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.

Retinoic acid drives hair follicle stem cell activation via Wnt/ß-catenin signalling in androgenetic alopecia.

BACKGROUND: Depletion or permanent quiescence of the hair follicle stem cell (HFSC) pool underlies pathogenesis in androgenetic alopecia (AGA). Reactivation of quiescent HFSCs is considered an efficient treatment strategy for hair loss. The retinoic acid (RA) is critical to ensure stem cell homeostasis and function. However, little is known about whether RA regulates HFSC homeostasis. We aimed to investigate the impact of RA on HFSC homeostasis and the underlying mechanisms, in order to provide new potential targets for medical therapies of AGA. METHODS: Microdissected hair follicles from the occipital and frontal scalp in AGA were obtained for RNA sequencing analysis and test. The C57BL/6 mice model in telogen was established to investigate the effect of exogenous RA. Miniaturized hair follicles from frontal scalp were incubated with or without RA in hair follicle organ culture to test the effects on hair shaft elongation, hair cycling and HFSC activities. A strategy to characterize the effect of RA on HFSC in primary culture was developed to identify novel mechanisms that control HFSC activation. A clinical study was performed to test the efficacy of RA treatment in AGA patients. RESULTS: RA signalling was inhibited in the course of AGA pathogenesis along with HFSC dysfunction. Hair regeneration was retarded in AGA miniaturized hair follicles with RA deficiency, but they tended to recover after treatment with RA. In addition, RA treatment during the telogen phase facilitated HFSC anagen entry and accelerated hair growth. Mechanistically, RA promoted hair growth by stimulating stem cells via Wnt/ß-catenin signalling and accelerating the transition from a dormant to an activated state. Furthermore, a clinical study suggested that RA has obvious advantages in the early intervention of AGA by reactivating HFSCs. CONCLUSIONS: Our study provides insights into the reactivation of HFSCs in AGA and provides potential targets for medical therapies.

Autophagy induces hair follicle stem cell activation and hair follicle regeneration by regulating glycolysis.

BACKGROUND: Hair follicle stem cells (HFSCs) typically remain quiescent and are activated only during the transition from telogen to anagen to ensure that the hair follicle enters a new cycle. The metabolic behavior of stem cells in tissues is regulated by macroautophagy/autophagy, and changes in HFSC metabolism directly affect their activation and maintenance. However, the role of autophagy in the regulation of HFSC metabolism and function remains unclear. METHODS: Back skin samples were obtained from mice at different hair follicle cycle stages, and immunofluorescence staining was used to monitor autophagy in HFSCs. Mouse and human hair follicles were treated with rapamycin (Rapa, an autophagy activator) or 3-methyladenine (3-MA, an autophagy inhibitor). The effects of autophagy on the hair follicle cycle and HFSC were investigated by imaging, cell proliferation staining, and HFSC-specific marker staining. The influence and mechanism of autophagy on HFSC metabolism were explored using RNA sequencing, real-time polymerase chain reaction, immunohistochemical staining, and detection of lactate and glucose concentrations. Finally, the influence of autophagy-induced glycolysis on HFSC and the hair follicle cycle was verified by stem cell characteristics and in vivo functional experiments. RESULTS: Autophagy in HFSC was highest during the transition from telogen to anagen. Inhibiting autophagy with 3-MA led to early entry into catagen and prolonged telogen, whereas Rapa promoted autophagy and hair growth. Autophagy activated HFSC by increasing the expression and activity of HFSC lactate dehydrogenase (Ldha), thereby transforming HFSC metabolism into glycolysis. Inhibition of Ldha expression counteracted the effects of autophagy. CONCLUSIONS: Autophagy activated HFSC by promoting the transition from HFSC metabolism to glycolysis, ultimately initiating the hair follicle cycle and promoting hair growth.

Recipient site scalp necrosis: A rare postoperative complication of hair transplantation.

