Long-hair follicular unit excision enhances the cosmetic results of hairline restoration: A retrospective study in Chinese recipients.

BACKGROUND: Long-hair follicular unit excision (LHF) is gaining popularity, especially for hairline restoration, because it helps avoid hair removal in the donor area and provides better immediate postoperative results. AIMS: This study aimed to assess the postoperative clinical outcomes of LHF for hairline restoration. PATIENTS/METHODS: Data from 248 patients (223 women and 25 men) who underwent hairline restoration with LHF between September 2018 and June 2022 were analyzed, and they were followed up immediately and 9 months postoperatively. The complications and survival rate of long-hair grafts were assessed. Patient postoperative satisfaction was assessed using a 5-Point Likert Scale. The Generic Quality of Life Inventory-74 (GQOLI-74) assessed the quality of the postoperative life. RESULTS: The planned extraction density was set at 15-25 FU/cm2. The mean number of total extracted hair grafts, transection rate in the extraction area, and extraction time were 1970 ± 124 FU, 3.9 ± 0.2%, and 3.2 ± 0.8 h, respectively. The hairline implantation density was set at 50-70 FU/cm2. The mean number of total transplanted hair grafts was 2031 ± 371 FU; the implant time was 3.8 ± 1.9 h. No serious complications occurred within 7 days postoperatively. The mean graft survival rate was 93.1 ± 1.3% at 9 months postoperatively. All patients were satisfied with the immediate postoperative results, and most were satisfied with the 9-month outcomes (mean overall satisfaction score: 4.7). The scores of physical function, psychological function, social function and material life function after operation were higher than those before operation (p < 0.0001). CONCLUSIONS: Hairline restoration with LHF could enhance the cosmetic outcomes and be widely used in clinical practice.

Rosacea treatment with mussel adhesive protein delivered via microneedling: In vivo and clinical studies.

BACKGROUND: Rosacea is a prevalent chronic dermatological condition marked by facial inflammation and erythema, significantly compromising the quality of life for affected individuals. Current treatment methods for rosacea are not considered ideal because of the complex etiology of the disease. Mussel adhesive protein (MAP) is a glycoprotein derived from the foot gland of mussels. The protein exhibits anti-inflammatory properties, relieves skin itching, and promotes wound healing. AIMS: We aimed to explore the feasibility of using MAP administered via microneedle delivery for treating rosacea and the potential molecular mechanism involved. MATERIALS AND METHODS: The therapeutic effect and mechanism of MAP microneedle delivery in an LL-37-induced rosacea-like mouse model were observed using morphological and histological methods. Twenty-seven patients with erythematotelangiectatic rosacea (ETR) underwent treatment once every 1 month, with three treatments constituting one treatment course. The therapeutic effect was evaluated by comparing the clinical images taken at baseline, after the first treatment course, and after the second treatment course. The red value, CEA, and GFSS score were also calculated. RESULTS: In response to the microneedle delivery of MAP, innate immunity, inflammatory infiltration, and abnormal neurovascular regulation improved significantly in rosacea-like mice. In the clinical experiments, the microneedle delivery of MAP significantly improved the symptoms of erythema, flushing, and telangiectasia in patients with ETR, and no obvious adverse reactions were observed. CONCLUSIONS: MAP delivered by microneedling is effective and safe for treating ETR.

Oleanolic acid regulates the proliferation and extracellular matrix of keloid fibroblasts by mediating the TGF-ß1/SMAD signaling pathway.

