Hair Transplantation: Basic Overview

Premade Incisions vs. Stick and Place: A Multicenter Retrospective Comparison of Hair Transplantation Outcomes in China

BACKGROUND

Based on the differences in the procedures of recipient site creation and graft placement, hair transplantation implantation techniques can be classified into premade incisions (PI) and stick and place (S&P). However, limited studies have systematically compared their clinical outcomes.

METHODS

A retrospective analysis was conducted on 191 Chinese patients (95 in the PI group and 96 in the S&P group) from four hospitals, undergoing follicular unit excision between August 2022 and August 2024. Intraoperative metrics such as graft density and implantation speed were compared, while postoperative evaluations included the maximum shedding rate, the survival rate, the complication rate, and patient satisfaction. Additionally, junior surgeons practicing one technique on simulation models were assessed for a learning curve.

RESULTS

The PI group demonstrated faster implantation speed (719.3 ± 50.7 vs. 553.9 ± 51.9 FUs/(hour*N), p < 0.001) and a shorter learning curve (7.3 ± 0.2 vs. 8.5 ± 0.2 FUs/(hour*day), p < 0.001). However, the S&P group achieved higher graft density (p = 0.003), lower maximum shedding rate (95.9 ± 2.9% vs. 70.3 ± 2.5%, p < 0.001), and higher patient satisfaction (p = 0.023). No significant differences were observed in the survival rate and the complication rate.

CONCLUSIONS

This study provides a comprehensive evaluation of the clinical outcomes of PI and S&P techniques in Chinese populations. While PI demonstrates procedural efficiency and a simplified learning curve, S&P is associated with enhanced precision and superior patient satisfaction.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Chia Seed Polysaccharide-Based Self-Assembled Microencapsulation Enhances Hair Regeneration by Inducing Glycolysis and Autophagy

Effective strategies for hair regeneration and maintenance focus on enhancing the hair growth cycle by expediting the transition from the telogen to anagen phases, extending the growth phase, and delaying the onset of the catagen phase. These measures ultimately improve hair density, vitality, and overall health. This study introduces a chia seed polysaccharide-based microencapsulation (CSMi) cream as a promising non-invasive approach for hair regeneration and maintenance through the stimulation of glycolysis and autophagy. The innovative formulation, derived from chia seed mucilage polysaccharides and oil, shows significant potential in promoting hair follicle (HF) neogenesis, as demonstrated in a hair removal mouse model. Single-cell transcriptomic analysis revealed that the CSMi cream influences cellular metabolism toward glycolytic pathways and modulating autophagy levels, the cream facilitates the telogen-to-anagen transition, extends the anagen phase, and delays the onset of catagen. These findings provide compelling evidence for the CSMi cream as a potential therapeutic option for treating hair loss, offering a safe and effective alternative to existing solutions in trichology.

Innovative strategies for the discovery of new drugs against androgenetic alopecia

INTRODUCTION

Androgenetic alopecia (AGA) is the most common cause of hair loss worldwide. The significant psychological and social impact of AGA continues to drive demand for more effective treatments beyond the limited options currently available.

AREAS COVERED

The authors review the key components of AGA pathogenesis, as well as current treatments, and therapeutic techniques under development. Innovative strategies for AGA drug discovery are still needed, given the significant unmet medical needs and the limited efficacy of both current and emerging treatments. The authors outline relevant preclinical models, such as hair follicle (HF) cell cultures, 3D spheroids, organoids, follicle explants, and animal models, highlighting their advantages and limitations in AGA research. Finally, they summarize the primary objectives in AGA treatment development, including direct hair growth promotion, interference with androgen signaling, and HF rejuvenation, identifying key pathogenesis intervention points for treatment development.

EXPERT OPINION

Developing better in vitro models, possibly using induced pluripotent stem cell (iPSC) systems, could greatly accelerate drug discovery. Similarly, a superior in vivo model could significantly expedite drug discovery. Near future development research should focus on drug delivery improvements. Longer term, treatments targeting AGA's underlying pathophysiology and promoting HF rejuvenation or true regeneration would provide the most benefit to prospective patients.

The Pharmacokinetics of Topical Finasteride 0.25% Spray in Chinese Adult Male Volunteers with Androgenic Alopecia: A Phase I Study

INTRODUCTION

This study aimed to evaluate the pharmacokinetics (PK), safety, and local tolerability of local finasteride spray (0.25% solution in HPCH, once daily, volume 200 μL) after single and multiple doses in Chinese male volunteers with androgenetic alopecia.

METHODS

Twelve male patients with androgenetic alopecia received once-daily scalp application of the solution for 7 days. Blood samples were collected at specified time points (on day 1, days 3-6, and day 7 of the trial) and plasma finasteride concentrations were determined by HPLC-MS.

RESULTS

After single-dose administration, the Cmax of finasteride was 15.2 ± 5.54 pg/mL, Tmax was 11.00 (3.00, 20.00) h, AUC0-24h was 263 ± 76.6 h·pg/mL, t1/2 was 35.3 ± 47.7 h, and CL/F was 974 ± 518 L/h. After 7 days of multiple doses, Cmax,ss was 29.7 ± 12.9 pg/mL, Tmax,ss was 8.00 (3.00, 12.00) h, AUCtau,ss was 530 ± 251 h·pg/mL, AUC0-t,ss was 790 ± 464 h·pg/mL, t1/2,ss was 22.6 ± 10.7 h, and CL/Tss was 1080 ± 658 L/h. No clinically significant adverse events occurred during the study.

CONCLUSION

Compared to single-dose administration, multiple-dose administration of finasteride resulted in a stable half-life, minimal changes in clearance rate, and approximately twofold accumulation in exposure over 7 days. Multiple-dose administration of finasteride spray was well tolerated in Chinese male volunteers with androgenetic alopecia.

From Scalp Flaps to Follicular Units: A Historical Perspective on Hair Transplantation Techniques

BACKGROUND

Hair has long held cultural and psychosocial significance, symbolizing health, status, and identity. Hair loss impacts quality of life, self-esteem, and psychological well-being. While treatments like minoxidil and finasteride exist, they often yield limited results. Hair transplantation (HT), first demonstrated by Johann Friedrich Dieffenbach in 1822, has evolved into the most effective hair restoration method. Since its inception in 1975, Dermatologic Surgery has been a main source for groundbreaking publications from major players in the field, while also playing a pivotal role in documenting the history of HT.

OBJECTIVE

This mini review examines the historical evolution of HT techniques over the past 200 years, highlighting their advantages and limitations.

MATERIALS AND METHODS

A literature search was conducted using PubMed and Google Scholar with the term "hair transplantation techniques." Relevant sources were reviewed to extract information on technique development and historical origins.

RESULTS

Key pioneers such as Dieffenbach, Menahem Hodara, and Shoji Okuda laid the groundwork for modern HT. Milestones include punch grafting, follicular unit transplantation (FUT), and follicular unit extraction (FUE). FUT emphasized natural follicular grouping, while FUE introduced minimally invasive methods with faster recovery and better aesthetics. Recent advancements include robotic-assisted procedures and bioengineered follicles, reflecting a shift toward precision and patient-centered care.

CONCLUSION

The continuous evolution of HT techniques underscores its position as the most effective method for hair restoration, particularly in androgenetic alopecia cases.

