Search

Assessing skin irritation potential is critical for the safety evaluation of topical drugs and other consumer products such as cosmetics. The use of advanced cellular models, as an alternative to replace animal testing in the safety evaluation for both consumer products and ingredients, is already mandated by law in the European Union (EU) and other countries. However, there has not yet been a large-scale comparison of the effects of topical-use compounds in different cellular skin models. This study assesses the irritation potential of topical-use compounds in different cellular models of the skin that are compatible with high throughput screening (HTS) platforms. A set of 451 topical-use compounds were first tested for cytotoxic effects using two-dimensional (2D) monolayer models of primary neonatal keratinocytes and immortalized human keratinocytes. Forty-six toxic compounds identified from the initial screen with the monolayer culture systems were further tested for skin irritation potential on reconstructed human epidermis (RhE) and full thickness skin (FTS) three-dimensional (3D) tissue model constructs. Skin irritation potential of the compounds was assessed by measuring tissue viability, trans-epithelial electrical resistance (TEER), and secretion of cytokines interleukin 1 alpha (IL-1α) and interleukin 18 (IL-18). Among known irritants, high concentrations of methyl violet and methylrosaniline decreased viability, lowered TEER, and increased IL-1α secretion in both RhE and FTS models, consistent with irritant properties. However, at low concentrations, these two compounds increased IL-18 secretion without affecting levels of secreted IL-1α, and did not reduce tissue viability and TEER, in either RhE or FTS models. This result suggests that at low concentrations, methyl violet and methylrosaniline have an allergic potential without causing irritation. Using both HTS-compatible 2D cellular and 3D tissue skin models, together with irritation relevant activity endpoints, we obtained data to help assess the irritation effects of topical-use compounds and identify potential dermal hazards.

Momordica charactia lin ( Bitter melon) has been the interest of many studies by researchers for a long time due to its very interesting human beneficial properties. It belongs to cucurbitacea family and momordica genus. It is used by human consumption all over the world in different forms such as a vegetable and /or medicine. The researchers have concentrated on the studies on its fruits and some times on its seeds and leaves. The present study is an extensive investigation of the quantitative elements such as Ca, Cd ,Co, Cr, Cu, Fe, Mg, Mn, Pb, Zn, K, N, and P of the fruit-skin, fruit-flesh, fruit-seed, tissue skin, leaf and root of the momordica charantia lin using flame atomic absorption spectrometry. The result shows a quite good variation of the concentration of the elements in different part of the plant.

This study investigates the effects of culture grown fibroblasts on contraction and dermal regeneration when used concurrently with full-thickness skin graft (FTSG) in full-thickness wounds.Fourteen Sprague-Dawley male rats were divided into two groups. In the first group, wound contraction was evaluated visually. Two full thickness tissue defects were produced on the back of the seven rats. The skin harvested from these areas was prepared as a full-thickness graft and sutured back to their original beds. Just before the last suture, autogenous fibroblast suspension was applied between the graft and the bed in area 1, and area 2 served as control. The surface area of grafts were calculated and compared with "Image J" program. In the second group, contraction and dermal regeneration were evaluated histologically. Three full-thickness tissue defects were produced on the back of seven rats. Area 1 and 2 were prepared as described above and area 3 was left to secondary healing. On the 14th and 30th days, punch biopsies were harvested from the center of the areas 1-3. Preparations were examined under light microscopy.Wound contraction was significantly less in area 1 on day 14 (p0.01). Histologically neovascularization, fibroblast density and collagen synthesis were more evident in cultured fibroblast applied areas on day 14. However epithelialization did not show any difference between areas both on days 14 and 30. On day 30, area 1 still a higher degree of fibroblast intensity than the other areas but neovascularization and collagen synthesis were not different than the other areas.According to the data obtained from the study, cultured fibroblasts, particularly with a dermal support, do not regress when transplanted to a living tissue. They contribute to the wound healing process; reduce the contraction of the wound; and support collagen synthesis and neovascularization.

Background. Large defects not easily repaired with local flaps and defects near anatomic free margins or crossing anatomic units present unique challenges for reconstruction. Cosmetic results of full-thickness skin grafts may appear unsatisfactory owing to differences in color, texture, and thickness between donor and recipient sites. Objective. The objective was to describe a skin-graft reconstructive method that better approximates skin characteristics between donor and recipient sites while following other criteria to improve the final aesthetic and functional result. Methods. Careful evaluation of the tissue surrounding a surgical defect determines tissue laxity available for skin grafting and whether the defect crosses anatomic units or may distort anatomic free margins or landmarks. Through partial closure of the large surgical defect, preferably within cosmetic units, a tricone is created large enough to graft the remaining wound. Results. Creating smaller wounds within cosmetic units or subunits, there is less chance of distortion of nearby anatomic free margins or landmarks. Skin grafting is accomplished with tissue of similar color, texture, and thickness Conclusion. Adjacent-tissue skin grafts provide a suitable reconstruction option for surgical defects too large for simpler repair or defects crossing cosmetic units or near free margins. This procedure permits repair with a full-thickness skin graft of more similar skin characteristics to the recipient site.

