Development of a functional wound dressing composed of hyaluronic acid spongy sheet containing bioactive components: evaluation of wound healing potential in animal tests.

This study aimed to develop a novel wound dressing composed of hyaluronic acid (HA) spongy sheet containing bioactive components. The wound dressing prepared by the freeze-drying method has a two-layered structure: an upper layer composed of cross-linked high-molecular-weight HA (HMW-HA) and a lower layer composed of low-molecular-weight HA (LMW-HA) containing arginine (Arg), magnesium ascorbyl phosphate (vitamin C derivative: VC), and epidermal growth factor (EGF) (referred to as EGF-dressing). A wound dressing containing only Arg and VC was prepared in a similar manner (referred to as EGF-free-dressing).

Development of anti-adhesive spongy sheet composed of hyaluronic acid and collagen containing epidermal growth factor.

Anti-adhesive products need to be designed while considering the concept of wound healing. Two main events must proceed simultaneously: facilitating wound healing in surgically excised tissue, as well as preventing injured tissue from adhering to the surrounding tissue. The present study aimed to develop an anti-adhesive spongy sheet composed of hyaluronic acid and collagen (Col) containing epidermal growth factor, and to investigate the potential of this spongy sheet using an in vitro wound surface model (placing a spongy sheet on a fibroblast-incorporating Col gel sheet) and an in vitro inter-tissue model (placing a spongy sheet between two fibroblast-incorporating Col gel sheets).

Development of cultured dermal substitute composed of hyaluronic acid and collagen spongy sheet containing fibroblasts and epidermal growth factor.

The present study aimed to develop a two-layered cultured dermal substitute (CDS). The upper layer is a hyaluronic acid (HA) and collagen (Col) spongy sheet with or without epidermal growth factor (EGF). The lower layer is a HA spongy sheet and Col gel containing fibroblasts.

Development of novel wound dressing composed of hyaluronic acid and collagen sponge containing epidermal growth factor and vitamin C derivative.

This study was designed to investigate the potential of a wound dressing composed of hyaluronic acid (HA) and collagen (Col) spongy sheet containing epidermal growth factor (EGF) and vitamin C derivative (VC). High-molecular-weight HA aqueous solution, hydrolyzed low-molecular-weight HA aqueous solution and heat-denatured Col aqueous solution were mixed, followed by freeze-drying to obtain a spongy sheet. Cross-linkage between Col molecules was induced by UV irradiation of the spongy sheet (C-wound dressing).

Potential of wound dressing composed of hyaluronic acid containing epidermal growth factor to enhance cytokine production by fibroblasts.

This study aimed to investigate the potential of a wound dressing composed of hyaluronic acid (HA) containing epidermal growth factor (EGF) to enhance cytokine production by fibroblasts. The present wound dressing has a two-layered spongy structure: an upper layer composed of crosslinked high-molecular-weight HA, and a lower layer composed of low-molecular-weight HA containing arginine (Arg) and vitamin C derivative (VC) with or without EGF. Human fibroblast-embedded collagen gel sheet (cultured dermal substitute: CDS) was elevated to the interface between the air and culture medium to create a wound surface model onto which each wound dressing was placed, which was followed by culture for 7 days.

Wound dressing composed of hyaluronic acid and collagen containing EGF or bFGF: comparative culture study.

We developed a novel wound dressing composed of a hyaluronic acid (HA) and collagen (Col) spongy sheet containing epidermal growth factor (EGF) or basic fibrolast growth factor (bFGF) by freeze-drying method (EGF-wound dressing or bFGF-wound dressing, respectively). A wound dressing without any growth factor was prepared as a control in a similar manner as above (C-wound dressing). Intermolecular cross-linkage between Col molecules was induced by UV irradiation.

Development of an artificial dermis composed of hyaluronic acid and collagen.

This study aimed to investigate the efficacy of an artificial dermis composed of hyaluronic acid (HA) and collagen (Col) with or without epidermal growth factor (EGF), both in in vitro and in vivo. The cross-linked high molecular weight HA spongy sheet was prepared by freeze-drying. The spongy sheet was immersed in a mixed solution of high molecular weight HA, low molecular weight HA, and heat-denatured Col, and then lyophilized to obtain a two-layered spongy sheet.

