A Novel Treatment for Giant Congenital Melanocytic Nevi Combining Inactivated Autologous Nevus Tissue by High Hydrostatic Pressure and a Cultured Epidermal Autograft: First-in-Human, Open, Prospective Clinical Trial.

Background: Giant congenital melanocytic nevi are large skin lesions associated with a risk of malignant transformation. The authors developed a novel treatment to reconstruct full-thickness skin defects by combining an inactivated nevus as the autologous dermis and a cultured epidermal autograft. The first-in-human trial of this treatment was performed.

Efficacy of the dual controlled release of HGF and bFGF impregnated with a collagen/gelatin scaffold.

Background: We previously developed collagen/gelatin sponges (CGS) able to sustain and release basic fibroblast growth factor (bFGF) and reported that this CGS impregnated with bFGF promoted dermis-like tissue formation. We herein confirmed the single-sustained release of hepatocyte growth factor (HGF) and the dual sustained release of HGF and bFGF from CGSs, and explored its efficacy using a murine model of skin defects.

Materials And Methods: The sustained release of HGF alone and both HGF and bFGF from CGSs were evaluated in vitro.

Melanin pigments in the melanocytic nevus regress spontaneously after inactivation by high hydrostatic pressure.

We report a novel treatment for giant congenital melanocytic nevi (GCMN) that involves the reuse of resected nevus tissue after high hydrostatic pressurization (HHP). However, the remaining melanin pigments in the inactivated nevus tissue pose a problem; therefore, we performed a long-term observation of the color change of inactivated nevus tissue after HHP. Pressurized nevus specimens (200 MPa group, n = 9) and non-pressurized nevus tissues (control group, n = 9) were subcutaneously implanted into nude mice (BALB/c-nu) and then harvested 3, 6, and 12 months later.

Development of a novel bioabsorbable implant that is substituted by adipose tissue in vivo.

Recently, adipose tissue has been regenerated by combining scaffolds, growth factors, and/or adipose-tissue-derived stromal cells. However, the safety of growth factors and adipose-tissue-derived stromal cells has not been confirmed in cancer patients. We reported the regeneration of adipose tissue in the internal space of a polypropylene mesh containing a collagen sponge (CS), without using any growth factors or cells.

Cultured Human Epidermis Combined With Meshed Skin Autografts Accelerates Epithelialization and Granulation Tissue Formation in a Rat Model.

Introduction: As the take rate of cultured epidermal autografts in burn wound treatment is variable, widely expanded meshed auto skin grafts are often used in combination with cultured epidermal autograft to increase the take rate and achieve definitive wound coverage. However, a long time (3-4 weeks) required to prepare a cultured epidermis sheet is a disadvantage. Allogeneic cultured epidermis can be prepared in advance and cryopreserved to be used in combination with auto meshed skin grafts for treating third-degree burns.

The superiority of the autografts inactivated by high hydrostatic pressure to decellularized allografts in a porcine model.

We are developing a novel skin regeneration therapy in which the inactivation of nevus tissue via high hydrostatic pressure (HHP) is used in the reconstruction of the dermis in combination with a cultured epidermal autograft. In this study, we used a porcine skin graft model to explore whether autologous skin including cellular debris inactivated by HHP or allogeneic skin decellularized by HHP is better for dermal reconstruction. Grafts (n = 6) were prepared for five groups each: autologous skin without pressurization group (control group), autologous skin inactivated by 200 MPa group, autologous skin inactivated by 1000 MPa group, allogeneic skin decellularized by 200 MPa group, and allogeneic skin decellularized by 1000 MPa group.

The Alteration of the Epidermal Basement Membrane Complex of Human Nevus Tissue and Keratinocyte Attachment after High Hydrostatic Pressurization.

We previously reported that human nevus tissue was inactivated after high hydrostatic pressure (HHP) higher than 200 MPa and that human cultured epidermis (hCE) engrafted on the pressurized nevus at 200 MPa but not at 1000 MPa. In this study, we explore the changes to the epidermal basement membrane in detail and elucidate the cause of the difference in hCE engraftment. Nevus specimens of 8 mm in diameter were divided into five groups (control and 100, 200, 500, and 1000 MPa).

An Exploratory Clinical Trial of a Novel Treatment for Giant Congenital Melanocytic Nevi Combining Inactivated Autologous Nevus Tissue by High Hydrostatic Pressure and a Cultured Epidermal Autograft: Study Protocol.

