Dermal Thickness Research Articles

Oral Administration of Lactilactobacillus curvatus LB-P9 Promotes Hair Regeneration in Mice.

This study was designed to examine the effect of Lactilactobacillus curvatus LB-P9 on hair regeneration. The treatment of LB-P9 conditioned medium increased the proliferation of both hair follicle dermal papilla cells and hair germinal matrix cells (hGMCs). Moreover, the expression levels of hair growth factors such as vascular endothelial growth factor (VEGF) and fibroblast growth factor 7 were significantly elevated in hGMCs co-cultured with LB-P9. After time-synchronized depilation, mice were orally administered with either 4×107 colony forming unit (CFU) of LB-P9 (low dose) or 4×108 CFU of LB-P9 (high dose), once daily for 4 weeks. Compared with the vehicle (phosphate-buffered saline)-administrated group, the LB-P9-treated groups exhibited accelerated hair regrowth rate and enhanced hair thickness in a dose-dependent manner. Supporting this observation, both hair follicle numbers and the dermal thickness in skin tissues of the LB-P9-treated groups were increased, compared to those of the vehicle-treated group. These results might be explained by the increased level of β-catenin and number of hair follicle stem cells (CD34+CD49f+ cells) in the skin tissues of mice administered with LB-P9, compared to the vehicle-treated mice. Also, increased serum levels of hair growth factors such as VEGF and insulin-like growth factor-1, and superoxide dismutase were found in the LB-P9-treated groups, compared to those of the vehicle-treated group. Taken together, these results might demonstrate that the oral administration of LB-P9 promotes hair regeneration by the enhancement of dermal papilla proliferation through the stimulation of hair growth factor production.

Bioactive additives from the dorsal dermis of mice for enhanced vascularization in 3D bioprinting.

Effective angiogenesis is essential for creating complex vascular networks in tissue engineering; however, there is a scarcity of safe and potent pro-angiogenic factors. Although a decellularized extracellular matrix (dECM) offers excellent biocompatibility and is widely used in tissue engineering as a pro-angiogenic additive, its conventional extraction technique resulting in significant loss of bioactivity limits clinical potential. The dorsal dermal tissue has rich blood perfusion and its dECM is rich in angiogenic factors. In this study, the dECM components from the dorsal dermis of mice (DD) were produced to enhance in vitro and in vivo pro-angiogenic abilities using a novel physical method. Morphological studies showed no significant difference between DD-wild-type (DD-wt) and DD-wild-type-newborn (DD-wtn), and there was also no difference in DNA or RNA concentration. In addition, DD-wtn outperformed DD-wt in maintaining the stemness of MSCs, promoting inflammatory response and facilitating endothelial cell differentiation. It is of greater significance to note that the dermal combined fibrous capsule thickness is greater in the DD-wt treated group than in the DD-wtn group. Furthermore, the number of blood vessels in the subcutaneously implanted scaffold with DD-wtn increased by 233%. Consequently, our current finding provides a promising strategy to produce a novel pro-angiogenic bioink additive for enhancing vascularization in 3D bioprinting.

Proteins extracted from pearl oyster (Pinctada martensii) with efficient accelerated wound healing in vitro through promoting cell proliferation, migration, and collagen formation

Ethnopharmacological relevancePearl oyster (Pinctada martensii) is used in Chinese traditional medicine use in photoprotective, anti-inflammatory, and wound treatment.Aim of the study: This study explored whether the mucus protein of Pearl oyster (protein of Pinctada martensii, PMP) affects human skin fibroblast (HSF) proliferation, migration, collagen-related gene expression related to collagen formation, and in vivo healing effects. Materials and methodsThe PMP component was analyzed by LC-MS/MS. The cell viability was evaluated using a CCK-8 kit. The expression genes were measured by reverse transcription polymerase chain reaction. A full-thickness excisional wounding model in Sprague-Dawley (SD) rats was used to test the repairing effect of PMP in vivo, and Hematoxylin-Eosin (H&E) and Masson's Trichrome staining were applied to evaluate skin structure. ResultsThe components of PMP were identified using LC-MS/MS proteomics, and a total of 3023 proteins were detected. The results of PMP-treated HSF showed that PMP effectively promoted cell proliferation by 1.6-fold and cell migration by 1.5-fold at a concentration of 1 mg/mL. Additionally, PMP treatment up-regulated the expression levels of collagen-related genes COL1A1, COL3A1, and MMP-1 in fibroblasts. Furthermore, PMP was applied in the therapy of full-thickness excisional wounds in rats. The results demonstrated that PMP significantly accelerated wound healing time, resulted in the recovery of dermal and epithelial thickness, and stimulated collagen regeneration. The regenerated skin closely resembled the structure of normal skin. ConclusionsThese findings provide solid evidence supporting the potential of PMP as a promising candidate for the treatment of skin wounds.