Development and evaluation of an integrated image-guided robotic system for hair transplant surgery

This study presented the development and evaluation of an integrated image-guided robotic system for hair transplant surgery. A novel surgical robot was designed, incorporating an image-guided system, a dual-function needle mechanism, and a comprehensive robotic system capable of performing both follicle harvesting and implantation in a unified setup. The robot comprised three main subsystems: the image-guidance system, the dual-function needle, and the robotic hardware. Each subsystem was meticulously developed and individually described, detailing the specific processes and mechanisms involved. Experimentation involved a silicone phantom embedded with filaments to mimic real human hair density, providing a realistic simulation for testing. The image-guided system demonstrated high precision in detecting the positions of hair follicles, achieving an accuracy rate of 89 %. Meanwhile, the dual-function needle proved effective in executing both the harvesting and implanting functions, achieving harvest and implant success rates of 83.3 % and 53.3 %, respectively. It was important to note, however, that the suction system integrated into the needle mechanism did not function as intended. Further simulations conducted on the robotic system affirmed its suitability for a wide range of head sizes, specifically those with a breadth diameter between 113 and 179 mm, effectively encompassing most of the Asian demographic. This integration of advanced robotics and image-guidance aimed to enhance the efficacy and precision of hair transplant procedures.

Follicular Unit Excision Hair Removal of Unwanted Facial Terminal Hair in Five Facial Areas: A Retrospective Multicenter Cohort Study

BACKGROUND

Conventional epilation methods commonly encounter challenges in achieving permanent removal of unwanted facial terminal hair (uFTH), particularly when it is interspersed among normal hairs.

OBJECTIVE

To assess the safety and effectiveness of follicular unit excision (FUE) for permanent removal of uFTH.

METHODS

The retrospective analysis included 231 patients who underwent FUE hair removal at three medical centers. uFTH in five facial areas was excised and assessed for follicular integrity. Surgical details, complications, in situ hair regrowth, and patient satisfaction were recorded and analyzed.

RESULTS

Scattered uFTH was excised using a fine punch (inner diameter, 0.6~0.7 mm) at a rate of 18.0~23.6 units per minute in five facial areas. The procedure yielded a low transection rate of only 6.2% (median), minimizing in situ hair regeneration and facilitating the intact harvesting of hair follicles for transplantation. Most sites exhibited optimal wound healing without visible scarring. The overall complication rate is 26.3%, with folliculitis accounting for 3%. Overall satisfaction was significantly high, reaching 96.6%.

CONCLUSION

FUE technique is a precise and effective potential approach for uFTH permanent removal in facial areas.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors   www.springer.com/00266 .

Self-management in the post-hair transplantation recovery period among patients with androgenetic alopecia: A qualitative study

Background

The success of hair transplantation surgeries for androgenetic alopecia is evaluated by postoperative long-term outcomes. Patients' self-management during the long recovery period affects this outcome.

Objective

This study aimed to explore patients' self-management status, facilitators, and impediments in the postoperative period and to provide a reference for developing a postoperative self-management intervention program.

Methods

Patients who underwent hair transplantation for androgenetic alopecia were selected using purposive sampling. They were interviewed using one-to-one semi-structured interviews at a general tertiary hospital in Hangzhou from March to April 2022. Qualitative research analysis software Nvivo 12.0 was used to analyze the collected data.

Results

The self-management of postoperative patients with androgenetic alopecia during the recovery period encompasses six areas: more problems with postoperative medication (e.g., not being able to take medication on time) and wound care (e.g., not daring to shampoo, etc.), not being able to review their postoperative condition on time (due to busy schedules at work and at home), more hindrances to the establishment of good living habits (affected by overtime work, socialising, and bad habits of the people around them), and seeking positive ways of relieving bad emotions (stress, anxiety, depression, etc.), worrying about one's image during recovery and taking the initiative to obtain and use resources to promote recovery (through the Internet, books, etc.).

Conclusions

Various factors impact the postoperative self-management abilities of patients, including medication, shampooing, and emotions. It is essential to design support programs to enhance these abilities and improve long-term hair transplantation outcomes.

Design, proof-of-concept of single robotic hair transplant mechanisms for both harvest and implant of hair grafts

The design and development of a prototype for a singular robotic hair transplant system capable of harvesting and implanting hair grafts were executed in this study. To establish a proof-of-concept for hair transplant procedures involving harvesting and implantation, a test system using a spherical phantom of the scalp was selected. The developed prototype of the robotic hair transplant system demonstrates the potential to reduce the duration that grafts remain without a blood supply, thereby minimizing hair graft damage. Additionally, the overall operation time for follicular unit extraction is comparatively shorter than that of conventional systems. Results from the robot vision tests indicate an 89.6% accuracy for hair graft detection with a 4 mm hair length phantom and 97.4% for a 2 mm hair length phantom. In the robot position control test, the root mean square error was found to be 1.268°, with a standard error of the mean of 0.203°. These outcomes suggest that the proposed system performs effectively under the conditions of a spherical phantom with a 2 mm hair length and a 5 mm distance between harvests.

Characterization and Risk Factors of Folliculitis after Hair Transplantation: A Multicenter Retrospective Study

BACKGROUND

Postoperative folliculitis is a common complication of hair transplantation (HT) requiring effective preventive interventions. This study characterized postoperative folliculitis and determined risk factors in patients undergoing HT.

METHODS

The authors retrospectively reviewed 1317 patients who underwent HT and completed 9-month follow-up between January of 2018 and June of 2021 at 4 medical centers. The incidence of postoperative folliculitis and demographic characteristics were assessed. Logistic regression analysis was used to identify risk factors, and the characteristics of different types of folliculitis were compared.

RESULTS

The overall incidence of postoperative folliculitis was 12.11%, and clinical characteristics varied among the different types of folliculitis. Surgery in summer (OR, 1.772 [95% CI, 1.05 to 2.992]), number of transplant grafts 4000 or greater (OR, 4.818 [95% CI, 1.45 to 16.014]), transplant density greater than 45 grafts/cm 2 (OR, 2.152 [95% CI, 1.376 to 3.367]), and first nursing time greater than 3 days (OR, 1.555 [95% CI, 1.088 to 2.223]) were the main risk factors for postoperative folliculitis.

CONCLUSIONS

Postoperative folliculitis after HT presents different characteristics. Surgical factors and postoperative nursing care were demonstrated to be related to folliculitis. The authors propose a preventive folliculitis model based on preoperative, intraoperative, and postoperative factors.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, III.

Exosomes derived from Umbilical cord mesenchymal stem cell promote hair regrowth in C57BL6 mice through upregulation of the RAS/ERK signaling pathway

Background and Objectives

Androgenetic alopecia is one of the common types of hair loss and has become a medical and social problem due to its increasingly young onset. Existing therapies, although effective, have serious side effects and therefore better treatments need to be sought. The aim of this study was to evaluate the efficacy of umbilical cord mesenchymal stem cell-derived exosomes in the treatment of androgenetic alopecia and to investigate the mechanism of exosome regulation of hair growth.

Methods

First, we randomly divided 20 C57BL/6J mice into blank group, model group, positive control group and exosomal hydrogel group, and mice were treated with hair removal on the back. The mice were injected intraperitoneally with dihydrotestosterone solution except for the blank group. At the end of the experiment, new hairs were collected and the differences in length, diameter and number of hair follicles were compared among the groups; the histopathological changes of hair follicles were observed by HE staining; the expression of androgen receptor mRNA and protein in skin tissues were compared; and the skin tissues were analyzed by real-time PCR, western blotting, immunofluorescence staining and transcriptome sequencing. Finally, the results of transcriptome sequencing experiments were verified by real-time PCR, western blotting and other techniques for the corresponding genes and proteins.

