Effect of internal wool lipid liposomes on skin repair

Intercellular lipids of the stratum corneum (SC) play a crucial role in keeping an optimal skin barrier function and in regulating the water-holding capacity. Recently, the internal lipids have been extracted from wool fibre. This lipid extract has a composition similar to that of the SC lipids. Two parameters were used to test the effect of topically applied internal wool lipids (IWL), structured as liposomes, on the water barrier functions of disturbed and intact skin: transepidermal water loss and skin capacitance. Liposomes made up of lipids that simulate the composition of the SC were also applied for comparison. The single application of the IWL liposomes on disturbed skin resulted in an accelerated recovery of water barrier functions. Daily application of these liposomes on intact skin for 5 days reinforced the skin barrier and increased the water-holding capacity. The repairing effect of the IWL enhances their suitability in the treatment, prevention and care of skin.     

Efficacy of stratum corneum lipid supplementation on human skin

Recent studies suggest that supplementing intercellular lipids of the stratum corneum in ageing populations or in people with dry skin can stimulate the functioning of the skin. This work lends support to the reinforcement capacity of two different stratum corneum lipid mixtures (synthetic stratum corneum lipid mixtures, SSCL, and internal wool lipid extracts, IWL) formulated as liposomes on healthy skin of two differently aged groups of individuals. Protection of healthy skin against detergent-induced dermatitis was evaluated. Transepidermal water loss and capacitance were used to evaluate the effect of these formulations in in vivo long-term studies. Increase in water-holding capacity is obtained only when the formulations applied are structured as liposomes. This is slightly more pronounced for aged skin. Subsequent SLS exposure reflected the protection of healthy human skin against detergent-induced dermatitis. Slightly better results were obtained with IWL containing a mixture of natural ceramides than with SSCL with only one ceramide present in the formulation. All these results support the beneficial effects of skin lipid supplementation given their resemblance to the lipids in the stratum corneum both in composition and in the structuring of the formulation.     

Protein kinase C inhibits human hair follicle growth and hair fibre production in organ culture

Summary In this study we have used a human hair follicle whole-organ culture system to examine the effects of 12-O-tetradecanoyl-phorbol-l3-acetatc (TPA), a potent activator of protein kinase C (PKC), on hair follicle growth and hair fibre production. Anagen hair follicles were isolated from human facial skin by microdissection and placed in suspension culture in supplemented Williams E medium. Hair follicle and hair fibre lengths were measured daily using an inverted microscope and cumulative growth values were calculated. Treatment with TPA resulted in a potent, dose-dependent inhibition of total cumulative hair follicle growth (lC₅₀=1 nm). Hair follicles grew at a comparable rate for 4 days in the presence or absence of 10 n m TPA. after which growth of TPA-treated follicles ceased while control follicles grew by a further 0–8 mm over the subsequent 6 days. In contrast. 10 n m TPA treatment did not affect hair fibre elongation for a period of 8 days, after which TPA-treated fibre production ceased while control fibres grew by a further 0–79 mm over the subsequent 7 days. Incubation of hair follicles with TPA resulted in a 41% inhibition of hair fibre protein synthesis, as measured biochemically from the incorporation of ³H-leucine using a differential akali extraction method. The inhibitory effect of TPA on follicle growth was partially prevented by preincubation with the selective PKC inhibitor H-7, and almost completely prevented by preincubation with the more potent PKC inhibitor Ro 31-7549. Neither agent alone significantly affected follicle growth at concentrations that reversed the TPA response. These findings indicate that PKC is a negative regulator of hair follicle growth, and suggest that PKC may play a part in the transduction of follicular growth-inhibitory signals.     

Cosmetic effectiveness of topically applied hydrolysed keratin peptides and lipids derived from wool

Background/purpose: Skin moisturisation, elasticity, feel and appearance can all be improved through the topical application of protein hydrolysates. Recent studies suggest that supplementing intercellular lipids of the stratum corneum can enhance the functioning of the skin.
Methods: In this study, a hydrolysed keratin peptide (molecular weight <1000 Da) was prepared from wool and tested on skin in two different formulations: an aqueous solution and an internal wool lipids (IWL) liposome suspension. In vivo long-term studies were performed to evaluate the water barrier function of the skin after topical application of different formulations. During the treatment period, hydration and elasticity were determined. A sorption–desorption test was also performed to assess the hygroscopic properties and water-holding capacity of the different treated skin sites.
Results: Significant differences were found between the control and treated sites, with the treated areas showing an increase in hydration and elasticity as a result of keratin peptide application. Measurements also indicated that the keratin formulations reinforce the skin barrier integrity, improving its water-holding capacity.
Conclusion: A combination of the keratin peptide with the IWL showed beneficial effects, indicating that this combination is suitable for designing new cosmetics products.     

