Other uses of homologous skin grafts and skin bank bioproducts

Pre-Emptive Priming of Human Skin Improves Cutaneous Scarring and Is Superior to Immediate and Delayed Topical Anti-Scarring Treatment Post-Wounding: A Double-Blind Randomised Placebo-Controlled Clinical Trial

The concept of pre-emptive priming of skin pre-surgery offers a novel approach in optimizing cutaneous scarring outcome. We previously showed an anti-scarring topical (epigallocatechin-3-gallate (EGCG)) is effective in improving skin scarring when applied post-surgery. The objective was to deliver an active compound at the optimal time in order to maximize its impact and improve cutaneous scarring. Therefore, pre-emptive application of anti-scarring topical pre-surgery compared with post-surgery can potentially be superior on scarring outcome. This double-blinded randomized placebo-controlled trial compares the effects of pre-emptive priming of skin with an anti-scarring topical pre-surgery versus post-surgery. Healthy volunteers (n = 40) were split into 4-groups; each undergoing different modes of application versus placebo: Group-1 = priming (7Days) pre-injury, Group-2 = priming (3D) pre-injury, Group-3 = immediate (0D) day-of-injury, Group-4 = delayed application (14D) post-injury. Excisional skin-biopsies in upper-arms were evaluated weekly with multiple quantitative devices over 8-weeks. Histological, immunohistochemical, mRNA sequencing and QRT-PCR studies were performed on tissue-biopsies. EGCG reduced mast cells at weeks-4 and 8 by gene and protein analyses (p < 0.01). Group 1 was superior to other groups (p < 0.01) in both clinical (blood flow) and laboratory parameters (elastin and immune marker expression). Additionally, there was down-regulation of angiogenic-markers by mRNA-sequencing and of CD31 and VEGF-A at weeks-4 and 8 (p < 0.01) by immunohistochemistry and at week-4 (p < 0.05) by QRT-PCR. EGCG increased antioxidant levels (HO-1) at week-4 (p < 0.01) plus elastin at week-8 (p < 0.01). In conclusion, pre-emptive priming of skin pre-injury has significant beneficial effects on surgically induced skin scarring shown by reducing mast cells, blood flow and angiogenesis plus increasing elastin content. This clinical trial was registered with ISRCTN (ISRCTN70155584).

Pre-Emptive Priming of Human Skin Improves Cutaneous Scarring and Is Superior to Immediate and Delayed Topical Anti-Scarring Treatment Post-Wounding: A Double-Blind Randomised Placebo-Controlled Clinical Trial

The concept of pre-emptive priming of skin pre-surgery offers a novel approach in optimizing cutaneous scarring outcome. We previously showed an anti-scarring topical (epigallocatechin-3-gallate (EGCG)) is effective in improving skin scarring when applied post-surgery. The objective was to deliver an active compound at the optimal time in order to maximize its impact and improve cutaneous scarring. Therefore, pre-emptive application of anti-scarring topical pre-surgery compared with post-surgery can potentially be superior on scarring outcome. This double-blinded randomized placebo-controlled trial compares the effects of pre-emptive priming of skin with an anti-scarring topical pre-surgery versus post-surgery. Healthy volunteers (n = 40) were split into 4-groups; each undergoing different modes of application versus placebo: Group-1 = priming (7Days) pre-injury, Group-2 = priming (3D) pre-injury, Group-3 = immediate (0D) day-of-injury, Group-4 = delayed application (14D) post-injury. Excisional skin-biopsies in upper-arms were evaluated weekly with multiple quantitative devices over 8-weeks. Histological, immunohistochemical, mRNA sequencing and QRT-PCR studies were performed on tissue-biopsies. EGCG reduced mast cells at weeks-4 and 8 by gene and protein analyses (p < 0.01). Group 1 was superior to other groups (p < 0.01) in both clinical (blood flow) and laboratory parameters (elastin and immune marker expression). Additionally, there was down-regulation of angiogenic-markers by mRNA-sequencing and of CD31 and VEGF-A at weeks-4 and 8 (p < 0.01) by immunohistochemistry and at week-4 (p < 0.05) by QRT-PCR. EGCG increased antioxidant levels (HO-1) at week-4 (p < 0.01) plus elastin at week-8 (p < 0.01). In conclusion, pre-emptive priming of skin pre-injury has significant beneficial effects on surgically induced skin scarring shown by reducing mast cells, blood flow and angiogenesis plus increasing elastin content. This clinical trial was registered with ISRCTN (ISRCTN70155584).