Results

Compared with the blank group, mice in the model group had shorter hair length and reduced hair diameter, and pathological observation showed that the total number of hair follicles was significantly reduced and the hair follicles were miniaturized; compared with the model group, mice in the positive control and exosome groups had longer hair length, larger hair diameter and more hair follicles; the androgen receptor mRNA content and protein expression in the skin tissue of mice in the model group were significantly higher than those in the blank group, and the protein expression in the exosome gel group was lower than that in the model group. Similarly, compared with the model group, the expression of stemness-related proteins K15 and CD200 in the skin tissues of mice in the exosome group increased, and the expression of PCNA, a protein related to cell proliferation, increased. The KEGG data showed that the differential genes were mainly enriched in the RAS/ERK pathway.

Conclusions

In this study, we demonstrated the therapeutic effect of umbilical cord MSC-derived exosomes on androgenetic alopecia and verified that exosomes regulate hair follicle stem cell stemness through the RAS/ERK pathway to promote hair proliferation and thus hair growth in mice with androgenetic alopecia, providing a potential therapeutic strategy for androgenetic alopecia.

The Proportion of Catagen and Telogen Hair Follicles in Occipital Scalp of Male Androgenetic Alopecia Patients: Challenging the Established Dogma

The hair follicle can cycle throughout a lifetime, undergoing periods of growth (anagen), regression (catagen) and relative quiescence (telogen). The time that a hair follicle spends in each of these stages is crucial to determine the length of hair fibre that it produces. Perturbations in this regard can manifest in various hair diseases such as anagen effluvium, or acute and chronic telogen effluvium. The established 'dogma' when considering how many hair follicles there are in each stage has long been that the majority are in anagen (85%-90%), followed by telogen (10%-15%) and catagen (1%-2%). These values are based on various studies using different methodologies such as hair plucking, phototrichograms and histology. However, these methods have flaws when it comes to differentiating between catagen and telogen follicles. We sought to determine the catagen: telogen ratio through the ex vivo stereomicroscopic examination of hundreds of hair follicles removed from the occipital scalp of 14 Caucasian males during routine hair transplantation procedures. Using this methodology, and in agreement with a similar observation by another research group, we found that the percentage of catagen hair follicles was higher (7.5%) than telogen (3.5%) in all patients assessed. Consequently, we believe that the percentage of catagen follicles is clearly underestimated and therefore challenge the current established dogma.

Diabetes Mellitus Inhibits Hair Follicle Regeneration by Inducing Macrophage Reprogramming-Mediated Pyroptosis

Background

Diabetes mellitus (DM) is known to inhibit skin self-renewal and hair follicle stem cell (HFSC) activation, which may be key in the formation of chronic diabetic wounds. This study aimed to investigate the reasons behind the suppression of HFSC activation in DM mice.

Methods

Type 1 DM (T1DM) was induced in 6-week-old mice via streptozotocin, and hair follicle growth was subsequently monitored. RNA sequencing, bioinformatics analyses, qRT‒PCR, immunostaining, and cellular experiments were carried out to investigate the underlying mechanisms involved.

Results

T1DM inhibited HFSC activation, which correlated with an increase in caspase-dependent programmed cell death. Additionally, T1DM triggered apoptosis and pyroptosis, predominantly in HFSCs and epidermal regions, with pyroptosis being more pronounced in the inner root sheath of hair follicles. Notably, significant cutaneous immune imbalances were observed, particularly in macrophages. Cellular experiments demonstrated that M1 macrophages inhibited HaCaT cell proliferation and induced cell death, whereas high-glucose environments alone did not have the same effect.

Conclusion

T1DM inhibits HFSC activation via macrophage reprogramming-mediated caspase-dependent pyroptosis, and there is a significant regional characterization of cell death. Moreover, T1DM-induced programmed cell death in the skin may be more closely related to immune homeostasis imbalance than to hyperglycemia itself. These findings shed light on the pathogenesis of diabetic ulcers and provide a theoretical basis for the use of hair follicle grafts in wound repair.

A randomized controlled trial on hair follicular-derived microtissue for promoting wound healing and alleviating postoperative complications after hair transplantation

BACKGROUND

Hair transplantation, particularly through follicular unit extraction (FUE), can lead to postoperative complications, such as numbness, itching, and pain in donor areas, primarily because of delayed wound healing. Efficient management of donor-site healing is crucial to mitigate these complications and improve overall patient outcomes.

OBJECTIVE

This study aimed to assess the efficacy of hair follicular-derived microtissue (HFMT) in promoting wound healing and alleviating postoperative complications in donor areas after FUE hair transplantation.

METHODS

Perifollicular tissue obtained during the trimming phase of hair transplantation was processed into HFMT and analyzed for its properties using histological and molecular techniques. In a single-blind, split-scalp study involving 98 participants, Group A received HFMT or mupirocin, whereas Group B received HFMT or no treatment. Dermatoscopic images were captured postoperatively, and visual analog scale scores were used to evaluate pain, itching, and numbness.

RESULTS

HFMT-treated donor sites in Group A demonstrated a significantly higher wound closure ratio on postoperative day 3 than mupirocin-treated sites. Pain scores for HFMT-treated sites were consistently lower on postoperative days 3, 5, and 7. Similar trends were observed for itching scores. Group B exhibited outcomes comparable with Group A.

CONCLUSION

The application of HFMT homogenates effectively accelerated wound healing and alleviated donor-site complications after FUE hair transplantation.

Strip Harvesting Follicular Unit Transplantation Versus Follicular Unit Excision: Comparing the Number of Hairs and the Ratio of Hairs to Follicular Unit

BACKGROUND

There are 2 extraction techniques for follicular units (FUs) in hair transplantation: strip harvesting follicular unit transplantation (FUT) and follicular unit excision (FUE). Currently, no extant studies have demonstrated that one technique is superior in extraction and donor area optimization for a dense result.

OBJECTIVE

This study compares the FUT and FUE techniques by evaluating the percentage of FUs with 3 or more hairs and the hairs-to-follicular-unit ratio in patients who underwent both procedures at different times.

MATERIALS AND METHODS

The medical records of patients who underwent at least 1 FUT procedure and at least 1 FUE procedure (with this being the second surgical procedure) were reviewed. The surgeries were performed in the same clinic with the same surgeon and surgical team.

RESULTS

There was a higher percentage of FUs with 3 or more hairs and a higher hairs-to-follicular-unit ratio with the FUE technique than with the FUT technique.

CONCLUSION

In FUE, surgeons tend to choose better-looking FUs with thick, plentiful hairs. Even with these results, it is impossible to declare one procedure superior because the correct indication considers multiple factors.

Construction of a Hair Implantation Needle Using Injection Needles and Assessment of its Efficiency Compared with Other Planting Methods

INTRODUCTION

Hair transplantation surgery requires the efficient completion of hair follicles and thus appropriate hair implantation needles. The objectives of this study were to evaluate the effectiveness and feasibility of self-made hair implantation needles using injection needles and evaluate the speed of different hair implantation methods.

METHODS

Four patients were randomly assigned to four groups. A gem knife pre-punching planting method was used for the patient in Group A, while Group B received immediate implantation after punching with ordinary injection needles, Group C was treated with synchronized punching and planting using hair implanters, and Group D was treated with a self-made hair implantation needle. The speed of the different implantation methods for single and double hair follicles and the differences between the planting of single and double hair follicles were assessed.

RESULTS

Group D was found to have the fastest hair planting speed for both single and double hair follicles, followed by Groups C and A, with the slowest speed observed in Group B. Groups A and B were associated with significantly lower speeds of double hair planting than single hair planting, There was no significant difference between Groups C and D.

CONCLUSIONS

The self-made hair implantation needle is a novel and efficient tool for synchronized punching and planting. It has a faster planting speed and does not require assistance.

