Use of Amniotic Membrane as a Biological Dressing for the Treatment of Torpid Venous Ulcers: A Case Report.

Chronic venous disease manifested as ulcers in the lower limb is a highly prevalent pathology in our population. Antiseptics and dressings designed to improve epithelialization are often used to cure the ulcer during outpatient therapy. Despite careful management, sometimes ulcers do not respond to treatment. In this report, we discuss the antiseptic and potentially immunomodulatory effects of the amniotic membrane as a biological dressing for the treatment of venous ulcers refractory to conventional therapy.

Controlled Delivery of Bioactive Molecules for the Treatment of Chronic Wounds.

A cut or break on the surface of the skin is usually referred to as a wound. Any wound has a potential to heal by itself through a complex cascade of events. However, some wounds show delayed healing due to their underlying physiology and are referred to as chronic wounds like diabetic ulcers, venous ulcers, pressure ulcers and chronic infected ulcers. Extensive care has to be taken for the management of chronic wounds and these have become a major concern in the current medical scenario. The use of bioactive molecules or in other words the molecules that can actively interact with the wound environment and help in wound healing are gaining much importance. The incorporation of bioactive molecules into a suitable matrix system which not only provide a controlled release of the molecules, but also enable better exudate management is desired to overcome the shortcomings of the conventional treatment modalities. A major problem associated with chronic wounds is that they are easily prone to infections. In such cases, the topical delivery of antibiotics helps eliminate infection. However, the continuous use of high dose of antibiotics has led to the development of multi drug resistant bacterial strains. To overcome these issues, other broad-spectrum antimicrobial agents like antiseptics, metallic nanoparticles and antimicrobial peptides are being adopted nowadays. Growth factors play a major role in the wound healing cascade, thus topical delivery of growth factor from a suitable matrix is an interesting strategy. The delivery of nucleic acids with the aid of suitable vectors for either silencing a particular gene or over expressing a gene of interest is also being investigated nowadays. This review is an attempt to draw light over some of the recent approaches adopted for the treatment of chronic wounds using bioactive molecules like antibiotics, antiseptics, metallic nanoparticles or ions, growth factors and nucleic acids.

Use of a Dehydrated Amniotic Membrane Allograft on Lower Extremity Ulcers in Patients with Challenging Wounds: A Retrospective Case Series.

Lower extremity ulcers in patients with diabetes mellitus may take a long time to heal despite the use of advanced topical therapies. A retrospective review of cases was conducted to assess the use of a dehydrated amniotic membrane allograft (DAMA) in a convenience sample of 9 wounds in 8 patients (5 men, 3 women, average age 62 years [range 31-81 years]) with diabetes mellitus and/or vascular disease. Wound data and patient characteristics were abstracted from medical records. Descriptive statistics were used to summarize the data. In 5 of 9 wounds, DAMA was applied after a failure to demonstrate a 50% reduction in area after 4 weeks of treatment with advanced wound care, offloading, and compression as indicated. In 4 wounds, DAMA was applied 2-4 weeks after presentation because of concerns about existing patient risk factors for nonhealing. Wounds were present for an average of 11 weeks (range 1-35 weeks) before application of DAMA. Mean baseline wound area and volume were 3.11 cm2 (± 3.73) and 0.55 cm3 (± 0.58), respectively. All wounds healed in an average of 5.7 (± 2.9) weeks (range: 1-9 weeks) after a mean of 2.7 applications (± 1.7) (range 1-5 applications). No adverse events occurred. These observations suggest prospective, randomized, controlled clinical studies to compare the use of DAMA to other topical treatment modalities are warranted.

Amniotic membrane: new concepts for an old dressing.