Healthy Hair: What Is it?

Shiny hair with a smooth texture and clean-cut ends or tapered tips is generally perceived to be healthy. Hair texture and shine relate to hair surface properties, whereas the integrity of hair ends relates to the hair cortex. Hair can be straight, wavy or curly, blonde, black, brown, red, gray white, and its natural variations are important to our identity. Manipulation of the normal structure of the hair shaft is epidemic and dictated by culture, fashion, and above all, celebrity. Although cosmetic procedures are intrinsically safe, there is potential for damage to the hair. Loss of lustre, frizz, split ends, and other hair problems are particularly prevalent among people who repeatedly alter the natural style of their hair or among people with hair that is intrinsically weak. This may be due to individual or racial variation or less commonly an inherited structural abnormality in hair fiber formation. Hair health is also affected by common afflictions of the scalp as well as age-related phenomena such as graying and androgenetic alopecia. Hair products that improve the structural integrity of hair fibers and increase tensile strength are available, as are products that increase hair volume, reduce frizz, improve hair manageability, and stimulate new hair growth.     

Selective biodegradation in hair shafts derived from archaeological, forensic and experimental contexts

BACKGROUND: Hair is degraded by the action of both dermatophytic and nondermatophytic microorganisms. The importance of understanding hair sample condition in archaeological and forensic investigation highlights the need for a detailed knowledge of the sequence of degradation in samples that have been either buried or left exposed at the ground surface. OBJECTIVES: To investigate the sequence of biodegradative change to human terminal scalp hair from archaeological and forensic contexts. METHODS: Cut modern scalp hair from three individuals with caucasoid-type hair was inoculated with soil microorganisms through soil burial in the field and under laboratory conditions to produce experimentally degraded samples. The degraded hair fibres were subjected to detailed histological examination using a combination of high-resolution light microscopy, transmission electron microscopy and scanning electron microscopy to investigate the nature and sequence of degradative change to hair structural components. RESULTS/DISCUSSION: Degradation was found to occur first within the least structurally robust components that afford the least resistance to microbial/chemical attack. The sequence of degradation (most to least-reflecting degree of vulnerability) in the hair cuticle was as follows: (1) intercellular delta-layer (cell membrane complex); (2) endocuticle; (3) cell membrane beta-layers; (4) exocuticle; (5) epicuticle; and (6) A-layer. In the hair cortex this was as follows: (I) intercellular delta-layer (cell membrane complex); (II) cell membrane beta-layers; (III) intermacrofibrillar matrix/nuclear remnants; (IV) microfibrils; (V) intermicrofibrillar matrix; and (VI) pigment granules (the hair fibre component that was the least vulnerable to degradation). CONCLUSIONS: The selective progress of degradation in the hair shaft has been charted and this provides a basis for further histological work in better understanding the condition of hair fibres derived from archaeological or forensic contexts as well as being relevant to investigation of diseased hair, in particular hair infected by dermatophytes and hair weakened by genetic hair shaft abnormalities.     

Hair loss in women: medical and cosmetic approaches to increase scalp hair fullness

Androgenetic alopecia affects both men and women. In men it produces male pattern hair loss with bitemporal recession and vertex baldness. In women it produces female pattern hair loss (FPHL) with diffuse alopecia over the mid-frontal scalp. FPHL occurs as a result of nonuniform hair follicle miniaturization within follicular units. Diffuse alopecia is produced by a reduction in the number of terminal fibres per follicular unit. Baldness occurs only when all hairs within the follicular units are miniaturized and is a relatively late event in women. The concepts of follicular units and primary and secondary hair follicles within follicular units are well established in comparative mammalian studies, particularly in sheep. However, discovery of these structures in the human scalp hair and investigation of the changes in follicular unit anatomy during the development of androgenetic alopecia have provided a clearer understanding of the early stages of androgenetic alopecia and how the male and female patterns of hair loss are related. FPHL is the most common cause of alopecia in women and approximately one-third of adult caucasian women experience hair loss. The impact of FPHL is predominantly psychological. While men anticipate age-related hair loss, hair loss in women is usually unexpected and unwelcome at any age. Treatment options to arrest hair loss progression and stimulate partial hair regrowth for FPHL include the androgen receptor antagonists spironolactone and cyproterone acetate, the 5α-reductase inhibitor finasteride and the androgen-independent hair growth stimulator minoxidil. These treatments appear to work best when initiated early. Hair transplantation should be considered in advanced FPHL that is resistant to medical treatments. Hair transplantation requires well-preserved hair growth over the occipital donor area. The psychological impact of FPHL may also be reduced by cosmetic products that improve the appearance of the hair. These agents work to minimize hair fibre breakage, improve hair volume or conceal visible bald scalp.     

