Preparation and processing of human allogenic dermal matrix for utilization in reconstructive surgical procedures.

Aim: This article presents the development of a novel preparation and processing method as well as indication for clinical applications of human allogeneic acellular dermal matrix, which was developed originally in the Central Tissue Bank (CTB) for use in burn medicine and reconstructive surgery.

Methods: Acellular dermal matrix (ADM) is a biological material assigned for utilization in several surgical procedures due to its unique structure and advantageous properties. The article focuses on a novel preparation and processing method developed by CTB, which differs in its impact on the structure, biological and biomechanical properties of the final ADM compared to the wide range of commercially available ADM products and currently available ADM products of other tissue banks.

Bromelain-based enzymatic debridement as a treatment of choice in high-risk patient with deep facial burns, a case report.

Introduction: Deep facial burns are often combined with inhalation injury that could lead to patient destabilization. Accurate timing of surgical debridement of deep burns in a critical patient is the real medical art. Especially in patients with deep burned face and hands, in whom early debridement promises better functional and aesthetic results.

Adipose derived mesenchymal stem cells harvesting.

Background: The lipografting is increasingly used in the field of plastic surgery. Widely used harvesting technique of fatderived stem-cells is lipoaspiration. There exist two big streams of fat harvesting for lipografting: mechanical liposuction and manual liposuction.

Deep frozen amniotic membrane used as a scaffold and/or carrier for different cell types.

Amniotic membrane is a biological material widely used in plastic and reconstructive surgery and in ophthalmology. Due to its excellent biocompatibility and strength we tried to use it as a scaffold for the in vitro cultivation of different cell types, especially keratinocytes and limbal stem cells. It was possible to cultivate limbal stem cells and keratinocytes without using 3T3 mouse fibroblast feeder cells on deep frozen amniotic membranes.

What happens to an acellular dermal matrix after implantation in the human body? A histological and electron microscopic study.

Acellular matrices are used for various purposes and they have been studied extensively for their potential roles in regenerating tissues or organs. The acellular matrix generates physiological cues that mimic the native tissue microenvironment. Acellular dermal matrix (ADM) is a soft connective tissue graft generated by a decellularization process that preserves the intact extracellular skin matrix.

High sustained virological response rates using imported generic direct acting antiviral treatment for hepatitis C.

Background: High prices of direct acting antivirals (DAAs) for hepatitis C virus (HCV) can lead to restrictions on access to treatment in high- and middle-income countries. An increasing number of people in these countries are treating their HCV infection with generic drugs produced in India, China, Bangladesh or Egypt. This analysis assessed the efficacy of generic imported DAAs.

Delayed post mastectomy breast reconstructions with allogeneic acellular dermal matrix prepared by a new decellularizationmethod.

Acellular dermal matrix (ADM) is a tissue graft of allogeneic origin from post-mortem tissue donors prepared by an innovative decellularization process. The newly developed non-toxic and low cost decellularization process of cadaver origin dermis included ADM in breast reconstruction procedures proved to help coverage of the lower-pole of breast expanders or implants. As the results have shown, it did help to eliminate autologous dermis donor site morbidity along with shortening the operation time by avoiding elevation of additional muscle or fascia during the operation.

Development of a new method for the preparation of an acellular allodermis, quality control and cytotoxicity testing.

Demand for use of acellular allodermis is high but commercially appropriate products are not used routinely because of very high price and limited availability. These facts did motivate us to prepare acellular allodermis using a new, simple and less expensive method. We have developed a original method for preparation of acellular allogeneic dermis based on action of a proteolytic enzyme in combination with distilled water.

Cytotoxicity testing of burn wound dressings: first results.

Topical antimicrobial therapy represents an essential part of burn wound care. In order to prevent and treat burn wound infection dressings with antimicrobial properties are applied directly on the wound surface. Not only the infection control but also promotion of healing is very important in burn wound management.

Cytotoxicity testing of a polyurethane nanofiber membrane modified with chitosan/β-cyclodextrin/berberine suitable for wound dressing application: evaluation of biocompatibility.

In this study we evaluated the biocompatibility of a modified polyurethane nanofiber membrane on a polypropylene spunbond substrate. This material was treated with plasma using diffuse coplanar surface barrier discharge, and subsequent modification was done by continuous spraying of a biologically active chitosan solution (CHIT) containing an inclusion complex of β-cyclodextrin (β-CD) encapsulating berberine (BRB). Biocompatibility was evaluated using several in vitro assays.

Cytotoxicity testing of scaffolds potentially suitable for the preparation of three-dimensional skin substitutes.

The preparation and study of three-dimensional functional skin substitutes has been the focus of intense research for several decades. Dermal substitutes are now commonly used in medical practice for a variety of applications. Here, we assess the toxicity of seven selected acellular dermal matrix materials to establish their potential for use in future three-dimensional skin substitute studies.

[Employment of current results of tissue engineering in the development of skin substitutes].

