, skin and gastrointestinal ulcers, papillomatosis, skin cancer, photosensitization, immunomodulator.Conclusions: Buddleja incana was a sacred and medicinal plant of the Incas. It is currently used for the treatment of liver, bronchial and urogenital diseases. It has diuretic, anti-inflammatory, analgesic, antirheumatic, antimicrobial, anti-hyperglycemic, wound regenerating effects, for the treatment of warts, skin ulcers, antiproliferative, and for its photoprotective effect on the skin. In veterinary medicine it is used to treat skin photosensitization in sheep, in bovine warts and in canine oral papillomatosis.Keywords: Buddleja incana, phytochemistry, medicinal plants, flora of the Andes.

Toxicological evaluation of exosomes derived from human adipose tissue-derived mesenchymal stem/stromal cells

Several studies report that the therapeutic mechanism of action of mesenchymal stem/stromal cells (MSCs) is mainly mediated by paracrine factors that are released from MSCs such as exosomes. Exosomes are nano-sized extracellular vesicles that are transferred to target cells for cell-to-cell communication. Although MSC-derived exosomes (MSC-exosomes) are suggested as novel cell-free therapeutics for various human diseases, evaluation studies for the safety and toxicity of MSC-exosomes are limited. The purpose of our study was to evaluate the toxicological profile, including skin sensitization, photosensitization, eye and skin irritation, and acute oral toxicity using exosomes derived from human adipose tissue-derived MSCs (ASC-exosomes) in accordance with the OECD guidelines and the principles of Good Laboratory Practice. The ASC-exosomes were classified as a potential non-sensitizer in the skin sensitization test, UN GHS no category in the eye irritation test, and as a skin non-irritant in the skin irritation test, and did not induce any toxicity in the phototoxicity test or in acute oral toxicity testing. Our findings are the first to suggest that ASC-exosomes are safe for use as a topical treatment, with no adverse effects in toxicological testing, and have potential application as a therapeutic agent, cosmetic ingredient, or for other biological uses.

Percutaneous hepatic injection of rose bengal disodium (PV-10) in metastatic uveal melanoma.

3143 Background: PV-10 is a small molecule autolytic immunotherapy in clinical development for treatment of solid tumors. When administered by intralesional (IL) injection, PV-10 can produce immunogenic cell death that may induce a T cell-mediated immune response against treatment refractory and immunologically cold tumors. Given this mechanism of action and clinical data that metastatic uveal melanoma (MUM) generates low response rates to immune checkpoint blockade (CB), we investigated treatment of MUM with percutaneously-delivered PV-10. Methods: This open-label Phase 1 basket study (NCT00986661) is evaluating the safety, tolerability, and preliminary efficacy of intralesional PV-10 in patients (pts) with solid tumors of the liver. PV-10 is injected into one or more designated hepatic tumor(s) with a maximum sum of diameters ≤4.9 cm. Response assessments using 2D EASL criteria are performed at Day 28, then every 3 months. Pts with additional injectable tumors are eligible to receive further PV-10 after Day 28. Pts can receive standard of care CB immunotherapy during treatment with PV-10. Results: As of February 1, 2020, the initial cohort of 15 pts with MUM to the liver was fully enrolled. Pts had received at least 1 IL injection of PV-10, with an average of 2 hepatic lesions injected per pt (range 1-4). Of these, 4 pts were refractory to prior CB. Three pts received PV-10 alone, 3 received PV-10 + anti-PD-1 and 9 received PV-10 + anti-PD-1 + anti-CTLA-4. Adverse events (AEs) were consistent with established patterns for PV-10 and CB: AEs attributed to PV-10 were transient and included 3 cases of Grade 3/4 transaminitis that resolved within 72 hrs, injection site pain, photosensitivity, and pink discoloration of skin, urine or feces; AEs attributed to CB included nausea, decreased WBC, and fatigue. Response assessments on 24 injected tumors were: 2 complete response (8%), 7 partial response (29%) and 11 stable disease (46%), per 2D EASL. Among the 4 CB-refractory pts, median overall survival (OS) was 9.2 months (range 5.3 - 11.4 months, with 2 pts alive at 5.3 months each), while among the 11 CB-naïve pts OS was undefined (range 0.5 - 21.9+ months, with 1 death at 7.9 months). Pts receiving PV-10 alone (1 CB-refractory, 2 naïve) achieved a median OS of 7.9 months with one CB-naïve pt alive with partial overall response at 21.9 months. Conclusions: Response indicative of regression or stabilization in a majority (83%) of injected lesions is encouraging in a disease of major unmet need. Enrollment and follow-up for safety, duration of response and survival are ongoing. Clinical trial information: NCT00986661 .