LEVEL OF EVIDENCE II

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Bioinspired engineering ADSC nanovesicles thermosensitive hydrogel enhance autophagy of dermal papilla cells for androgenetic alopecia treatment

Androgenic alopecia (AGA) is a highly prevalent form of non-scarring alopecia but lacks effective treatments. Stem cell exosomes have similar repair effects to stem cells, suffer from the drawbacks of high cost and low yield yet. Cell-derived nanovesicles acquired through mechanical extrusion exhibit favorable biomimetic properties similar to exosomes, enabling them to efficiently encapsulate substantial quantities of therapeutic proteins. In this study, we observed that JAM-A, an adhesion protein, resulted in a significantly increased the adhesion and resilience of dermal papilla cells to form snap structures against damage caused by dihydrotestosterone and macrophages, thereby facilitating the process of hair regrowth in cases of AGA. Consequently, adipose-derived stem cells were modified to overexpress JAM-A to produce engineered JAM-A overexpressing nanovesicles (JAM-AOE@NV). The incorporation of JAM-AOE@NV into a thermosensitive hydrogel matrix (JAM-AOE@NV Gel) to effectively addresses the limitations associated with the short half-life of JAM-AOE@NV, and resulted in the achievement of a sustained-release profile for JAM-AOE@NV. The physicochemical characteristics of the JAM-AOE@NV Gel were analyzed and assessed for its efficacy in promoting hair regrowth in vivo and vitro. The JAM-AOE@NV Gel, thus, presents a novel therapeutic approach and theoretical framework for promoting the treatment of low cell adhesion diseases similar to AGA.

Polydopamine Synergizes with Quercetin Nanosystem to Reshape the Perifollicular Microenvironment for Accelerating Hair Regrowth in Androgenetic Alopecia

Accumulated reactive oxygen species (ROS) and their resultant vascular dysfunction in androgenic alopecia (AGA) hinder hair follicle survival and cause permanent hair loss. However, safe and effective strategies to rescue hair follicle viability to enhance AGA therapeutic efficiency remain challenging. Herein, we fabricated a quercetin-encapsulated (Que) and polydopamine-integrated (PDA@QLipo) nanosystem that can reshape the perifollicular microenvironment to initial hair follicle regeneration for AGA treatment. Both the ROS scavenging and angiogenesis promotion abilities of PDA@QLipo were demonstrated. In vivo assays revealed that PDA@QLipo administrated with roller-microneedles successfully rejuvenated the "poor" perifollicular microenvironment, thereby promoting cell proliferation, accelerating hair follicle renewal, and facilitating hair follicle recovery. Moreover, PDA@QLipo achieved a higher hair regeneration coverage of 92.5% in the AGA mouse model than minoxidil (87.8%), even when dosed less frequently. The nanosystem creates a regenerative microenvironment by scavenging ROS and augmenting neovascularity for hair regrowth, presenting a promising approach for AGA clinical treatment.

Refractory alopecia areata with single hairs imitating frontal fibrosing alopecia: a prospective observational study

BACKGROUND

Lonely hair sign is considered as a clue to the diagnosis of frontal fibrosing alopecia (FFA).

OBJECTIVE

To report an undescribed variant of alopecia areata (AA) with which the patient developed single hairs and other features similar to FFA and to determine the underlying mechanism.

METHODS

We conducted a prospective observational study in patients who presented with receding hairline and single hairs, evaluating the clinical, trichoscopic, and histological features and their correlation. Immunochemistry studies were performed to describe the microenvironment.

RESULTS

Eighteen patients were enrolled in the study. Despite the similarity to FFA clinically, these patients showed different histopathology which revealed a normal number of pilosebaceous units, one anagen hair in one or more pilosebaceous units, and others in telogen stage, consistent with single hairs under the naked eye or under trichoscopy. The severity of the hair loss assessed by SALT was no more than 50, but the response to conventional therapy was poor.

CONCLUSIONS

This study reports a unique variant of AA. The pathological basis is an increase in the telogen hair follicles, with one anagen hair in one or more pilosebaceous units. Minimal inflammation consisting of CD3+ T lymphocytes and mast cells was demonstrated in the microenvironment.

The promising prospect of human hair follicle regeneration in the shadow of new tissue engineering strategies

Hair loss disorder (alopecia) affects numerous people around the world. The low effectiveness and numerous side effects of common treatments have prompted researchers to investigate alternative and effective solutions. Hair follicle (HF) bioengineering is the knowledge of using hair-inductive (trichogenic) cells. Most bioengineering-based approaches focus on regenerating folliculogenesis through manipulation of regulators of physical/molecular properties in the HF niche. Despite the high potential of cell therapy, no cell product has been produced for effective treatment in the field of hair regeneration. This problem shows the challenges in the functionality of cultured human hair cells. To achieve this goal, research and development of new and practical approaches, technologies and biomaterials are needed. Based on recent advances in the field, this review evaluates emerging HF bioengineering strategies and the future prospects for the field of tissue engineering and successful HF regeneration.

Concepts, Terminology, and Innovations in Follicular Unit Excision Hair Restoration Surgery

Follicular unit excision (FUE) has emerged as the preferred method for hair transplants. Standardized terms and definitions established by members of the International Society of Hair Restoration Surgery and prominent hair restoration surgeons have become the standard, enabling effective knowledge sharing. This chapter provides an overview of the terminology relating to the field.The historical evolution of FUE and its pivotal role in modern hair transplantation is summarized. Anatomical terminology and graft-related definitions follow, providing insights into the scalp's complex structures and graft characteristics. The subsequent sections detail the terminology associated with graft excision and extraction, shedding light on the precise techniques and procedures employed. An exploration of various FUE techniques and the evolving landscape of FUE devices underscores the continual refinement of hair restoration practices. The chapter proceeds to discuss the "safe'" scalp donor zones, donor assessment terminology, and elements in identifying the optimal donor area for a successful FUE procedure. Additionally, punch dynamics and technique characteristics are examined, emphasizing their pivotal role in achieving superior FUE outcomes. The chapter concludes by discussing the classification of punches and graft evaluation terms, offering insights into the tools, and criteria used to assess graft quality and viability.

Post-Hair Transplantation Complication: Kinky or Severely Curly Hair

OBJECTIVE

To investigate the etiology and preventive measures of posttransplant kinky or curly hair growth after female hairline correction surgery.

BACKGROUND

Hair transplant surgery can be accompanied by various adverse effects, one of which is severely kinky or curly hair after surgery. Posttransplant kinky or curly hair is not well-understood for its cause or prevention.

METHODS

The study was targeted at a total of 980 patients who were confirmed whether they developed kinky or curly hair after female hairline correction surgery. Incidence, surgical method, degree of curliness, predisposed location, characteristics, hair caliber (thin, medium, and thick), and left-right differences were examined.

RESULTS

Among the total 980 patients, posttransplant curly hair (PTCH) was manifested in 38(3.9%) patients. None of the patients who underwent surgery at the present clinic developed posttransplant kinky hair; all 38 patients showed PTCH growth. In 36 cases, transplanted hair started to grow in curly patterns around 4 months after surgery. However, the remaining 2 cases showed no curly growth pattern when the transplanted hair was short at postoperative 4 months, but started to grow curly starting at 6 to 8 months after surgery as the hair growth direction was obstructed or compressed by the existing hair.

CONCLUSION

Familiarity with the cause, prevention, and management of posttransplant kinky hair and PTCH will be of great help to hair surgeons.