Background. Reconstruction in the periorbital area is challenging owing to the complex function of the eye, relative lack of adjacent loose tissue, free anatomic margin, central facial location, and the need to maintain symmetry with the contralateral eye. Reconstructive options risk crossing anatomic margins, deviation of the lid margin (ectropion), persistent lymphedema, and repair with skin of dissimilar color, texture, and thickness. Objective. The purpose was to describe a reconstructive option that would avoid crossing cosmetic units or subunits, minimize the risk of ectropion, repair with tissue of similar surface characteristics, and maintain function and symmetry with the contralateral side. Methods. The adjacent-tissue skin graft provides closure in cosmetic units and subunits, avoids tension on the lid margin, and provides similar skin for repair. The procedure is demonstrated by graphic and photographic examples. Results. The procedure provides for esthetic repair of the periorbital area and minimizes the risk of ectropion, lymphedema, asymmetry, and dysfunction of the lids and lacrimal system. Conclusion. Adjacent-tissue skin grafts are a useful alternative for reconstruction of partial-thickness defects on the eyelid and periorbital area. ANDREW J. KAUFMAN, MD, HAS INDICATED NO SIGNIFICANT INTEREST WITH COMMERCIAL SUPPORTERS.

Two bilateral 6.0 mm round skin defects were made on 60 DDY strain mice. The mice were divided into four groups and treated with low incident doses of laser energy at different wavelengths for 15 days: (a) Group I- Control; (b) Group II - 830 nm wavelength; (c) Group III - 680 nm wavelength; and (d) Group IV - 632.8 nm wavelength. For the treatment groups, only the right skin defect was irradiated. The rate of healing was assessed by examination through a monitor microscope, measurement of skin defect area and histological examination. No significant difference was observed between the four groups by macroscopic examination. The area of skin defect of the treated groups was significantly smaller than that of the control groups (p < 0.05) from the 1st-13th day after irradiation. For both irradiated and non-irradiated skin defects of treatment groups, Group III was smaller than Group II (p < 0.05) and Group IV was smaller than Group II (p < 0.05) Histological examination of the tissue skin defect showed greater proliferation of connective tissue and blood vessels in the dermis in treated groups than in control.

Patients with bleeding disorders are at a high risk of bleeding complications during surgical procedures. Cyanoacrylates have been used successfully in many procedures and surgeries. This study was undertaken to evaluate the effectiveness of Glubran 2 and Glubran tissue skin adhesive (Glubran Tiss) in patients with hereditary bleeding disorders who underwent circumcision or dental extraction. Seven patients with congenital bleeding disorders who underwent circumcision or dental extraction were evaluated during 2009. A historical control group was considered for comparison. Glubran 2 acrylic glue was applied in cases of dental extraction and Glubran Tiss in circumcision. The patients were followed up for 6 months to detect complications. Five patients had hemophilia A, one patient had hemophilia B, and one patient had Bernard–Soulier syndrome; six were boys or men and one was a girl. Mean age was 15 ± 8 years (range 5 to 25 years). The results in all patients under circumcision were good with significantly less factor consumption (P = 0.043). But in patients who underwent dental extraction, Glubran was effective only in a 5-year-old girl with mandibular premolar tooth extraction, but not successful in a 21-year-old man with extraction of maxillary wisdom tooth. After 6 months of follow-up, no complications were observed in any patients. Our experiences in this small series of patients suggest that adjunct use of Glubran Tiss, in addition to systemic replacement therapy, can be effective in the control of bleeding in patients with hemophilia who undergo circumcision, and helps to lessen factor consumption. But, further studies with larger sample size are needed. However, our experience in using Glubran in dental extraction was not successful.

Exploratory human tissue skin (HTS)-based memristors and their networks (two in series/parallel combination) with essential memristance characteristics are presented. Exploratory effects of variables viz. applied emf E+/–, memristor forming probe distance (d), size and shape of probes and their polarisation (with respect to finger alignment), on resistance R variation with applied emf E+/–, R retainablility with elapsed time, and charge Q variation with time for continuous flow of applied current are studied and depicted in brief. Applications in bio-electronics and bio-medical electronics are envisaged.

For the first time exploratory feasibility study on the ‘physical model of human tissue skin-based electronic transistor’ (HTSBET) is presented. Effects of variables like 1 distance (d) between device forming probes 2 applied voltages 3 probes pressure (p) 4 probes polarisation and shape, on the input/output characteristics as well as current gain factor β of the transistor are studied. Emerging applications of bio-material human tissue blood/skin-based electronic circuits towards cyborg implants, human-machine interface, human disease detection/healing, human health sensors and digital signal processing is visualised.