Scanning electron microscopy analysis of hair index on Karachi's population for social and professional appearance enhancement

Melanin-mediated accumulation of polycyclic aromatic hydrocarbons in human hair: Insights from biomonitoring and cell exposure studies

While human hair is widely used to monitor micro-organic contaminants (MOCs), their incorporation mechanisms are poorly understood. Melanin, known to facilitate the accumulation of drugs in hair, hasn't been studied in the field of MOCs. Here, polycyclic aromatic hydrocarbons (PAHs), a class of priority MOCs, were investigated through hair biomonitoring as well as cell exposure experiments. PAH concentrations and melanin contents were measured in black and white hairs from the same individual. The results showed that five dominant PAHs (phenanthrene, fluoranthene, pyrene, benzo[a]anthracene and chrysene) in black hair (0.66 ng/g - 35.1 ng/g) were significantly higher than those in white hair (0.52 ng/g - 29.6 ng/g). Melanin contents in black hair (14.9 - 48.9 ng/g) were markedly higher than in white hair (0.35 - 2.15 ng/g) and were correlated to PAH concentrations, hinting melanin-mediated accumulation of PAHs in hair. The in vitro experiment using murine melanoma cells demonstrates that PAH levels in cells were affected by melanin, suggesting the affinity of melanin to PAHs. Both biomonitoring and cell exposure experiment implicate the pivotal role of melanin in PAH accumulation in hair. Therefore, to ensure the accuracy of hair biomonitoring for MOCs, attention must be paid to the melanin content uniformity.

The Use of Natural Collagen Obtained from Fish Waste in Hair Styling and Care

Chemically speaking, polymers are multi-molecular compounds that have specific physicochemical properties. Hair cosmetics utilize their ability to create a protective film and make the cosmetic formulation more viscous, which facilitates its application. Natural polymers are encountered in nature, but, in hair cosmetics, artificially modified ones are more often used. Unfortunately, artificially modified polymers are characterized by high resistance to biological factors, which creates an ecological problem. Another reason for a search for natural polymers is their milder action when compared to synthetic ones. One of the new sources of obtaining collagen is the waste connective tissue materials of aquatic animals—skins, spines, dorsal chords and scales, and swim bladders. These raw materials are most often disposed of in landfills, processed into fish meal, or destined for food for animals. The conducted research was aimed at proving the action of natural collagen in hair cosmetics as a substitute for synthetic polymers. In the patients using collagen laminate, it is possible to notice the complete elimination of excessive sebum production, restoration of the correct pH value, and reduction in skin inflammations.

Performance scanning electron microscopic investigations and elemental analysis of hair of the different animal species for forensic identification

Veterinary forensics have attracted less attention compared with human forensics. Animal hair morphological examination using scanning electron microscopy (SEM) and hair mineral analysis using energy-dispersive X-ray fluorescence (ED-XRF) provide reference databases for animal hair identification used in forensic investigations. This study was performed on four different animal species: large ruminants (buffalo and cattle), small ruminants (goat and sheep), carnivores (cat and dog), and equines (donkey and horse). The hair scale pattern, scale margin type, and distance between scales were identified. The hair scale pattern was imbricate in large ruminants, goat, and horse; coronal (crown-like) in carnivores and donkey; and spinous in sheep. The morphometric measurements, including cuticle layer thickness, cuticle scale height, cortex diameter, and hair shaft width were recorded. The highest cuticle thickness was found in horse, and the highest cuticle hair scale was detected in cattle. Moreover, the largest cortex diameter was measured in buffalo, whereas the smallest one was in cat. With regard the content of hair elements, some elements were specific for the hair of certain tested animals, such as bromine in sheep and magnesium and phosphorus in buffalo. In addition, vanadium and titanium were found only in cattle and dog, and the latter element was also detected in sheep. In conclusion, this study provides two techniques for animal hair identification that can be used in forensic investigations.

A novel method for non-destructive determination of hair photo-induced damage based on multispectral imaging technology

Extended exposure to sunlight may give rise to chemical and physical damages of human hairs. In this work, we report a novel method for non-destructive quantification of hair photodamage via multispectral imaging (MSI) technology. We show that the multispectral reflectance value in near-infrared region has a strong correlation with hair photodamage. More specifically, the hair segments with longer growing time and the same hair root segment after continuous ultraviolet (UV) irradiation displaying more severe photodamage observed via scanning electron microscopy (SEM) micrographs showed significantly higher multispectral reflectance value. Besides, the multispectral reflectance value of hair segments with different growing time was precisely reproduced by exposing the same hair root segment to specific durations of UV irradiation, suggesting that MSI can be adequately applied to determine the sunlight exposure time of the hair. The loss of cystine content of photodamaged hairs was identified to be the main factor that physiologically contributed to the morphological changes of hair surface fibers and hence the variation of their multispectral reflectance spectra. Considering the environmental information recording nature of hairs, we believe that MSI for non-destructive evaluation of hair photodamage would prove valuable for assessing sunlight exposure time of a subject in the biomedical fields.

Scanning Electron Microscopy Study of Hair Shaft Damage Secondary to Cosmetic Treatments of the Hair

Introduction and Background:

Cosmetic procedures for hair, such as bleaching, dyeing, and straightening, are commonly used around the world. It has been suggested that excessive use of such procedures can cause damage to the hair shaft. We aimed to assess hair shaft changes using scanning electron microscopy (SEM) in female volunteers who frequently use hair treatment procedures such as bleaching, dyeing, or straightening.

Methods:

A cross-sectional, controlled study in a sample of 25 female volunteers (19 study group and 6 controls) in the age group of 18–45 years. The study group was composed of volunteers who regularly used different cosmetic hair treatment procedures such as bleaching, dyeing, and straightening (any one of these or a combination). The control group had never used any specific hair treatment procedure. The hair shaft damage as seen on SEM was assessed using a standardized scoring system and compared among the two groups statistically. The hair shafts were also examined clinically and with light microscopy.

Results:

No significant differences were seen between the test and control groups with regard to normal clinical examination and light microscopy findings. A higher degree of hair shaft damage was evident under SEM in the study group as compared to the control group. This difference was statistically significant.

Conclusions:

Regular use of procedures such as bleaching, dyeing, or straightening can lead to subtle changes in the hair shaft which can be detected early by SEM.