Innovative liposomes as a transfollicular drug delivery system: penetration into porcine hair follicles

Liposomes had been widely used for drug delivery in the past. In this study, five different liposomes were used as a follicular delivery system in pig ear skin. The liposomes mainly differed in their sphere diameter, lipid composition, and surface charge. A novel class of liposomes being amphoteric in their charge behavior are compared to established anionic and cationic liposomes. Two different fluorescent dyes, hydrophilic carboxyfluoresceine or lipophilic curcumin, were enclosed in the liposomes and used as model drugs. The fluorescent dyes were also applied in a standard formulation for reference. The penetration depth of the dyes was measured by laser scanning microscopy in histological sections. One hour, 3, 5, and 7 days after application, biopsies were taken and the penetration depth into the hair follicle was measured in longitudinal sections. The liposomes showed a higher penetration depth compared to the standard formulation. The relative penetration depth of the dyes, applied in the standard formulation, averaged 30% of the full follicle length during the whole observation period, whereas the liposomal formulations penetrated considerably deeper into the hair follicles. Amphoteric and cationic liposomes reached an average relative penetration depth of approximately 70% of the full hair follicle length.     

毛干异常

毛发发育不良可分为先天性和获得性,经常累及毛干。外胚层发育不良、某些代谢性疾病、神经系统疾病、精神疾病中可以发现毛干的改变,外源性的物理、化学性刺激也会引起毛干的变化。毛干的异常表现为毛发颜色、密度、结构和长度的改变。毛干疾病的正确诊断不仅需要系统的病史和体检,光镜、扫描电镜和生化检查也很重要。     

Hair shaft abnormalities--clues to diagnosis and treatment

Hair dysplasias are congenital or acquired alterations which often involve the hair shaft. Hair shaft abnormalities are characterized by changes in color, density, length and structure. Hair shaft alterations often result from structural changes within the hair fibers and cuticles which may lead to brittle and uncombable hair. The hair of patients with hair shaft diseases feels dry and looks lusterless. Hair shaft diseases may occur as localized or generalized disorders. Genetic predisposition or exogenous factors produce and maintain hair shaft abnormalities. Hair shaft diseases are separated into those with and those without increased hair fragility. In general, optic microscopy and polarized light microscopy of hair shafts provide important clues to the diagnosis of isolated hair shaft abnormalities or complex syndromes. To establish an exact diagnosis of dysplastic hair shafts, a structured history and physical examination of the whole patient are needed which emphasizes other skin appendages such as the nails, sweat and sebaceous glands. Profound knowledge on hair biology and embryology is necessary to understand the different symptom complexes. Therapy of hair shaft disorders should focus on the cause. In addition, minimizing traumatic influences to hair shafts, such as drying hair with an electric dryer or permanent waves and dyes, is important. A short hairstyle is more suitable for patients with hair shaft disorders.     

Getting under the skin of hair aging: the impact of the hair follicle environment

Like the skin, our hair shows striking changes with age, producing hairs with altered diameter, lustre and texture. The biology of hair aging has focused predominately on various aspects of the hair cycle, follicle size and the fibre produced, but surprisingly the impact of the aging scalp dermal environment on the hair follicle and fibre has been generally overlooked. Hair loss affects both sexes with incidence increasing with age. In men, male pattern-balding (androgenetic alopecia) is driven by androgens and follows a specific pattern of frontotemporal and vertex regression. Women also experience female pattern hair loss (FPHL), presenting as more general, diffuse hair thinning. Hair thinning in women is commonly associated with the menopause, corresponding with other age-related changes in skin. The rapidly growing hair follicle undergoes continued renewal throughout the life span of an individual, where it is exposed to a substantial number of extrinsic and intrinsic stressors. As the hair follicle sits deep within the dermis with its bulb residing in the hypodermis, detrimental age-related changes in the surrounding scalp skin may likely disrupt the hair follicle machinery. The impacts of these changes are unknown, but evidence suggests that scalp skin aging and hair follicle aging go hand-in-hand. Herein, we summarize the evidence that the age-related changes observed in sun-exposed human skin also occur in scalp skin and that these changes are likely to play a contributing role in the aging hair phenotype.     