Safety and utility of a PMMA-based tissue adhesive for closure of surgical incision wounds.

This study aimed to investigate the safety and utility of the polymethylmethacrylate (PMMA)-based tissue adhesive (PMMA-ta) for wound closure. This product is composed of 4-methacryloyloxyethyl trimellitate anhydride and methylmethacrylate as monomers, tri-n-butylborane as initiator, and PMMA powder as filler. These components are mixed at the time of use.

Potential of a cryopreserved cultured dermal substitute composed of hyaluronic acid and collagen to release angiogenic cytokine.

An allogeneic cultured dermal substitute (CDS) was prepared by culturing fibroblasts on a spongy matrix of hyaluronic acid (HA) and collagen (Col), which was then cryopreserved. This cryopreserved allogeneic CDS (CDS-1; cryopreserved for 1 month, CDS-6; cryopreserved for 6 months) was thawed and re-cultured for a period of 7 days to investigate the potential of the CDS for wound treatment. The cell metabolic activity in the CDS and their cytokine production were measured using an MTT assay and ELISA.

Clinical trial of allogeneic cultured dermal substitutes for intractable skin ulcers.

The effect of allogeneic cultured dermal substitute (CDS) on wound healing was evaluated in 9 intractable skin ulcers in 5 patients who had failed to improve despite conventional topical treatment with basic fibroblast growth factor (bFGF) for more than 2 months. In general, the topical application of bFGF is effective in facilitating wound healing. However, skin regeneration was very slow in the present 9 cases.

Evaluation of a wound dressing composed of hyaluronic acid and collagen sponge containing epidermal growth factor in diabetic mice.

This study investigated the effect of a wound dressing composed of hyaluronic acid (HA) and collagen (Col) sponge containing epidermal growth factor (EGF) on wound healing in diabetic mice. High-molecular-weight (HMW) HA aqueous solution, hydrolyzed low-molecular-weight (LMW) HA aqueous solution and heat-denatured Col aqueous solution were mixed, followed by freeze-drying to obtain a spongy sheet. Cross-linkage between Col molecules was induced by UV irradiation to the spongy sheet (Type-I wound dressing).

Treatment of intractable skin ulcers caused by vascular insufficiency with allogeneic cultured dermal substitute: a report of eight cases.

Chronic leg ulcers have various causes and can be difficult to treat, although topical treatments, including basic fibroblast growth factor and PGE1, have been used. We applied an allogeneic cultured dermal substitute (CDS) to eight patients with intractable ulcers. The patients had various underlying diseases, including diabetes mellitus, systemic lupus erythematosus, antiphospholipid syndrome, necrobiosis lipoidica, stasis dermatitis, livedo vasculopathy, and rheumatoid arthritis.

Effect of EGF and bFGF on fibroblast proliferation and angiogenic cytokine production from cultured dermal substitutes.

Growth factors accelerate wound healing but the underlying mechanisms remain poorly understood. The aim of this study was to investigate the effect of epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF) on fibroblast proliferation and production of angiogenic factors from cultured dermal substitutes (CDS). In the first experiment, fibroblasts were seeded into a flask at a density of 1 × 10(4) cells/cm(2).

Development of a wound dressing composed of hyaluronic acid and collagen sponge with epidermal growth factor.

This study was designed to investigate the effect of a wound dressing composed of hyaluronic acid (HA) and collagen (Col) sponge containing epidermal growth factor (EGF) on various parameters of wound healing in vitro and in vivo. High-molecular-weight (HMW) HA solution, hydrolyzed low-molecular-weight (LMW) HA solution and heat-denatured Col solution were mixed, followed by freeze-drying to obtain a spongy sheet. Cross-linkage between Col molecules was induced by UV irradiation to the spongy sheet (Type-I dressing).

Optimum preservation for autologous cultured dermal substitutes.

The application of autologous cultured dermal substitute (CDS) is a promising procedure for improving burn scar contracture. Preparation of CDS requires a period of about 3 weeks before the date of surgery. When the date of surgery is postponed, CDS must be preserved under optimum conditions.

Development of a wound dressing composed of hyaluronic acid sponge containing arginine and epidermal growth factor.