Exosomes derived from uMSCs promote hair regrowth in alopecia areata through accelerating human hair follicular keratinocyte proliferation and migration

Alopecia areata (AA) is a complex genetic disease that results in hair loss due to an autoimmune-mediated attack on the hair follicle. Mesenchymal stem cells (MSCs) have great potential to induce hair regeneration due to their strong secretion ability and multidirectional differentiation. Recent studies have revealed that the therapeutic potential of MSCs comes from their secretion ability, which can produce large amounts of bioactive substances and regulate the key physiological functions of subjects. The secretion products of MSCs, such as vesicles, exosomes, and conditioned media, have significant advantages in preparing of biological products derived from stem cells. Human umbilical cord mesenchymal stem cells (uMSCs) are the best choice for exosome production. uMSCs are obtained from the human umbilical cord. The umbilical cord is easy to obtain, and the efficiency of uMSCs isolation and culture higher than that of obtaining MSCs from bone marrow or adipose tissue. In this study, we investigated the effects of exosomes released from uMSCs in AA mice. In summary, due to easy isolation and cultivation, simple preparation, and convenient storage, it is possible to obtain uMSCs, or uMSCs exosomes for research and clinical treatment.

Comparative efficacy of 2% minoxidil alone against combination of 2% minoxidil and low-level laser therapy in female pattern hair loss-A randomized controlled trial in Chinese females

OBJECTIVES

To investigate the effectiveness and safety of combination of 655 nm low level laser helmet device with topical 2 % minoxidil solution at FPHL in Chinese population.

MATERIALS AND METHODS

Randomized, parallel, controlled, single-blind clinical trial was conducted. FPHL subjects were randomly allocated into 2 % minoxidil group and combination group. The 2 % minoxidil group received 1 ml topical 2 % minoxidil solution twice daily for 24 weeks. The combination group received 1 ml topical 2 % minoxidil solution twice daily together with 20 min 655 nm low-level laser helmet once every other day for 24 weeks. Hair parameters in two scalp areas including midscalp and vertex were evaluated at baseline, 12th week and 24th week.

RESULTS

In midscalp area, the combination group showed a lower increase in intermediate hair percentage than 2 % minoxidil group, which was statistically significant. Besides, the combination group had statistically significant increase than 2 % minoxidil group in mean hair diameter. Reported relative adverse events included slightly hair loss (27.8 %), desquamation (19.0 %), pruritus (15.2 %), seborrhea (2.5 %) and hypertrichosis (2.5 %).

CONCLUSION

In our trial, LLLT was demonstrated as a useful supplementary treatment for FPHL and the combination with 2 % minoxidil accomplished better improvement in intermediate hair enlargement and hair diameter of midscalp for FPHL.

An androgenetic alopecia remedy based on marine collagen peptide-incorporated dissolving microneedles

Given that current androgenetic alopecia (AGA) medications have adverse effects such as sexual dysfunction and drug dependence, researchers are actively exploring natural bioactive ingredients and innovative approaches (e.g., transdermal drug delivery systems) to effectively combat hair loss with minimal side effects. Herein, we develop a new transdermal drug delivery system incorporating globefish skin collagen peptides with dissolving microneedles (GSCPs-MNs) for hair regrowth. These microneedles generate skin micro-wounds upon application, which not only improves the efficiency of bioactive ingredients delivery, but also stimulates signals involved in hair follicle (HF) regeneration. Our in vivo study shows that minimally invasive implanted GSCPs-MNs are more effective than topical GSCPs in reducing inflammation and promoting collagen formation. Additionally, the upregulation of vascular markers including VEGF and CD31 alongside the downregulation of TNF-α, IL-1β, and malondialdehyde (MDA) index indicate that GSCPs-MNs can significantly alleviate inflammation and oxidation, as well as promoting vascularization and HF functionalization. Overall, our findings suggest that GSCPs-MNs can effectively promote hair regrowth in AGA mice, which offer excellent prospects for the development of new therapeutics and cosmetic supplements for hair loss, along with the combined drug delivery optimization, which could alleviate hair loss in patients with AGA.

Progress on the mechanism of natural products alleviating androgenetic alopecia

Androgenetic alopecia (AGA) has become a widespread problem that leads to considerable impairment of the psyche and daily life. The currently approved medications for the treatment of AGA are associated with significant adverse effects, high costs, and prolonged treatment duration. Therefore, natural products are being considered as possible complementary or alternative treatments. This review aims to enhance comprehension of the mechanisms by which natural products treat AGA. To achieve this, pertinent studies were gathered and subjected to analysis. In addition, the therapeutic mechanisms associated with these natural products were organized and summarized. These include the direct modulation of signaling pathways such as the Wnt/β-catenin pathway, the PI3K/AKT pathway, and the BMP pathway. Additionally, they exert effects on cytokine secretion, anti-inflammatory, and antioxidant capabilities, as well as apoptosis and autophagy. Furthermore, the review briefly discusses the relationship between signaling pathways and autophagy and apoptosis in the context of AGA, systematically presents the mechanisms of action of existing natural products, and analyzes the potential therapeutic targets based on the active components of these products. The aim is to provide a theoretical basis for the development of pharmaceuticals, nutraceuticals, or dietary supplements.

Management of androgenic alopecia: a systematic review of the literature

We aimed to determine the efficacy of the various available oral, topical, and procedural treatment options for hair loss in individuals with androgenic alopecia. Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a systematic review of the National Library of Medicine was performed. Overall, 141 unique studies met our inclusion criteria. We demonstrate that many over the counter (e.g. topical minoxidil, supplements, low-level light treatment), prescription (e.g. oral minoxidil, finasteride, dutasteride), and procedural (e.g. platelet-rich plasma, fractionated lasers, hair transplantation) treatments successfully promote hair growth, highlighting the superiority of a multifaceted and individualized approach to management.

Stem cell-derived conditioned medium for alopecia: A systematic review and meta-analysis

BACKGROUND

Alopecia is a common and distressing medical condition that has been related to psychiatric disorders. Stem cell-derived conditioned medium (CM), a novel therapy for hair regeneration, has shown effectiveness in several trials.

METHODS

This meta-analysis aims to explore the effectiveness of stem cell-derived CM in improving hair growth for patients of alopecia. We prospectively registered this systematic review and meta-analysis in PROSPERO (CRD42023410249). Clinical trials that the enrolled participants suffering from alopecia applied stem cell-derived CM were included. We calculated the mean and standard deviation for the hair density and thickness.

RESULTS

Ten clinical trials were included in our analysis. On the basis of eight clinical trials (n = 221), our pooled results indicate that stem cell-derived CM is effective in increasing hair density (mean difference [MD]: 14.93, confidence interval [95% CI]: 10.20-19.67, p < 0.0001) and thickness (MD: 18.67, 95% CI: 2.75-34.59, p < 0.0001) (μm) in patients with alopecia. Moreover, our findings suggest that longer treatment duration is associated with significantly greater improvement than shorter treatment duration (p = 0.02). Three of the included studies were randomized controlled trials (RCTs), and when we specifically analyzed these RCTs; statistical significance could also be observed in terms of hair density (MD: 9.23, 95% CI: 1.79-16.68, p < 0.00001).

KEY MESSAGES

Stem cell-derived conditioned medium can effectively increase hair density and thickness for alopecia, and there is no difference between each method (topical application, microneedling, or injection).

Follicular unit extraction megasession treatment of high-grade androgenetic alopecia in Asians: Introducing novel principles for surgical design

BACKGROUND

Male androgenetic alopecia (MAGA) has been one of the most common reasons for hair consultation, which affects more than half of men under the age of 50. Recently, follicular unit extraction (FUE) megasession has been an attractive treatment option for patients with severe AGA. However, compared with hair transplant surgery by traditional FUE or follicular unit transplantation (FUT), a megasession lacks a suitable surgical design solution for Asian high-grade AGA patients. Therefore, we introduced novel principles for surgical design into FUE megasession for Asians.