Efficacy and safety of skin grafting in treatment of vasculitic ulcer and pyoderma gangrenosum-A systematic review

Chronic painful ulcers caused by pyoderma gangrenosum (PG) and cutaneous vasculitis remain to be a therapeutic challenge. Skin grafts have been used with success in selected cases but are generally avoided due to the fear of pathergy. The aim of this study was to investigate the safety and efficacy of skin grafting in the treatment of primary vasculitic ulcer (PVU) and PG. MEDLINE, Embase, the Cochrane Library, Clinicaltrial.gov, and WHO International Clinical Trials Registry Platform (ICTRP) were searched from inception to March 2020. A search for grey literature was conducted in May 2020. We included studies assessing the efficacy and safety of skin grafting in the treatment of PG and PVU. Studies were only included if skin grafting was performed after establishment of PG or PVU diagnosis. A total of 721 articles was identified through the database search of which 92 were included in this study. Ten articles were identified by handsearching the reference list of included studies. Finally, 102 articles describing 212 wounds in 153 patients were included. Complete healing was found in 75.5% of the wounds. The average time to complete was 10.8 weeks (95% CI 6.1-15.6). The mean donor site healing time was 1.9 weeks (95% CI 0.52-3.20). Pathergy was reported in 8 (5.2%) patients. One patient had severe infection related to skin grafting. A statistically significant difference in the number of patients receiving preoperative (P = .0079) and postoperative (P = .002) immunosuppressive therapy was found between the groups with complete healing/reduction and no improvement/aggravation. This systematic review finds the current evidence on efficacy and safety of skin grafting in treatment of PG and PVU to be promising but limited to the size and lack of studies superior to case reports and case series. Future placebo-controlled trials are required to draw a stronger conclusion.

An Open-Label Study of Low-Level Laser Therapy Followed by Autologous Fibroblast Transplantation for Healing Grade 3 Burn Wounds in Diabetic Patients

Introduction: Low-level laser therapy (LLLT) has been used as an effective therapeutic modality since the mid-1960s. Although there have been several clinical studies using LLLT in wound healing, especially diabetic, pressure and venous ulcers, there are few reports of using this technique in burn ulcers. Autologous fibroblast transplantation is a novel treatment for patients with burns or venous ulcers. In this study for the first time, we used LLLT along with autologous fibroblast skin transplantation to treat grade 3 burn ulcers in diabetic patients. This case series describes the successful management of grade 3 burn ulcers in 10 diabetic patients using autologous fibroblast transplantation along with LLLT. Methods: After the approval of the Tehran University Ethics Committee (IR.TUMS.REC.1394.1683) and the Iran Registry of Clinical Trials (IRCT2016050226069N3), 10 diabetic patients with 10 grade 3 burn ulcers, who were a candidate for skin graft surgery, entered the study. Donor skin was biopsied using a 3 mm punch. Fibroblasts were extracted and cultured in vitro in the GMP Technique laboratory. The patients were treated using LLLT in 3-4 weeks during the time that fibroblast cultures became ready to use. Laser irradiation was done using red light, 650 nm, 150 mW, 1 J/cm² for the bed of the ulcer and infra-red light 808 nm, 200 mW, 6 J/cm² for the margins every other day for 10 sessions. Results: The mean wound size before treatment was 16.28 cm² . All patients' burn wounds healed completely after 10-12 weeks. Conclusion: We conclude that this method can be used as an effective method for treating large wounds, especially in complicated patients including the diabetics.

Cadaveric Skin Grafts May Greatly Increase the Healing Rate of Recalcitrant Ulcers When Used Both Alone and in Combination With Split-Thickness Skin Grafts

BACKGROUND

Leg ulcers that do not heal despite appropriate treatment are defined as recalcitrant ulcers. Large surface area, depth, and long duration represent some of most important factors impeding ulcer healing. After sharp debridement, dermal substitutes including skin from cadaver donors may increase the healing rate of recalcitrant ulcers reducing the risk of scar formation and recurrence.

OBJECTIVE

Assessing if, after sharp debridement, dermal substitutes including skin from cadaver donors may increase the healing rate of recalcitrant ulcers reducing the risk of scar formation and recurrence.

PATIENTS AND METHODS

Among patients admitted to our hospital for all types of chronic leg ulcers, we retrospectively reviewed the records of patients affected by recalcitrant ulcers (surface greater than 100 cm, tissue loss involving epidermis, dermis, and subcutaneous tissue, duration longer than 1 year, and showing no healing tendency). After sharp debridement, the ulcers were covered by allografts with strict follow-up after discharge. Multiple allografts were performed when necessary, and a final autograft was applied in case of incomplete healing.

RESULTS

The records of 414 patients were analyzed. Forty-three patients were lost at follow-up, and the remaining 371 healed after 765 grafting procedures. In 163 patients, the ulcers healed by means of a final autograft. In all the remaining cases, allograft led to ulcer healing.

CONCLUSION

Allografts represent an effective treatment option in case of recalcitrant, large, deep and long-lasting leg ulcers.