BACKGROUND: Keloid (KD) is a unique pathological fibroproliferative disease that seriously affects the appearance of patients. This study investigated the effect of oleanolic acid (OA) on the proliferation of keloid fibroblasts (KFs) and the expression of extracellular matrix (ECM)-related proteins. METHODS: The proliferation of KFs was evaluated using an MTT assay. The effects of OA on intra- and extracellular levels of fibronectin (FN), procollagen I, matrix metalloproteinase-1 (MMP-1), and α-smooth muscle actin (α-SMA) were evaluated using Western blotting. To simulate the KD microenvironment, TGF-ß1 was added to the serum-free culture medium, and KFs were incubated with TGF-ß1 and OA for 24 h. The intra- and extracellular levels of the ECM-related proteins and the effect of OA on TGF-ß1-induced phosphorylation of the SMAD2 and SMAD3 proteins were evaluated using Western blotting. RESULTS: OA inhibited the proliferation of KFs in a concentration- and time-dependent manner. Furthermore, OA treatment of KFs reduced the intra- and extracellular levels of FN, procollagen I, and α-SMA and increased those of MMP-1. OA also reduced TGF-ß1-induced increases in the intra- and extracellular levels of FN, procollagen I, and α-SMA and increased the levels of the MMP-1 protein. Additionally, OA significantly reduced TGF-ß1-induced phosphorylation of SMAD2 and SMAD3 in KFs. CONCLUSIONS: OA inhibited KF proliferation and reduced ECM deposition through the TGF-ß1/SMAD pathway, which suggests that OA may be an effective drug for the prevention and treatment of KD.

Mussel adhesive protein treatment delivered by microneedling for sensitive skin: A clinical study.

BACKGROUND: Mussel adhesive protein (MAP) is extracted from the mycelial glands of marine mussels. It has anti-inflammatory properties and may relieve skin itching and other symptoms. AIMS: Based on the anti-inflammatory effect of MAP, this study was designed to treat sensitive skin (SS) using MAP delivered by skin microneedling. PATIENTS/METHODS: Twenty-three Chinese female patients with SS were enrolled. Treatments were delivered three times at one-month intervals. Symptom improvement and recurrence rates, treatment safety, and patient satisfaction levels were evaluated. RESULTS: After one course of treatment, 20 patients had a Symptom Score Reducing Index (SSRI) of >20%, with an effectiveness rate of 87%. At the end of treatment, all patients had an SSRI of >20%, and the effectiveness rate was 100%. Dryness, tightness, desquamation, flushing, burning, itching, and tingling improved. After treatment, the Clinical Erythema Assessment and Lesion Severity Index of Facial Telangiectasia scores were significantly decreased. Clinical photographs following treatment revealed improved erythema reaction and decreased capillary density. During treatment, the patients experienced mild pain and erythema and swelling reaction without exudation. Complications, such as pigmentation changes or scarring, were absent. Additionally, there were no cases of recurrence, and patient satisfaction levels were high. CONCLUSION: MAP combined with microneedling can help treat SS, showing satisfactory safety outcomes and high patient satisfaction.

Novel technique for rosacea treatment using optimal pulse technology: In vivo and clinical studies.

BACKGROUND: Rosacea is a chronic inflammatory skin disease affecting the face, and the current treatment effect is not satisfactory. Based on the photomodulation of optimal pulse technology (OPT), we developed a novel treatment mode, namely, advanced OPT with low energy, three pulses, and long pulse width (AOPT-LTL). AIMS: We aimed to explore the feasibility and underlying molecular mechanisms of AOPT-LTL treatment in a rosacea-like mouse model. Furthermore, we evaluated the safety and efficacy in patients with erythematotelangiectatic rosacea (ETR). MATERIALS AND METHODS: Morphological, histological, and immunohistochemical analyses were used to investigate the efficacy and mechanisms of AOPT-LTL treatment in the LL-37-induced rosacea-like mouse model. Moreover, 23 patients with ETR were included and received different times of treatment at intervals of 2 weeks depending on the severity of their condition. The treatment effect was assessed by comparing clinical photographs at baseline, 1 week, and 3 months after treatment, combined with the red value, GFSS, and CEA scores. RESULTS: After the AOPT-LTL treatment of the mice, we observed that the rosacea-like phenotype, inflammatory cell infiltration, and vascular abnormalities were significantly ameliorated, and the expression of the core molecules of rosacea was significantly inhibited. In the clinical study, the AOPT-LTL treatment exerted satisfactory therapeutic effects on erythema and flushing of ETR patients. No serious adverse events were observed. CONCLUSIONS: AOPT-LTL is a safe and effective method for the treatment of ETR.

