Cell Membrane Complex Research Articles

Dyeability of Acid Dyes on Wool Fabrics Treated with Ozone and an Enzyme

In a previous paper, the dyeability of leveling acid dyes for shrink-proofed wool fabrics treated with permonosulfate (PMS) and a keratinase was discussed on the basis of the dyeing rate and sorption isotherms. In the present study, ozone was employed instead of PMS for the pretreatment of wool fabrics to achieve a zero-AOX shrink-resist process. Three kinds of leveling acid dyes, which have one, two, or three sulfonate groups, were used. The dyeing rate and sorption isotherms were determined to elucidate the effects of the dye structure and the treatment of the wool fibers. The apparent diffusion coefficients were considerably diminished by the ozone treatment, but they were restored by the subsequent treatment with the enzyme. The sorption isotherms were analyzed using dual sorption mechanism to evaluate the three sorption parameters, which are the number of binding site, S, the intrinsic binding constant for the Langmuir type sorption, KL, and the partition coefficient, KP. The equilibrium dye uptake and the S values were almost unchanged by the ozone treatment. The KL values for the ozone-treated fibers were slightly decreased compared to those of the untreated ones. The ESCA spectra showed the presence of cystine monoxide (-SO-S-), cystine dioxide (-SO2-S-), and cysteic acid (-SO3-) after the treatment with ozone. If cysteic acid was generated on the fiber surface and also cell membrane complex (CMC) after the ozone treatment, the dyeing behavior should be influenced by the repulsion between the negatively charged cysteic acid and negatively charged acid dyes. The decreased dyeing rate and the unchanged dye uptake after the ozone treatment suggest that the action of ozone is limited onto the fiber surface and CMC, and does not affect the bulk structure of the fibers.

Microstructural Analysis of Wool Fibers by SEM Images of Their Cross-Sections Etched by Alkali Treatment

We found that scanning electron microscopy (SEM) of alkali-etched cross-sections of wool fibers provides characteristic images consisting of stitch patterns (SP) and amoeba patterns (AP) at the cortex and that both the SP and AP appearing as convex structures are originated from cell membrane complexes, nuclear remnants, and intermacrofibril materials. When the sample fiber had primarily been extracted with chloroform/methanol, the SP became disintegrated, because of the removal of free lipids from CMC, particularly from the β-layers. When the fiber had been extracted with chloroform/methanol/water, the SP was almost completely lost. These results suggested that the SP and AP are derived from the internal lipids and some non-keratinous proteins involved in the cortex and that the extraction of wool fibers with the mixed solvents should disrupt both the β- and δ-layers to increase the susceptibility of the CMC to the alkaline hydrolysis. The post-washing of the alkali-etched cross-section with ethanol made the SP and AP clearer. The agglomerated and scattered AP detected in the outlines of the cortical cells were shown to be originated from the nuclear remnants and the intermacrofibril materials, respectively.

Effects of Neutral Detergent on Strength and Elongation of Wool Fibers Shrink-Proofed with Chlorine

Kroy-treated wool and dichlorocyanuric acid treated wool (DCCA-treated wool) were selected for wool fibers shrink-proofed with chlorine. The laundering treatment with domestic neutral detergent including non-ionic surfactant made the breaking strength and elongation decrease greatly for DCCA-treated wool at initial laundering treatment, but for Kroy-treated wool as well as intact wool, it made the elongation decrease gradually with increase of the laundering treatment times. After 5 times laundering treating each wool sample, the value of final elongation became almost equal in the value of the elongation of each wool sample which is pretreated with isopropanol (IPA) aqueous solution. The elongation of each wool sample which was pretreated with IPA aqueous solution hardly changed even if the laundering treatment times increased. These experiments showed that non-ionic surfactant including neutral detergent acted like IPA aqueous solution to wool fibers, and It was thought that the decrease of the breaking strength and elongation of wool by the laundering treatment with neutral detergent was dependent on the easiness of the extraction of the cell membrane complex (CMC) component of wool, which had been deteriorated by the each shrinkproof process with chlorine, by non-ionic surfactant.

Photoaggravation of hair aging.

