Engineered Skin Substitute Regenerates the Skin with Hair Follicle Formation

Currently, engineered skin substitutes (ESS) are unable to regenerate cutaneous appendages. Recent studies have shown that skin-derived precursors (SKPs), which are extensively available, have the potential to induce hair follicle neogenesis. Here, we demonstrate that ESS consisting of culture-expanded SKPs and epidermal stem cells (Epi-SCs) reconstitute the skin with hair follicle regeneration after grafting into nude mice. SKPs seeded in a C-GAG matrix proliferated and expressed higher levels of hair induction signature genes—such as Akp2, Sox2, CD133 and Bmp6—compared to dermal fibroblasts. Moreover, when ESS prepared by seeding a mixture of culture-expanded murine SKPs and human adult Epi-SCs into a C-GAG matrix was grafted into full-thickness skin wounds in nude mice, black hairs were generated within 3 weeks. Immunofluorescence analysis showed that the SKPs were localized to the dermal papillae of the newly-formed hair follicle. Our results indicate that SKPs can serve as the hair-inductive cells in ESS to furnish it with hair genesis potential

Role of Androgen on Physiological Function of Pilosebaceous Unit

The pilosebaceous unit is a sebaceous gland with hair follicles. One of the hormones that affects the pilosebaceous unit is androgen, a steroid hormone that plays an important role in the expression of the phenotype of men and women. Androgen consist of testosterone and dihydrotestosterone which are activated by androgen receptors. Androgen in the pilosebaceous unit affect sebum production and hair growth. Androgen receptors in the sebaceous glands are found on sebocytes and in hair follicles in the dermal papillae of hair follicles

Role of Androgen on Physiological Function of Pilosebaceous Unit

The pilosebaceous unit is a sebaceous gland with hair follicles. One of the hormones that affects the pilosebaceous unit is androgen, a steroid hormone that plays an important role in the expression of the phenotype of men and women. Androgen consist of testosterone and dihydrotestosterone which are activated by androgen receptors. Androgen in the pilosebaceous unit affect sebum production and hair growth. Androgen receptors in the sebaceous glands are found on sebocytes and in hair follicles in the dermal papillae of hair follicles

Evaluation of capillary density in psoriasis: An intrapatient study and literature review

Background Dilated and tortuous vessels within elongated dermal papillae represent a histopathological clue of psoriasis. However, the number of dilated capillaries (capillary density) in psoriasis remains undefined as the results from the available studies differ significantly. Objectives To evaluate the capillary density in psoriasis using dermoscopy and horizontal histopathological sections (HHS), two techniques that share the horizontal view of the skin, and to compare the results with the existing data. Methods Twenty adult patients with stable plaque psoriasis were enrolled and, in each patient, a target area of the examined plaque, previously engraved by gently rotating a 5-mm biopsy punch device, underwent dermoscopy and biopsy for HHS. In all examined fields, capillary density was evaluated in a centered 4-mm diameter area, counting the number of red dots at dermoscopy and of dermal papillae at HHS. Results A total of 20 target lesions located on the trunk, arms and tights were evaluated. The mean capillary density resulting from dermoscopy was 43.02±6.60/mm 2 whereas that from HHS was 50.30±9.05/mm 2. These data showed a statistically significant difference (p = 0.006), with a strong correlation at Pearson’s test (r = 0.88). Conclusions Our results when compared with those from the existing literature showed some differences. The peculiarity of our work is represented by the precise measurement and correlation of the capillary density using two different methods, as the preliminary skin engraving allowed a perfect match between the area undergoing dermoscopy and that of skin sampling for HHS. Compared to dermoscopy in which deep-located vessels might have gone undetected, HHS seems to reflect more precisely and reliably the real capillary density showing an average of 50 capillaries/mm 2 that in a common 5x5 cm psoriatic patch corresponds to an average of 125.000 capillaries. These results highlight the extraordinary potential of psoriatic skin to develop such a complex and intricate vascular network.

Comparison Of Effectiveness Of Silver Sulfadiazine And Gentamicin On Abrasion Wound Healing

Abrasion is injury to skin due to trauma that affects the surface of the epidermis or superficial epithelium, especially from friction to the depth of the dermal papillae. The basic principle of abrasion treatment is to maintain moist condition in wound surface. This study aims to compare the effectiveness of silver sulfadiazine (SSD) and gentamicin cream in the process of healing abrasions. A total of 30 samples of abrasion patients who came for treatment at the ED were sampled, and divided into 3 groups, namely wound care by providing SSD, gentamicin and tulle. The wound dimensions are assessed from the length and width measured at the 1st day, the 5th day, and the 10th day. At the 10th day assessment, SSD was found to be more effective in healing abrasions compared to other groups. The use of SSD in abrasion wound treatment is believed to have advantages in proliferation phase where SSD is a sulfonamide class antibiotic that produces synergic effects along with silver which constantly absorbs exudates and bacteria, combines chloride tissue and several other proteins in the process of wound healing.

Peculiar epidermal peg pattern in cane rat skin

Skin is the largest organ in the body of man and animal where interdigitation of the dermal papillae with epidermal pegs enhances structural stability of the skin especially where frequent pressure is applied. Cane rats are robust rodents with stocky bodies. They are only found in Africa and only a single species known as Thryonomys has been found to exist. This work was designed to establish the nature of the interdigitating structural disposition of the epidermal-dermal interface in T. swinderianus (Greater cane rat) which may account for the fragility and easy tear of their skin. A total of twenty adult male greater cane rats were used. Three samples sized 1cm to 2cm were taken from each of 14 different body sites for histological evaluation for rete pegs. These pegs were generally few in six regions with the following average per light microscopic field: head (5.5±3.7), neck (1.0±1.7), forelimb (5.6±3.7), trunk (4.3±4.2), tail (1.0±1.7) and the hindlimb (6.3±5.3). The neck and the tail parts of the body have the least concentration of this structure compared to other regions evaluated. This few in number of rete pegs may account for the fragility of the skin which makes it difficult to restrain or handle without damage during research work procedures and management during domestication. Keywords: Epidermal pegs, Fragility, Histology, Peculiar, Thryonomys

Cushion Mechanism of Goat Hoof Bulb Tissues

The hoof bulb sections of white goats were observed via scanning electron microscopy and stereomicroscopy in order to explore the cushion mechanism in the bulb tissue microstructures of hoofed animals. The hoof bulbs consisted of multilayer tissues, including an epidermal layer, a dermal layer, and subcutaneous tissues from outside to inside. A bionic model based on hoof bulb tissue composite structures was built with a normal model as the control. The microcosmic mechanics of the bulb tissues was analyzed via the finite element method. Simulations showed that when the bionic model was impacted by the top plates at the speed of 1-10 m/s, stress was concentrated in the epidermal layer and uniformly distributed in the dermal layer and dermal papillae, which effectively reduced the impact onto the ground. The cornified epidermal layer can resist the instant impact onto the ground, while the dermal papillae embedded in the dermal layer can store, release, and dissipate the impulsive energy, and the three parts synergically act in the cushion.