Fibrin Gel as a Scaffold for Skin Substitute – Production and Clinical Experience

Abstract

SUMMARY -Th e purpose of this study was to create a fi brin-based human skin substitute in vitro with epidermal and dermal component and to assess its healing potential in deep partial and full thickness burns. Fibrin scaff olds were prepared from commercial fi brin glue kits. Human fi broblasts were cultured in fi brin gel. Human keratinocytes were seeded on the top of the gel. Viability of cells was determined fl uorimetrically. Scanning electron microscope and immunocytochemistry analysis of cultured cells were performed. After hydrosurgical preparation of deep burn necrotic tissue, wound bed was prepared for skin substitutes. Progress of healing was documented using visual estimation and photos. Scanning electron microscope images showed good cell attachment and colony spreading of keratinocytes and fi broblasts on fi brin scaff old. Immunofl uorescent staining of cell cultures on fi brin scaff old showed expression of vimentin, a marker of fi broblast cells, cytokeratin 19, a marker of epithelial stem cells, as well as involucrin, a marker of diff erentiated keratinocytes. Clinical results clearly showed that appearance of the skin did not diff er signifi cantly from the areas of transplanted skin using split-thickness skin graft techniques. In conclusion, using these fi brin-cultured autografts on massive full-thickness burn resulted in good healing.

Macrophages significantly enhance wound healing in a vascularized skin model

“…We therefore reduced the seeding time from 7 days to 1 day after fibrin gel molding. In other studies, HDKs were seeded only when embedded fibroblasts had reached a certain confluence . Our molding process did not address the confluence of embedded cells but focused on a shorter manufacturing time.…”

“…In other studies, HDKs were seeded only when embedded fibroblasts had reached a certain confluence. 22 Our molding process did not address the confluence of embedded cells but focused on a shorter manufacturing time. We regarded fibrin as an ideal scaffold because autologous fibrin can be extracted from blood and is highly biocompatible.…”

Cellular human tissue-engineered skin substitutes investigated for deep and difficult to heal injuries

“…In one of the cases where allogeneic cells were used, CSSs did not take and the engraftment of more autografts was required 93 . Rest of comparative studies, reported positive results for CSSs in terms of percentage of TBSA closed ([20.5 ± 2.5% for CSSs vs. 52.1 ± 2% for autografts 95 ], [29.9 ± 3.3% for CSSs vs. 47.0 ± 2% for autografts 104 ] after 28 days in both cases), time of healing (7.4 ± 0.9 days for CSSs vs. 7.9 ± 1.5 days for autografts 90 ), appearance (scars were less raised than autografts 88 ), percentage of wound area closed (95.4% for CSSs vs. 99% for autografts after 28 days 92 ), manipulation (easy in comparison with CESs 102 ), protein expression (keratin 19 and type IV collagen 105 ) or percentage of epithelialization (63.5 ± 35% after 21 days of engraftment 106 ).…”

“…Epithelialization was observed 99 Autologous keratinocytes and fibroblasts Prospective Uncontrolled Case Study 5 (1/4) 55.2 ± 18.5 (26–74) None Skin ulcers – 100 100 52–63 6–19 Effective treatment of long-standing hard-to-heal venous or mixed ulcers 100 Autologous keratinocytes and fibroblasts Case Report 4 (1/3) 42.3 ± 14.7 (29–63) None Burns 64.8 ± 26.9 (40–98) – 94.8 ± 4.3 (90–100) 21 1–9 Dermal part had a well-vascularized dermal matrix and bilayer structure was conserved 101 Autologous keratinocytes and fibroblasts Case Report 1 (1/0) 48 None Burns 40 – 88 19 1 CSS completely covered the wound area and smoothly adapted to the wound ground. Color resemblance of the transplant to the healthy skin increased through the follow-up period 102 Autologous keratinocytes and fibroblasts Case Report 2 9.5 ± 6.3 (4–14) None Burns 80 ± 21.2 (65–95) – – – 36 Appearance of the skin did not differ significantly from the areas treated with autografts 103 Autologous keratinocytes and fibroblasts Case Report 1 (0/1) 29 None Burns 70 100 100 28 6 Patient was discharged after 163 days of hospital admission with a complete skin coverage, correct functioning of the four limbs and autonomous walking 104 (NCT00591513) Autologous keratinocytes and fibroblasts Prospective Randomized Open-Label Paired-Site Comparison Clinical Trial ...…”

“…In those cases where different treatments were compared, engraftment of autografts was the gold standard treatment used as reference for each patient 88 , 90 , 92 , 93 , 95 , 101 , 102 , 104 – 106 . In one of the cases where allogeneic cells were used, CSSs did not take and the engraftment of more autografts was required 93 .…”