Coping Strategies Adopted by Patients Sustaining Major Burns

Objective: To explore the various coping strategies used by patients sustaining major burns. Study Design: Qualitative, exploratory study. Place and Duration of Study: Department of Plastic and Reconstructive Surgery, Combined Military Hospital, RawalpindiPakistan, from Jan to Jun 2021. Methodology: A total of 15 patients were selected who had been admitted to CMH Rawalpindi after sustaining 20-45% total body surface area deep dermal or full thickness burns requiring operative intervention. Semi-structured interviews comprising eleven questions were conducted, and the strategies which these patients used to cope with different psychological issues post-major burns were identified. Subthemes and themes were identified, and the data was analyzed by manual thematic analysis. Results: Eight coping strategies were identified: help from religion, support from family and friends, use of recreational activities, getting out of the house, doing exercise, getting back into a routine, the role of doctors and the use of the internet. Conclusion: Solace from religion and support from family and friends were the most widely used coping strategies in our setup. Getting back to routine helped them feel normal. Relaxation techniques and exercise were helpful but infrequently used. Social media and the internet were used as a diversion and recreational tool. None of our patients went for psychological counselling or group therapy sessions or used anxiolytics or antidepressants, which are an important part of treatment in the West.

Report of outcomes in burn patients enrolled in the Cultured epidermal autograft prospective Registry

Cultured epidermal autograft (CEA) is a permanent skin replacement indicated for use in adult and pediatric patients with deep dermal or full thickness burns comprising a total body surface area (TBSA) ≥ 30 %. CEA (Epicel®) was approved for use in adults in the United States in 2007 as a Humanitarian Use Device (HUD) under a Humanitarian Device Exemption (HDE) and was approved for pediatric use in 2016. In 2019, a CEA Registry was established with an objective of prospective data collection and analysis of demographic, treatment, and outcome data for the real-world use of CEA. At the time of data cut–off (June 2022), 68 patients (50 adults and 18children) had completed data in the registry, up through hospital discharge, for this analysis. Mean total body surface area (TBSA) of the burn was 58 % in adults and 56 % in pediatric patients, and almost half had inhalation injury in each group. Approximately 74 % of adults and 67 % of pediatric patients had TBSA ≥ 50 %. Overall survival was 87 % (84 % adults, 94 % pediatric). Mean % graft take (engraftment) of CEA was 81 % in adults and 84 % in pediatric patients. Outcomes from this prospective collection of data in severely burned patients treated with CEA demonstrate favorable engraftment and survival rates and are in general agreement with recent literature.

Role of Dermabrasion Assisted Tangential Excision in Burns

Burn injury of second degree deep dermal and full thickness delays in healing and heals by scarring. Deep dermal burns need early treatment by tangential excision and skin grafting to promote healing. While wound irrigation, debridement, and local wound care may be sufficient for managing superficial burns (involving the epidermis and superficial dermal layer), deep burns (involving the deep dermal layer and other structures deeper to it) require tangential excision and skin grafting. If performed early it is associated with better outcomes in terms of reduced infection risk and hastened wound healing.

Hydrogel loaded with exosomes from Wharton's Jelly-derived mesenchymal stem cells enhances wound healing in mice.