FoxO3 restricts liver regeneration by suppressing the proliferation of hepatocytes.

Upon injury, the liver is capable of substantial regeneration from the original tissue until an appropriate functional size. The underlying mechanisms controlling the liver regeneration processes are not well elucidated. Previous studies have proposed that the transcription factor FoxO3 is involved in various liver diseases, but its exact role in the regulation of liver regeneration remains largely unclear. To directly test the detailed role of FoxO3 in liver regeneration, both a constitutive Albumin-Cre driver line and adeno-associated virus serotype 8 (AAV8)-Tbg-Cre (AAV-Cre)-injected adult FoxO3fl/fl mice were subjected to 70% partial hepatectomy (PH). Our data demonstrate that FoxO3 deletion accelerates liver regeneration primarily by limiting polyploidization and promoting the proliferation of hepatocytes during liver regeneration. RNA-seq analysis indicates that FoxO3 deficiency greatly alters the expression of gene sets associated with cell proliferation and apoptosis during liver regeneration. Chromatin immunoprecipitation-PCR (ChIP-PCR) and luciferase reporter assays reveal that FoxO3 promotes the expression of Nox4 but suppresses the expression of Nr4a1 in hepatocytes. AAV8 virus-mediated overexpression of Nox4 and knockdown of Nr4a1 significantly suppressed hepatocyte proliferation and liver regeneration in FoxO3-deficient mice. We demonstrate that FoxO3 negatively controls hepatocyte proliferation through Nox4 upregulation and Nr4a1 downregulation, thereby ensuring appropriate functional regeneration of the liver. Our findings provide novel mechanistic insight into the therapeutic mechanisms of FoxO3 in liver damage and repair.

Integrated bioinformatics analysis of core regulatory elements involved in keloid formation.

BACKGROUND: Keloid is a benign fibro-proliferative dermal tumor formed by an abnormal scarring response to injury and characterized by excessive collagen accumulation and invasive growth. The mechanism of keloid formation has not been fully elucidated, especially during abnormal scarring. Here, we investigated the regulatory genes, micro-RNAs (miRNAs) and transcription factors (TFs) that influence keloid development by comparing keloid and normal scar as well as keloid and normal skin. METHODS: Gene expression profiles (GSE7890, GSE92566, GSE44270 and GSE3189) of 5 normal scar samples, 10 normal skin samples and 18 keloid samples from the Gene Expression Omnibus (GEO) database were interrogated. Differentially expressed genes (DEGs) were identified between keloid and normal skin samples as well as keloid and normal scar samples with R Project for Statistical Computing. Gene Ontology (GO) functional enrichment analysis was also performed with R software. DEG-associated protein-protein interaction (PPI) network was constructed by STRING, followed by module selection from the PPI network based on the MCODE analysis. Regulatory relationships between TF/miRNA and target genes were predicted with miRnet and cytoscape. Core regulatory genes were verified by RT-qPCR. RESULTS: We identified 628 DEGs, of which 626 were up-regulated and 2 were down-regulated. Seven core genes [neuropeptide Y(NPY), 5-hydroxytryptamine receptor 1A(HTR1A), somatostatin (SST), adenylate cyclase 8 (ADCY8), neuromedin U receptor 1 (NMUR1), G protein subunit gamma 3 (GNG3), and G protein subunit gamma 13 (GNG13)] all belong to MCODE1 and were enriched in the "G protein coupled receptor signaling pathway" of the GO biological process category. Furthermore, nine core miRNAs (hsa-mir-124, hsa-let-7, hsa-mir-155, hsa-mir-26a, hsa-mir-941, hsa-mir-10b, hsa-mir-20, hsa-mir-31 and hsa-mir-372), and two core TFs (SP1 and TERT) were identified to play important roles in keloid formation. In the TF/miRNA-target gene network, both hsa-mir-372 and hsa-mir-20 had a regulatory effect on GNG13, ADCY8 was predicted to be target by hsa-mir-10b, and HTR1A and NPY were potentially by SP1. Furthermore, the expression of core regulatory genes (GNG13, ADCY8, HTR1A and NPY) was validated in clinical samples. CONCLUSIONS: GNG13, ADCY8, NPY and HTR1A may act as core genes in keloid formation and these core genes establish relationship with SP1 and miRNA (hsa-mir-372, hsa-mir-20, hsa-mir-10b), which may influence multiple signaling pathways in the pathogenesis of keloid.

