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.

Application of Free Flaps in Reconstruction of Head and Neck Soft Tissue Defects With Bone Exposure.

BACKGROUND: Reconstruction of head and neck soft tissue defects with bone exposure is both challenging and technically demanding for plastic surgeon. Objectives in head and neck soft tissue defects with bone exposure reconstruction are consistent restoration of functionality while also improving appearance. This study retrospectively analyzed the results of head and neck reconstructions using various types of free flaps over the past 4 years. METHODS: A retrospective analysis was conducted from June 2019 to June 2023 on 12 patients treated at our hospital for head and neck soft tissue defects with bone exposure due to various causes. These included 4 cases of trauma from car accidents, 1 burn case, and 7 postoperative malignant tumor removals. The defect sizes ranged from 4 × 6 to 15 × 45 cm. Different free flaps were used for repair based on the defect, including 6 anterolateral thigh flaps, 3 forearm flaps, 2 latissimus dorsi flaps, and 1 dorsalis pedis flap. Flaps were designed and harvested to match the defect size and transplanted via anastomosed vessels. RESULTS: All 12 flaps survived successfully. One patient required flap thinning surgery postoperatively. All patients were followed up for over 3 months, showing good color and texture of the transplanted flaps, satisfactory healing, and significant aesthetic improvement. Donor sites showed significant scarring without functional impairment. CONCLUSION: Free flap repair for head and neck soft tissue defects with bone exposure is feasible and yields good results.

Risk Factors and Hazards of Recipient-Area Perifollicular Erythema After Hair Transplantation: A Multicenter Retrospective Cohort Study.

BACKGROUND: Recipient-area perifollicular erythema (RPE) may delay graft growth after hair transplantation. However, there is currently a lack of observational clinical studies of RPE. OBJECTIVE: To study the clinical features and risk factors associated with RPE while analyzing its correlation with graft growth. METHODS: We conducted a multicenter retrospective cohort study between June 2020 and January 2023. RESULTS: A total of 1090 participants were included, 178 (16.33%) showed mild RPE, 56 (5.14%) showed moderate RPE, and 10 (0.92%) showed severe RPE. Patients with RPE had severe hair shaft shedding (P < 0.001) and a lower survival rate (P < 0.001) of grafts. Logistic regression analysis showed that folliculitis is a significant risk factor for mild RPE (OR 6.061, 95% CI 3.343-10.991, P < 0.001) and moderate RPE (OR 3.397, 95% CI 1.299-8.882, P = 0.013). Besides, untimely first postoperative hair washing was associated with the development of moderate RPE (OR 0.724, 95% CI 0.553-0.947, P = 0.018) and severe RPE (OR 1.553, 95% CI 1.156-2.086, P = 0.003). CONCLUSION: RPE is a postoperative complication closely related to high hair shaft shedding proportion and low graft survival rate. Both postoperative folliculitis and untimely first postoperative hair washing may induce the occurrence of RPE. 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 .

Innate lymphoid cell-based immunomodulatory hydrogel microspheres containing Cutibacterium acnes extracellular vesicles for the treatment of psoriasis.

Psoriasis is a chronic skin inflammation influenced by dysregulated skin microbiota, with the role of microbiota in psoriasis gaining increasing prominence. Bacterial extracellular vesicles (bEVs) serve as crucial regulators in the interaction between hosts and microbiota. However, the mechanism underlying the therapeutic potential of bEVs from commensal bacteria in psoriasis remains unclear. Here, we investigated the therapeutic role of Cutibacterium acnes (C. acnes)-derived extracellular vesicles (CA-EVs) in psoriasis treatment. To prolong the active duration of CA-EVs, we encapsulated them in gelatin methacrylate (GelMA) to fabricate hydrogel microspheres (CA-EVs@GHM) with sustained release properties. As GelMA degraded, CA-EVs were gradually released, maintaining a high concentration in mouse skin even 96 h post-treatment. In human keratinocyte cells (HaCaT), CA-EVs@GHM enhanced resistance to Staphylococcus aureus (S. aureus), promoted proliferation and migration of HaCaT cells exposed to S. aureus, and significantly reduced the expression of inflammatory genes such as interleukin (IL)-6 and C-X-C motif chemokine ligand 8 (CXCL8). In vivo, CA-EVs@GHM, more potent than CA-EVs alone, markedly attenuated proinflammatory gene expression, including tumor necrosis factor (TNF), Il6, Il17a, Il22 and Il23a in imiquimod (IMQ)-induced psoriasis-like mice, and restored skin barrier function. 16S rRNA sequencing revealed that CA-EVs@GHM might provide therapeutic effects against psoriasis by restoring microbiota diversity on the back skin of mice, reducing Staphylococcus colonization, and augmenting lipid metabolism. Furthermore, flow cytometry analysis showed that CA-EVs@GHM prevented the conversion of type 2 innate lymphoid cells (ILC2) to type 3 innate lymphoid cells (ILC3) in psoriasis-like mouse skin, reducing the pathogenic ILC3 population and suppressing the secretion of IL-17 and IL-22. In summary, our findings demonstrate that the long-term sustained release of CA-EVs alleviated psoriasis symptoms by controlling the transformation of innate lymphoid cells (ILCs) subgroups and restoring skin microbiota homeostasis, thus offering a promising therapy for psoriasis treatment. STATEMENT OF SIGNIFICANCE: Cutibacterium acnes, which is reduced in psoriasis skin, has been reported to promote skin homeostasis by regulating immune balance. Compared to live bacteria, bacterial extracellular vesicles (bEVs) are less prone to toxicity and safety concerns. bEVs play a pivotal role in maintaining bacterial homeostasis and modulating the immune system. However,bEVs without sustained release materials are unable to function continuously in chronic diseases. Therefore, we utilized hydrogel microspheres to encapsulate Cutibacterium acnes (C. acnes)-derived extracellular vesicles (CA-EVs), enabling long term sustained release. Our findings indicate that, CA-EVs loaded gelatin methacrylate hydrogel microspheres (CA-EVs@GHM) showed superior therapeutic effects in treating psoriasis compared to CA-EVs. CA-EVs@GHM exhibited a more significant regulation of pathological type 3 innate lymphoid cells (ILC3) and skin microbiota, providing a promising approach for microbiota-derived extracellular vesicle therapy in the treatment of skin inflammation.

