Clinical Application of Cultured Stratified Epithelial Sheets Grown Under Feeder or Feeder-Free Conditions for Stable Vitiligo

Autologous Cultured Tissue Engineering Epidermal Sheet Transplantation to Treat Vitiligo of the Hands

BACKGROUND

Despite numerous therapeutic modalities for vitiligo, their efficacy varies. Managing vitiligo affecting the hands poses a particularly intricate challenge, with outcomes trailing those in other anatomical regions.

OBJECTIVE

Assess the determinants influencing the efficacy and safety of autocultured tissue engineering epidermal sheets transplantation in treating hand vitiligo, observed over a 6-month follow-up period.

METHODS

A retrospective analysis was conducted on 33 patients who underwent treatment for hand vitiligo using autocultured tissue engineering epidermal sheets transplantation. Repigmentation extent was evaluated by 2 dermatologists.

RESULTS

The cohort comprised 33 patients, including 24 males and 9 females, with an average age of 26.91 ± 9.24 years (range: 10-49 years). The mean duration of the disease was 11.61 ± 7.83 years (range: 1.5-34 years). Vitiligo lesion stability ranged from 6 months to 4 years, with an average duration of stability calculated at 1.715 ± 1 year. After 6 months, 75.8% (25/33) of patients exhibited a favorable response, with 39.4% (13/33) showing complete or near-complete repigmentation. No adverse events, such as infections or scar formation, were recorded.

CONCLUSION

The authors' investigation suggests that autocultured tissue engineering epidermal sheets transplantation is a highly effective and safe therapeutic approach for hand vitiligo, offering a promising treatment avenue.

The Treatment of Refractory Vitiligo With Autologous Cultured Epithelium Grafting: A Real-World Retrospective Cohort Study

BACKGROUND

Surgical intervention is the main therapy for refractory vitiligo. We developed a modified autologous cultured epithelial grafting (ACEG) technique for vitiligo treatment. Between January 2015 and June 2019, a total of 726 patients with vitiligo underwent ACEG in China, with patient characteristics and clinical factors being meticulously documented. Using a generalized linear mixed model, we were able to assess the association between these characteristics and the repigmentation rate.

RESULTS

ACEG demonstrated a total efficacy rate of 82.81% (1754/2118) in treating 726 patients, with a higher repigmentation rate of 64.87% compared to conventional surgery at 52.69%. Notably, ACEG showed a better response in treating segmental vitiligo, lesions on lower limbs, age ≤ 18, and stable period > 3 years. A keratinocyte:melanocyte ratio below 25 was found to be advantageous too. Single-cell RNA sequencing analysis revealed an increase in melanocyte count and 2 subclusters of keratinocytes after ACEG, which remained higher in repigmented sites even after 1 year.

CONCLUSIONS

ACEG is a promising therapy for refractory vitiligo. Patient age, clinical type, lesion site, and stability before surgery influence repigmentation in ACEG. The mechanism of repigmentation after ACEG treatment is likely not confined to the restoration of melanocyte populations. It may also involve an increase in the number of keratinocytes that support melanocyte function within the affected area. These keratinocytes may aid the post-transplant survival and function of melanocytes by secreting cytokines and extracellular matrix components.

TRIAL REGISTRATION

registered with Chictr.org.cn (ChiCTR2100051405).

Single-cell sequencing reveals increased LAMB3-positive basal keratinocytes and ZNF90-positive fibroblasts in autologous cultured epithelium

Autologous cultured epithelium grafting (ACEG) presents a promising treatment for refractory vitiligo, yet concerns regarding infections and immunological reactions hinder its surgical use due to serum and feeder dependencies. Addressing this, we culture autologous epithelium under serum- and feeder-free (SFF) conditions, comparing its safety and efficacy with serum- and feeder-dependent (SFD) conditions in stable vitiligo patients, and we discover no significant differences in repigmentation between the SFF and SFD grafts. Single-cell RNA transcriptomics on SFF- and SFD-cultured epithelium alongside healthy skin reveal increased populations of LAMB3+ basal keratinocytes and ZNF90+ fibroblasts in the SFF sheets. Functional analyses showcase active cellular metabolism in LAMB3+ basal keratinocytes, vital in extracellular matrix homeostasis, while ZNF90+ fibroblasts demonstrate increased differentiation, essential in collagen formation for cell adhesion. Importantly, these cell populations in SFF sheets exhibit enhanced interactions with melanocytes compared to SFD sheets. Further, knockdown experiments of LAMB3 in keratinocytes and ZNF90 in fibroblasts lead to a downregulation in melanocyte ligand-receptor-related genes. Overall, SFF sheets demonstrate comparable efficacy to SFD sheets, offering superior safety. LAMB3+ basal keratinocytes and ZNF90+ fibroblasts act as potential drivers behind repigmentation in ACEG under SFF conditions. This study provides translational insights into ACEG repigmentation and potential therapeutic targets for vitiligo.