Effect of Chrysanthemum zawadskii Extract on Dermal Papilla Cell Proliferation and Hair Growth.

BACKGROUND: Chrysanthemum zawadskii (CZ) belongs to the genus Chrysanthemum, also known as 'Gu-Jeol-Cho' in Korea. CZ has been used as herbal remedy to manage cough, hypertensive disorders, pharyngitis, bronchitis, gastroenteritis, pneumonia, bladder diseases and common cold. However, its effect on hair growth has not been documented. OBJECTIVE: The aim of present study was to elucidate the beneficial effects of CZ on hair growth. METHODS: Proliferation of follicular dermal papilla (DP) cells from human scalp skin was evaluated by MTT assay. The expression of various molecules in DP cells was checked by western blot assay. Effect of CZ extract on the hair growth was evaluated by hair organ culture and C57BL/6 mice model. RESULTS: Cultivation of DP cells with CZ extract increased cellular proliferation, increased expression of phosphorylated protein kinase B (p-Akt), p-ERK, B-cell lymphoma 2, and decreased expression of Bax. Treatment of human hair follicles with CZ extract significantly enhanced hair growth. Additionally, CZ markedly shortened telogen period, increased anagen transformation and stimulated hair growth in the animal study. CONCLUSION: These results suggest that CZ extract has an effect of promoting hair growth and may therefore be a useful a therapeutic remedy for preventing hair loss.

Expression Pattern and Role of Klotho in Human Hair Follicles.

BACKGROUND: Klotho protein plays a pivotal role in aging regulation. However, it is unclear whether klotho is expressed in human hair follicles and is correlated with hair growth. OBJECTIVE: The purpose of this study was to determine the expression pattern and role of klotho in human hair follicles. METHODS: We examined the klotho expression patterns in human hair follicles from young and aged donors. Furthermore, we examined the functional roles of klotho on human hair growth using klotho siRNA and klotho recombinant protein. RESULTS: Interestingly, klotho was expressed in human hair follicles at both gene and protein levels. In hair follicles, prominent klotho expression was mainly observed in the outermost regions of the outer root sheath and hair bulb matrix cells. Quantification of klotho protein expression in young and aged donors showed that klotho expression decreased with aging. In human hair follicle organ culture, klotho silencing promoted premature catagen induction and inhibited human hair growth. Otherwise, klotho protein prolonged human hair growth. CONCLUSION: These results indicate that klotho might be an important regulatory factor for human hair growth and hair cycle change.

Targeting of CXXC5 by a Competing Peptide Stimulates Hair Regrowth and Wound-Induced Hair Neogenesis.

The Wnt/ß-catenin pathway has been implicated in hair follicle development and hair regeneration in adults. We discovered that CXXC-type zinc finger protein 5 (CXXC5) is a negative regulator of the Wnt/ß-catenin pathway involved in hair regrowth and wound-induced hair follicle neogenesis via an interaction with Dishevelled. CXXC5 was upregulated in miniaturized hair follicles and arrector pili muscles in human balding scalps. The inhibitory effects of CXXC5 on alkaline phosphatase activity and cell proliferation were demonstrated using human hair follicle dermal papilla cells. Moreover, CXXC5-/- mice displayed accelerated hair regrowth, and treatment with valproic acid, a glycogen synthase kinase 3ß inhibitor that activates the Wnt/ß-catenin pathway, further induced hair regrowth in the CXXC5-/- mice. Disrupting the CXXC5-Dishevelled interaction with a competitor peptide activated the Wnt/ß-catenin pathway and accelerated hair regrowth and wound-induced hair follicle neogenesis. Overall, these findings suggest that the CXXC5-Dishevelled interaction is a potential target for the treatment of hair loss.

