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Allogeneic Keratinocytes

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Eva Matoušková – 1st expert on this subject based on the ideXlab platform

  • Y chromosome and vimentin used to trace the fate of Allogeneic Keratinocytes delivered to the wound by the recombined human/pig skin.
    Folia Biologica, 2020
    Co-Authors: Pokorná E, Pavel Veselý, Broz L, Eva Matoušková

    Abstract:

    : RHPS, composed of confluent Allogeneic Keratinocytes cultured on cell-free pig dermis, stimulates wound healing when applied with the keratinocyte layer facing the wound. So far it has not been clarified whether the confluent Keratinocytes implanted ‘upside-down’ can ‘take’ or only stimulate healing by producing growth factors. Confluent male Keratinocytes were grafted onto donor sites of three female patients. Biopsies were taken on days 4, 6 and 9 after grafting. The fate of donor cells was followed in paraffin sections by FISH for the Y chromosome and by persisting expression of vimentin taken as a marker of cultured Keratinocytes. Histological evaluation was complemented by detection of keratin 10 and involucrin. All three donor sites healed within one week. On day 4 the early neoepidermis was multilayered but disordered after transplantation. A large proportion of cells were apparently of donor origin as indicated by the presence of Y chromosomes, irregular morphology, expression of vimentin in the bottom and upper layers of the neoepidermis, and by irregular expression of involucrin and keratin 10 only in the central layer of the neoepidermis. From day 6 onwards, the new epidermis acquired an ordered stratification. Involucrin and keratin 10 renewed normal distribution in suprabasal layers. Concomitantly, vimentin expression was decreasing. The Y chromosome was still found on day 6 but not on day 9. We concluded that confluent Allogeneic Keratinocytes temporarily ‘take’ to the wound and contribute to rapid wound closure, being replaced by the patient’s epidermal cells after about one week.

  • human Allogeneic Keratinocytes cultured on acellular xenodermis the use in healing of burns and other skin defects
    Bio-medical Materials and Engineering, 2006
    Co-Authors: Eva Matoušková, Radana Königová, L Broz, Vlasta Stolbova, Leo Klein, Pavel Veselý

    Abstract:

    The tissue engineered skin should be composed of both dermal and epidermal layers. We combined cultured human Allogeneic Keratinocytes with acellular xenodermis prepared from pig xenografts. The resulting composite skin was termed recombined human/pig skin (RHPS), and could be cultured in both, undifferentiated and differentiated phenotype. The undif- ferentiated RHPS was grown submerged and formed 1-2 layers of Keratinocytes. The differentiated phenotype (D-RHPS) was grown at the air-liquid interface and formed 5-20 cell layers similar to the normal epidermis, including the granular and horny layers. Undifferentiated RHPS has skin-like consistency and has been successfully used for treatment of burns and skin defects using “upside-down” application. Donor sites and deep dermal burn wounds prepared by tangential excision or deep dermabra- sion grafted with RHPS healed in the course of about one week after keratinocyte transplantation. Simple acellular xenodermis without Keratinocytes can also be used as temporary cover for donor sites, small to medium leg ulcers and other skin defects. Xenodermis can be fully sterilized and stored at the room temperature.

  • Prevention of burn wound conversion by Allogeneic Keratinocytes cultured on acellular xenodermis
    Cell and Tissue Banking, 2002
    Co-Authors: Eva Matoušková, Ludomír Brož, Eva Pokorná, Radana Königová

    Abstract:

    Deep dermal burns frequently tend to convert into full-thickness skin loss. We found that this wound deepening may be prevented by recombined human/pig skin (RHPS), consisting of human Allogeneic Keratinocytes cultured on acellular pig dermis. RHPS has skin-like consistency and therefore optimal adhesiveness to the wound. It can be easily removed from the dish and transferred to the recipient. The wound bed has to be prepared by tangential excision or deep dermabrasion to the level of capillary bleeding. RHPS has to be applied ‘upside-down’, with the epidermal layer facing the wound, to avoid the dermal matrix forming a barrier to the nutrients for the Keratinocytes. In our practice, more than 70% of early excised or deeply dermabraded wounds grafted with RHPS healed in the course of one week after keratinocyte transplantation.