The effect of co-transplantation of nerve fibroblasts and Schwann cells on peripheral nerve repair

Combinations of fibroblasts (Fbs) and corresponding epithelial cells have been widely used in many tissues, such as the skin and breast tissues, to augment tissue repair and remodeling. Recently, a large amount of new data has indicated that nerve Fbs play critical roles in Schwann cells (SCs) and axons in vitro. However, little is known regarding the effects of co-transplanting nerve Fbs and SCs on peripheral nerve repair in vivo. The aim of this study was to investigate the effect of co-transplanting sciatic nerve Fbs (SN-Fbs) and sciatic nerve SCs (SN-SCs) on nerve regeneration. We developed a 5 mm nerve-defect model in mice using a polyurethane (PUR) catheter and then injected one of four different mixtures of cells into the catheters to form the following four groups: pure Matrigel (Control group), SN-Fbs alone (SN-Fb group), SN-Fbs combined with SN-SCs at a ratio of 1:2 (Fb&SC group) and SN-SCs alone (SN-SC group). Histological and functional analyses were performed 3 months later. The results indicated that in vitro, the expression levels of NGF, BDNF and GDNF were significantly higher, and in vivo, a more moderate amount of extracellular matrix was produced in the Fb&SC group than in the SN-SC group. Compared to the other groups, co-transplanting SN-Fbs with SCs at a 1:2 ratio had significantly positive effects on nerve regeneration and functional recovery.

5th Congress of WUWHS Abstract book Florence, Italy September 25–29 2016

The abstract book contains the abstracts of keynote lectures, focus sessions, symposia, workshops, AIUC annual meeting, AISLEC annual meeting, EPUAP annual meeting, ETRS special session, sponsor symposia, oral presentations, poster presentations and the subject index.

Biomaterials and tissue engineering for scar management in wound care

Scars are a natural and unavoidable result from most wound repair procedures and the body's physiological healing response. However, they scars can cause considerable functional impairment and emotional and social distress. There are different forms of treatments that have been adopted to manage or eliminate scar formation. This review covers the latest research in the past decade on using either natural agents or synthetic biomaterials in treatments for scar reduction.

Stem Cell Markers (Cytokeratin 17 and Cytokeratin 19) in Scarring and Nonscarring Alopecia

BACKGROUND

Alopecia is one of the most important hair follicle (HF) disorders, which is divided into scarring (cicatricial) and nonscarring (noncicatricial) types.

OBJECTIVE

The aim of this study is to investigate the expression of stem cell (SC) markers such as cytokeratin (CK) 17 and CK19 in scarring and nonscarring alopecia.

MATERIALS AND METHODS

Thirty patients with scalp alopecia (15 with scarring alopecia and 15 without) together with ten healthy volunteers were included in this study. Biopsies were taken from all participants and stained for CK17 and CK19 using immunohistochemistry.

RESULTS

There was a statistically significant difference between the nonscarring group and the control group with regard to CK17 expression in the outer layers of the HFs (P = 0.00) and CK19 staining of the inner layers of the HFs (P = 0.008). There was a statistically significant difference between the scarring and the control groups regarding CK17 expression in the outer (P = 0.00) and the inner layers (P = 0.00) of the HFs and CK19 expression in the inner layers of the HFs (P = 0.00). CK17 expression in the outer layers (P = 0.02) and the inner layers of the HFs (P = 0.00) together with CK19 expression in the inner layers of the HFs (P = 0.00) showed statistically significant differences between scarring and nonscarring alopecia groups.

CONCLUSIONS

The presence of SC markers (CK17 and CK19) in the HFs was affected in both scarring and nonscarring alopecia, but the defect in scarring alopecia is more evident than that of nonscarring alopecia. The persistence of SC markers in some types of scarring alopecia could give a hope for the recovery of these lesions. Further studies are recommended to clarify the benefit from using HF SCs in the treatment of alopecia.

Morphological, functional and biochemical characterization of canine gingival fibroblasts

As dogs are good models for in vivo studies, it is interesting to evaluate the behavior of canine gingival fibroblasts (CGF) in vitro, so that these cells could be seeded on a matrix and later studied in vivo. The aim of this study was to perform a morphological, functional and biochemical analysis of CGF, comparing it with human gingival fibroblasts (HGF), as well as to evaluate the change of their characteristics over several passages. Using gingival fibroblasts from 3 dogs and 3 humans in the subculture (Sub), first (P1), third (P3), fifth (P5) and seventh (P7) passages, the following parameters were assessed: cell morphology, spreading, adhesion, viability and total protein content. The results showed no major differences between the passages in terms of morphology and spreading, and a tendency of greater adhesion and viability for HGF when compared with CGF. The total protein content was significantly higher for HGF. HGF exhibited greater functional and biochemical activity in vitro compared to CGF. Higher numbers at Sub were observed for both CGF and HGF in all evaluated parameters. The differences do not prevent the use of CGF for tissue engineering, but its use seems to be more appropriate in the subculture or first passage.