BACKGROUND: Recipient area scalp necrosis is considered a potential complication of hair transplantation, but has rarely been reported. A small number of patients have developed scalp necrosis after hair transplantation with the widely used Follicular unit excision (FUE) technique. There are no guidelines to prevent and manage this complication. The aim of this study was to provide an insight into the pathogenesis, prevention, and management of scalp necrosis following hair transplantation. METHODS: From 2012 to 2021, among more than 10 000 patients who underwent hair transplantation, only three developed scalp necrosis in our clinical experience, besides, one patient transferred to our hospital because of scalp necrosis after undergoing hair transplantation. According to the disease etiology and patients' symptom, a combination of wound management and antimicrobial therapy was employed. This study was approved by the institutional ethics committee of Nanfang Hospital. RESULTS: Of the four patients, three received timely treatment and had a good prognosis. Necrosis became confined and healed within 2-3 weeks. Grafts in the lesion area partially survived. In case 4, due to improper treatment at the early stage, the lesion developed extensively and deeply, which not only delayed wound healing, but also resulted in complete loss of grafts. CONCLUSION: Preoperative prophylaxis, timely diagnosis, and immediate treatment of scalp necrosis can prevent serious complications and reduce morbidity after hair transplantation.

The homing of exogenous hair follicle mesenchymal stem cells into hair follicle niches.

Hair loss is a debilitating condition associated with the depletion of dermal papilla cells (DPCs), which can be replenished by dermal sheath cells (DSCs). Hence, strategies aimed at increasing the populations of DPCs and DSCs hold promise for the treatment of hair loss. In this study, we demonstrated in mice that introduced exogenous DPCs and DSCs (hair follicle mesenchymal stem cells) could effectively migrate and integrate into the dermal papilla and dermal sheath niches, leading to enhanced hair growth and prolonged anagen phases. However, the homing rates of DPCs and DSCs were influenced by various factors, including recipient mouse depilation, cell passage number, cell dose, and immune rejection. Through in vitro and in vivo experiments, we also discovered that the CXCL13/CXCR5 pathway mediated the homing of DPCs and DSCs into hair follicle niches. This study underscores the potential of cell-based therapies for hair loss by targeted delivery of DPCs and DSCs to their respective niches and sheds light on the intriguing concept that isolated mesenchymal stem cells can home back to their original niche microenvironment.

Hair follicle extraction combined with an expanded scalp flap for facial organ reconstruction.

BACKGROUND: Use of scalp skin for facial organ reconstruction represents a mainstream procedure for organ reconstruction. In most cases, adequate amounts of skin can be obtained by using tissue expanders, but harvesting sufficient scalp tissue in patients with low hairlines is challenging. Hair follicular unit extraction (FUE) is one approach to resolve this problem. With FUE, hair follicles are removed from the scalp skin, which can then be prepared as a donor site to obtain sufficient amounts of hairless skin. OBJECTIVES: To evaluate the safety and efficacy of FUE when combined with an expanded scalp flap for facial organ reconstruction. MATERIAL AND METHODS: Patients with low hairlines requiring facial organ reconstruction were selected for this study. The area of skin extension and hair removal were determined prior to surgery, a process which was performed in three stages. Stage I consisted of hair follicle removal using the FUE technique at the donor site. Stage II involved expander implantation using water injections. In Stage III facial organ reconstruction was completed. RESULTS: With the use of the FUE technique, hair follicles from the donor scalp were thoroughly removed and the donor scalp tissue was successfully expanded. Postoperatively, no evident scar formation at the reconstruction site or contracture of the expanded flap was observed. All patients were satisfied with the outcome of their reconstruction procedure. CONCLUSION: FUE provides a means for hair follicle removal from the donor site and can be employed to achieve a safe and effective procedure for facial reconstruction in patients with low hairlines.

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 underwent HT. METHODS: We retrospectively reviewed 1317 patients who underwent HT and completed 9-month follow-up between January 2018 and June 2021 at four medical centers. The incidence of postoperative folliculitis and patient demographics 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 (odds ratio [OR], 1.772, 95% confidence interval [CI]: 1.05-2.992), number of transplant grafts ≥4000 (OR: 4.818, 95% CI: 1.45-16.014), transplant density >45 grafts per/cm 2 (OR: 2.152, 95% CI: 1.376-3.367), and first nursing time >3 days (OR: 1.555, 95% CI: 1.088-2.223) were the main risk factors for postoperative folliculitis. CONCLUSIONS: Postoperative folliculitis after HT presents different characteristics. Surgical factors and postoperative nursing were demonstrated to be related to folliculitis. Therefore, we propose a preventive folliculitis model based on preoperative, intraoperative, and postoperative factors.