Has the core outcome (domain) set for vitiligo been implemented? An updated systematic review on outcomes and outcome measures in vitiligo randomized clinical trials

BACKGROUND

In 2015, a major achievement in vitiligo research was the development of an internationally agreed upon core outcome domain set for randomized clinical trials (RCTs). Three outcomes were identified as being essential: repigmentation, side-effects/harms and maintenance of gained repigmentation. Four items were further recommended for inclusion. The following recommendations then followed: repigmentation should be assessed by measuring the percentage of repigmentation in quartiles (0-25%, 26-50%, 51-79%, 80-100%) and cosmetic acceptability of the results should be assessed using the Vitiligo Noticeability Scale.

OBJECTIVES

The primary objective of this study was to assess uptake of the core outcome domain set for RCTs in vitiligo. Secondary objectives were to update the systematic review on outcomes reported in vitiligo RCTs, and to assess whether repigmentation and cosmetic acceptability of the results were measured using the above-mentioned recommended scales.

METHODS

We searched PubMed, Cochrane Library (CENTRAL and Systematic Reviews) and ClinicalTrials.gov for vitiligo RCTs between November 2009 and March 2021. Screening and data extraction were independently performed on title and summary by two researchers. All outcomes and outcome measures reported in eligible RCTs were retrieved and collated.

RESULTS

In total, 174 RCTs were identified: 62 were published between 2009 and 2015, and 112 were published between 2016 and 2021.Thirty-eight different outcomes were reported. Repigmentation was the primary outcome in 89% of trials (150 of 169). Forty-nine different tools were used to measure repigmentation. Side-effects and harms were reported in 78% of trials (136 of 174). Maintenance of gained repigmentation was reported in only 11% of trials (20 of 174) and duration of follow-up varied greatly from 1 to 14 months. Cosmetic acceptability of the results and cessation of disease activity were assessed in only 2% of trials (four of 174). Quality of life of patients with vitiligo was assessed in 13% of trials (22 of 174). Finally, only 11 of 112 RCTs (10%) published between 2016 and 2021 reported all three essential core outcome domains (repigmentation, side-effects and maintenance of gained repigmentation) and none of the trials reported both essential and recommended core outcome domains.

CONCLUSIONS

Efforts are still needed to close the gap between set recommendations and RCT outcome reporting.

Effect of Rho-Associated Protein Kinase Inhibitors on Epidermal Keratinocytes: A Proposed Application for Burn Wound Healing

Rho-associated protein kinases (ROCKs) affect a variety of cellular functions, including cell attachment, migration, and proliferation. ROCK inhibitors therefore have potential as tools for optimizing cell behavior in tissue engineering applications, including the manufacturing of cultivated epithelial autografts (CEAs) used in the treatment of burn patients. For example, ROCK inhibitors may facilitate earlier engraftment of CEA sheets by increasing the proliferation of skin keratinocytes ex vivo. Nevertheless, the current understanding of ROCK inhibitor action on epidermal keratinocytes is unclear owing to multiple drug formulations, drug concentrations, and cellular function assays having been used. The aim of this review article therefore is to identify consistent patterns of ROCK inhibitor action on human keratinocytes, as well as revealing key knowledge gaps. In doing so, we propose a clearer course of action for pursuing the potential benefits of ROCK inhibitors for the future treatment of burn patients. Impact statement The properties of Rho-associated protein kinase (ROCK) inhibitors are already used clinically within the fields of cardiology, neurology, and ophthalmology. These results encourage the broadening of ROCK inhibitor uses for other clinical applications. With respect to burn patients, ROCK inhibitors may facilitate improvements in patient survival and healing by reducing the time required for generating cultivated epithelial autograft (CEA) sheets from patient biopsies. Nevertheless, varying approaches to studying the effects of ROCK inhibitors on skin cells in vitro have complicated the development of improved protocols. Our review aims to clarify a diverse and growing body of literature as to the potential benefits for burn patients.

New Pigmentation After Medical Treatment Suggests Increased Efficacy of Dermabrasion and Noncultured Epidermal Cell Suspension Techniques in Stable Vitiligo

BACKGROUND

Stable vitiligo has been treated by dermabrasion and noncultured epidermal cell suspension (NCES) effectively. However, not all patches respond well.

OBJECTIVE

To investigate the efficacy of new pigmentation after medical treatment in the therapy of stable vitiligo.

MATERIALS AND METHODS

Medical records were retrospectively reviewed from October 2016 to March 2019, and 134 patients with stable vitiligo after medical therapy were further treated with NCES. They were divided into 2 groups: 70 patients in Group 1 had new pigmentation, whereas 64 patients in Group 2 did not. Repigmentation and satisfaction of patients and third-party assessors were evaluated at 3 and 6 months postoperatively.

