Comparison of Skin Transcriptome between Responder and Non-Responder Vitiligo Lesions to Cell Transplantation: A Clinical Trial Study

OBJECTIVE

Autologous transplantation of epidermal cells has been used increasingly to treat vitiligo patients and is a simple, safe, and relatively efficient method. However, the outcome is not always satisfactory, and some patients show less or no response to this treatment. This study was evaluated to identify genes expressed differently among responders and non-responders to cell transplantation to find potential markers that could predict 'patients' responses to this type of cell therapy.

MATERIALS AND METHODS

Eleven stable vitiligo patients who received autologous epidermal cell transplantation were included in this clinical trial study. Before cell transplantation, skin samples were obtained from the recipient's vitiligo lesions. After epidermal cell transplantation, patients were followed for at least six months to assess the response to epidermal cell injection. RNA sequencing was used to determine potential gene expression profile differences between responder and non-responder vitiligo patients.

RESULTS

The RNA sequencing results showed differences in expression levels of 470 genes between the skin specimens of responder versus non-responder patients. There were 269 up-regulated genes and 201 down-regulated genes. Upregulated genes were involved in processes, such as Fatty Acid Omega Oxidation. Down-regulated genes were related to PPAR signaling pathway, and estrogen signaling pathway. Among the most differentially expressed genes (DEGs) with the most altered RNA expression levels in responders versus non-responder patients, we selected three genes (up-regulated genes KRTAP10-11 and down-regulated genes IP6K2 and C9) as potential biomarkers, which are involved in associated pathways.

CONCLUSION

Based on our findings, it is estimated that proposed genes might predict the response of vitiligo patients to cell therapy. However, further studies are required to clarify the role of these genes in pathogenesis and to characterize gene expression in a larger number of vitiligo patients in the context of epidermal cell transplantation therapy (registration number: IRCT201508201031N16).

Long-Term Follow-up of Autologous Fibroblast Transplantation for Facial Contour Deformities, A Non-Randomized Phase IIa Clinical Trial

Objective

Recently, the promising potential of fibroblast transplantation has become a novel modality for skin rejuvenation. We investigated the long-term safety and efficacy of autologous fibroblast transplantation for participants with mild to severe facial contour deformities.

Materials and Methods

In this open-label, single-arm phase IIa clinical trial, a total of 57 participants with wrinkles (n=37, 132 treatment sites) or acne scars (n=20, 36 treatment sites) who had an evaluator’s assessment score of at least 2 out 7 (based on a standard photo-guide scoring) received 3 injections of autologous cultured fibroblasts administered at 4-6 week intervals. Efficacy evaluations were performed at 2, 6, 12, and 24 months after the final injection based on evaluator and patient’s assessment scores.

Results

Our study showed a mean improvement of 2 scores in the wrinkle and acne scar treatment sites. At sixth months after transplantation, 90.1% of the wrinkle sites and 86.1% of the acne scar sites showed at least a one grade improvement on evaluator assessments. We also observed at least a 2-grade improvement in 56.1% of the wrinkle sites and 63.9% of the acne scar sites. A total of 70.5% of wrinkle sites and 72.2% of acne scar sites were scored as good or excellent on patient assessments. The efficacy outcomes remained stable up to 24-month. We did not observe any serious adverse events during the study.

Conclusion

These results have shown that autologous fibroblast transplantation could be a promising remodeling modality with long-term corrective ability and minimal adverse events (Registration Number: NCT01115634).

A randomized, double-blind, phase I clinical trial of fetal cell-based skin substitutes on healing of donor sites in burn patients

BACKGROUND

Due to limited graft donor sites in extensive burns, re-harvesting of a single donor area is very common. Given the importance of fetal fibroblasts in accelerating fetal wound healing, fetal cell-based skin substitutes have emerged as a novel therapeutic modality for regenerating damaged skin. In this trial, we aimed to evaluate the safety, feasibility and potential efficacy of application of amniotic membranes seeded with fetal fibroblasts for accelerating donor sites healing in burn patients.

METHODS

In this randomized, double-blind, phase I clinical trial, 10 patients with total burn surface area of 10-55% were enrolled. Three equal parts (10×10cm) were selected in donor site of each patient and covered by Vaseline gauze (control group), amniotic membrane (AM group), or amniotic membrane seeded with fetal fibroblasts (AM-F group). Adverse events, pain intensity scores, and wound sizes were recorded on days 4, 8, 11, 14, and 20 post-treatment. Also, histological assessments were done on days 0 and 14 after the surgery.

RESULTS

All patients underwent surgery, and no adverse events occurred during the procedure and follow-up period. Significantly lower pain intensity and higher healing rates were observed in AM-F and AM groups compared to the control group. Moreover, mean complete re-epithelializatin in AM-F and AM groups were 10.1±2.4 and 11.3±2.9 days, showing that the healing process was significantly accelerated compared to the control group with mean closure time of 14.8±1.6 days. Histological assessment showed lower inflammatory cells infiltration in AM-F and AM groups compared to control group.