The AR/miR-221/IGF-1 pathway mediates the pathogenesis of androgenetic alopecia.

Androgenetic alopecia (AGA) affects more than half of the adult population worldwide and is primarily caused by the binding of dihydrotestosterone (DHT) to androgen receptors (AR). However, the mechanisms by which AR affects hair follicles remain unclear. In our study, we found that miR-221 significantly suppressed hair growth and the proliferation of dermal papilla cells (DPCs) and dermal sheath cells (DSCs) in AGA patients. Interestingly, miR-221 and AR were mainly co-located in the same part of the hair follicle. Mechanistic analysis revealed that AR directly promoted the transcription of miR-221, which in turn suppressed IGF-1 expression, leading to the inactivation of the MAPK pathway in DPCs and the PI3K/AKT pathway in DSCs. In AGA patients, miR-221 expression was positively correlated with AR expression and negatively correlated with IGF-1 expression. Our findings indicate that miR-221, as a direct target of AR, plays a crucial role in the pathogenesis of AGA, making it a novel biomarker and potential therapeutic target for treating AGA.

Minimal Invasive Removal of Leukotrichia and Hair Transplantation: A Two-step Surgery in the Treatment of Stable Follicular Vitiligo.

BACKGROUND: Follicular vitiligo is a distinct subtype of vitiligo characterized by the selective destruction of the follicular melanocytic reservoir. The treatment of follicular vitiligo-associated leukotrichia has always been a clinical challenge. METHODS: Twenty participants with stable follicular vitiligo were recruited between 2020 to 2021 and accepted two-stage surgery. In stage one, an incision around the vitiligo lesion was performed to subcutaneously dissect and scrape the leukotrichia. In stage two, healthy follicles obtained from the occipital donor site were transplanted into the vitiligo area. Follow-up examinations were conducted for a year postoperatively by the camera and dermatoscope to observe the growth state, the color and the surviving number of the transplanted hairs. Besides, the satisfaction of the patients was recorded to evaluate the potential surgical improvement. RESULTS: Twenty patients with stable follicular vitiligo underwent two-stage surgery and their mean age was 29 years old. The transplanted hair grew with natural texture as expected. The average survival rate of the transplanted hair follicles was 93.8%. No recurrence of leukotrichia showed up in the recipient area. No complications were observed and the postoperative scars in the recipient area were entirely covered by black hair. All patients were satisfied with the resulting cosmetic appearance. CONCLUSIONS: Minimally invasive removal of leukotrichia combined with hair transplantation might be an appropriate surgical option for stable follicular vitiligo to create natural and stable pigmented hair.

A clinical trial of treating androgenic alopecia with mesenchymal stem cell suspension derived from autologous hair follicle.

BACKGROUND: Androgenic alopecia (AGA) is characterized by progressive hair follicle miniaturization, and novel treatments are needed to intervene in the miniaturization process. We aimed to evaluate the efficacy, safety, effectiveness, and effective population of autologous hair follicle mesenchymal stem cell therapy for the treatment of advanced AGA in Chinese people. METHODS: 50 patients ranging from 25 to 45 years old, with an average age of 32 ± 1.24 years were included. None of them had ever used minoxidil, finasteride, or other drugs to promote hair growth. Healthy hair follicles were extracted from the occipital area and treated to obtain hair follicle mesenchymal stem cells suspensions. The recipient sites were divided into two groups. Nine points were injected in a 1 cm 2 area, and 100 µl of solution containing either 1 × 10 5 cells or normal saline was injected at each point. The follow-up duration was 9 months. Observers were blinded to patient groupings and measurements. RESULTS: An increased proportion of terminal hair and hair shaft diameter was observed in the experimental group at 1 month; the effect lasted until 3 months. The hair thickening effect of advanced miniaturized hair follicles with hair shaft diameter less than 60 µm was more notable than that above 60 µm. None of the patients experienced any obvious side effects. CONCLUSIONS: Hair follicle mesenchymal stem cells were effective in the treatment of Chinese advanced AGA, and a hair shaft diameter of 60µm can be used as a key index to predict the effectiveness of the therapy.

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.

Platelet lysate promotes hair growth: In vitro and in vivo mechanism and randomized, controlled trial.