RESULTS

Repigmentation was scored as excellent (≥76%), good (51%-75%), fair (26%-50%), or poor (≤25%). Repigmentation of the 2 groups at 6 months postoperatively was excellent in 82.9% versus 23.4%, good in 10.0% versus 15.6%, fair in 7.1% versus 13.0%, and poor in 0% versus 48.4%, respectively. A positive correlation between satisfaction and repigmentation was found.

CONCLUSION

New pigmentation after medical treatment suggests increased efficacy of NCES in treating stable vitiligo.

Cryopreserved skin epithelial cell sheet combined with acellular amniotic membrane as an off-the-shelf scaffold for urethral regeneration

BACKGROUND

Autologous tissue transplantation for urethral repair is often limited and causes donor site complications. Here, a cryopreserved rabbit skin epithelial cell sheet (SEC) combined with an acellular amniotic membrane (AM) was used to repair rabbit urethral defects.

METHODS

Abdominal skin was collected from 4-week-old New Zealand rabbits, and primary epithelial cells were extracted and cultured to form a cell sheet. Fresh SEC-AMs were constructed and cryopreserved. A cryopreservation system including optimized medium, two-pump perfusion, a programmed freezer and liquid nitrogen storage was established. Cell viability, mechanical strength, electron microscopy, and histological staining were performed in vitro after 1 month. Next, the sheets were transplanted subcutaneously for 2 weeks, and the graft was used to repair the rabbit urethral defect. Urinary function was measured and samples were collected for histological staining after 1 month.

RESULTS

We confirmed that cryopreservation damage of SECs was reduced by composition with acellular AMs in terms of high cell activity. The SEC mechanical strength was also enhanced by AMs, which was convenient for the operation. In in vivo experiments, we transplanted sheets into the groin area for two weeks and found that cryopreservation reduced inflammatory cell infiltration and significantly improved vascular density. In the urethral repair experiment, the near-normal passive urine flow rate, smooth mucosa of the gross specimen, intact epithelialization and abundant neovascularization were confirmed in the cryopreserved-SEC-AM group compared with the other groups.

CONCLUSIONS

Cryopreserved SEC-AMs demonstrated similar outcomes of rabbit urethral defect repair as fresh SEC-AMs, showing good clinical application prospects.

Biobanked human foreskin epithelial cell sheets reduce inflammation and promote wound healing in a nude mouse model

BACKGROUND

Human epithelial cell sheets (ECSs) are used to clinically treat epithelial conditions such as burns, corneal blindness, middle ear cholesteatoma and vitiligo. As a widely used material in clinic, there is little information on the biobanking of ECSs and its repair effect after storage.

RESULTS

Two methods for biobanking foreskin ECSs were compared in a short term (7 days): 4-degree storage and programmed cryopreservation. Cell sheet integrity, viability, apoptosis, immunogenicity, mechanical properties and function were evaluated. In vivo, ECSs were directly transplanted to skin defect models and histological examination was performed at 1 week postoperatively. We successfully extracted human foreskin-derived primary epithelial cells and fabricated them into ECSs. Compared with 4-degree storage, programmed cryopreservation preserved the ECS structural integrity, enhanced the mechanical properties, decreased HLA-I expression, and increased cell viability and survival. An increased proportion of melanocytes with proliferative capacity remained in the cryopreserved sheets, and the undifferentiated epithelial cells were comparable to those of the fresh sheets. In vivo, cryopreserved ECSs could reduce inflammatory cell infiltration and promote connective tissue remodeling, epithelial cell proliferation and vascular regeneration.

CONCLUSIONS

Programmed cryopreservation of ECSs was superior and more feasible than 4-degree storage and the cryopreserved ECSs achieved satisfying skin wound healing in vivo. We anticipate that the off-the-shelf ECSs could be quickly used, such as, to repair human epithelial defect in future.

Extracellular fraction of adipose tissue as an innovative regenerative approach for vitiligo treatment

Vitiligo is a common, disfiguring autoimmune disease that negatively affects patients' self-esteem and quality of life. Current treatments are moderately effective in reversing disease and promoting melanocyte regeneration. Thus, therapeutic advanced strategies are emerging from regenerative medicine. It has recently emerged that adipose tissue secretome may be used as a cell-free therapy in skin regeneration since paracrine functions of adipose-derived stem cells alone are responsible for most of the therapeutic effect of stem cells in several animal disease models. In this study, we tested the effect of adipose tissue extracellular fraction (AT-Ex) isolated from lipoaspirates on dermal and epidermal vitiligo cells in vitro. Using this experimental model, we demonstrated that molecules secreted by adipose tissue ameliorate the capability to counteract oxidative stress by a physiological stimulation of intracellular antioxidant enzymes and positively impact on cell proliferation. Due to the presence of Wnt-secreted factors, AT-Ex treatment promotes glycogen synthase kinase 3β inactivation and consequently Wnt/β-catenin pathway activation. Collectively, our findings show that AT-Ex could be useful as a natural approach to improve treatment of vitiligo.