Protective effect of Korean Red Ginseng against chemotherapeutic drug-induced premature catagen development assessed with human hair follicle organ culture model.

BACKGROUND: Chemotherapy-induced alopecia (CIA) is one of the most distressing side effects for patients undergoing chemotherapy. This study evaluated the protective effect of Korean Red Ginseng (KRG) on CIA in a well-established in vitro human hair follicle organ culture model as it occurs in vivo. METHODS: We examined whether KRG can prevent premature hair follicle dystrophy in a human hair follicle organ culture model during treatment with a key cyclophosphamide metabolite, 4-hydroperoxycyclophosphamide (4-HC). RESULTS: 4-HC inhibited human hair growth, induced premature catagen development, and inhibited proliferation and stimulated apoptosis of hair matrix keratinocytes. In addition, 4-HC increased p53 and Bax protein expression and decreased Bcl2 protein expression. Pretreatment with KRG protected against 4-HC-induced hair growth inhibition and premature catagen development. KRG also suppressed 4-HC-induced inhibition of matrix keratinocyte proliferation and stimulation of matrix keratinocyte apoptosis. Moreover, KRG restored 4-HC-induced p53 and Bax/Bcl2 expression. CONCLUSION: Overall, our results indicate that KRG may protect against 4-HC-induced premature catagen development through modulation of p53 and Bax/Bcl2 expression.

Hot water extract of oriental melon leaf promotes hair growth and prolongs anagen hair cycle: In vivo and in vitro evaluation.

Effects of hot water extracts of oriental melon leaves (OML) on promotion of hair growth were investigated. Topical OML extract administration for hair regeneration was investigated using an in vivo model with C57BL/6 mice. Effects of OML extracts on the human hair growth were investigated using a hair follicle organ culture. OML extracts induced a shortened telogen to anagen conversion and promoted hair growth in the C57BL/6 mouse model. Culture of human hair follicles in the presence of OML extracts for 8 days promoted hair growth and prolonged the anagen duration due to induction of hair follicle cell proliferation in the bulb region. OML extracts exert a hair growth promotion effect and, therefore, can be used as a therapeutic agent for prevention of hair loss.

FoxO3a suppresses the senescence of cardiac microvascular endothelial cells by regulating the ROS-mediated cell cycle.

FoxO3a plays an important role in the aging process and decreases with age. However, the potential regulatory roles of FoxO3a in processes involved in cardiac microvascular endothelial cell (CMEC) senescence, and its underlying molecular mechanisms have not been elucidated. This study demonstrates that FoxO3a is deactivated in senescent CMECs together with the inhibition of proliferation and tube formation. Furthermore, the activation of the antioxidant enzymes catalase and SOD, downstream FoxO3a targets, was significantly decreased, thereby leading to cell cycle arrest in G1-phase by increased ROS generation and subsequently the activation of the p27(Kip1) pathway. However, FoxO3a overexpression in primary low-passage CMECs not only significantly suppressed the senescence process by increasing the activation of catalase and SOD but also markedly inhibited ROS generation and p27(Kip1) activation, although it failed to reverse cellular senescence. Moreover, both cell viability and tube formation were greatly increased by FoxO3a overexpression in primary CMECs during continuous passage. In addition, FoxO3a, deficiency in low-passage CMECs, accelerated the senescence process. Collectively, our data suggest that FoxO3a suppresses the senescence process in CMECs by regulating the antioxidant/ROS/p27(Kip1) pathways, although it fails to reverse the cellular senescent phenotype.

Comparison of hair shaft damage after chemical treatment in Asian, White European, and African hair.