Hair breakage in normal and weathered hair: focus on the Black patient

Hair breakage and fragility are a large problem for many patients as well as a treatment challenge to the dermatologist. Understanding the factors that lead to acquired hair shaft fragility and breakage is paramount to recommending appropriate treatment to affected patients. African or Black hair is known to be more affected by breakage with easily observed fragility in vivo. To date there are no known structural or chemical differences in Black hair as compared to Caucasian or Asian hair that explains this observed fragility. This review explores the impact of hair care practices on the development of hair breakage with a focus on patients of color. The examination and recommended ancillary testing for the process are discussed, and advances in the measurement of mechanical fracture of human hair are reviewed.     

Genes that are differentially expressed in rat vibrissa follicle germinative epithelium in vivo show altered expression patterns after extended organ culture

Hair growth depends on maintenance of signalling between the dermal papilla and the germinative epithelium (GE), from which the differentiated layers of the hair fibre originate. Because no molecular studies have been reported which concentrate specifically on GE cells either in vivo or in vitro, we prepared a cDNA library enriched for messages which were highly expressed in GE cells to identify genes that may be involved in hair growth control. Of 35 subtracted library clones sequenced, 23 shared extensive homology with previously determined cDNA sequences, including LEF-1 and id4. Hair follicle organ culture models are often used to investigate the molecular basis of hair growth, although hair growth arrest occurs relatively rapidly in vitro. As an indicator of their role in follicle activities, we compared the expression of GE-specific clones in different regions of freshly isolated vibrissa follicles, with the corresponding regions of growth arrested, cultured follicles. Changes in the expression of some of these clones indicates that they could be related to fundamental cellular activities in the follicle. A library enriched for GE-specific clones therefore provides a useful source of candidate molecules for studies of follicular epithelial cell behaviour, both in vivo and in vitro.     

Wanted,dead and alive: Why a multidisciplinary approach is needed to unlock hair treatment potential

Human recorded history is littered with attempts to improve the perceived appearance of scalp hair. Throughout history, treatments have included both biological and chemical interventions. Hair “quality” or “perceived appearance” is regulated by multiple biological intervention opportunities: adding more hairs by flipping follicles from telogen to anagen, or delaying anagen follicles transiting into catagen; altering hair “apparent amount” by modulating shaft diameter or shape; or, in principle, altering shaft physical properties changing its synthesis. By far the most common biological intervention strategy today is to increase the number of hairs, but to date this has proven difficult and has yielded minimal benefits. Chemical intervention primarily consists of active material surface deposition to improve shaft shine, fibre‐fibre interactions and strength. Real, perceptible benefits will best be achieved by combining opportunity areas across the three primary sciences: biology, chemistry and physics. Shaft biogenesis begins with biology: proliferation in the germinative matrix, then crossing “Auber's Critical Line” and ceasing proliferation to synthesize shaft components. Biogenesis then shifts to oxidative chemistry, where previously synthesized components are organized and cross‐linked into a shaft. We herein term the crossing point from biology to chemistry as “The Orwin Threshold.” Historically, hair biology and chemistry have been conducted in different fields, with biological manipulation residing in biomedical communities and hair shaft chemistry and physics within the consumer care industry, with minimal cross‐fertilization. Detailed understanding of hair shaft biogenesis should enable identification of factors necessary for optimum hair shaft production and new intervention opportunities.     

Exogen involves gradual release of the hair club fibre in the vibrissa follicle model

Abstract:  Exogen is a distinct phase of the hair cycle describing the process by which the hair club fibre is shed from the follicle. This process is difficult to study in human skin and little is known about the mechanisms involved in the release of club fibres. We sought an alternative model system to study exogen in more detail, and therefore utilised the vibrissa system on the rodent mystacial pad. The time at which a vibrissa club hair will be lost can be predicted, based on the relative lengths of the new growing fibre and old club fibre. This timing phenomenon was exploited to investigate the club fibre within the follicle as it approaches final release, revealing key changes in the adhesive state of the club fibre within the epithelial sac as it approached release. We propose that exogen should be subdivided to represent variations in the club fibre status.     