OBJECTIVE

The goal was to investigate the naturalness of hair, patient and doctor satisfaction level, and safety assessment of FUE megasession with the specific surgical design, to explore a novel technique for an efficient, satisfactory, and safe FUE megasession procedure.

METHODS

Thirty-six Asian male patients with AGA in Hamilton Grade V-VI were enrolled in the research. All participants underwent FUE megasession treatment with the specific surgical design. The investigators observed the patients' general conditions, surgical information, naturalness of hair, and patient and doctor satisfaction level and adverse reactions.

RESULTS

Before surgery, the average age of patients was 36.8 ± 9.6 years, and average duration of disease was 8.3 ± 3.8 years. During surgery, we harvested an average of 3705 ± 383 grafts. Recipient density ranged from 30 FUs/cm2 to 50 FUs/cm2 , and the total operation time was 10.6 ± 0.9 h. After surgery, patient-rated Likert score for naturalness of hair was as high as 4.72, and the doctor rated 4.61. Patient satisfaction score was up to 4.64, and the doctor scored 4.75. No serious side effects occurred in the study.

CONCLUSION

FUE megasession with the introduced surgical design is a satisfactory treatment option for patients with high-grade AGA in Asians, with few side effects. The application of the novel design method can effectively lead to relatively natural density and appearance in one operation. Due to its remarkable effect, high satisfaction level, and few postoperative complications, FUE megasession with the introduced surgical design has great potential for Asian high-grade AGA patients.

Efficacy of autologous dermal sheath cup cell transplantation in male and female pattern hair loss: A Single-Arm, Multi-Center, phase III equivalent clinical study

A previous, proof-of-concept clinical study suggested that dermal sheath cup cell injections into the affected areas of male/female pattern hair loss (PHL) may have some amelioratory effects, the clinical efficacy of which needs further examination. A phase III equivalent clinical study was conducted to further probe the therapeutic potential of this novel approach and verify its safety and efficacy in improving the appearance of PHL. Thirty-six participants with PHL were injected with dermal sheath cup cell harvested from non-affected occipital hair follicles twice in quarterly intervals. Global photographic assessment and phototrichogram were performed in a blinded manner. Patient-reported outcomes were assessed for 12 months. On global photographic assessment, 30% of the participants showed improvement. The analysis of phototricogram data detected the increases in the cumulative hair diameter, hair cross-sectional area, and mean hair diameter of 107.6 ± 152.6 μm/cm2 , 13069.1 ± 10960.7 μm2 /cm2 , and 0.9 ± 0.9 μm (ratios vs. baseline: +1.4%, +3.4%, and +2.2%), respectively. The female and high terminal hair ratio groups achieved better improvement. Of the total participants, 62.9% noted some degree of improvement. No serious adverse events were detected. This novel approach exhibited visible effects while ensuring safety and patient satisfaction. Therefore, it holds promise as a possible therapeutic option for treating PHL, especially in women.

An international expert consensus statement focusing on pre and post hair transplantation care

AIM

To achieve international expert consensus and give recommendations on best practices in hair transplantation surgery, focusing on pre- and post-transplantation care.

METHODS

A modified Delphi method was used to reach consensus. An international scientific committee developed an 81-statement questionnaire. A panel of 38 experts in hair transplantation from 17 countries across 4 continents assessed the questionnaire.

RESULTS

Two consensus rounds were carried out, with 59 out of 81 statements (73%) reaching consensus. Expert recommendations emphasize the correct selection of candidates for hair transplantation and the need for patients to have received adequate medical treatment for alopecia before transplant. Comorbidities should be assessed and considered while planning surgery, and an individualized plan for perioperative care should be drawn up before transplant. Certain medications associated with increased risk of bleeding should be withdrawn before surgery. Specific recommendations for post-transplantation care are given. After transplantation, patients should gradually resume their normal haircare regimen. Close follow-up should be carried out during the first year after transplant.

CONCLUSIONS

This study presents numerous consensus-based recommendations on general aspects of hair transplantation, including candidate selection, medical therapy prior to transplantation, anesthesia, and resuming haircare after transplantation.

Nanotechnology-based techniques for hair follicle regeneration

The hair follicle (HF) is a multicellular complex structure of the skin that contains a reservoir of multipotent stem cells. Traditional hair repair methods such as drug therapies, hair transplantation, and stem cell therapy have limitations. Advances in nanotechnology offer new approaches for HF regeneration, including controlled drug release and HF-specific targeting. Until recently, embryogenesis was thought to be the only mechanism for forming hair follicles. However, in recent years, the phenomenon of wound-induced hair neogenesis (WIHN) or de novo HF regeneration has gained attention as it can occur under certain conditions in wound beds. This review covers HF-specific targeting strategies, with particular emphasis on currently used nanotechnology-based strategies for both hair loss-related diseases and HF regeneration. HF regeneration is discussed in several modalities: modulation of the hair cycle, stimulation of progenitor cells and signaling pathways, tissue engineering, WIHN, and gene therapy. The HF has been identified as an ideal target for nanotechnology-based strategies for hair regeneration. However, some regulatory challenges may delay the development of HF regeneration nanotechnology based-strategies, which will be lastly discussed.

The Training and Application of Silicone Products in Eyebrow Transplantation Simulation

BACKGROUND

Because the structure of eyebrows is complicated, students need a lot of practice to become familiar with the distribution pattern of eyebrow hair.

OBJECTIVES

The current study was designed to investigate training methods for eyebrow design and planting practice before eyebrow hair transplantation to improve planting quality.

METHODS

Twelve surgical students were selected. The 6 students in the experimental group had never performed eyebrow transplantation surgery, whereas the 6 in the control group had experience of the procedure. Students in both groups received theoretical and simulated eyebrow hair transplantation instruction. Students were required to master standard eyebrow transplantation. The results of the experimental group and the control group were compared before and after training.

RESULTS

The results revealed that the overall results of the experimental and control groups significantly improved compared with before training (P < .05). After theoretical training, 2-dimensional simulation training, and 3-dimensional simulation training, eyebrow shape, symmetry, hair angle, and density after the 3-dimensional simulation training were statistically significantly improved (P < .05). There was no statistically significant difference, and the students in the control group did not demonstrate any improvement in their capacity to arrange the eyebrows or shape them symmetrically. After training, however, the angle and density of the hair substantially improved.

CONCLUSIONS

The experimental group's technical ability in simulated eyebrow planting significantly improved. The present study demonstrated that the students could develop their skills and get closer to the level of surgeons with experience in eyebrow transplant surgery by integrating theoretical lectures with practiced procedures.

Considerations and recommendations on camouflage in alopecia in Black women

Alopecia is among the leading dermatological concerns affecting Black women. For many women, hair is a central component of identity and self-expression, the loss of which can have significant psychosocial effects. Hair camouflage is often utilized to minimize the visibility of hair loss, provide aesthetic benefits, and improve quality of life. The versatility and affordability of hair camouflage allows patients with alopecia to conceal hair loss, increasing self-confidence, and decreasing social stigma. However, hair camouflage practices often involve adhesives, chemicals, and/or high-tension braiding, all of which can exacerbate alopecia. Accordingly, special considerations should be made to protect patients' natural hair from damage while using these styling practices. A better understanding of best practices for some of the most widely used camouflage options-wigs, extensions, topical hair fibers, and micropigmentation-can help clinicians establish rapport with Black women and optimize individually-tailored therapeutic plans during active treatment and end-stage hair loss.