To explore the effect of hydrogel loaded with exosomes from Wharton's Jelly-derived mesenchymal stem cell (WJMSC) on wound healing. Exosomes were extracted from WJMSC, and the morphology and size of WJMSC-derived exosomes (WEX) were analyzed by transmission electron microscopy and nanoparticle size analyzer, respectively. The surface markers CD9, CD81, and Calnexin of WEX were detected by Western blotting. Exosome-loaded alginate hydrogel (WEX-gel) was prepared; its morphology was studied by scanning electron microscope, and its rheological behavior was examined by a rheometer. The in vitro drug release performance of WEX-gel was investigated by BCA method. RAW264.7 cells were treated with alginate hydrogel, WEX and WEX-gel, respectively; and the expression of CD86 and CD206 in macrophages was detected by flow cytometry. A full-thickness skin wound model was established in mice; the model mice were randomly divided into blank control group, WEX control group and WEX-gel group, and PBS, WEX and WEX-gel were applied to the wound area of mice, respectively. On day 3, the skin tissue of mice was excised, and the antibacterial effect of WEX hydrogel was evaluated by plate counting. On day 15, the mice were euthanized and the percentage of residual wounds was calculated. The histological changes of the skin wound were observed after hematoxylin and eosin (HE) and Masson stainings. The expression of CD86, CD206, CD31 and vascular endothelial growth factor (VEGF) in the skin wound tissue was detected by immunohistochemistry. Exosomes were successfully extracted from WJMSC. WEX-gel presented a regular three-dimensional network structure, good rheology and controlled drug release performance. WEX-gel promoted the polarization of RAW264.7 cells from the M1 phenotype to M2 phenotype in vitro. The residual wound percentage in blank control group, WEX control group and WEX-gel group were (27.5±3.4)%, (15.3±1.2)% and (7.6±1.1)%, respectively (P<0.05). The antibacterial property of WEX-gel is better than that of WEX (P<0.05). The dermis thickness, the number of new hair follicles, and the rate of collagen deposition in the WEX-gel group were significantly higher than those in the other two groups (all P<0.05). The expression of CD206, CD31 and VEGF in skin wound tissue was higher and the expression of CD86 was lower in WEX-gel group than those in other two groups (all P<0.05). WEX-gel can significantly promote wound healing in mice by regulating the polarization of macrophages.

Aging in the dermis: Fibroblast senescence and its significance.

Skin aging is characterized by changes in its structural, cellular, and molecular components in both the epidermis and dermis. Dermal aging is distinguished by reduced dermal thickness, increased wrinkles, and a sagging appearance. Due to intrinsic or extrinsic factors, accumulation of excessive reactive oxygen species (ROS) triggers a series of aging events, including imbalanced extracellular matrix (ECM) homeostasis, accumulation of senescent fibroblasts, loss of cell identity, and chronic inflammation mediated by senescence-associated secretory phenotype (SASP). These events are regulated by signaling pathways, such as nuclear factor erythroid 2-related factor 2 (Nrf2), mechanistic target of rapamycin (mTOR), transforming growth factor beta (TGF-β), and insulin-like growth factor 1 (IGF-1). Senescent fibroblasts can induce and accelerate age-related dysfunction of other skin cells and may even cause systemic inflammation. In this review, we summarize the role of dermal fibroblasts in cutaneous aging and inflammation. Moreover, the underlying mechanisms by which dermal fibroblasts influence cutaneous aging and inflammation are also discussed.

Tanshinone IIA ameliorates the development of dermal fibrosis in systemic sclerosis.

We previously revealed the role of tanshinone IIA (TAN IIA) on endothelial cells and the impact of TAN IIA on the endothelial-to-mesenchymal transition in systemic sclerosis (SSc). In this study, we sought to further determine whether TAN IIA can directly act on the skin fibroblasts of scleroderma and look into its underlying anti-fibrotic mechanisms. Bleomycin was used to establish the SSc mouse model. After TAN IIA treatment, dermal thickness, type I collagen and hydroxyproline content were measured. Primary fibroblasts were acquired from SSc patients and cultured in vitro, and the effects of TAN IIA on proliferation, apoptosis and the cell cycle of fibroblasts were detected. In a bleomycin-induced SSc model, we discovered that TAN IIA significantly improved skin thickness and collagen deposition, demonstrating a potent anti-fibrotic action. TAN IIA inhibits the proliferation of skin fibroblasts derived from SSc patients by causing G2/M cell cycle arrest and promoting apoptosis. Additionally, TAN IIA downregulated extracellular matrix gene transcription and collagen protein expression in skin fibroblasts in a dose-gradient-dependent manner. Furthermore, we showed how TAN IIA can reduce the activation of the transforming growth factor-β (TGF-β)/Smad and mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) pathways, which are important factors in SSc. In summary, these data suggest that TAN IIA can reduce SSc-related skin fibrosis by modulating the TGF-β/Smad and MAPK/ERK signalling pathways. More importantly, our results imply that TAN IIA can directly act on the skin fibroblasts of SSc, therefore, inhibiting fibrosis.