Photoaggravation of hair aging includes various chemical and physical changes in fiber properties which lead to an increase in fiber porosity, loss of mechanical strength and an increase in surface roughness. These changes come from lipid oxidation, disulfide bond cleavage, tryptophan degradation and cysteic acid formation. Hair exposed to sunlight is claimed to be more brittle, stiffer and drier than before irradiation and exhibits a reduced water-absorption capacity. Hair pigments function to provide photochemical protection to hair proteins. Hair pigments accomplish this protection by absorbing and filtering the impinging radiation and subsequently dissipating this energy as heat. However, in the process of protecting the hair proteins from light, the pigments are degraded or bleached. Dark hair is more resistant to photodegradation than light hair, because of the higher photostability of eumelanin compared to pheomelanin. Integral lipids of hair fibers are degraded by ultraviolet light, as well as by visible light, helping to explain the weakening of the cell membrane complex exposed to light radiation.

Analysis of fluconazole effect on viability during extended incubations

Fluconazole is an azole agent with primarily fungistatic activity in standard in vitro susceptibility tests. However, recent work has demonstrated that this drug can reduce Candida albicans viability during prolonged incubations under non-growing conditions. The present study was undertaken to examine more closely some of the parameters of this killing activity. Fungicidal effects of 1·0 μg ml−1 of fluconazole were found during 7–14-day exposures in each of two media that prevented proliferation, distilled water and metal-depleted RPMI 1640 tissue-culture medium. Fluconazole appeared to be stable after being incubated at 37 °C for either 7 or 14 days. Strains of C. albicans resistant to fluconazole in standard short-term growth-inhibition assays were also found to be resistant to fluconazole's effect on viability in prolonged culture, suggesting similar mechanisms of action for these effects. C. albicans yeast cells pre-incubated for 7 days in distilled water were not more sensitive to the drug in short-term susceptibility assays. Although all proliferation of the organisms in distilled water cultures appeared to cease after 3 days, fluconazole added at 7 days still reduced C. albicans viability. Therefore, the drug appeared to kill the non-proliferating organisms directly rather than preventing growth and thereby the emergence of younger organisms that would live longer. Transmission electron microscopy demonstrated damage to the cell wall–cell membrane complex and interior contents of yeast cells incubated in distilled water alone; fluconazole appeared to increase the percentages of cells so affected. In summary, extended-incubation susceptibility tests demonstrated that fluconazole has direct fungicidal activity of non-proliferating C. albicans yeast cells. These results may be relevant to the manner in which this drug promotes clearance of chronic fungal infections.

Effect of oil films on moisture vapor absorption on human hair

In this paper sorption and desorption of water vapor on hair fibers treated with various oils is investigated, using a dynamic vapor sorption (DVS) apparatus. Results show lower "equilibrium" sorption of moisture for various oil-treated samples compared to the untreated sample. Coconut oil-treated hair had a higher regain than mineral oil-treated hair. Although treating the hair samples with oil reduced moisture pickup, a considerable amount of moisture vapor was still able to penetrate into hair fibers. Calculated hysteresis plots show that the samples treated with different oils have slightly higher moisture retention at low relative humidities compared to that of the untreated sample, which suggests a beneficial effect. The calculated moisture diffusion coefficients for oil-treated samples were much lower compared to the untreated hair fibers, suggesting that surface oil films and penetrated oil molecules form a diffusion barrier. A moisture diffusion model is discussed in terms of the possible role of fiber swelling on restrictive narrowing of the cell membrane complexes (CMCs), which form the diffusion pathways in the fiber. The effect of film thickness on moisture absorption and the reverting of the sorption isotherm to that of the untreated hair after removal of the oil film shows that oil film is the main resistance to moisture diffusion. The lowering of the diffusion coefficient of water vapor by oil films will slow the loss of moisture, an effect similar to "moisturization" of hair.

Effects of Domestic Alkaline Detergents on Strength and Elongation of Wool Fibers Shrink Proofed with Chlorine

Kroy-treated wool and Dichlorocyanuric acid treated wool (DCCA-treated wool) were selected for wool fibers shrink proofed with chlorine. The laundering treatment with domestic alkaline detergents included any proteolytic enzyme decreased the strength and elongation at break of DCCA-treated wool with increasing of the laundering treatment time, but led to no significant changes for intact and Kroy-treated wool. From SEM images of fiber surface and cross section of each wool sample before and after the laundering treatment, it was found that cell membrane complex (CMC) regions in both cuticle and cortex phase of DCCA-treated wool fibers were damaged by the detergents. It was suggested that CMC structure of DCCA-treated wool fibers was deteriorated extremely, but that of Kroy-treated wool fibers was almost retained its original form as well as intact wool fibers. It was consider that DCCA-treated wool was decreased of the structural function of CMC to resist entering of enzyme and surfactant in cortex region, and it was became easy to receive any action of the detergent.