Hyaluronic acid (HA) has the ability to promote wound healing. Epidermal growth factor (EGF) is able to promote the proliferation of various cell types, in addition to epidermal cells. A novel wound dressing was designed using high-molecular-weight hyaluronic acid (HMW-HA) and low-molecular-weight hyaluronic acid (LMW-HA).

A case of lower-extremity deep burn wounds with periosteal necrosis successfully treated by use of allogenic cultured dermal substitute.

In patients with burns, bone exposure accompanies serious problems which occasionally lead to amputation. We present a case of an 82-year-old woman who sustained 22% of total body surface area flame burns on her bilateral lower extremities with bone exposure. Despite fascial excision and mesh skin graft, muscles, bones, and tendons were widely exposed on her right leg.

Response of intractable skin ulcers in recessive dystrophic epidermolysis bullosa patients to an allogeneic cultured dermal substitute.

Recessive dystrophic epidermolysis bullosa (RDEB) is an inherited skin disorder caused by mutations in the COL7A1 gene, which encodes collagen VII (COL7). Skin ulcers in RDEB patients are sometimes slow to heal. We describe here the therapeutic response of intractable skin ulcers in two patients with generalized RDEB to treatment with an allogeneic cultured dermal substitute (CDS).

Therapeutic angiogenesis by autologous bone marrow cell implantation together with allogeneic cultured dermal substitute for intractable ulcers in critical limb ischaemia.

Therapeutic angiogenesis by autologous bone marrow cell implantation improves blood supply in patients with critical limb ischaemia. In addition, allogeneic cultured dermal substitute is effective for intractable ulcers. The present study determined the effectiveness of bone marrow cell implantation combined with allogeneic cultured dermal substitute in treating severely ischaemic ulcers.

Design of a matrix for cultured dermal substitute suitable for simultaneous transplantation with auto-skin graft: evaluation in animal test.

This study focused on the design of a matrix for a cultured dermal substitute (CDS). Two types of cross-linked spongy matrix were designed. The weight ratio of hyaluronic acid (HA) to a cross-linking agent was adjusted to 5:1 (c-5) or 15:1 (c-15).

Effective treatment of intractable skin ulcers using allogeneic cultured dermal substitutes in patients with systemic lupus erythematosus.

Skin ulcers in systemic lupus erythematosus (SLE) patients are non-healing or intractable, because various factors or complications, including vasculitis and immunosuppressants, impair wound healing. In the present study, we applied cultured dermal substitutes (CDSs) to 3 cases of SLE skin ulcers because various systemic or topical therapies were ineffective. CDSs are prepared by culturing human fibroblasts on two-layered spongy matrices of hyaluronic acid and atelo-collagen, and they effectively promote the healing of severe skin defects.

Development of a wound dressing composed of a hyaluronic acid sponge containing arginine.

Spongy sheets composed of cross-linked high-molecular-weight (HMW) hyaluronic acid (HA) were prepared by freeze-drying an aqueous HMW-HA solution containing cross-linking agent (Group I). The Group I sheet was immersed into an aqueous low-molecular-weight (LMW) HA solution with or without L-arginine (Arg) and was then freeze-dried to prepare several types of spongy sheets (Groups II-V). The amount of Arg was 1.

Standardization for mass production of allogeneic cultured dermal substitute by measuring the amount of VEGF, bFGF, HGF, TGF-beta, and IL-8.

Fibroblasts were isolated from a piece of donated skin measuring about 1 x 1 cm and were proliferated over nine successive cultivations. Fibroblasts obtained from the fourth cultivation were cryopreserved in 10 cryotubes as master cells. Fibroblasts obtained from the fifth to ninth cultivations were cryopreserved in 49 cryotubes in total as working cells.

Comparative evaluation of re-epithelialization promoted by fresh or cryopreserved cultured dermal substitute.

Allogeneic cultured dermal substitute (CDS) was prepared by plating cultured fibroblasts on a two-layered spongy matrix of hyaluronic acid and atelocollagen, followed by culturing for 1 week. The resulting fresh CDS was then cryopreserved in a freezer at -152 degrees C in accordance with conventional procedures. Fresh CDS was rinsed thoroughly with lactated Ringer's solution to remove fetal bovine serum (FBS) and was then used in the clinical study, whereas cryopreserved CDS was thawed and then rinsed with lactated Ringer's solution to remove cryoprotectant and FBS.