Dosis eritematosa mínima: correlación con el fototipo y método de medición en una muestra de población colombiana

Background and objectiveThe minimal erythema dose (MED), an essential measurement in studies of skin photosensitivity, requires establishing MED values for specific populations, given genetic variation. Different ways to assess erythema are also relevant. We aimed to determine MED values in a sample of Colombian patients and correlations between MED and Fitzpatrick skin type. We also studied concordance correlation between MEDs and two alternative ways to assess erythema. Patients and methodsCross-sectional study of 113 individuals in Bogotá, Colombia. We used a solar simulator to measure UV-A radiation and combined UV-A and UV-B (UVA+UVB) radiation, o se podría suprimir este término porque UVA y UVB son términos conocidos for MED calculation. Narrowband UV-B (NBUVB) radiation was measured in a phototherapy cabin. Erythema was assessed visually and with a Mexameter MX 18 device. ResultsThe median MEDs of UVA+UVB radiation were 22mJ/cm2 for Fitzpatrick skin typesI andII, and 33 and 43mJ/cm2, respectively, for typesIII andIV. The MEDs of UV-A radiation were 22, 42, 86, and 100J/cm2 for typesI, II, III, andIV, respectively. The MEDs of NBUVB light were 390, 550, 770, and 885mJ/cm2 for the 4 skin types. The correlation between MEDs and skin types ranged from 0.5 to 0.69. Lin's concordance correlation coefficients between visual and Mexameter assessments of erythema were greater than 0.8 in all cases. ConclusionThis study allowed us to understand MED values for UV-A, UVA+UVB, and NBUVB according to different skin types in the Colombian population. Concordance correlation coefficients between the different methods of erythema assessment were very good. Correlations between MEDs and skin types were moderate to good.

A Toxicity study of exosomes derived from mesenchymal stem cells

Background & Aim Exosomes are being developed as therapeutics including regenerative and immune-modulatory therapies, and drug delivery vehicles. Especially, mesenchymal stem cells-derived exosomes (MSC-Exo) have been suggested and highlighted as therapeutics for variety of human diseases. For the development of therapeutics, toxicity evaluation is the important first step in the nonclinical phase to ensure the safety of exosome therapeutics. Currently, the efficacies of MSC-Exo have been verified in a variety of disease animal models, but the toxicity evaluation is limited. The aim of this study was to evaluate toxicological profiles with MSC-Exo in according to the OECD guidelines and GLP regulation. Methods, Results & Conclusion We conducted toxicological studies of MSC-Exo according to the OECD guidelines such as skin sensitization (OECD TG 442B), photosensitization (OECD TG 432), eye irritation (OECD TG 437), skin irritation (OECT TG 439), and acute oral toxicity studies (OECD TG 423). As results, MSC-Exo were classified as a potential non-sensitizer in skin sensitization test, UN GHS no category in eye irritation test, and a skin non-irritant in skin irritation test, respectively. Additionally, MSC-Exo did not induce any toxicity in phototoxicity test and acute oral toxicity test. MSC-Exo have proven to be safe without side effects when topical treatment on skin, and can be applied for the development of exosomes therapeutics for topical formulation. Exosomes are being developed as therapeutics including regenerative and immune-modulatory therapies, and drug delivery vehicles. Especially, mesenchymal stem cells-derived exosomes (MSC-Exo) have been suggested and highlighted as therapeutics for variety of human diseases. For the development of therapeutics, toxicity evaluation is the important first step in the nonclinical phase to ensure the safety of exosome therapeutics. Currently, the efficacies of MSC-Exo have been verified in a variety of disease animal models, but the toxicity evaluation is limited. The aim of this study was to evaluate toxicological profiles with MSC-Exo in according to the OECD guidelines and GLP regulation. We conducted toxicological studies of MSC-Exo according to the OECD guidelines such as skin sensitization (OECD TG 442B), photosensitization (OECD TG 432), eye irritation (OECD TG 437), skin irritation (OECT TG 439), and acute oral toxicity studies (OECD TG 423).

