Treatment Of Deep Wounds Research Articles

Bioengineered Wound Healing Skin Models: The Role of Immune Response and Endogenous ECM to Fully Replicate the Dynamic of Scar Tissue Formation In Vitro.

The healing of deep skin wounds is a complex phenomenon evolving according with a fine spatiotemporal regulation of different biological events (hemostasis, inflammation, proliferation, remodeling). Due to the spontaneous evolution of damaged human dermis toward a fibrotic scar, the treatment of deep wounds still represents a clinical concern. Bioengineered full-thickness skin models may play a crucial role in this direction by providing a deep understanding of the process that leads to the formation of fibrotic scars. This will allow (i) to identify new drugs and targets/biomarkers, (ii) to test new therapeutic approaches, and (iii) to develop more accurate in silico models, with the final aim to guide the closure process toward a scar-free closure and, in a more general sense, (iv) to understand the mechanisms involved in the intrinsic and extrinsic aging of the skin. In this work, the complex dynamic of events underlaying the closure of deep skin wound is presented and the engineered models that aim at replicating such complex phenomenon are reviewed. Despite the complexity of the cellular and extracellular events occurring during the skin wound healing the gold standard assay used to replicate such a process is still represented by planar in vitro models that have been largely used to identify the key factors regulating the involved cellular processes. However, the lack of the main constituents of the extracellular matrix (ECM) makes these over-simplistic 2D models unable to predict the complexity of the closure process. Three-dimensional bioengineered models, which aim at recreating the closure dynamics of the human dermis by using exogenous biomaterials, have been developed to fill such a gap. Although interesting mechanistic effects have been figured out, the effect of the inflammatory response on the ECM remodelling is not replicated yet. We discuss how more faithful wound healing models can be obtained by creating immunocompetent 3D dermis models featuring an endogenous ECM.

A bilayer scaffold prepared from collagen and carboxymethyl cellulose for skin tissue engineering applications

Treatment of chronic skin wound such as diabetic ulcers, burns, pressure wounds are challenging problems in the medical area. The aim of this study was to design a bilayer skin equivalent mimicking the natural one to be used as a tissue engineered skin graft for use in the treatments of problematic wounds, and also as a model to be used in research related to skin, such as determination of the efficacy of transdermal bioactive agents on skin cells and treatment of acute skin damages that require immediate response. In this study, the top two layers of the skin were mimicked by producing a multilayer construct combining two different porous polymeric scaffolds: as the dermis layer a sodium carboxymethyl cellulose (NaCMC) hydrogel on which fibroblasts were added, and as the epidermis layer collagen (Coll) or chondroitin sulfate-incorporated collagen (CollCS) on which keratinocytes were added. The bilayer construct was designed to allow cross-talk between the two cell populations in the subsequent layers and achieves paracrine signalling. It had interconnected porosity, high water content, appropriate stability and elastic moduli. Expression of vascular endothelial growth factor (VEGF), basic-fibroblast growth factor (bFGF) and Interleukin 8 (IL-8), and the production of collagen I, collagen III, laminin and transglutaminase supported the attachment and proliferation of cells on both layers of the construct. Attachment and proliferation of fibroblasts on NaCMC were lower compared to performance of keratinocyte on collagen where keratinocytes created a dense and a stratified layer similar to epidermis. The resulting constructs succesfully mimicked in vitro the natural skin tissue. They are promising as grafts for use in the treatment of deep wounds and also as models for the study of the efficacy of bioactive agents on the skin.

Clinical research progress on tissue defect repairing with acellular dermal matrices

Acellular dermal matrix(ADM) is a special biological material that contains only collagen, elastin and other extracellular matrix. ADMs are made by special methods of separating skin epidermis and dermis, and removing Langerhans cells, vascular endothelial cells, fibroblasts cells and major histocompatibility complex (MHC) within the dermis. ADM causes no graft rejection, and provides a good scaffold for tissue reconstruction, angiogenesis and implantation of host cells. The preparation process of ADM includes the separation of epidermis and dermis, decellularization, perforation and freeze-drying. According to the classification method, ADMs can be classified into allogeneic and xenogeneic ADM, patch and injection type ADM, as well as cross-linked and non-crosslinked ADM, which can meet various clinical requirements. ADM is widely used in surgical field, such as treatment of deep burn wounds, breast reconstruction after mastectomy, oral mucosa repair, abdominal wall hernia repair, and treatment of vocal cord paralysis. Due to the characteristics ADM, its application prospect is considerable. The research progress of ADM in recent years was summarized. Key words: Acellular dermal matrix; Preparation; Clinical application

Persistent Subcutaneous Oedema and Aseptic Fatty Tissue Necrosis after Using Octenisept®

Wound management and the prevention and treatment of tissue infections are part of daily routine. Octenisept (Schülke & Mayr), an antiseptic with a broad antimicrobiological effect, is widely used for various indications. This paper reports prolonged oedema and tissue swelling after treatment of deep wounds with Octenisept in three children. Three paediatric patients, aged between 2 months and 4 years, were treated with Octenisept in different hospitals. One initially presented with an abscess of the gluteal area, two with deep wounds of the cheek following injury with a wooden stick. The wounds were cleaned and washed out with Octenisept. Adequate drainage was in place at all times. COMMON FINDINGS: We observed aseptic, non painful subcutaneous tissue swelling and oedema in all three cases after wound lavage with Octenisept. This occurred shortly after the wound was initially treated and lasted for weeks until the symptoms slowly declined. It was not accompanied by persistent general infection parameters. A biopsy taken from one patient demonstrated an aseptic inflammatory reaction and oedema of the subcutaneous tissue, with partial tissue necrosis. Neither surgical revision nor antibiotic therapy brought any improvement. Retrospectively, one can consider these occurrences as a consequence of the use of Octenisept, since the changes are consistent with those described by Schülke & Mayr when Octenisept was accidentally administered by subcutaneous injection or under pressure to flush deep hand stab wounds that were not drained. The underlying pathobiological mechanism remains unclear. Hence, we recommend not to apply Octenisept in any wound cavity until further investigation has taken place. If aseptic fatty tissue necrosis and oedema develop after using Octenisept, further surgical intervention or antibiotic treatment will not give any benefit. Changes subside slowly. So far, adequate treatment is not available.

Surgical treatment of osteomyelitis in the metacarpal and metatarsal bones of the horse

The case histories of four horses with osteomyelitis involving the metacarpal and metatarsal bones are reviewed and the surgical treatments discussed. The horses recovered after curettage of all infected tissue and post operative drainage. The role of antibiotics in treatment is considered and reference is made to the acute treatment of deep wounds to avoid osteomyelitis.