BACKGROUND: Platelet lysate (PL), a novel platelet derivative, has been widely used in regenerative medicine and is a potential therapy for improving hair growth. It is necessary to fully clarify the potential mechanism and evaluate preliminary clinical effect of PL on hair growth. METHODS: We used the C57BL/6 model, organ-cultured hair follicles, and RNA-seq analysis to explore the mechanisms of PL regulating hair growth. Then, we performed a randomized, controlled, double-blind study of 107 AGA patients to verify the therapeutic efficacy of PL. RESULTS: The results confirmed that PL improved hair growth and accelerated hair cycling in mice. Organ-cultured hair follicle evaluation confirmed that PL prolonged anagen remarkably and down-regulated IL-6, C-FOS, and p-STAT5a. Clinically, diameter, hair counts, absolute anagen counts and changes from baseline in the PL group showed a significant improvement at 6 months. CONCLUSIONS: We elucidated the specific molecular mechanism of PL action on hair growth and proved equal changes in hair follicle performance after PL vs PRP in AGA patients. This study provided novel knowledge of PL, making it ideal for AGA.

Efficacy of Platelet-Rich Plasma plus Basic Fibroblast Growth Factor on the Treatment of Androgenic Alopecia.

BACKGROUND: Studies have identified platelet-rich plasma (PRP) as a novel adjuvant therapy in androgenetic alopecia (AGA). However, the efficacy of PRP still needs to be improved. The purpose of this study was to assess the efficacy of PRP plus basic fibroblast growth factor (PRPF) for the treatment of AGA. METHODS: This was a prospective randomized, double-blind, placebo-controlled, half-head study. Eighty patients whose AGA was staged Norwood-Hamilton stages III to VII or Ludwig stages I to III were enrolled in the study from February of 2019 to September of 2019. Patients were divided randomly into two groups of 40 patients each and were given the following treatment: group 1, PRPF was injected in the right half and the left half with placebo; group 2, PRPF was injected in the right half and the left half with PRP. The treatment was processed three times, 1 month apart. Hair growth parameters were evaluated by trichoscope monthly until the sixth month of the study. Patient satisfaction, hair pull test, and side effects were recorded during follow-up. RESULTS: Of the 80 patients included in the study, 47 were men and 33 were women with a mean age of 28.96 ± 4.82 years (range, 21 to 46 years). Both PRP and PRPF showed positive improvement ( P < 0.05) on hair count, terminal hair, and anagen hair after the treatment. Efficacy of PRPF revealed a significant improvement ( P < 0.05) in hair count, terminal hair, vellus hair, and anagen hair versus PRP. There was no statistical difference among any of the parameters in the placebo group. CONCLUSION: PRPF can be a safe and valuable form of AGA treatment, and has proven to be more effective than PRP. CLINICAL RELEVANCE STATEMENT: Hybrid therapy of PRP with relative growth factors, such as basic fibroblast growth factor, have prominent efficacy on treatment of AGA. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, II.

Modeling human gray hair by irradiation as a valuable tool to study aspects of tissue aging.

As one of the earliest and most visible phenomenon of aging, gray hair makes it a unique model system for investigating the mechanism of aging. Ionizing radiation successfully induces gray hair in mice, and also provides a venue to establish an organ-cultured human gray hair model. To establish a suitable organ-cultured human gray HF model by IR, which imitates gray hair in the elderly, and to explore the mechanisms behind the model. By detecting growth parameters, melanotic and senescence markers of the model, we found that the model of 5 Gy accords best with features of elderly gray hair. Then, we investigated the formation mechanisms of the model by RNA-sequencing. We demonstrated that the model of organ-cultured gray HFs after 5 Gy irradiation is closest to the older gray HFs. Moreover, the 5 Gy inhibited the expression of TRP-1, Tyr, Pmel17, and MITF in hair bulbs/ORS of HFs. The 5 Gy also significantly induced ectopically pigmented melanocytes and increased the expression of DNA damage and senescence in HFs. Finally, RNA-seq analysis of the model suggested that IR resulted in cell DNA damage, and the accumulation of oxidative stress in the keratinocytes. Oxidative stress and DNA damage caused cell dysfunction and decreased melanin synthesis in the gray HFs. We found that HFs irradiated at 5 Gy successfully constructed an appropriate aging HF model. This may provide a useful model for cost-effective and predictable treatment strategies to human hair graying and the process of aging.