Evaluation of hair transplantation for improving unnatural hairlines after laser hair removal: A multicenter retrospective study.

CONTEXT: Laser hair removal treatment for hairlines with an unsatisfactory appearance often leads to an unnatural appearance; however, few studies have reported treatment outcomes. OBJECTIVE: To explore the satisfaction rate of laser hair removal involving the hairline. DESIGN: Retrospective analysis. SETTING: Data from 5 clinical institutions. PATIENTS: Patients (915; 630 female and 285 male) who underwent laser hair removal. INTERVENTIONS: Issues associated with hair removal were classified, and their proportions were calculated. Hair transplantation was performed to improve the appearance of different hairline issues. MAIN OUTCOME MEASURES: Relevant indicators of hair transplantation and postoperative effects. RESULTS: Overall, 82 patients were unsatisfied with their hairline appearance; of these patients, 58 underwent hair transplantation to improve the hairline. Additionally, demographic statistics showed that 68% and 32% of patients were in the 20 to 30 and 30 to 40 years age groups, respectively; there were no patients in the 40 to 50 years age group. Among female patients who underwent hair transplantation, 25% had a poor hairline position, 64% had a stiff hairline appearance, and 11% experienced both issues. Among male patients, 50% had a stiff hairline appearance, 28% had temporal absence, and 22% experienced both issues. Surgical treatment included moving the hairline forward and rebuilding the frontal curves. All patients were satisfied with hair transplantation outcomes. CONCLUSIONS: Laser hair removal can result in diverse types of unnatural hairlines. Hair transplantation has been proven to effectively improve the aesthetic appearance of the hairline.

Shape-fixing hydrogel promotes scarless healing of wounds under tension.

The healing of a wound under tension (hereafter, "tension wound") often coincides with the development of hypertrophic scars in clinical settings. Currently, compress bandages offer a potential alternative for the healing of tension wounds; however, their application in surgery is limited due to their prefabricated patch form. To overcome this, a tension-shielding hydrogel system was designed using photocurable catechol-grafted hyaluronic acid and tannic-acid silver nanoparticles (hereafter, "HTA system"). The hydrogel exhibited tension-shielding capacity, reducing wound tension via shape-fixation and ultimately reducing scar formation. The HTA hydrogel exhibited superior photothermal antibacterial efficacy, self-healing properties, and effective dissipation of energy, thereby promoting tissue regeneration. The hydrogel significantly inhibited the mechanotransduction pathway, thus preventing Engrailed-1 activation and reducing the fibrotic response. The HTA hydrogel system, therefore, provides a treatment strategy for tension wounds, burn wounds and other wounds that are prone to form hypertrophic scars via creating a tension-free local environment. STATEMENT OF SIGNIFICANCE: In our study, we presented a wound-dressing hydrogel system (HTA) that exhibit shape-fixing capacity in tension wound model. Here, we designed and modified a tension regulator, applied it to mice, and furthermore, established a tension wound model in mice with adjustable tension. Outcomes showed that the HTA hydrogel system can effectively form a shape-fixed environment on tension wounds and dynamic wounds, thus promoting scarless healing. Additionally, HTA performs injectability, rapid crosslinking, biocompatibility, wet adhesion, hemostasis and photothermal antibacterial properties. We believe this research has various potential clinical applications, including scarless-healing in tension wounds, treatment of acute bleeding, treatment of infected wounds, and even internal organ repair.

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.

Duo-role Platelet-rich Plasma: temperature-induced fibrin gel and growth factors' reservoir for microneedles to promote hair regrowth.