General aspects of xeroderma pigmentosum: A review

Xeroderma Pigmentoso (XP) is a rare, recessive and autosomal genetic disease that also affects both sexes and all ethnicities, being closely associated with communities with a high rate of inbreeding. The aim of this review was to detail the main routes of DNA repair of XP, the different functional defects that result in the development of the 8 types of XP, the main characteristics of the clinical picture of a patient with XP, the main comorbidities associated with XP, and the treatments available or that are still in studies for individuals affected by XP. The bibliographic research was carried out in the databases: Redalyc, Institutional Repository of the Federal University of Juiz de Fora, Scielo, Brazilian Digital Library of Theses and Dissertations, Science Research.com, Lilacs and Pub Med, using keywords or their associations: Xeroderma – Xeroderma Pigmentoso. XP is a genetic disease that has no cure; the individual with XP has a photosensitive skin and, when exposed to UV radiation, may develop several dermatological complications; the manifestations of XP are directly linked to the genetic defect; NER is undoubtedly the main route of DNA repair when it comes to XP; in XP-V the by-pass of the tape with the DNA lesion is not done by polymerase pol eta but by another polymerase of the Family Y; defects in DNA repair pathways can cause not only XP, but also other diseases; and the treatment for XP is palliative. It consists of the use of specific UV protectors, drugs, repair enzymes and adenoviral vectors, as well as cryosurgery, photodynamic therapy (PDT), surgical removal of tumors and psychological follow-up.

Diagnosis of Bloom Syndrome in a Patient with Short Stature, Recurrence of Malignant Lymphoma, and Consanguineous Origin

Bloom syndrome is an autosomal recessive disorder characterized by prenatal and postnatal growth deficiency, photosensitive skin changes, immune deficiency, insulin resistance, and a greatly increased risk of early-onset cancer and development of multiple malignancies. Loss-of-function variants of the BLM gene, which codes for a RecQ helicase, cause Bloom syndrome. We report a consanguineous family, with 2 siblings showing clinical signs of suspected chromosome breakage disorder. One of them developed recurrent malignant lymphoma during lifetime. We performed next-generation sequencing analysis, focusing on cancer predisposition syndromes. We identified a homozygous pathogenic nonsense variant c.1642C>T (p.Gln548*) in the BLM gene in the proband, associated with Bloom syndrome. Sanger sequencing validated the presence of a homozygous pathogenic variant in the proband and also in the brother with short stature. In this article, we will focus on the clinical presentation of the syndrome in this particular family as well as the characteristics of malignancies found in the proband.

Analysis on the Optical Response of Ldr and Phototransistor in Photoplethysmography

In photoplethysmography, light source and light detector are employed such that the received signal corresponds to a particular information needed. This research used five different LEDs as light sources. Phototransistor and LDR, on the other hand, were used as light detectors to assess the photosensitivity of human skin. Backscatter simulation was used to compare the photoplethysmographic detection of LDR and phototransistor. The aims of this study include: determine the optical response of a human skin, particularly the skin on the dorsal and palmar parts of the hand; conduct simultaneous simulation using modular and backscattered setup; provide measured value based on the conducted simulations. In every LED color and for both light detectors, ten test conditions were performed, namely: (1) room light on; (2) room light off; (3) room light on - black paper; (4) room light off - black paper; (5) room light on - white paper; (6) room light off – white paper; (7) room light on – dorsal skin; (8) room light off – dorsal skin; (9) room light on – palmar skin; and (10) room light off – palmar skin. Two different simulations were conducted involving all test conditions. The second simulation used light meter which showed similarity in behaviour of obtained values vis-à-vis barcode meter and ADC voltage. The modular involved a lux sensor which checked the findings on the reflectivity of skin Types III and IV of the Fitzpatrick scale and melanocytic naevi skin. The series of simulations conducted proved that the yellow LED provided highest sensor response and phototransistor greater sensitivity than LDR in detecting the received signals. Room light off condition was necessary to reduce the effects of ambient light.

Catechin reduces phototoxic effects induced by protoporphyrin IX-based photodynamic therapy in the chick embryo chorioallantoic membrane.