Normal Trichoscopic Findings after Hair Transplantation in Androgenetic Alopecia: A Prospective Case Series

Background

Trichoscopy can be very useful for evaluation for hair transplantation (HT), helping rule out simulators of androgenetic alopecia (AGA). There are only a few reports about normal trichoscopic findings after HT.

Objective

The aim of this study was to evaluate donor and recipient area trichoscopy after FUE in HT without complications in AGA patients.

Method

A prospective study was carried out with 10 patients, for 24 weeks, with photographic follow-up, using FotoFinder®. Patients were evaluated from week 1 (w1) to week 8 weekly, then, at week 12 and week 24 post-HT.

Results

Main results were perifollicular crusts, donor area erythema, recipient area erythema, perifollicular erythema, white circles, perifollicular whitish halos, repilation black dots, dystrophic hairs, folliculitis, yellow dots. We discussed the meaning of each of these findings in the period in which they occurred.

Conclusion

Normal trichoscopic findings in post-transplant patients have not been well established yet. Our findings are an attempt to define a normal pattern. Future studies with a longer follow-up may be necessary to corroborate these results.

Application of Autologous Hair Transplantation Technique in Children with Cicatricial Alopecia

INTRODUCTION

Cicatricial alopecia not only affects the appearance of children's heads and faces but also their mental health in the long term. This study aims to explore the therapeutic characteristics and clinical effects of autologous hair transplantation technology in children with cicatricial alopecia.

METHODS

Children in our department who received autologous hair transplantation technology for cicatricial baldness of the scalp from February 2019 to October 2022 were collected. Their basic information was analyzed, and postoperative follow-up was conducted, including calculation of hair follicle survival rate, hair growth, complications, and an efficacy satisfaction survey given to the children's family members.

RESULTS

Thirteen children were included in this study (10 males and 3 females), aged from 4 years 1 month to 12 years 10 months, with an average age of 7 years 5 months. Two hundred to 2500 hair follicular units were extracted, with an average recipient area of 22.7 cm2, an average hair follicle unit density of 55.3 ± 9.1 per cm2, and an average hair/follicular unit (hair/FU) ratio of 1.75 ± 0.07. Thirteen children in this group were followed up for 6-12 months with the following treatment options: FUE (follicular unit extraction, 9 cases), FUT (follicular unit transplantation, 3 cases), and FUT combined with FUE (1 case). The average hair survival rate was 85.3%. Except for one child with temporary folliculitis, there were no complications. The GAIS score is divided into five levels: complete improvement (2 cases), obvious improvement (10 cases), partial improvement (1 case), no improvement (0 cases), and deterioration (0 cases). The patient satisfaction results included very satisfied (2 cases), mostly satisfied (10 cases), and dissatisfied (1 case).

CONCLUSION

Autologous hair transplantation technology is a safe and effective method for children with cicatricial alopecia.

Medical and procedural treatment of androgenetic alopecia - Where are we?

Novel medical and procedural options for androgenetic alopecia have arrived. Low-dose oral minoxidil has made its clinical debut, while data on spironolactone, finasteride, and nutritional supplements have advanced. Minimally invasive technological advancements include photobiomodulation and platelet-rich plasma. Within hair transplantation, follicular unit extraction and robotics are now at the clinicians' fingertips.

Comparison of 2 Incisional Methods in Hair Transplantation

Hair transplantation has been an effective technique for facial contour modification. Hair follicular units (FU) harvested from scalp strip is the gold-standard method for hair transplantation. The difference in obtaining FU from different shapes of scalp strips is not clear yet. Follicular units of 127 patients were harvested from scalp strip through parallelogram incision or fusiform incision from October 2017 to January 2020. The number of FU in 1 cm 2 scalp strip were calculated and paired t test were used to compare the difference in hair follicle acquirement rate between 2 incisions. The number and acquisition rate of FU by parallelogram incision were significantly higher than that by fusiform incision. Therefore, parallelogram incision might be more suitable to harvest FU for hair transplantation surgery.

Male pattern hair loss: Can developmental origins explain the pattern?

Male pattern hair loss (MPHL), also referred to as male androgenetic alopecia (AGA) is the most common type of non-scarring progressive hair loss, with 80% of men suffering from this condition in their lifetime. In MPHL, the hair line recedes to a specific part of the scalp which cannot be accurately predicted. Hair is lost from the front, vertex, and the crown, yet temporal and occipital follicles remain. The visual effect of hair loss is due to hair follicle miniaturisation, where terminal hair follicles become dimensionally smaller. Miniaturisation is also characterised by a shortening of the growth phase of the hair cycle (anagen), and a prolongation of the dormant phase (kenogen). Together, these changes result in the production of thinner and shorter hair fibres, referred to as miniaturised or vellus hairs. It remains unclear why miniaturisation occurs in this specific pattern, with frontal follicles being susceptible while occipital follicles remain in a terminal state. One main factor we believe to be at play, which will be discussed in this viewpoint, is the developmental origin of the skin and hair follicle dermis on different regions of the scalp.

Evaluation of a Novel Graft-Holding Solution in Hair Transplantation: A Randomized Controlled Clinical Study

BACKGROUND

Hair transplantation has become a popular choice for alopecia treatment; however, postsurgical hair shedding still annoys both patients and surgeons.

OBJECTIVE

To explore the impact of graft-holding solution on postsurgical hair shedding and testify the protective efficacy of histidine-tryptophan-ketoglutarate solution with adenosine triphosphate and deferoxamine (HTK-AD).

METHODS

There were 240 patients enrolled in the study, and the follicles were placed into either HTK-AD or Ringer solution (RS). Masson staining and live/dead staining were performed to evaluate graft morphology and apoptosis levels, respectively. The between-group comparison of postsurgical graft shedding, survival rate, complications, and patient satisfaction was performed.

RESULTS

Grafts in HTK-AD maintained organized dense collagen construction and higher cell viability, but those preserved in RS became soft, which hindered implantation. Histidine-tryptophan-ketoglutarate solution with adenosine triphosphate and deferoxamine significantly reduced the incidence of postsurgical hair shedding (73.81% vs 95%), delayed shedding onset, and diminished shedding amount versus RS ( p < .05) when ≥3,000 grafts were transplanted. The shedding duration was shortened, and hair regrowth started earlier in HTK-AD versus RS ( p < .05); thus, satisfaction was increased. The final survival rate showed no difference between 2 groups.

CONCLUSION

Histidine-tryptophan-ketoglutarate solution with adenosine triphosphate and deferoxamine is superior to RS for hair graft preservation because it improves graft viability and alleviates postsurgical shedding.

iPSC-based approach for human hair follicle regeneration

Hair follicles (HFs) are a multifunctional structure involved in physical protection, thermoregulation, sensational detection, and wound healing. Formation and cycling of HFs require dynamic interaction between different cell types of the follicles. Although the processes have been well studied, the generation of human functional HFs with a normal cycling pattern for clinical utilization has yet to be achieved. Recently, human pluripotent stem cells (hPSCs) serve as an unlimited cell source for generating various types of cells including cells of the HFs. In this review, HF morphogenesis and cycling, different cell sources used for HF regeneration, and potential strategies for HF bioengineering using induced pluripotent stem cells (iPSCs) are depicted. Challenges and perspectives toward the therapeutic use of bioengineered HFs for hair loss disorder are also discussed.