CONCLUSIONS

This study indicated the safety of transplantation of amniotic membrane seeded with fetal fibroblasts for treatment of donor sites in burn patients; however, preliminary assessments showed no benefits for this therapeutic modality over amniotic membrane alone. Thus, to draw accurate conclusions, further trials in larger populations should be conducted.

LEVEL OF EVIDENCE

This study is assigned as level I.

A single-arm open-label clinical trial of autologous epidermal cell transplantation for stable vitiligo: A 30-month follow-up

BACKGROUND

Recently, we introduced intralesional injection of autologous epidermal cells as a safe and feasible approach for transplantation in patients with stable vitiligo. This approach resulted in less pain during and after the procedure, no scarring or cobblestone formation at the recipient site, and was more feasible to perform on curved surfaces such as joints, lips, eyelids, ears, and face.

OBJECTIVE

In this study, we aimed to investigate the long-term efficacy and safety of this transplantation technique.

METHODS

In this open-label and single-arm clinical trial, we enrolled 300 patients with stable vitiligo. We obtained a partial thickness normo-pigmented skin specimen from the patients' thigh-buttock junction with an area of one tenth to one third of the recipient site area. The epidermal cell suspension was prepared by processing the autologous skin specimen. We injected the cell suspension into 1060 vitiligo patches in 300 patients. Patients did not use any adjuvant phototherapy during the study. An experienced dermatologist and patients respectively defined the repigmentation score and self-assessment score at regular follow-up visits for up to 30 months after treatment. The scores represented the repigmentation percentage as follows: 0 (0), I (1%-24%), II (25%-49%), III (50%-74%), and IV (75%-100%).

RESULTS

The mean repigmentation score at 3 months post-transplantation was 1.12±0.73. A significant upward trend existed in the mean repigmentation score until 9 months after cell transplantation, when the mean repigmentation score reached to 1.98±1.20. At 9 months after treatment, repigmentation of >50% was obtained in 32.2% of treated patches. Acquired repigmentation remained stable in 79.3% of treated patches during the follow-up period. The number of received cells per cm² positively influenced the repigmentation score. Patches located on face, neck and trunk showed significantly higher response to the treatment.

CONCLUSION

The results of our study demonstrated efficacy and safety of autologus epidermal cell transplantation on repigmentation of vitiligo patches. The achieved repigmentation was stable in the majority of treated patches during the follow-up period.

Cell-based skin substitutes accelerate regeneration of extensive burn wounds in rats

BACKGROUND

This study investigated the effects of amniotic membrane combined with adipose-derived stem cells or fetal fibroblasts on regenerating extensive burns in rats.

METHODS

Third degree burns of 1100-1800 mm² were induced on 32 Sprague-Dawley rats. Burned sites were excised and randomly covered with Vaseline gauze (control), human amniotic membrane (HAM), human fetal fibroblasts seeded on HAM (HAM-FF), or human adipose-derived stem cells seeded on HAM (HAM-ASC), and followed by wound closure and histological assessments.

RESULTS

Wound closure rates of HAM-FF, HAM-ASC, HAM and control groups at seven and 14 days after the treatment were 42.2% and 81.9%, 41.9% and 81.7%, 33.5% and 74.2%, and 16.5% and 69.7%, respectively. Wounds of HAM-FF, HAM-ASC, HAM and control groups were closed on 40, 40, 50 and 60 days after the treatment, respectively (P < 0.05). Histological assessments revealed lower inflammatory cell infiltration in HAM-ASC and HAM-FF groups.

CONCLUSIONS

Cell-based engineered skin substitutes seem to accelerate wound regeneration, especially within the first 14 days.

Treatment of Hypertrophic Scar in Human with Autologous Transplantation of Cultured Keratinocytes and Fibroblasts along with Fibrin Glue

Objective

Hypertrophic scar involves excessive amounts of collagen in dermal layer and may be painful. Nowadays, we can’t be sure about effectiveness of procedure for hypertrophic scar management. The application of stem cells with natural scaffold has been the best option for treatment of burn wounds and skin defect, in recent decades. Fibrin glue (FG) was among the first of the natural biomaterials applied to enhance skin deformity in burn patients. This study aimed to identify an efficient, minimally invasive and economical transplantation procedure using novel FG from human cord blood for treatment of hypertrophic scar and regulation collagen synthesis.

Materials and Methods

In this case series study, eight patients were selected with hypertrophic scar due to full-thickness burns. Human keratinocytes and fibroblasts derived from adult skin donors were isolated and cultured. They were tested for the expression of cytokeratin 14 and vimentin using immunocytochemistry. FG was prepared from pooled cord blood. Hypertrophic scars were extensively excised then grafted by simply placing the sheet of FG containing autologous fibroblast and keratinocytes. Histological analyses were performed using Hematoxylin and eosin (H&E) and Masson’s Trichrome (MT) staining of the biopsies after 8 weeks.