Superiority of systemic bleomycin to intradermal HOCl for the study of interstitial lung disease

Systemic sclerosis (SSc) is an autoimmune disease characterized by vasculopathy, immune dysregulation, and multi-organ fibrosis. Interstitial lung disease (ILD) is a complication of SSc and a leading cause of SSc-death. The administration of hypochlorous acid (HOCl) intradermally in the mouse (HOCl-SSc) purportedly shows several features typical of SSc. We studied the model by injecting BALB/c mice daily intradermally with HOCl for 6-weeks, an exposure reported to induce lung fibrosis. On day 42, the skinfold thickness and the dermal thickness were two and three times larger respectively in the HOCl group compared to controls. HOCl treatment did not result in histological features of pulmonary fibrosis nor significant changes in lung compliance. Automated image analysis of HOCl mice lungs stained with picrosirius red did not show increased collagen deposition. HOCl injections did not increase pulmonary mRNA expression of pro-fibrotic genes nor induced the production of serum advanced oxidation protein products and anti-topoisomerase 1 antibodies. Immune cells in bronchoalveolar lavage fluid (BALF) and whole lung digests were not increased in HOCl-treated animals. Since lung fibrosis is proposed to be triggered by oxidative stress, we injected HOCl to Nrf2−/− mice, a mouse deficient in many antioxidant proteins. Lung compliance, histology, and BALF leukocyte numbers were comparable between Nrf2−/− mice and wild-type controls. We conclude that the HOCl-SSc model does not manifest SSc-lung disease.

Microstructural characterization of the skin in the African straw-coloured fruit bat, Eidolon helvum (Pteropodidae).

The African straw-coloured fruit Bat, Eidolon helvum, is a Yinpterochiroptera bat that is of public health and ecological importance. This study investigated the light microscopic morphology, morphometry and histochemistry of the skin and its glands across the cheek, withers, croup, ventral abdomen, perianal region, wing membrane, intercrural membrane and foot pad of the species. Sweat glands were absent and hypodermis was observed only in the withers, croup and ventral abdomen. The croup had the highest density of hair follicles while the perianal region had the highest density of sebaceous gland acini. The thicknesses of the dermis and epidermis were significantly high in the withers and foot pad respectively. Hair follicles and sebaceous glands were absent in the wing membrane. The sebaceous glands had melanin pigmentation at the periphery and stained positive to Alcian Blue-periodic acid Schiff at the withers and ventral abdomen. Epidermal and dermal thicknesses reported in this study were generally higher than those of Yangochiroptera bats and the presence of sebaceous glands and hair follicles in the wing membrane were variable in different bat species. This study has provided baseline information on the light microscopic morphology and morphometry of the skin and its glands across the various body regions in the African straw-coloured fruit bat. This information would be helpful in the understanding, handling, skin disease treatment and management of the bat in captivity for biomedical research purposes.

Brown adipose tissue transplantation improves skin fibrosis in localized scleroderma.