M Frey – 2nd expert on this subject based on the ideXlab platform

  • the treatment of deep dermal hand burns how do we achieve better results should we use Allogeneic Keratinocytes or skin grafts
    Burns, 2010
    Co-Authors: W Haslik, Larspeter Kamolz, David B Lumenta, M Hladik, Harald Beck, M Frey

    Abstract:

    Abstract The treatment of deep dermal burns has a broad spectrum and has been subject to discussion over the past years. The treatment of hand burns is challenging due to the high requirements to aesthetic and functional outcome. 27 patients, 7 women and 20 men with deep dermal hand burns with a mean age of 41.3 ± 16.5 and a mean TBSA of 15% ± 19.6% were treated either with Allogeneic cryopreserved Keratinocytes or with split skin grafts. Long-term follow-up revealed no statistical significant differences between the two groups concerning Vancouver Scar Scale as well as hand function judged by the DASH score; however there was a tendency to higher VSS scores and impaired aesthetic results in the keratinocyte group. Allogeneic Keratinocytes are a suitable armentarium for the treatment of deep dermal hand burns; and, if used correctly, they can produce a timely healing comparable to split-thickness skin grafts. Limited availability, high costs as well as the need for special skills are key factors, which render application of this technique outside specialist burn centres virtually impossible. In our opinion, the cultivation and use of Keratinocytes should be reserved to these centres in order to facilitate a sensible application for a full range of indications. We recommend usage of Allogeneic Keratinocytes for deep dermal hand burns only in severely burned patients with a lack of donor sites. Patients with unrestricted availability of donor sites seem to profit from the application of split-thickness skin grafts according to our results.

  • the use of Allogeneic cultivated Keratinocytes for the early coverage of burns the viennese concept
    Osteosynthesis and Trauma Care, 2007
    Co-Authors: L P Kamolz, H Andel, B Eisenbock, S Burjak, J Roka, T Rath, M Frey

    Abstract:

    In the past ten years more than 350 patients suffering from burns were treated in our centre with Allogeneic Keratinocytes, which were cultivated and transplanted as Allogeneic sheet grafts for the coverage of deep dermal defects. In our institution donor skin samples were mostly acquired from other burn patients or organ donors. Seventy-five patients with deep partial thickness burns of the face were treated according to following concept: Other indications include deep dermal burns (especially scalds) in children and coverage of early excised deep dermal wounds in adults. In both patient groups, a significant reduction of donor-site morbidity and perioperative blood loss was noted. Moreover, Allogeneic keratinocyte sheet grafts were used to cover donor sites of patients with burns exceeding 50% TBSA. In these patients the use of Keratinocytes allowed earlier repeated harvesting of skin grafts. A modified sandwich technique (widely meshed autografts in combination with Allogeneic Keratinocytes) was used in selected patients who were suffering from very large full-thickness burns (>60% TBSA full thickness). This technique was used in order to decrease epithelialisation time of these widely expanded autologous skin grafts. In our hands the use of Allogeneic keratinocyte sheet grafts is a procedure that renders constantly reliable results in deep dermal burns. It minimises the areas of autologous skin harvesting and reduces the amount of blood transfusions.

  • should dermal scald burns in children be covered with autologous skin grafts or with Allogeneic cultivated Keratinocytes the viennese concept
    Burns, 2005
    Co-Authors: Rupert Koller, Larspeter Kamolz, Margot Ruzicka, G Burda, Bettina Bierochs, Guenther Meissl, M Frey

    Abstract:

    Abstract The treatment of scald burns in children is still under discussion. The aim of the present study was to evaluate an optimised treatment regime for scald burns in children. Between 1997 and 2002, 124 children underwent surgical intervention due to burn injuries. Thirty-six out of these 124 children were enrolled into the evaluation of our recent treatment protocol. Twenty-two children with scald burns covering an average body surface area (TBSA) of 18.5% were treated by early excision and coverage with Allogeneic Keratinocytes in case of partial thickness lesions (keratinocyte group). Fourteen children with a TBSA of 17.2% were treated with autologous skin grafts alone (skin graft group). Both groups were comparable according to age, burn depth and affected TBSA. The complete clinical follow-up examination of at least 17 months was performed in 12 out of 22 children of the keratinocyte group and in 9 out of 14 patients of the comparative group. Visible scar formations were classified according to the Vancouver Scar Scale (VSS) in each patient. The use of Allogeneic Keratinocytes led to complete epithelialisation within 12 days in 20 of the 22 cases. No secondary skin grafting procedures had to be done. Skin take rate at the sixth postoperative day was 100% in the skin graft group. Blood transfusions were administered intraoperatively according to the clinical need of the patients by the responsible anaesthesiologist. The mean volume of blood, which had to be transfused was 63.9 ml in the keratinocyte group and significantly lower than the volume of 151.4 ml, which was administered in the skin graft group ( p  = 0.04). At follow up the VSS observed in areas covered by Keratinocytes was 2.33 on the average and therefore, significantly lower than the VSS of 5.22 in skin grafted areas of the comparative group ( p  = 0.04). In children the use of cultivated Keratinocytes in partial thickness scald burns is a procedure, which renders constantly reliable results. It minimizes the areas of autologous skin harvesting and reduces the amount of blood transfusions. The fact that less scarring is observed after keratinocyte grafting leads to the conclusion that skin grafting in children should be restricted to scalded areas, which have to be excised to the subcutaneous fat tissue.