Feasibility of adipose-derived therapies for hair regeneration: Insights based on signaling interplay and clinical overview.

Dermal white adipose tissue (dWAT) is a dynamic component of the skin and closely interacts with the hair follicle. Interestingly, dWAT envelops the hair follicle during anagen and undergoes fluctuations in volume throughout the hair cycle. dWAT-derived extracellular vesicles can significantly regulate the hair cycle, and this provides a theoretical basis for utilizing adipose tissue as a feasible clinical strategy to treat hair loss. However, the amount and depth of the available literature are far from enough to fully elucidate the prominent role of dWAT in modulating the hair growth cycle. This review starts by investigating the hair cycle-coupled dWAT remodeling and the reciprocal signaling interplay underneath. Then, it summarizes the current literature and assesses the advantages and limitations of clinical research utilizing adipose-derived therapies for hair regeneration.

Natural Reconstruction: A Comprehensive Standardized Operating Procedure for Restoring Eyebrow Loss Due to Scarring.

BACKGROUND: Scarring that results in eyebrow loss is a cosmetic problem that can result in severe psychological distress. Although hair transplantation is increasingly used for eyebrow restoration, graft loss may occur, preventing achievement of desired results. Single-hair follicle transplantation, however, may be effective. The authors describe outcomes of a standardized method of eyebrow reconstruction, involving single-hair follicle transplantation combined with follicular unit extraction, in patients with absent eyebrows because of scarring. METHODS: This study was approved by the institutional ethics committee of Nanfang Hospital and all patients provided written informed consent before surgery. The medical records of patients who underwent eyebrow reconstruction from 2012 to 2019 for eyebrow loss caused by scar formation were reviewed retrospectively. Outcomes evaluated included satisfaction, graft survival rate, and long-term complications. A nine-step standardized operating procedure was established for eyebrow reconstruction in patients with eyebrow absence attributable to scarring. RESULTS: During the study period, 167 patients (205 eyebrows) underwent eyebrow reconstruction. Following the first stage of reconstruction, 95 percent of patients were highly satisfied with the density and natural appearance of their eyebrows. The average graft survival rate was 85 percent (range, 70 to 90 percent), significantly higher than the 75 percent survival rate previously reported. Fewer than 5 percent of patients underwent the second stage of reconstruction, with these patients expressing satisfaction with their outcomes. No obvious complications were observed. CONCLUSION: This standardized method may optimize outcomes in patients with eyebrow absence attributable to scarring. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Cellular Heterogeneity Facilitates the Functional Differences Between Hair Follicle Dermal Sheath Cells and Dermal Papilla Cells: A New Classification System for Mesenchymal Cells within the Hair Follicle Niche.

Mesenchymal stem cells (MSCs) are known for their self-renewal and multi-lineage differentiation potential, with these cells often being evaluated in the regulation and maintenance of specific cellular niches including those of the hair follicle. Most mesenchymal stem cells in the hair follicles are housed in the dermal papilla (DP) and dermal sheath (DS), with both niches characterized by a broad variety of cellular subsets. However, while most previous studies describing the hair follicle mesenchymal niche treated all DP and DS cells as Hair Follicle Mesenchymal Stem Cells (HF-MSCs), the high number of cellular subsets would suggest that these cells are actually too heterogenous for such a broad definition. Given this we designed this study to evaluate the differentiation processes in these cells and used this data to create a new set of classifications for DP and DS cells, dividing them into "hair follicle mesenchymal stem cells (HF-MSCs)", "hair follicle mesenchymal progenitor cells (HF-MPCs)", and "hair follicle mesenchymal functional cells (HF-MFCs)". In addition, those cells that possess self-renewal and differentiation were re-named hair follicle derived mesenchymal multipotent cells (HF-MMCs). This new classification may help to further our understanding of the heterogeneity of hair follicle dermal cells and provide new insights into their evaluation.

Ficoll density gradient sedimentation isolation of pelage hair follicle mesenchymal stem cells from adult mouse back skin: a novel method for hair follicle mesenchymal stem cells isolation.