.Significance: Side effects of many cancer treatments are associated with the production of reactive oxygen species (ROS) in normal tissues. This explains why patients treated by photodynamic therapy (PDT) often suffer from skin photosensitization, whereas those subject to radiotherapies frequently experience damages in various organs, including the skin.Aim: Catechin, which belongs to the natural flavanols family, is well known for its antioxidant properties. Hence, our main objective was to investigate whether catechin can reduce damages induced by PDT using protoporphyrin IX (PpIX-PDT), an endogenous photosensitizer commonly used in dermatology.Approach: An in vivo model, the chick embryo chorioallantoic membrane (CAM), was used for this study. An amount of of a solution containing 5-aminolevulinic acid, a natural precursor of PpIX, was applied topically on the CAM 4 h before PDTs (405 nm, , ). Catechin was applied at different concentrations (1 to ) and times (0 to 240 min) before PDT. In addition, we assessed the potency of catechin to reduce the PpIX fluorescence photobleaching induced by PDT.Results: We observed that catechin significantly reduces the vascular damages generated by PpIX-PDT. Moreover, we have shown that catechin inhibits PpIX photobleaching.Conclusions: These observations suggest that catechin significantly reduces the level of ROS produced by PpIX-PDT.

Photodynamic therapy produces enhanced efficacy of antitumor immunotherapy by simultaneously inducing intratumoral release of sorafenib

Photodynamic therapy (PDT) can destroy local tumor cells and induce effective antitumor immune responses, and has been applied in the treatment of patients with superficial solid tumors. Numerous systemic side effects of PDT, such as pain and skin photosensitivity, however, limit this therapeutic option. In addition, the immunosuppressive tumor microenvironment has been found to be another critical barrier for the antitumor immunity induced by PDT. Therefore, effectively enhancing the cytotoxicity to tumor cells of low-dose PDT and inhibiting the tumor immunosuppressive tumor microenvironment may be a feasible strategy to overcome these drawbacks of PDT. Here, a sorafenib and chlorin e6 co-loaded reactive oxygen species (ROS)-responsive nanoparticle (NP-sfb/ce6) is developed to improve antitumor responses by intratumoral release of sorafenib at the time of PDT. Under 660-nm laser irradiation, ROS produced by chlorin e6 (ce6) destruct the nanoparticles, resulting in boosted sorafenib cascade release. The rapidly released sorafenib acts synergistically with the low-dose PDT to inhibit tumor growth by inducing strong T cell-dependent local and systemic antitumor immune responses, reprograming the tumor immune microenvironment, and limiting the interaction between cytotoxic CD8+ T cells and immunosuppressive cells. This study provides new avenues for cascade-amplifying antitumor effects of photodynamic therapy.

Skin photosensitivity in photodynamic therapy: fluorescence measurement and pharmacokinetic model

Skin photosensitivity in photodynamic therapy: fluorescence measurement and pharmacokinetic model

Direct detection of diclofenac radical produced by ultraviolet irradiation using electron spin resonance method.

Diclofenac, a nonsteroidal anti-inflammatory drug, is commonly used as an antipyretic analgesic owing to its strong anti-inflammatory action in clinical treatment. However, diclofenac can cause injury, with gastrointestinal mucosal lesions and skin photosensitivity as the main side effects. In general, photosensitive drugs contain photosensitive chemical sites, and form free radicals under ultraviolet irradiation, leading to phototoxic reactions. Therefore, this study focuses on free radical production in photosensitive reactions of diclofenac. The free radical production mechanism of diclofenac under ultraviolet irradiation, which might result in photo-toxicity, was clarified using a direct electron spin resonance method. When diclofenac was irradiated with ultraviolet light (254nm), diclofenac radicals were generated depending on the ultraviolet irradiation time and stably present for 30min at room temperature. Diclofenac radicals were produced by the ultraviolet irradiation system depending on the dose of diclofenac until 2mM. Therefore, diclofenac radicals might directly or indirectly react with various biomolecules to cause phototoxicity, other side effects, and new diclofenac pharmacology owing to its stability of diclofenac radicals.

GBS Data Identify Pigmentation-Specific Genes of Potential Role in Skin-Photosensitization in Two Tunisian Sheep Breeds.

Simple SummaryMaintaining the flexibility of the genetic resources of native animals to face local environment constraints is still a major challenge. In Tunisia, the Noire de Thibar breed is a local sheep, typically with black coloration, known for its ability to tolerate “hypericum perforatum”, which causes skin photosensitization in white colored sheep. The goal of this study was to perform a genome scan, by considering genotyping-by-sequencing (GBS) markers that were genotyped in divergent coat colored sheep (black vs. white) to identify strong, and recent, artificial selection that is involved in skin-photosensitization. Interestingly, the genomic differentiation analysis identified FST markers within genomic regions containing key pigmentation and photosensitivity related-genes. These findings help in understanding the background of coat color genetics and its potential role in adaptation to local environment constraints.The Tunisian Noire de Thibar sheep breed is a composite breed, recently selected to create animals that are uniformly black in order to avoid skin photosensitization after the ingestion of toxic “hypericum perforatum” weeds, which causes a major economic loss to sheep farmers. We assessed genetic differentiation and estimated marker FST using genotyping-by-sequencing (GBS) data in black (Noire de Thibar) and related white-coated (Queue fine de l’ouest) sheep breeds to identify signals of artificial selection. The results revealed the selection signatures within candidate genes related to coat color, which are assumed to be indirectly involved in the mechanism of photosensitization in sheep. The identified genes could provide important information for molecular breeding.