Herbert B Slade – 3rd expert on this subject based on the ideXlab platform

  • the influence of patient and wound variables on healing of venous leg ulcers in a randomized controlled trial of growth arrested Allogeneic Keratinocytes and fibroblasts
    Journal of Vascular Surgery, 2013
    Co-Authors: John C Lantis, William A Marston, Alik Farber, Robert S Kirsner, Yuxin Zhang, Innes D Cargill, Herbert B Slade

    Abstract:

    Objective To examine patient and wound variables presumed to influence healing outcomes in the context of therapeutic trials for chronic venous leg ulcers. Methods This double-blind, vehicle-controlled study was conducted with randomized assignment to one of four cell therapy dose groups (n = 46, 43, 44, 45) or vehicle control (n = 50). A 2-week run-in period was used to exclude rapid healers and those with infection or uncontrolled edema. This was a multicenter (ambulatory, private, hospital-based and university-based practices, and wound care centers in North America) study. Adults ≥18 years old with chronic venous insufficiency associated with an uninfected venous leg ulcer (2-12 cm 2 area, 6-104 weeks’ duration) were included in the study. Excluded were pregnant or lactating women, wounds with exposed muscle, tendon or bone, patients unable to tolerate compression bandages, or patients who had exclusionary medical conditions or exposure to certain products. Exclusion during run-in included patients with infection, uncontrolled severe edema or with healing rates ≥0.349 cm/2 wk. Screen fail rate was 37% (134/362), and the withdrawal rate was ∼10% (23 of 228). Growth-arrested neonatal dermal fibroblasts and Keratinocytes were delivered via pump spray in a fibrin sealant-based matrix, plus a foam dressing and four-layer compression bandaging. Treatment continued for 12 weeks or until healed, whichever occurred first. Patient demographic and wound-related variables were evaluated for influence on complete wound healing in all patients, as well as the subsets of treated and control patients. Results Wound duration ( P  = .004) and the presence of specific quantities of certain bacterial species ( P P  = .012), wound area ( P  = .026), wound location ( P  = .011), and specific quantities of certain bacterial species ( P  = .002). Age, sex, race, diabetes, HbA1C, peripheral neuropathy, and serum prealbumin did not significantly affect healing. Body mass index was positively associated with healing in cell-treated patients. Conclusions Wound duration is a quantifiable surrogate for one or more undefined variables that can have a profound negative effect on venous leg ulcer healing. Although cell therapy overcame barriers to healing, the only specific barrier identified was the presence of certain bacterial species. Interventional trials of potentially effective new therapies can be most informative when patients with suspected barriers to healing are included. The specific measurement of candidate barriers such as microbial pathogens, wound inflammatory state, and fibroblast function should be considered in future randomized trials to improve our understanding of the basis for chronicity.

  • cell persistence of Allogeneic Keratinocytes and fibroblasts applied in a fibrin matrix to acute full thickness wounds
    Cell medicine, 2012
    Co-Authors: Jaime E Dickerson, John V Planz, Barry T Reece, Kathy A Weedon, Sandy D Kirkpatrick, Herbert B Slade

    Abstract:

    HP802-247 is a living cell suspension of cultured Allogeneic growth-arrested human male Keratinocytes and fibroblasts (1:9 ratio), intended for spray application to chronic wounds. In this study, a small wound was created on the arms of 28 healthy female volunteers (3-mm punch), followed by a single application of HP802-247. At each subsequent week for 8 weeks, a punch excision of the wounds was performed on a cohort of three subjects. Excised specimens were analyzed for Allogeneic fibroblast and keratinocyte DNA determined by Y-chromosome short-tandem repeats using PCR amplification followed by capillary electrophoresis, a method with estimated sensitivity of 1 male cell in a background of 8,000 female cells. A complete haplotype attributable to HP802-247 fibroblasts was detected in three of three samples at 1 week, with one partial and one complete fibroblast haplotype detected at 2 weeks, and one partial keratinocyte haplotype detected at 3 weeks postapplication. The findings indicate that HP802-247 can be expected to persist in an acute wound bed for up to 2 weeks postapplication.