Skin grafts : local quest for viable alternatives to autologous grafts using silk and acellular dermal matrices

The gold standard with regards to skin transplantation is the use of the patient’s own skin obtained from a healthy donor site. Such grafts can be either full thickness skin or more commonly nowadays, split thickness skin. Various materials, having either natural and or synthetic origins, have been used in the engineering of skin substitutes to-date and these grafts are then confronted against autologous skin grafts. If proven to be successful, such matrices could be utilised in clinical applications such as in the treatment of burn wounds and in cases of skin ulcers amongst others. In this study the primary cells used, keratinocytes and fibroblast, were obtained from donor skin and cultured. Scaffolds of xenogenic (raw silk) as well as of allogenic (acellular dermal matrices) origins were obtained via low-cost methods and seeded using the fibroblasts and keratinocytes so as to determine which gave the closest mimic to skin grafts. Out of the matrices assessed, the raw silk matrix allowed the best colonisation with skin cells in our hands. The ADM matrice also showed some cell colonisation, but will need further experimentation.peer-reviewe

Applied of image processing technique on semi-auto count of skin spot

Skin is the biggest organ in the human body and works to separate the inner body part from outer environment. In the skin, there are sebaceous glands found inside the pores of the skin. They are at all over the body except for the palms of the hands and the feet soles. There are more sebaceous glands on the face and scalp than elsewhere. Sebaceous gland secretes an oily protective skin surface, sebum, which is against pathogens and also help to slow down the skin ageing process [1]. They can help to maintain the moisture of the skin. However, the sebaceous glands become overactive sometimes, thus, producing too much sebum and the pores can get clogged together with dead skin [2][3]. This will results in having blackheads along with other factors. Blackhead is one of an acne vulgaris type [4]. It is a small dark spots on the skin that sometimes hard to be seen under a naked eye. If the clogged pores infect the glands, the accumulated sebum may form a sac and slowly increase in size. Lack of sebum production can also provide unsatisfied result that could cause dry skin, which makes the skin, looks rough and dull

IC-integrated flexible shear-stress sensor skin

This paper reports the successful development of the first IC-integrated flexible MEMS shear-stress sensor skin. The sensor skin is 1 cm wide, 2 cm long, and 70 /spl mu/m thick. It contains 16 shear-stress sensors, which are arranged in a 1-D array, with on-skin sensor bias, signal-conditioning, and multiplexing circuitry. We further demonstrated the application of the sensor skin by packaging it on a semicylindrical aluminum block and testing it in a subsonic wind tunnel. In our experiment, the sensor skin has successfully identified both the leading-edge flow separation and stagnation points with the on-skin circuitry. The integration of IC with MEMS sensor skin has significantly simplified implementation procedures and improved system reliability

An in vivo comparative study on ageing skin: bio-mimetic versus traditional approach to skin moisturisation

Skin dryness is a common condition in elderly individuals. The two main mechanisms to cosmetically alleviate this state rely on the effects of humectants and occlusive substances, mostly in combination. However, products nowadays aim to go beyond the simple humectant and occlusive effects and to deliver ‘moisturising actives’, such as skin-identical lipids, natural moisturising factor (NMF) components, lipid precursors, peptides and amino acids. A relatively recent approach to increasing skin moisturisation is the bio-mimetic mechanism, i.e. using active ingredients with skin-identical lipids and lamellar structure. This study has demonstrated that providing the skin with lipids identical to those that make up the natural skin barrier can improve the skin hydration to a greater extent than a conventional o/w emulsion based on occlusive materials and humectants. In addition, it suggests that using bio-mimetic moisturisers is an effective and long-lasting method to elevate dry skin condition in people over 60

Helical damping and anomalous critical non-Hermitian skin effect

Non-Hermitian skin effect and critical skin effect are unique features of non-Hermitian systems. In this Letter, we study an open system with its dynamics of single-particle correlation function effectively dominated by a non-Hermitian damping matrix, which exhibits $\mathbb{Z}_2$ skin effect, and uncover the existence of a novel phenomenon of helical damping. When adding perturbations that break anomalous time reversal symmetry to the system, the critical skin effect occurs, which causes the disappearance of the helical damping in the thermodynamic limit although it can exist in small size systems. We also demonstrate the existence of anomalous critical skin effect when we couple two identical systems with $\mathbb{Z}_2$ skin effect. With the help of non-Bloch band theory, we unveil that the change of generalized Brillouin zone equation is the necessary condition of critical skin effect.Comment: 7+5 pages, 4+5 figure

Interplay of Staphylococcal and Host Proteases Promotes Skin Barrier Disruption in Netherton Syndrome.

Netherton syndrome (NS) is a monogenic skin disease resulting from loss of function of lymphoepithelial Kazal-type-related protease inhibitor (LEKTI-1). In this study we examine if bacteria residing on the skin are influenced by the loss of LEKTI-1 and if interaction between this human gene and resident bacteria contributes to skin disease. Shotgun sequencing of the skin microbiome demonstrates that lesional skin of NS subjects is dominated by Staphylococcus aureus (S. aureus) and Staphylococcus epidermidis (S. epidermidis). Isolates of either species from NS subjects are able to induce skin inflammation and barrier damage on mice. These microbes promote skin inflammation in the setting of LEKTI-1 deficiency due to excess proteolytic activity promoted by S. aureus phenol-soluble modulin α as well as increased bacterial proteases staphopain A and B from S. aureus or EcpA from S. epidermidis. These findings demonstrate the critical need for maintaining homeostasis of host and microbial proteases to prevent a human skin disease

Fingertip skin models for analysis of the haptic perception of textiles

This paper presents finite element models of the fingertip skin which have been created to simulate the contact of textile objects with the skin to gain a better understanding of the perception of textiles through the skin, the so-called hand of textiles. Many objective and subjective techniques have already been developed for analysing the hand of textiles; however, none of them provide exact overall information concerning the sensation of textiles through the skin. As the human skin is a complex heterogeneous hyperelastic body composed of many particles, some simplifications had to be made at the early stage of building the models; however, their utilitarian value was maintained. The models relate only to mechanical loading of the skin. They predict a low deformation of the fingertip skin under the pressure of virtual heterogeneous material: acrylic, coarse wool, and steel