Structural analysis of the cell membrane complex in the human hair cuticle using microbeam X‐ray diffraction: relationship with the effects of hair dyeing

This article deals with the structure of the cell membrane complex (CMC) in the human hair cuticle. The microbeam X-ray provided a pattern of small-angle scattering from the CMC in the cuticle with no sample preparations, including slicing and pre-staining of hair. The thickness of the beta- and delta-layers, substructure in CMC, was estimated by analysis of the scattering pattern. We used hair samples extracted with several solvents, and found that solvent extraction changed the thickness of the beta- and delta-layers in a manner dependent on the type of solvent. Extraction of hair with solvent was also shown to have effects on the extent of dyeing. There was a high correlation between the extent of dyeing and the thickness of the delta-layer, i.e., a thin layer tended to show a high amount of dyeing, whereas there was no significant correlation between the thickness of the beta-layer and the extent of dyeing.

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

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. To investigate the sequence of biodegradative change to human terminal scalp hair from archaeological and forensic contexts. 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. 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). 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.

Morphological changes in human head hair subjected to various drug testing decontamination strategies

Morphological changes in hair subjected to decontamination protocols were evaluated by scanning electron microscopy (SEM) as part of the National Laboratory Certification Program's (NLCP) efforts to develop proficiency testing materials in support of Federal Workplace Drug Testing programs. Hair from five different donors was evaluated. Hair samples were subjected to three decontamination protocols: (1) aqueous phosphate buffer, (2) methanol or (3) methylene chloride as models for aqueous, alcohol and polar organic solvent protocols, respectively. Under these protocols, samples of hair were treated for 225 min (aqueous), 15 min (alcohol), or 15 min (polar organic). After decontamination, hair strands were sputter coated with gold/palladium (AuPd) and observed by SEM. Modest lifting of cuticle scales was observed in hair treated with methanol and methylene chloride consistent with some changes to the cell membrane complex (CMC) between cuticle scales. Damage resulting from aqueous buffer treatment ranged from substantial degradation to apparent complete loss of cuticle scales. Fracture structures consistent with cuticle damage were also observed. Each decontamination protocol had a different impact on the cuticle of the hair shaft.

Thermal analysis of merino wool fibres without internal lipids

AbstractMerino wool is made up of cuticle and cortical cells held together by the cell membrane complex (CMC), which contains a small amount of internal lipids (IWL) (1.5% by mass). IWL have been extracted from wool on account of their considerable dermatological interest owing to their proportion of ceramides. IWL have been extracted by different methods and solvents, methanol and acetone at laboratory and pilot plant levels. Thermal analysis of these extracted wool fibers is presented using thermogravimetry (TG) and differential scanning calorimetry (DSC). TG provides a measurement of the weight loss of the sample as a function of time and temperature. DSC gives information about possible structure modification of extracted wool fibers. Thermoporometry was applied to evaluate the pore size distribution of extracted wool fibers. The results showed that the extraction process increased the pore size distribution and the cumulated pore volume, which is consistent with some changes in the extracted wool CMC. Extracted fiber becomes more hydrophilic and absorbs a large amount of water. We can conclude that the lipid extraction of wool produced no relevant changes in the crystalline fraction when extracted with acetone. However, part of the amorphous keratin material was extracted with methanol, the rest of the crystalline material becoming more stable. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 545–551, 2007

Enzymatic Degradation and Dyeability of Kroy-finished Wool Treated with Shellac

The sorption of natural thermosetting resin, Shellac, by the Kroy-finished wool and the effects of Shellac on enzymatic degradation and dyeability were investigated. The amounts of Shellac sorbed by the Kroy-finished and the regularly scoured wools were almost the same. Although the weight loss of the Kroy-finished wool by enzymatic degradation was significantly larger than that of the scoured wool, the values of strength retention for both wools were substantially the same at the same sorption amounts of Shellac. The color change and color fastness of the Shellac modified wools were tested for the fabrics dyed with three different acid dyes and three different reactive dyes. It was found that the sorption of Shellac on the Kroy-finished wool improves considerably the color fastness of rubbing and brings about the color change in higher levels as compared with the scoured wool. Present results obtained led to the conclusions that the sorption site of Shellac is the cell membrane complex (CMC) and Shellac retards enzymatic degradation for both the Kroy-finished and regularly scoured wools.