Background: Giant congenital melanocytic nevi (GCMNs) are large brown to black skin lesions that appear at birth and are associated with a risk of malignant transformation. It is often difficult to reconstruct large full-thickness skin defects after the removal of GCMNs.

Objective: To overcome this difficulty we developed a novel treatment to inactivate nevus tissue and reconstruct the skin defect using the nevus tissue itself.

A Comparison of Conventional Collagen Sponge and Collagen-Gelatin Sponge in Wound Healing.

The objective of this study was to compare the effectiveness of the collagen-gelatin sponge (CGS) with that of the collagen sponge (CS) in dermis-like tissue regeneration. CGS, which achieves the sustained release of basic fibroblast growth factor (bFGF), is a promising material in wound healing. In the present study, we evaluated and compared CGSs and conventional CSs.

Preparation of Partial-Thickness Burn Wounds in Rodents Using a New Experimental Burning Device.

Objective: The manual application of hot water or hot metal to an animal's skin surface is often used to prepare burn wound models. However, manual burn creation is subject to human variability. We developed a new device that can control the temperature, time, and pressure of contact to produce precise and reproducible animal burn wounds and investigated the conditions required to prepare various burn wounds using our new device.

Efficacy of gelatin gel sheets sustaining epidermal growth factor for murine skin defects.

Background: Epidermal growth factor (EGF) plays an important role in wound healing. However, EGF must be applied daily due to rapid inactivation in vivo. We investigated the sustained release of EGF from gelatin gel sheets (GGSs) and the efficacy of GGSs impregnated with EGF for promoting wound healing.

Efficacy of gelatin gel sheets in sustaining the release of basic fibroblast growth factor for murine skin defects.

Background: Gelatin has been used as a material sustaining the release of basic fibroblast growth factor (bFGF), which promotes fibroblast proliferation and capillary formation and accelerates wound healing. In the application of these materials, bFGF is impregnated immediately before application, and it is difficult to conform the shape to the wound. In this study, we prepared a pliable and plastic gelatin gel sheet (GGS) that sustains bFGF and conforms to the shape of the wound as a result of cross-linking just before application.

Verification of the Inactivation of Melanocytic Nevus in vitro Using a Newly Developed Portable High Hydrostatic Pressure Device.

High hydrostatic pressure (HHP) technology is a physical method for inactivating tissue. We reported that nevus specimens were inactivated after HHP at 200 MPa and that the inactivated nevus could be used as autologous dermis for covering skin defects. In this study, we verified the inactivation of nevus specimens using a newly developed portable HHP device which will be used in a clinical trial.

An evaluation of the engraftment and the blood flow of porcine skin autografts inactivated by high hydrostatic pressure.

We previously reported that exposure to a high hydrostatic pressure (HHP) of 200 MPa could completely inactivate porcine skin without damaging the extracellular matrix. In this study, we used an autologous porcine skin graft model and explored whether the skin inactivated by HHP could be engrafted without inflammation to the residual cellular components. Twenty-one full-thickness skin grafts of 1.

Preparation of Inactivated Human Skin Using High Hydrostatic Pressurization for Full-Thickness Skin Reconstruction.

We have reported that high-hydrostatic-pressure (HHP) technology is safe and useful for producing various kinds of decellularized tissue. However, the preparation of decellularized or inactivated skin using HHP has not been reported. The objective of this study was thus to prepare inactivated skin from human skin using HHP, and to explore the appropriate conditions of pressurization to inactivate skin that can be used for skin reconstruction.

Inactivation of Human Nevus Tissue Using High Hydrostatic Pressure for Autologous Skin Reconstruction: A Novel Treatment for Giant Congenital Melanocytic Nevi.

Giant congenital melanocytic nevi are intractable lesions associated with a risk of melanoma. High hydrostatic pressure (HHP) technology is a safe physical method for producing decellularized tissues without chemicals. We have reported that HHP can inactivate cells present in various tissues without damaging the native extracellular matrix (ECM).

The rapid inactivation of porcine skin by applying high hydrostatic pressure without damaging the extracellular matrix.

We previously reported that high hydrostatic pressure (HHP) of 200 MPa for 10 minutes could induce cell killing. In this study, we explored whether HHP at 200 MPa or HHP at lower pressure, in combination with hyposmotic distilled water (DW), could inactivate the skin, as well as cultured cells. We investigated the inactivation of porcine skin samples 4 mm in diameter.