Hair colouring, permanent styling and hair structure

Hair is an important component of body image and has immense psychological importance for both men and women. Women, in particular, over the ages have modified their appearance through changing their hair colour or style. Hair can be straight, wavy or curly, blonde, black, brown or red. These natural variations are an important part of our identity that can be manipulated according to the dictates of fashion, culture or society. Different types of hair have varying affinity for the different colouring and waving methods. Damaged hair also has a different affinity for hair products than normal healthy hair. The hair shaft is remarkably strong and resistant to the extremes of nature. Hair cosmetics are widely available and manipulate the structural properties of hair. Whilst most procedures are safe, there is considerable potential for damage to the hair and hair problems of acute onset, including hair breakage, hair loss and loss of condition, are frequently blamed on the last product used on the hair. Hair problems are particularly prevalent among people who repeatedly alter the natural style of their hair.     

A Case of Trichorrhexis Nodosa Developed in Winter

A young Japanese man developed localized trichorrhexis nodosa (LTN) of the scalp hair in the winter season. To investigate the roles of shampoo, severe sunlight exposure and/or mechanical injuries, we performed the following studies. Hair was collected from the patient and from a control. The study was performed in two steps. In the first step, hair was put into shampoo, rinsed with saline water, and then exposed to ultraviolet B (UVB) radiation once a day for one week. In the second step, the hair was similarly treated, but each shaft was bent gently with forceps before UVB exposure. Scanning electron microscopic studies revealed cuticular changes when the hair was treated only with shampoo and UVB. When it was treated with shampoo, UVB, and mechanical bending, the patient's hair developed longitudinal and transverse fractures of the hair shafts, while the control hair showed only partial damage to the hair shaft. On the basis on the above findings, we conclude that mechanical bending may damage the hair shaft.     

Burden of hair loss: stress and the underestimated psychosocial impact of telogen effluvium and androgenetic alopecia

Hair loss, as it occurs with telogen effluvium and androgenetic alopecia, provokes anxieties and distress more profound than its objective severity would appear to justify. This reflects the profound symbolic and psychosocial importance of hair. Stress has long been implicated as one of the causal factors involved in hair loss. Recently, in vivo studies in mice have substantiated the long-held popular belief that stress can exert profound hair growth-inhibitory catagen-inducing and hair-damaging pro-inflammatory effects. Insights into the negative impact of stress on hair growth and the integration of stress-coping strategies into the management of hair loss disorders as well as the development of new pharmacotherapeutic strategies might lead to enhanced therapeutic modalities with the alleviation of clinical symptoms as well as the concomitant psychological implications.     

Pili annulati. A scanning electron microscopy study

A case of ringed hair studied by light and electron microscopy is reported. The patient, a 20-year old girl, had been presenting with the hair abnormality since birth. At naked eye examination the hairs were dry, 6 to 7 cm long, and they showed dull and shining areas giving the scalp hair a scintillating appearance (fig. 1). Several samples of hair were taken and examined by light microscopy under white and polarized light. Hair shafts and cryo-fractured surfaces were examined by scanning electron microscopy. RESULTS. 1. Light microscopy. Lesions were found in every hair examined. There were abnormal, opaque and fusiform areas alternating with normal areas all along the hair shaft (fig. 2). The abnormal areas resulted from intracortical air-filled cavities. Fractures similar to those of trichorrhexis nodosa were found in the opaque areas of the distal parts of the hairs. 2. Scanning electron microscopy. A. Hair shaft surface. The abnormal areas showed a longitudinal, "curtain-like" folding of the cuticular cells which had punctiform depressions on their surface and worn free edges (fig. 4, 5, 6); trichorrhexis-type fractures were seen in the distal parts of the hair shafts (fig. 7, 8). Normal areas regularly presented with longitudinal, superficial, short and non-systematized depressions (fig. 9); the cuticular cells were worn, and there were places where the denuded cortex showed dissociated cortical fibres (fig. 10).(ABSTRACT TRUNCATED AT 250 WORDS)