Characterization of hair lipid images by argon sputter etching‐scanning electron microscopy

Hair lipid images, as visualized by argon sputter etching-scanning electron microscopy (ASE-SEM), reveal convex structures with a stitch pattern (SP) at the cell membrane complex (CMC) in the transverse hair plane. Based on interindividual variation, different features of the convex SP were classified into Types 0 to 4 with the corresponding scores 0 to 4. Observations using hair fibers collected from 27 Japanese females revealed significant positive correlations between the scores and the levels of exogenous lipids, which suggests that exogenous lipids internalized at the CMC predominantly constitute the convex SP. Intraindividual variation with different levels of exogenous lipids among hair fibers derived from individual females may be relevant to the uneven physicochemical properties of hair fibers on the scalp. Observations of 380 hair fibers collected from Japanese (Mongoloid), German and American (Caucasoid) females aged 3 to 77 yr demonstrated similar age-related changes in the lipid images, which represent an increase and then a decrease in levels of exogenous lipids with increasing age. This suggests that age-related changes in exogenous lipids are attributable to alterations in sebum excreted during aging and that this elicits age-related changes in physical parameters, which affect human hair texture.

A novel method for visualizing hair lipids at the cell membrane complex: Argon sputter etching/scanning electron microscopy1

Hair lipids localized at the cell membrane complex (CMC) play a part in chemical diffusion, cell cohesion, and mechanical strength. There is no method currently available to visualize hair lipids at the CMC. We found that scanning electron microscopy (SEM) of a transversely polished hair plane followed by argon sputter etching (ASE) provides a specific characteristic image consisting of circular patterns (CP) and stitch patterns (SP) at the cortex. Both the CP and the SP are formed as convex structures and are associated with melanin granules and the CMC, respectively. While the convex formation of the CP is not affected by any treatments tested, that of the SP disappeared following treatment of hair fibers with organic solvents and reappeared following incubation of the solvent-treated hair fibers with melting lipids, which suggests that the hair lipids are responsible for the convex SP. Other treatments, such as chemical fixation, thin sectioning, and pre-/post-incubation of the hair plane, reduce or abolish the convex formation of the SP. These findings suggest that the following pathway leads to the convex formation of SP during ASE: (a) joule heat is generated on the surface by violent collisions of argon ions, (b) melting CMC lipids ooze out from the inside to the surface, and (c) CMC lipids that have oozed out are chemically changed, leading to the final convex formation of the SP. With ASE-SEM, visualization of hair lipids as convex structures of SP should enable us to characterize the fine structure and localization of hair lipids and to clarify the roles and functions of the CMC of human hair.

Function of the Cell Membrane Complex on Dyeing of Wool Fibers with Oxidation Dye

The effect of a modification of cell membrane complex (CMC) on the color developed by oxidation dye reaction of three precursors with a coupler was investigated. From the results of dyeing in the presence of ascorbic acid and ethylenediaminetetraacetic acid (EDTA), it was found that the dye uptake of the wool samples modified with 98-99% formic acid decreased apparently compared to that of unmodified wool sample. The decreased extent of their uptake was dependent on the extent of modification of CMC. However, if unmodified and CMC-modified wool samples were dyed with the preformed dyeing system, the dye uptake of all the modified samples ware approximately same as that of unmodified sample. Also, it was found that the mechanically pulverized cortex cells seem to be inactive to dyeing with both oxidative dyeing system and preformed dyeing system. Consequently, it is assumed that not only the CMC regions play an important role as accumulation regions of the finished dye, but also any components of the intercellular material take strongly part in color formation on the wool fibers as catalyst.

Sorption Behavior of Natural Thermosetting Shellac Resin on Wool Fiber

Sorption behavior of Shellac, which is of natural thermosetting resin, on wool fibers and enzymatic degradation of Shellac-modified wool fibers were investigated. Although immersed temperature had little effect, Shellac exhaustion depended on Shellac concentration, treatment time, the number of treated times, and also on the nature of solvents. Using methanol for a solvent, the amount of sorbed Shellac was obtained maximum about 0.03g/g-wool and decreased with increase of the molecular weight or size of the alcohol from methanol to t-butanol. The weight loss by enzymatic degradation for wool fibers could be controlled effectively by the sorption of Shellac. From SEM observation of surface morphology of Shellac-modified wool fiber and fractures morphology when extended to break, it was found that Shellac sorbs selectively into the cuticle intercellular regions and affects the strength of cell adhesion. From differential scanning calorimetric curves for untreated wool fiber and wool fiber treated for different treatment time in Shellac methanol solution, it was suggested that the Shellac was sorbed within the cell membrane complex and followed by gradual penetration into the cortex cell, under the treatment conditions of the solvents with smaller molecular weight or size.