Considering the risk of a coloring shampoo with the function of gray hair cover cosmetology and skin barrier: A systematic review

Background and Aims

As the number of demanders who want to easily cover gray hair increases, the demand market is rapidly expanding along with the demand for coloring shampoos that can be dyed while shampooing. Among these coloring shampoo ingredients, it is necessary to differentiate products that are safe and harmless to the human body in consideration of hair loss or skin barrier problems caused by trihydroxybenzene (THB) ingredients. The correct selection criteria were presented by examining the problems, effectiveness, and side effects when used in relation to the skin barrier through previous studies by consideration of the ingredients of the coloring shampoo and the skin barrier of the scalp.

Methods

The analysis of this study looked at previous studies through a systematic literature review through related keywords for coloring shampoo. After reviewing 150-200 related prior papers, a total of 39 review papers were finally selected using the PRISMA flow diagram.

Results

It was confirmed through a literature review that the coloring shampoo containing THB, which is harmful to the human body, has a detrimental effect on the scalp-skin barrier.

Conclusion

This study examined the harmfulness of coloring shampoo on the scalp skin barrier. It was confirmed that frequent coloring shampoo procedures can have various harmful effects on the scalp. Therefore, it is important to reduce side effects caused by the use of harmful ingredients and maintain a healthy scalp condition through analysis of sufficient scalp conditions and consultation with experts. In addition, various studies on the standard standards and age for harmful ingredients are suggested.

Innovative Approaches and Advances for Hair Follicle Regeneration

Pathological hair loss (also known as alopecia) and shortage of hair follicle (HF) donors have posed an urgent requirement for HF regeneration. With the revelation of mechanisms in tissue engineering, the proliferation of HFs in vitro has achieved more promising trust for the treatments of alopecia and other skin impairments. Theoretically, HF organoids have great potential to develop into native HFs and attachments such as sweat glands after transplantation. However, since the rich extracellular matrix (ECM) deficiency, the induction characteristics of skin-derived cells gradually fade away along with their trichogenic capacity after continuous cell passaging in vitro. Therefore, ECM-mimicking support is an essential prelude before HF transplantation is implemented. This review summarizes the status of providing various epidermal and dermal cells with a three-dimensional (3D) scaffold to support the cell homeostasis and better mimic in vivo environments for the sake of HF regeneration. HF-relevant cells including dermal papilla cells (DPCs), hair follicle stem cells (HFSCs), and mesenchymal stem cells (MSCs) are able to be induced to form HF organoids in the vitro culture system. The niche microenvironment simulated by different forms of biomaterial scaffold can offer the cells a network of ordered growth environment to alleviate inductivity loss and promote the expression of functional proteins. The scaffolds often play the role of ECM substrates and bring about epithelial-mesenchymal interaction (EMI) through coculture to ensure the functional preservation of HF cells during in vitro passage. Functional HF organoids can be formed either before or after transplantation into the dermis layer. Here, we review and emphasize the importance of 3D culture in HF regeneration in vitro. Finally, the latest progress in treatment trials and critical analysis of the properties and benefits of different emerging biomaterials for HF regeneration along with the main challenges and prospects of HF regenerative approaches are discussed.

Emerging Therapies for Full-Thickness Skin Regeneration

The classical treatment of extensive full-thickness skin loss due to trauma or burns has been the split-thickness skin graft. While split-thickness skin grafts close the wound, they leave patients with visible scars, dry skin, pruritis, pain, pigmentation alterations, and changes in sensation. The optimal replacement for full-thickness skin loss is replacement with intact full-thickness skin. New technologies combined with advances in the understanding of the mechanisms behind wound healing have led to the development of techniques and products that may eventually recapitulate the functions, appearance, and physical properties of normal skin. Autologous homologous skin constructs, minimal functional skin units, and composite bioengineered skin with dermal substitutes all represent potential avenues for full-thickness composite skin development and application in extensive wounds. This article summarizes the progress, state, and future of full-thickness skin regeneration in burn and massive wound patients.

The physiological and pharmacological roles of prostaglandins in hair growth

Hair loss is a common status found among people of all ages. Since the role of hair is much more related to culture and individual identity, hair loss can have a great influence on well-being and quality of life. It is a disorder that is observed in only scalp patients with androgenetic alopecia (AGA) or alopecia areata caused by stress or immune response abnormalities. Food and Drug Administration (FDA)-approved therapeutic medicines such as finasteride, and minoxidil improve hair loss temporarily, but when they stop, they have a limitation in that hair loss occurs again. As an alternative strategy for improving hair growth, many studies reported that there is a relationship between the expression levels of prostaglandins (PGs) and hair growth. Four major PGs such as prostaglandin D2 (PGD₂), prostaglandin I2 (PGI₂), prostaglandin E2 (PGE₂), and prostaglandin F2 alpha (PGF₂α) are spatiotemporally expressed in hair follicles and are implicated in hair loss. This review investigated the physiological roles and pharmacological interventions of the PGs in the pathogenesis of hair loss and provided these novel insights for clinical therapeutics for patients suffering from alopecia.

Minimally invasive procedures for the management of female pattern hair loss

BACKGROUND

Female Pattern Hair Loss (FPHL) is one of the most common types of hair loss in women. It is characterized by progressive follicular miniaturization leading to diffuse hair thinning over the midfrontal scalp with a negative impact on quality of life. Pharmacological treatments are commonly used, and hair follicle transplantation is an option for those cases with adequate donor area. Minimally invasive procedures, such as microneedling, mesotherapy, microinfusion of drugs into the scalp with tattoo machines (MMP®), and platelet-rich plasma (PRP) have been reported as adjuvant treatments.

AIMS

This study aims to summarize and discuss the efficacy of minimally invasive procedures described for the management of FPHL.

METHODS

Published articles indexed on the Pubmed database and Scopus that described minimally invasive procedures for the management of FPHL in humans were considered. Citations were reviewed and added for completeness. The search was for articles in English only. After excluding duplicate titles, 23 relevant articles were considered.

CONCLUSION

Minimally invasive procedures are promising options and may play a role in FPHL treatment. They can be used as adjunctive therapy for FPHL, in case of poor response to clinical therapy, or when patients prefer other care than the standard. We reinforce that these methods should be performed by an experienced medical professional following strict aseptic techniques. However, microneedling, mesotherapy, MMP, and PRP lack standardization and are supported by a low level of evidence yet. For the future, larger randomized clinical trials are essential to determine the efficacy and optimal protocols for these treatments.

Inflammatory complications after hair transplantation: Report of 10 cases

BACKGROUND

Androgenetic alopecia (AGA) is a pathology involving the aesthetic prognosis. Hair transplantation is among best treatments. The principle of hair micro-grafts during AGA consists in taking hair from the non-androgen-dependent occipital area to transplant them with their root in the sparse androgen-dependent areas. Herein, we report 10 cases of the different types of post-transplant inflammatory complications.

MATERIALS AND METHODS

We included patients referred to our center by their dermatologists or hair transplant surgeons for inflammatory cicatricial alopecia or hair loss observed after the hair transplant.

RESULTS

Ten patients (eight men and two women) were included. These patients represented 0.08% of all consultations in our center. The indication for hair transplantation was AGA in all of our patients. The technique used for the transplant was follicular unit extraction (FUE) in seven cases and follicular unit transplantation (FUT) strip in three cases. None of the patients had pathology of the scalp or an inflammatory dermatosis before the operation. The inflammatory complications found were lichen planopilaris (LPP) in seven cases, erosive pustulosis of the scalp (EPS) in two cases, and superficial folliculitis (SF) in 1 case.

CONCLUSION

Our series highlight the rarity of inflammatory complications that occur after a hair transplant. We demonstrate through this work that a hair transplant can trigger inflammatory pathology a few months after the act. We show also, the importance of detecting the rough forms of lichen before an intervention, hence the interest of the systematic dermatoscopic examination during the preoperative consultation.