BACKGROUND: Hair follicle mesenchymal stem cells (HF-MSCs) have great potential for cell therapy. Traditional method to isolate whisker HF-MSC is time-consuming and few in cell numbers. How to quickly and conveniently obtain a large number of HF-MSC for experimental research is a problem worth exploring. METHODS: Two-step Ficoll Density Gradient Sedimentation (FDGS) was performed to isolate pelage HF-MSC from adult mice. The characteristic of the isolated cells was identified and compared with whisker HF-MSC by immunofluorescence staining, flow cytometry, three-lineage differentiation and hair follicle reconstruction. Pelage HF-MSC and exosomes were injected into the dorsal skin of mice as well as hair follicle organ culture to explore its role in promoting hair growth. The cells and exosomes distribution were located by immunofluorescence staining. RESULTS: Isolated pelage HF-MSC expressed similar markers (ALP, Versican, NCAM, Nestin), showed similar growth pattern, possessed similar mesenchymal stem cells function and hair follicle induction ability as whisker HF-MSC. A large number of cells can be obtained with fewer mice compared to traditional method. Injected pelage HF-MSC promoted hair growth by secreting exosomes. CONCLUSION: A large number of Pelage HF-MSC can be isolated by FDGS, which can promote hair growth by secreting exosomes which may target the dermal papilla and hair matrix region of host hair follicle.

Restoration of appearance for women after aesthetic eyelash transplantation using a novel eyelash resection technique.

BACKGROUND: Hair transplantation based on the follicular unit extraction provides a new opportunity to improve the appearance of patients with congenital sparse eyelashes. However, disparity between transplanted grafts and original eyelashes and the physiological characteristics of upper eyelid skin cause difficulties with this technique and result in low satisfaction. Removal of unsatisfactory eyelashes is indispensable for restoration of appearance and a second transplantation. Unfortunately, existing methods for hair removal have variable success rates, and hairs frequently regrow. OBJECTIVE: This article introduces an effective method to remove unsatisfactory eyelashes in patients with congenital sparse eyelashes who have undergone eyelash transplantation. METHODS: We used a new technique, which involves resection of eyelashes with a composite strip, to remove unsatisfactory eyelashes in patients who underwent eyelash transplantation. The demographic and clinical characteristics of patients were recorded. Outcomes evaluated included patient satisfaction, hair regrowth, and long-term complications. RESULTS: From 2017 to 2021, 10 patients (20 sides) underwent eyelash removal. All patients were highly satisfied with the outcomes. Unsatisfactory eyelashes were thoroughly removed, and none regrew during 1 year of follow-up. No complications were observed. CONCLUSION: Strip composite eyelash excision is a safe and effective method for patients who have undergone unsatisfactory eyelash transplantation.

Tissue engineering ECM-enriched controllable vascularized human microtissue for hair regenerative medicine using a biomimetic developmental approach.

Introduction: Regenerative medicine is a promising approach for hair loss; however, its primary challenge is the inductivity of human dermal papilla cells (DPCs), which rapidly lose hair growth-inducing properties in 2D culture. Despite extensive research efforts to construct DPCs, current 3D microenvironments fabricated to restore hair inductivity remain insufficient. Objectives: Here, we aimed to fabricate ECM-enriched controllable vascularized dermal papilla (DP) spheroids that highly mimic in vivo DPCs microenvironments to restore their hair inductivity. Methods: We employed layer-by-layer (LbL) self-assembly using gelatin and alginate to construct nanoscale biomimetic ECM for DPCs, with Ca2+ as a cross-linking agent to create controllable DP spheroids. DPCs were also co-cultured with human umbilical vein endothelial cells to construct vascularized DP spheroids. Immunofluorescence staining and angiography was used to detect angiogenesis in vitro and in vivo. RNA sequencing and in vivo implantation were employed to investigate DPCs signature. Results: LbL technology enabled DPCs to aggregate into controllable DP spheroids of size and cell numbers similar to those of primary DP. Vascularization prevented hypoxia-induced necrosis and functioned in association with host vessels post-transplantation. Compared with traditional 3D culture, nanoscale ECM and vascularization were found to restore the transcriptional signature of DPCs and triple hair induction efficiency following engraftment. Conclusion: Our novel biomimetic developmental tissue engineering strategy is a crucial step toward the recovery of human DPC hair inductivity, which would enable the rapid clinical application of large-scale hair regeneration platforms.