BACKGROUND: Diverse causes of extrinsic damage to the hair shaft have been documented and can be roughly divided into physical and chemical causes. Chemical causes of hair damage include bleaching, hair dyeing, and perming. OBJECTIVES: The goal of this study was to investigate differences in patterns of serial damage in Asian, White European (WE), and African hair after chemical stress imposed by straightening and coloring treatments. METHODS: Hairs were divided into control and treatment groups (straightening, coloring, and a combination of straightening and coloring). At 24 hours after the final treatment, patterns of hair damage were evaluated using transmission electron microscopy (TEM) and lipid TEM. Grades of hair cuticle and cortex damage were evaluated by three dermatologists. RESULTS: In the TEM examination, the cuticle of Asian hair proved to be resistant to damage caused by straightening treatments, whereas the WE hair cuticle and cortex were relatively susceptible to stress imposed by coloring treatments. In the combination treatment of straightening and coloring, African hair emerged as the most resistant to stress. In the lipid TEM examination, no notable differences in cell membrane complex damage were observed among the three groups of hairs. CONCLUSIONS: The present study suggests that WE hair is relatively susceptible and African hair is more resistant to chemical stresses, such as those imposed by straightening and coloring.

The ethnic differences of the damage of hair and integral hair lipid after ultra violet radiation.

BACKGROUND: Genetic factors account for the majority of differences in skin color and hair morphology across human populations. Although many studies have been conducted to examine differences in skin color across populations, few studies have examined differences in hair morphology. OBJECTIVE: To investigate changing of integral hair lipids after ultraviolet (UV) irradiation in three human ethnic groups. METHODS: We studied the UV irradiation induced hair damage in hairs of three human populations. UV irradiation had been performed with self-manufactured phototherapy system. Damaged hair samples were prepared at 12 and 48 hours after UVA (20 J/sec) and UVB (8 J/sec) irradiation. We evaluated the changes of hair lipid using scanning electron microscopy (SEM), transmission electron microscopy (TEM), lipid TEM and HP-TLC. After UV irradiation, hair surface damage was shown. RESULTS: African hair showed more severe damage on hair surface than others. The lipid compositions across human populations were similar, but Asian hair had more integral hair lipids than other groups as a whole. Especially, free fatty acid contents were higher than other lipids. After UV irradiation, lipid contents were decreased. These patterns were shown in all human populations. Asian hair has more integral hair lipid than European or African hair. After UV irradiation, European and African hair samples exhibited more damage because they have less integral hair lipids. However, Asian hair samples have less damage. CONCLUSION: We conclude that integral hair lipid may protect the hair against the UV light.

Effects of calcitonin gene-related peptide on the immune privilege of human hair follicles.

The hair follicle is a widely available and instructive miniature organ in the human body that experiences major histocompatibility complex (MHC) class I dependent immune privilege (IP). There are various regulation factors that act on the generation, maintenance, and collapse of hair follicle IP. Neuropeptides such as calcitonin gene-related peptide (CGRP) are created in many organs, including skin, and display various immune regulation effects. The purpose of this study was to investigate the phenotypic effect of CGRP on the hair follicle's IP. First, we used interferon-γ (IFN-γ) to generate ectopic MHC antigen expression model in cultured human hair follicles as previously described. Then, we examined the effects of CGRP on the regulation of ectopic MHC antigen expression in cultured human hair follicles using reverse transcriptase-polymerase chain reaction (RT-PCR) and immunohistochemical staining techniques. IFN-γ (75 IU/ml) induced ectopic MHC expression. CGRP down-regulated INF-γ-induced ectopic MHC class I mRNA expression. These down-regulated effects were especially evident in 10(-8)M. In addition, CGRP also suppressed the staining intensity related to the expression of MHC class I and MHC class I-pathway related molecules (ß2-microglobulin), but had no effect on MHC class II antigen expression. Taken together, these results indicate that CGRP might be an important regulatory factor for IP maintenance and restoration of IP via suppression of MHC class I antigen.

Qualitative investigation of fresh human scalp hair with full-field optical coherence tomography.