Detection of the small oligonucleotide products of nucleotide excision repair in UVB-irradiated human skin

UVB radiation results in the formation of potentially mutagenic photoproducts in the DNA of epidermal skin cells. In vitro approaches have demonstrated that the nucleotide excision repair (NER) machinery removes UV photoproducts from DNA in the form of small (∼30-nt-long), excised, damage-containing DNA oligonucleotides (sedDNAs). Though this process presumably takes place in human skin exposed to UVB radiation, sedDNAs have not previously been detected in human skin. Using surgically discarded human skin, we have optimized the detection of the sedDNA products of NER from small amounts of human epidermal tissue ex vivo within minutes of UVB exposure and after UVB doses that normally lead to minimal erythema. Moreover, sedDNA generation was inhibited by treatment of skin explants with spironolactone, which depletes the epidermis of the essential NER protein XPB to mimic the skin of xeroderma pigmentosum patients. Time course experiments revealed that a partially degraded form of the sedDNAs could be readily detected even 12 hours following UVB exposure, which indicates that these repair products are relatively stable in human skin epidermis. Together, these data suggest that sedDNA detection may be a useful assay for determining how genetic, environmental, and other factors influence NER activity in human skin epidermis and whether abnormal sedDNA processing contributes to photosensitive skin disorders.

INNOVATIVE UV BARRIER MATERIALS MADE OF ORGANIC COTTON DYED WITH NATURAL DYESTUFFS

The paper presents the results of research works on ecological materials that protect humans against the harmful effects of ultraviolet (UV) radiation, made of organic cotton, obtained through the application of selected natural dyes and a new reactive UV absorber with high molar absorption. These materials are intended for clothing, in particular for children and people with photosensitive skin. Instrumental evaluation of obtained colours and barrier properties of textile products for UV radiation were performed, expressed in the UPF (Ultraviolet Protection Factor) value, determined on the basis of measurements of UV transmittance by a textile product. Due to the application area of the new materials, the colour fastness to washing, perspiration, friction and artificial light. For selected newly developed organic cotton products containing in their structure a natural dye and a new UV organic absorber, specialized irritation tests according to OECD were carried out. In addition, the results of studies on antimicrobial properties are presented on the basis of the assessment of antibacterial activity against Gram (+) Staphylococcus aureus and Gram (-) Escherichiacoli.

The Dark Side: Photosensitizer Prodrugs.

Photodynamic therapy (PDT) and photodiagnosis (PD) are essential approaches in the field of biophotonics. Ideally, both modalities require the selective sensitization of the targeted disease in order to avoid undesired phenomena such as the destruction of healthy tissue, skin photosensitization, or mistaken diagnosis. To a large extent, the occurrence of these incidents can be attributed to “background” accumulation in non-target tissue. Therefore, an ideal photoactive compound should be optically silent in the absence of disease, but bright in its presence. Such requirements can be fulfilled using innovative prodrug strategies targeting disease-associated alterations. Here we will summarize the elaboration, characterization, and evaluation of approaches using polymeric photosensitizer prodrugs, nanoparticles, micelles, and porphysomes. Finally, we will discuss the use of 5-aminolevulinc acid and its derivatives that are selectively transformed in neoplastic cells into photoactive protoporphyrin IX.

Lupus erythematosus tumidus: clinical perspectives.

Lupus erythematosus tumidus (LET) is an uncommon and photosensitive inflammatory skin disorder which is characterised by erythematous urticarial plaques. In the last 20 years, extensive research on clinical and histological aspects of the disease have led to a better characterization of this nosological entity and to differentiate it from other similar or related diseases. Today, LET is considered as a separate subtype of cutaneous lupus erythematosus (CLE) with a benign, intermittent clinical course (intermittent CLE, ICLE) and only rarely associated with systemic lupus erythematosus (SLE).