INTRODUCTION: Alopecia concerns more than half our adult population. Platelet-rich plasma (PRP) has been applied in skin rejuvenation and hair loss treatment. However, the pain and bleeding during injection and the troublesome for fresh preparation of each action limit PRP's in-depth applying dedication to clinics. OBJECTIVES: We report a temperature-sensitive PRP induced fibrin gel included in a detachable transdermal microneedle (MN) for hair growth. RESULTS: PRP gel interpenetrated with the photocrosslinkable gelatin methacryloyl (GelMA) to realize sustained release of growth factors (GFs) and led to 14% growth in mechanical strength of a single microneedle whose strength reached 1.21 N which is sufficient to penetrate the stratum corneum. PRP-MNs' release of VEGF, PDGF, and TGF-ß were characterized and quantitatively around the hair follicles (HFs) for 4-6 days consecutively. PRP-MNs promoted hair regrowth in mice models. From transcriptome sequencing, PRP-MNs induced hair regrowth through angiogenesis and proliferation. The mechanical and TGF-ß sensitive gene Ankrd1 was significantly upregulated by PRP-MNs treatment. CONCLUSION: PRP-MNs show convenient, minimally invasive, painless, inexpensive manufacture, storable and sustained effects in boosting hair regeneration.

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.

Sorting Technology for Mesenchymal Stem Cells from a Single Tissue Source.

Mesenchymal stem cells (MSCs) are adult stem cells that can be obtained, enriched and proliferated in vitro. They owned enormous potential in fields like regenerative medicine, tissue engineering and immunomodulation. However, though isolated from the same origin, MSCs are still essentially heterogeneous cell populations with different phenotypes and functions. This heterogeneity of MSCs significantly affects their therapeutic efficacy and brings obstacles to scientific research. Thus, reliable sorting technology which can isolate or purify MSC subpopulations with various potential and differentiation pathways is urgently needed. This review summarized principles, application status and clinical implications for these sorting methods, aiming at improving the understanding of MSC heterogeneity as well as providing fresh perspectives for subsequent clinical applications.

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.

Influence of Carbonation on the Properties of Steel Slag-Magnesium Silicate Hydrate (MSH) Cement.

Magnesium silicate hydrate (MSH) cement has the advantages of low energy consumption, minimal environmental pollution, carbon negativity, and reduced alkalinity, but excessive drying shrinkage inhibits its application. This paper analyzed the influence of steel slag (SS) dosage, carbon dioxide partial pressure, and carbonation curing time on the compressive strength, shrinkage rate, and phase composition of MSH cement. Various analysis methods, including X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and mercury intrusion porosimetry (MIP), were used to study the hydration products and microstructure. The results showed that under normal curing conditions, MSH cement mixed with different steel slag contents experienced a decline in strength at all ages. However, the greater the amount of SS incorporated, the lesser the degree of drying shrinkage. The compressive strength of all groups was improved, and the drying shrinkage was reduced by carbonation treatment. The samples with 5%, 10%, and 15% SS content exhibited shrinkage rates of 2.19%, 1.74%, and 1.60%, respectively, after 28 days of curing. The reason was that after carbonation treatment, hydrated magnesium carbonates (HMCs) were generated in the SS-MSH cement, and a Ca-Mg-C amorphous substance formed by hydration and carbonation of C2S in steel slag filled in the pores, which enhanced the density of the matrix, improved the compressive strength of the specimen, and reduced the shrinkage rate.

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.

Mixed Ionic-Electronic Conduction Increases the Rate Capability of Polynaphthalenediimide for Energy Storage.

Conjugated polymers offer a number of unique and useful properties for use as battery electrodes, and recent work has reported that conjugated polymers can exhibit excellent rate performance due to electron transport along the polymer backbone. However, the rate performance depends on both ion and electron conduction, and strategies for increasing the intrinsic ionic conductivities of conjugated polymer electrodes are lacking. Here, we investigate a series of conjugated polynapthalene dicarboximide (PNDI) polymers containing oligo(ethylene glycol) (EG) side chains that enhance ion transport. We produced PNDI polymers with varying contents of alkylated and glycolated side chains and investigated the impact on rate performance, specific capacity, cycling stability, and electrochemical properties through a series of charge-discharge, electrochemical impedance spectroscopy, and cyclic voltammetry measurements. We find that the incorporation of glycolated side chains results in electrode materials with exceptional rate performance (up to 500C, 14.4 s per cycle) in thick (up to 20 µm), high-polymer-content (up to 80 wt %) electrodes. Incorporation of EG side chains enhances both ionic and electronic conductivities, and we found that PNDI polymers with at least 90% of NDI units containing EG side chains functioned as carbon-free polymer electrodes. This work demonstrates that polymers with mixed ionic and electronic conduction are excellent candidates for battery electrodes with good cycling stability and capable of ultra-fast rate performance.

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.