Adipose tissue transplantation shows great therapeutic potential in reversing localized scleroderma-associated skin fibrosis. Brown adipose tissue (BAT) can specifically secrete various cytokines against fibrosis, but its therapeutic potential in improving skin fibrosis has not yet been demonstrated. In this study, we have demonstrated the superior therapeutic efficacy of BAT transplantation for sclerotic skin by transplanting two distinct types of adipose tissue. In comparison to the white adipose tissue (WAT) group, mice treated with BAT transplantation exhibited a significant reduction in dermal thickness. BAT transplantation effectively reverses skin sclerosis through mechanisms involving inflammation reduction, promotion of angiogenesis, inhibition of myofibroblast accumulation, and collagen deposition. This therapeutic effect can be attributed to its unique paracrine effects. Furthermore, transcriptome sequencing (RNA-Seq) revealed upregulation of pathways associated with lipogenesis and fatty acid metabolism in BAT while downregulating pathways are related to transforming growth factor β(TGF-β), epithelial-mesenchymal transition (EMT), and inflammatory response. These findings suggest that BAT transplantation holds great promise as a novel approach for localized scleroderma treatment.

Efficacy of skin rejuvenation with a fractional 1927-nm thulium laser alone or combined with a chemical peel: a controlled histopathological preliminary study in a mouse model.

Many patients demand minimally invasive treatments for skin rejuvenation, such as nonablative laser and superficial chemical peels. Combination therapy yet has not been studied histopathologically. The purpose of this study is to assess the histopathological efficacy of a 1927-nm thulium laser-assisted salicylic acid (SA) peel in skin rejuvenation. A six-segment table was drawn on the shaved back of C57BL/6 mouse. All segments were irradiated with the thulium laser-different tips and passes were used for specific segments. A 30% SA peel was then applied to the right-hand segments. After treatment, the skin samples were collected from each segment and examined for dermal thickness, collagen density, and melanin content. Greater thickness was seen in the combination therapy group compared with the laser alone group and in those segments receiving more passes with larger beam-sized tip. Collagen density increased in all treated skin segments, irrespective of the group. No adverse events were noted in the treated areas. The sample size was small and mouse skin has histological differences with human skin. The combination of a thulium laser and 30% SA peel has a synergistic effect on dermal thickness, so that can be suggested as a novel skin rejuvenation technique.

Changes in the skin characteristics of Nellore steers during the rearing phase in hot climate pasture supplemented with protein sources

We hypothesized that the protein source in supplements and the insolation and ambient temperature changes in different seasons could cause changes in the skin of Nellore steers during the rearing phase on warm-climate pasture. The objective of this study was to evaluate the effects of replacing true protein (soybean meal) with NPN (extruded urea) in the supplement on the skin characteristics of steers grazing on Marandu grass pastures. Thirty-six Nellore steers with an average initial weight of 250.0 kg and 15 months of age were used. Skin biopsies were performed at three different times: summer, autumn, and winter. The protein source has effects on the length of the glandular portion, number of follicles, and gland area in steers during the rearing phase at different seasons of the year. In the summer, the skin presented a higher compact structure, while in the autumn and winter, the skin presented a sparser arrangement. Skin from steers that received soybean meal in supplement had a more significant number of follicles in the summer and a smaller area and length of sweat glands. The dermis thickness of steers supplemented with soybean meal was greater than that of urea supplemented. The epidermis thickness and dermis of the steers' skin were greater at the autumn (April). Sweat gland depth was greater in autumn (April) and winter (July) than in summer (December). The protein source in the supplement alters the skin characteristics by increasing of dermis thickness of Nellore steers during the growth phase. The insolation and ambient temperature changes in different seasons alter the skin structure by increasing the epidermis and dermis thickness, sweat glands depth, and glands area of the skin of steers during the growth phase.

Assessment of the utility of the novel Phenion® full thickness human skin model for detecting the skin irritation potential of antimicrobial cleaning products

The skin is a potential route of exposure to antimicrobial cleaning products (ACP). Skin irritation, reversible damage to the skin, is an endpoint for protecting consumers and operators accidently exposed to these complex mixtures. To assess skin irritation of 24 ACP formulations, a new protocol was developed and adapted from OECD Test Guideline No. 439 with EpiDerm™ (epidermis model) replaced by Phenion® FT (full thickness tissue, including epidermis and dermis) as the test system. A full thickness tissue was utilized to provide a more human in vivo-like model. Formulations were applied to Phenion® FT and cell viability measured by MTT reduction after a 15-min exposure and 42 h post exposure period. A prediction model was applied, and results compared with in vivo rabbit skin irritation data. Concordance between in vivo and in vitro was demonstrated to be suitable (i.e., sensitivity 78%, specificity 83%, and accuracy 79%) using this modified OECD Test Guideline No. 439 method with a 70% cell viability selected as the most reasonable cut off for discriminating non-irritants (EPA Class IV). These results were considered suitable to develop a draft IATA i.e., with any ACP formulation identified as EPA Category IV in this test. The method will be further refined to distinguish irritant categories.