We have investigated depth-resolved cellular structures of unmodified fresh human scalp hairs with ultrahigh-resolution full-field optical coherence tomography (FF-OCT). The Linnik-type white light interference microscope has been home-implemented to observe the micro-internal layers of human hairs in their natural environment. In hair shafts, FF-OCT has qualitatively revealed the cellular hair compartments of cuticle and cortex layers involved in keratin filaments and melanin granules. No significant difference between black and white hair shafts was observed except for absence of only the melanin granules in the white hair, reflecting that the density of the melanin granules directly affects the hair color. Anatomical description of plucked hair bulbs was also obtained with the FF-OCT in three-dimensions. We expect this approach will be useful for evaluating cellular alteration of natural hairs on cosmetic assessment or diagnosis of hair diseases.

Effect of IGF-I on Hair Growth Is Related to the Anti-Apoptotic Effect of IGF-I and Up-Regulation of PDGF-A and PDGF-B.

BACKGROUND: Insulin-like growth factor-I (IGF-I) shares a high degree of structural and functional homology with insulin and is a potent mitogen supporting cell growth and survival in many kinds of the tissues and cells. It also plays a role in some differentiation and anti-apoptotic functions. In previous reports, it has been shown that IGF-I stimulates hair follicle (HF) growth, maintains the anagen stage, and postpones the catagen stage. OBJECTIVE: The exact mechanism of the effect of IGF-I on HF growth is not yet established. Therefore, we investigated the relationships between IGF-I and various other factors (i.e. apoptosis related molecules, pro-inflammatory cytokines, other growth factors, etc.) in the control of HF growth. METHODS: The effect of IGF-I on human hair growth was measured using an organ culture model of human HFs and compared with a control group that did not receive IGF-I. We also measured mRNA expression of factors related to hair growth and apoptosis (which was determined by reverse transcription polymerase chain reaction (RT-PCR). RT-PCR was done on days 2, 4, 6, and 8 of organ culture. RESULTS: In organ cultured human hair follicles, IGF-I had a positive effect on the rate of linear hair growth. IGF-I maintained the anagen phase. IGF-I increased the expression of platelet-derived growth factor (PDGF)-A, PDGF-B and the expression ratio of Bcl-2/Bax. CONCLUSION: The effect of IGF-I on hair growth appears to be related to the upregulation of PDGF-A and PDGF-B and to the anti-apoptotic effect of IGF-I.

Hair shaft damage from heat and drying time of hair dryer.

BACKGROUND: Hair dryers are commonly used and can cause hair damage such as roughness, dryness and loss of hair color. It is important to understand the best way to dry hair without causing damage. OBJECTIVE: The study assessed changes in the ultra-structure, morphology, moisture content, and color of hair after repeated shampooing and drying with a hair dryer at a range of temperatures. METHODS: A standardized drying time was used to completely dry each hair tress, and each tress was treated a total of 30 times. Air flow was set on the hair dryer. The tresses were divided into the following five test groups: (a) no treatment, (b) drying without using a hair dryer (room temperature, 20℃), (c) drying with a hair dryer for 60 seconds at a distance of 15 cm (47℃), (d) drying with a hair dryer for 30 seconds at a distance of 10 cm (61℃), (e) drying with a hair dryer for 15 seconds at a distance of 5 cm (95℃). Scanning and transmission electron microscopy (TEM) and lipid TEM were performed. Water content was analyzed by a halogen moisture analyzer and hair color was measured with a spectrophotometer. RESULTS: Hair surfaces tended to become more damaged as the temperature increased. No cortex damage was ever noted, suggesting that the surface of hair might play a role as a barrier to prevent cortex damage. Cell membrane complex was damaged only in the naturally dried group without hair dryer. Moisture content decreased in all treated groups compared to the untreated control group. However, the differences in moisture content among the groups were not statistically significant. Drying under the ambient and 95℃ conditions appeared to change hair color, especially into lightness, after just 10 treatments. CONCLUSION: Although using a hair dryer causes more surface damage than natural drying, using a hair dryer at a distance of 15 cm with continuous motion causes less damage than drying hair naturally.