Substitution of skin, particularly in extensive burns, is one of the key points for patients mortality reduction. In addition to the use of allogeneic and autologous skin substitutes, new developments in tissue engineering would enable the use biosynthetic and combined skin substitutes, which could mimic the structure and functions of normal skin. Several such types of substitutes like cultured allogeneic and autologous keratinocytes, allogeneic/autologous composites, acellular matrices, matrices based on biological substances such as collagen/hyaluronic acid, and matrices seeded by different cell types (keratinocytes, dermal fibroblasts, stem cells) already exist.

Skin explant cultures as a source of keratinocytes for cultivation.

Cultivated human keratinocytes can be used successfully in the treatment of burn patients, but efforts to heal burns and other wounds can be hampered by the very small skin biopsies available for cultivation of transplantable keratinocyte sheets. A small biopsy (and correspondingly small number of enzymatically isolated keratinocytes for use in classical cultivation techniques) can lead to a low yield of multilayer sheets for clinical application or unacceptably long cultivation times. One way of addressing this is to make use of skin remnants remaining after enzymatic digestion and culture cells migrating out of these skin explants.

Experience gained during the long term cultivation of keratinocytes for treatment of burns patients.

Both allogenic and autologous cultured skin cells have been used clinically on burn patients. In vitro cultivation of human keratinocytes has been routinely provided by the Central Tissue Bank in Bratislava since 1996, with an average annual production of around 7,000 cm(2). Keratinocytes have been cultivated using a version of the original by Rheinwald and Green (Cell 6:317-330, 1975) methodology which has been modified over time in our laboratory as we gained more experience with this serial passage system.

Induction of metalloproteinase 9 secretion from human keratinocytes by pleuran (beta-glucan from Pleurotus ostreatus).

Glucan preparations, primarily modified water-soluble glucans, are involved in the activation of the body's natural defense mechanisms and in the acceleration of the skin's wound-healing processes. Pleuran, an insoluble beta-D-glucan in hydrogel form, offers a natural alternative to more common chemically derivated soluble beta-D-glucans. Pleuran was applied to human keratinocyte primary cultures, and after 24 h of incubation the release of matrix metalloproteinase 9 (MMP-9) and metalloproteinase 2 (MMP-2) by stimulated keratinocytes was detected using gelatine zymography.

Comparison the cytotoxicity of hydroxyapatite measured by direct cell counting and MTT test in murine fibroblast NIH-3T3 cells.

The worldwide growing interest to biomaterials over the last years results from their irreplaceable role in medical clinic. Hydroxyapatite is used in bone reconstruction because of its similar chemical structure compared to the inorganic composition of human bone and it is basic building component of many newly prepared biomaterials. In this study, we evaluated cytotoxic/antiproliferative activity of hydroxyapatite extract using murine fibroblast cell line NIH-3T3 and two in vitro different cytotoxic assays: growth inhibition assay and MTT assay.

The syn3 strain HSZP of herpes simplex virus type 1 (HSV-1) is not pathogenic for mice and shows limited neural spread.

Strain HSZP of the herpes simplex virus type 1 (HSV-1) forms large giant cells in vitro. This property was found associated with a mutation that alters the codon CGC (in the strain KOS or 17 sequence) to CAC (in the HSZP sequence), changing the amino acid 857 from arginine to histidine in the cytoplasmic domain of the glycoprotein B (gB) polypeptide chain. Giant cell formation by ANGpath was attributed to a mutation that alters the codon GCC (in KOS and strain 17 sequences) to GTC (in ANGpath sequence) changing the amino acid 854 in the same (syn3) region of the gB molecule.

Phenotypic mixing between vesicular stomatitis and Uukuniemi viruses.

The population of vesicular stomatitis virus (VSV) which reproduced in cells preinfected with Uukuniemi virus (UUK) contained a proportion of VSV (UUK) pseudotypes. The virions containing the VSV genome were resistant to anti-VSV serum and neutralized with anti-UUK serum. In addition to previous reports on phenotypic mixing of different families of enveloped viruses, the combination of rhabdovirus surface antigen with bunyavirus genome is described.

Vesicular stomatitis virus pseudotype with neutralization antigen of tick-borne encephalitis virus.

Vesicular stomatitis virus (VSV), when grown in dual infection with tick-borne encephalitis (TBE) virus, produced pseudotype VSV (TBE) with surface proteins provided by TBE virus. This phenomenon can be employed in a rapid, accurate and sensitive test for detection and assay of neutralizing antibodies specific for TBE virus.

Cross-neutralization between vesicular stomatitis virus type Indiana and Chandipura virus.

Using highly potent immune sheep sera, it was possible to demonstrate that: (1) Two rhabdoviruses, classified in the Vesiculovirus genus on morphological grounds but previously considered unrelated, viz., the vesicular stomatitis virus type Indiana (VSV), and Chandipura virus (ChV), show a low-level, but distinct cross-neutralization. This was, in most combinations, considerably increased by complement.