Integral Lipid in Human Hair Follicle

On the hair surface, cells are covered with a thin lipid layer (LL) covalently bonded to hair proteins. This integral hair lipid is different from sebaceus lipid. We conducted this study to examine the lipid distribution in human hair follicle. Transmission electron microscopy was performed to observe the ultrastructure of the LL. Hair follicles were cut and observed longitudinally along the hair axis. For transmission electron microscopy, new fixative (Lee's fixative: composed of OsO4 and RuO4) was designed as the conventional fixatives such as OsO4 or RuO4 alone were not appropriate for staining for hair follicle lipid. In addition, we measured the chemical composition of integral hair lipid by high-performance thin-layer chromatography. From the above experimental procedure, it was discovered that the lipid in the hair follicle was mainly distributed in hair cuticle and keratinized inner root sheath. A multitude of lamellar granule is observed in the vicinity of the above LL. The chemical composition of integral hair lipid was different from those of epidermal or sebaceous lipids. It is assumed that the LL in the hair follicle is similar to the epidermal LL playing an important role as a skin barrier in the stratum corneum. We proposed here the new terminology "hair barrier" from this point of view.

Morphological, nanomechanical and cellular structural characterization of human hair and conditioner distribution using torsional resonance mode with an atomic force microscope

Characterization of the cellular structure and chemical and physical properties of hair are essential to develop better cosmetic products and advance the biological and cosmetic sciences. Although the morphology of the fine cellular structure of human hair has traditionally been investigated using scanning electron microscopy and transmission electron microscopy, atomic force microscopy can be used for characterization in ambient conditions without requiring specific sample preparations and surface treatment. In this study, the tapping and torsional resonance modes in an atomic force microscope are compared for measurements of stiffness and viscoelastic properties. The materials were mapped using amplitude and phase angle imaging. The torsional resonance mode showed advantages in resolving the in-plane (lateral) heterogeneity of materials. This mode was used for investigating and characterizing the fine cellular structure of human hair. Various cellular structures (such as the cortex and the cuticle) of human hair and fine sublamellar structures of the cuticle, such as the A-layer, the exocuticle, the endocuticle and the cell membrane complex were easily identified. The distribution and thickness of conditioner on the treated hair surface affects the tribological properties of hair. The thickness of the conditioner was estimated using force distance measurements with an atomic force microscope.

Chitosan application on wool before enzymatic treatment

AbstractThe influence of a chitosan application on wool fabric before a treatment with a proteolytic enzyme has been investigated. The enzymatic treatment enhances whiteness and confers shrink resistance to wool, but an increase in the enzyme concentration leads to a detrimental effect on the physicomechanical properties. A chitosan treatment before the enzymatic treatment additionally improves the shrink resistance and increases the weight loss. To better investigate the role played by the chitosan, surface‐related properties, such as the friction coefficient, the compressional behavior (compressibility, linearity of compression, and thickness), the wearing resistance (weight loss after abrasion), the bursting resistance (bursting strength and deformation), and surface topography, have been studied. The results suggest that the chitosan pretreatment reduces the damage caused by the subsequent enzymatic treatment. They also imply a protective effect of the bursting and wearing resistance, which prevent excessive weight loss due to abrasion. A significant influence of the wool fiber cell membrane complex on the surface‐related properties has been demonstrated through regression analysis and scanning electron microscopy observations. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1938–1946, 2005

Mapping penetration of cosmetic compounds into hair fibers using time‐of‐flight secondary ion mass spectrometry (TOF‐SIMS)

In this communication, penetration of vegetable oils into hair fibers has been investigated by the TOF‐SIMS (Time‐Of‐Flight Secondary Ion Mass Spectrometry) method. In earlier work [1], the method was found suitable to study the penetration of coconut and mineral oils into human hair. Therefore, the study has been extended to a group of vegetable oils with different types of unsaturation in the fatty acid components. Different patterns of penetration have been observed for oils of different molecular structure. The general pattern which emerges from this study is that polyunsaturated oils do not penetrate at all, or do so only sparingly into the structure of hair. Most of these molecules seem to penetrate only into the cuticular region of the hair fiber. Oils with polyunsaturated fatty acids seem to have difficulty in penetrating hair. It is possible that these molecules do not fit into the fiber's cell membrane complexes, which are known to be the diffusion pathways in the keratin fiber. On the other hand, monounsaturated oils, such as olive oil, with more compact molecular structure seem to penetrate readily into the hair fiber.