Results

Cultured keratinocytes showed a high level of cytokeratin 14 expression and also fibroblasts showed a high level of vimentin. Histological analyses of skin biopsies after 8 weeks of transplantation revealed re-epithelialization with reduction of hypertrophic scars in 2 patients.

Conclusion

These results suggest may be the use of FG from cord blood, which is not more efficient than previous biological transporters and increasing hypertrophic scar relapse, but could lead to decrease pain rate.

Fabrication and characterization of spongy denuded amniotic membrane based scaffold for tissue engineering

Objective

As a biological tissue material, amniotic membrane (AM) has low immunogenicity and to date has been widely adopted in clinical practice. However, some features such as low biomechanical consistency and rapid biodegradation is limited the application of AM. Therefore, in this study, we fabricated a novel three-dimensional (3D) spongy scaffold made of the extracellular matrix (ECM) of denuded AM. Due to their unique characteristics which are similar to the skin, these scaffolds can be considered as an alternative option in skin tissue engineering.

Materials and Methods

In this experimental study, cellular components of human amniotic membrane (HAM) were removed with 0.03% (w/v) sodium dodecyl sulphate (SDS). Quantitative analysis was performed to determine levels of Glycosaminoglycans (GAGs), collagen, and deoxyribonucleic acid (DNA). To increase the low efficiency and purity of the ECM component, especially collagen and GAG, we applied an acid solubilization procedure hydrochloridric acid (HCl 0.1 M) with pepsin (1 mg/ml). In the present experiment 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide hydrochloride (EDC)/N-hydroxysuccinimide (NHS) cross linker agent was used to improve the mechanical properties of 3D lyophilized AM scaffold. The spongy 3D AM scaffolds were specified, by scanning electron microscopy, hematoxylin and eosin (H&E) staining, a swelling test, and mechanical strength and in vitro biodegradation tests. Human fetal fibroblast culture systems were used to establish that the scaffolds were cytocompatible.

Results

Histological analysis of treated human AM showed impressive removal of cellular components. DNA content was diminished after treatment (39 ± 4.06 μg/ml vs. 341 ± 29.60 μg/ml). Differences were observed between cellular and denude AM in matrix collagen (478 ± 18.06 μg/mg vs. 361 ± 27.47 μg/mg).With the optimum concentration of 1 mM NHS/EDC ratio1:4, chemical cross-linker agent could significantly increase the mechanical property, and resistance to collagenase digestion. The results of 2, 4, 6-Trinitrobenzenesulfonic acid (TNBS) test showed that cross-linking efficiency of AM derived ECM scaffolds was about 65% ± 10.53. Scaffolds treated with NHS/EDC cross-linker agent by 100 μg/ml collagenase, lost 75% of their dry weight after 14 days. The average pore size of 3D spongy scaffold was 160 µm measured from scanning electron microscope (SEM) images that it is suitable for cell penetration, nutrients and gas change. In addition, the NHS/ EDC cross-linked AM scaffolds were able to support human fetal fibroblast cell proliferation in vitro. Extracts and contact prepared from the 3D spongy scaffold of AM showed a significant increase in the attachment and proliferation of the human fetal fibroblasts cells.

Conclusion

The extra-cellular matrix of denuded AM-based scaffold displays the main properties required for substitute skin including natural in vitro biodegradation, similar physical and mechanical characterization, nontoxic biomaterial and no toxic effect on cell attachment and cell proliferation.

Intraepidermal injection of dissociated epidermal cell suspension improves vitiligo

This study was initiated to evaluate the safety and effectiveness of intraepidermal injection of dissociated epidermal cells into the lesions of stable vitiligo patients. Autologous dissociated epidermal cell suspensions were injected intraepidermally into 10 stable vitiligo patients. None of the patients received adjuvant therapy. The response was evaluated as: marked (76-100%), moderate (51-75%), mild (26-50%) and minimal repigmentation (0-25%). Transmission electron microscopy was used to evaluate the transplanted cells and immunohistochemical staining with HMB-45 was performed to assess the repigmentation in vivo. In all cases, repigmentation started during the 4-week period after transplantation. Six months after transplantation, a marked repigmentation in four (40%), moderate repigmentation in two (20%) and mild repigmentation in two (20%) patients were observed. Two (20%) patients with white patches on their lids showed minimal repigmentation. No side effects were observed in any patients. Interestingly, repigmentation of gray hair in one patient, 4 months post transplantation was observed. Analysis of the ultrastructure of transplanted cells showed 1.5% of the cells had melanocyte morphology. HMB-45 positive cells were observed after cell transplantation. This method is an effective, simple and safe therapeutic option for stable vitiligo lesions.