Differences in the microanatomy of skin of sole and palm in humans

Background: The prevalence of skin diseases has increased over the last few decades and they contribute to a significant burden on the health-care systems all across the world. In some forms of reconstructive or plastic surgery, palm skin has successfully been replaced with sole skin, removed to form a full-thickness graft that covered almost the entire palm of the hand without impairing the weight-bearing areas of the feet or encumbering the gait. In cases such as these, the skin of the palm and sole is preferred for grafts. Aims and Objectives: The study was conducted to learn the microanatomy of palm and sole. Materials and Methods: The present observational study was carried out in the Department of Anatomy, King George Medical University, Lucknow, from the period of September 2017 to August 2018. Ethical clearance was obtained from Institutional Ethics Committee (Ref. code:63/Ethics/R-Cell-18). For the present study, skin was procured from the palm and sole of six freshly embalmed human cadavers (three males and three females). The mean age of the cadavers was 67 years. Tissues were preserved in 10% of formaldehyde for 48 h, fixed, Stained in H and E, and observed under light microscope. Results: The study showed that the thickness of epidermis and ratio of epidermis to stratum corneum (Edp: sc) of the sole are greater than palm, dermoepidermal junctions were more in sole. Thickness of dermis both papillary and reticular dermis was more in sole than palm. Conclusion: The values of thickness of skin of palm and sole region provide data for plastic surgeons to plan cosmetic surgeries.

Influence of cryopreservation techniques and low concentrations of permeating cryoprotectants on the conservation of ear cartilage and skin derived from six-banded armadillos (Euphractus sexcinctus Linnaeus, 1758)

Considering the importance of efficiently obtaining somatic resource banks as an ex-situ conservation strategy for wild mammals, we evaluated two techniques (slow freezing - SF and solid-surface vitrification - SSV) for the cryopreservation of ear cartilage and skin from six-banded armadillos. Additionally, we analyzed the effects of two combinations of intracellular cryoprotectants (3.0 M or 6.0 M ethylene glycol - EG and dimethyl sulfoxide - Me2SO) on SSV. Tissues not subjected to cryopreservation were used as controls. All samples were evaluated for morphological analysis and cell ability during culture. The thickness of the basal layer was similar to the control only for tissues derived from SF, while SSV ensured the preservation of the cartilage thickness. Moreover, fragments derived from SF and SSV, especially in the 3.0 M EG-Me2SO group, resulted in dermis thickness and total skin similar to the control. All cryopreserved techniques maintained normal patterns of the fibroblasts, epidermal cells, and melanocytes. While only SF-derived fragments maintained the number of degenerated chondrocytes similar to the control, no difference was observed between groups for normal chondrocytes and lacunae. Moreover, SSV maintained the collagen fibers percentage of the tissues even after warming. After culture, SF and SSV techniques were efficient for the recovery of the somatic cells in all parameters evaluated, except the day of subconfluence, which was greater for the SSV group with 6.0 M EG-Me2SO. In summary, SSV, especially with 3 M EG-Me2SO, was as efficient as SF in preserving ear skin and cartilage derived from six-banded armadillos.

Comparison of the Effectiveness of Lyophilized Amniotic Membranes in the Partial Thickness Wound Healing Process in Mus musculus