Biologicals and fetal cell therapy for wound and scar management

Few biopharmaceutical preparations developed from biologicals are available for tissue regeneration and scar management. When developing biological treatments with cellular therapy, selection of cell types and establishment of consistent cell banks are crucial steps in whole-cell bioprocessing. Various cell types have been used in treatment of wounds to reduce scar to date including autolog and allogenic skin cells, platelets, placenta, and amniotic extracts. Experience with fetal cells show that they may provide an interesting cell choice due to facility of outscaling and known properties for wound healing without scar. Differential gene profiling has helped to point to potential indicators of repair which include cell adhesion, extracellular matrix, cytokines, growth factors, and development. Safety has been evidenced in Phase I and II clinical fetal cell use for burn and wound treatments with different cell delivery systems. We present herein that fetal cells present technical and therapeutic advantages compared to other cell types for effective cell-based therapy for wound and scar management.

Artificial skin in perspective: concepts and applications

Skin, the largest organ of the human body, is organized into an elaborate layered structure consisting mainly of the outermost epidermis and the underlying dermis. A subcutaneous adipose-storing hypodermis layer and various appendages such as hair follicles, sweat glands, sebaceous glands, nerves, lymphatics, and blood vessels are also present in the skin. These multiple components of the skin ensure survival by carrying out critical functions such as protection, thermoregulation, excretion, absorption, metabolic functions, sensation, evaporation management, and aesthetics. The study of how these biological functions are performed is critical to our understanding of basic skin biology such as regulation of pigmentation and wound repair. Impairment of any of these functions may lead to pathogenic alterations, including skin cancers. Therefore, the development of genetically controlled and well characterized skin models can have important implications, not only for scientists and physicians, but also for manufacturers, consumers, governing regulatory boards and animal welfare organizations. As cells making up human skin tissue grow within an organized three-dimensional (3D) matrix surrounded by neighboring cells, standard monolayer (2D) cell cultures do not recapitulate the physiological architecture of the skin. Several types of human skin recombinants, also called artificial skin, that provide this critical 3D structure have now been reconstructed in vitro. This review contemplates the use of these organotypic skin models in different applications, including substitutes to animal testing.

Dressings used in epidermolysis bullosa blister wounds: a review

There is little rigorous evidence on the management of epidermolysis bullosa, so management is based on the patient's and clinician's preferences. However, there is a consensus that advanced dressings help promote healing and reduce pain.

Consistency and safety of cell banks for research and clinical use: preliminary analysis of fetal skin banks

Current restrictions for human cell-based therapies have been related to technological limitations with regards to cellular proliferation capacity, maintenance of differentiated phenotype for primary human cell culture, and transmission of communicable diseases. We have seen that cultured primary fetal cells from one organ donation could possibly meet the exigent and stringent technical aspects for development of therapeutic products. We could develop a master cell bank (MCB) of 50 homogenous ampoules of 4-5 million cells each from one fetal organ donation (skin) in short periods of time compared to other primary cell types. Safety tests were performed at all stages of the cell banking. MCB ampoules could create a working cell bank to be used for clinical or research use. Monolayer culture of fetal skin cells had a life span of 12-17 passages, and independent cultures obtained from the same organ donation were consistent for protein concentration (with 1.4-fold maximal difference between cultures) as well as gene expression of MMP-14, MMP-3, TIMP-3, and VEGF (1.4-, 1.9-, 2.1-, and 1.4-fold maximal difference between cultures, respectively). Cell cultures derived from four independent fetal skin donations were consistent for cell growth, protein concentration, and gene expression of MDK, PTN, TGF-beta1, and OPG. As it is the intention that banked primary fetal cells can profit from the potential treatment of hundreds of thousands of patients with only one organ donation, it is imperative to show consistency, tracability, and safety of the process, including donor tissue selection, cell banking, cell testing, and growth of cells in upscaling for the preparation of cell transplantation.

The role of fibroblasts in tissue engineering and regeneration

Fibroblasts are mesenchymal cells that can be readily cultured in the laboratory and play a significant role in epithelial-mesenchymal interactions, secreting various growth factors and cytokines that have a direct effect on epidermal proliferation, differentiation and formation of extracellular matrix. They have been incorporated into various tissue-engineered products such as Dermagraft (Advanced BioHealing, La Jolla, CA, U.S.A.) and Apligraf (Novartis, Basel, Switzerland) and used for a variety of clinical applications, including the treatment of burns, chronic venous ulcers and several other clinical applications in dermatology and plastic surgery. In this article we review the cell biology of dermal fibroblasts and discuss past and current experience of the clinical use of cultured fibroblasts.