Background: Currently, tulle or gentamicin ointment is generally used to prevent wound infections in wound care. Human amniotic membrane has been used in medical fields such as wound care. So far, there is no comparative evidence of the effectiveness of each ingredient. This study aimed to compare the effectiveness of lyophilized amniotic membrane, tulle, and 0.1% gentamicin ointment in the wound healing process. partial thickness on Mus musculus clinically and histologically.&#x0D; Methods: This type of research is experimental with a post-test-only control group design. There were 24 rats divided into each group. This research was conducted at the anatomical pathology laboratory, Faculty of Medicine, Universitas Andalas, and INA lab in July - September 2023 using rats (Mus musculus), which were divided into 3 treatment groups and one control group.&#x0D; Results: Clinically, lyophilized amniotic membrane, 0.1% gentamicin ointment, and tulle provided better results than controls regarding erythema variables. Histologically, the results showed that the lyophilized amniotic membrane group had the thinnest epidermis and dermis, as well as better histological scores for granulation, fibroblasts, and collagen than the 0.1% gentamicin ointment, tulle, and control groups. In this study, significant differences in effectiveness were found in terms of erythema, skin thickness, granulation, fibroblast, and collagen histological scores, with better results in the lyophilized amniotic membrane group.&#x0D; Conclusion: Clinically, lyophilized amniotic membrane, tulle, and 0.1% gentamicin ointment were more effective than controls for wound treatment due to faster reduction in erythema. However, histologically, the lyophilized amniotic membrane was proven to be more effective than tulle, 0.1% gentamicin ointment, and control in terms of epidermis and dermis thickness, granulation level, fibroblasts, and collagen.

Comparison of the histological features in the photoaged animal model

Background: Photoaging is a type of aging primarily caused by exposure to radiation, such as Ultraviolet B (UVB). This radiation penetrates the upper epidermis and papillary dermis leading to sunburn, tanning, photoaging, and photocarcinogenesis. Its light is a significant cause of direct deoxyribonucleic acid (DNA) damage. Furthermore, it induces transcription factors, such as NF- and other pro-inflammatory cytokines, the expression of matrix metalloproteinase (MMP), and generates reactive oxygen species (ROS). Therefore, this study aimed to determine the differences in the histologic features of the photoaged animal models. Methods: There were three groups, including P1, P2, and P3. Group P1 consists of male Wistar rats (Rattus norvegicus), aged 10-12 weeks, with average body weight between 100-150 grams. Group P2 consists of C57BL aged 5-6 weeks with an average weight of 50-75 grams. P3 comprises BABL/c mice aged 5-6 weeks with an average weight of 50-75 grams. They were photoaged for 6 weeks using UV lamps (Ultraviolet B Broadband TL lamps. Phillips TL 20W/01 RS) with a 290-315 nm wavelength. Results: The results showed a significant difference in epidermal thickness, dermal thickness, and sunburn cell (SBC) between groups after exposure to UVB radiation (p&lt;0.05). Meanwhile, there was no significant difference in their blood vessels (p&gt;0.05). Conclusion: The exposure to UVB for six weeks affects epidermal and dermal thickness, amount of SBC, and blood vessels in the photoaged animal model.

The effect of long exposure to uvb rays on histological features of wistar rats (Rattus norvegicus) in photoaging model

Introduction: Indonesia is a tropical country with exposure to UV rays from the sun throughout the year, so the Indonesian population is very vulnerable to skin aging, especially extrinsic skin aging due to prolonged exposure to UV rays. This study aimed to determine the effect of long exposure to UVB rays on the thickness of the epidermis, the thickness of the dermis, and the number of blood vessels and sunburn cells in (Rattus norvegicus) Wistar strain. Methods: This research was a post-test-only control group design using 27 rats which were divided into 3 groups, namely: control group K was untreated rats, and treatment groups P1 and P2 were rats exposed to UVB radiation for 3 weeks and 6 respectively exposure weeks. Test the effect on the study using the One-Way ANOVA test and Tukey’s Post Hoc Test. Results: The results indicated an increase in epidermal thickness of groups P1 (44.87 μm) and P2 (56.90 μm) (significant p&lt;0.05). A decrease in dermis thickness occurred in groups P1 (726.91 μm) and P2 (559.40 μm) (significant p&lt;0.05). In the photoaging area, there was an increased amount of sunburn cells in group P1 (6.40) and P2 (11.40) (significant p&lt;0.05). There was a difference in the number of blood vessels between groups K and P2 and groups P1 and P2 (p&lt;0.05). Conclusion: There was an effect of long exposure to UVB rays on histology in rats (Rattus norvegicus) of the photoaging model including the thickness of the epidermis layer and dermis layer, the number of blood vessels, and sunburn cells.