The amniotic membrane is the innermost layer of fetal membranes that surrounds and protects the embryo. The amniotic epithelial cells are a rich source for biologically active factors known to promote cell proliferation and differentiation. Therefore, the amniotic membrane is considered to be an attractive wound dressing material. Despite a large number of publications reporting anti-inflammatory, bacteriostatic, reepithelializing, and scar-preventing properties of amniotic membrane, not all the molecular mechanisms underlying the beneficial actions of the amniotic membrane dressing have been fully elucidated. This review summarizes current knowledge on the properties of the amniotic membrane and its various clinical applications. It includes an overview of the main biologically active factors that may be responsible for the observed clinical effects of amnion dressings. This issue is briefly discussed in the context of the role of amnion processing and inter- and intradonor variations between amniotic membrane specimens. Finally, future directions for the use of amnion derivatives in wound care are indicated.

[Human amniotic membrane in the management of chronic venous leg ulcers]. / La membrane amniotique humaine dans la prise en charge des ulcères de jambe veineux chroniques.

BACKGROUND: The aim of our paper is to examine changes in the use of human amniotic membrane for venous leg ulcers through clinical studies and to present different models of tissue engineering employing human amniotic membrane for the purpose of future therapeutic use in wound healing. MATERIALS AND METHODS: This review is based on information obtained from a PubMed search using the following keywords "Amnion"[Mesh] AND "Leg Ulcer"[Mesh]; "Amnion"[Mesh] AND "Dermatology"[Mesh]. The selected articles are in English or French and deal with the sole use of human amniotic membrane in venous leg ulcers alone. RESULTS: Human amniotic membrane has a positive impact on chronic venous leg ulcers by promoting granulation tissue formation, reducing fibrosis and inducing re-epithelialisation. Nevertheless, further randomized clinical studies are needed. At the same time, tissue engineering models using human amniotic membrane may help to reduce wound healing time, thereby creating renewed interest in the use of human amniotic membrane. CONCLUSION: Considering its properties and the clinical studies analysed, human amniotic membrane could be useful in venous leg ulcer care.

Update on tissue-engineered biological dressings.

Tissue-engineered biological dressings offer promise in the treatment of burns, chronic ulcers, donor site and other surgical wounds, and a variety of blistering and desquamating dermatologic conditions. For example, the prevalence of diabetic foot ulcers ranges from 4.4% to 10.5% of diabetics, resulting in 82,000 lower extremity amputations annually; venous leg ulcers affect 0.18% to 1.35% of the population; and pressure ulcers are found in 5.0% to 8.8% of institutionalized patients and 14.8% of patients in acute care facilities. Despite the large number of potential beneficiaries, cellular tissue-engineered products have suffered setbacks in recent years and have garnered considerably lower market share than commercial promoters anticipated. The mechanism of action of these products is not universally agreed upon, but delivery of growth factors and extracellular matrix components to the wound is thought to be important; graft "take" is not usually considered to occur. These "engineered" products do not specifically match a treatment modality to an underlying pathology. Clinical effect is often modest, and sometimes not justi- fiable from a cost-benefit perspective. Nevertheless, clinical reports in the literature of uses of tissueengineered biological dressings continue to mount, indicating that these products are finding niche applications where clinical utility is high and the cost can be defended. Despite commercial setbacks, the first-approved products, Dermagraft, Apligraf, and Cultured Epidermal Autograft (Epicel) are still being marketed, and new ones, such as OrCel, continue to be developed. The major indications for these products are summarized and a brief review of the available clinical literature is offered.

[Development of new biologically active dressings and methodology of their use]. / Razrabotka novykh biologicheski aktivnykh pereviazochnykh sredstv i metodologiia ikh primeneniia.

Results of development of new biologically active dressings and up-to-date methodology of local treatment of wounds (based on their differential application according to phase and features of wound process) are demonstrated. Data about main properties and specific activity of new biologically active dressings based on natural and synthetic polymers with immobilized drugs are presented. Future trends and efficacy of their appliance in complex treatment of purulent and necrotic wounds are demonstrated.

Wound repair: advanced dressing materials.

Georgina Casey examines the process of wound healing and describes the roles of the main cells and biologically active molecules found in the wound bed.

Amniotic membranes - Are they useful?

Amniotic membrane is gaining increasing use in ophthalmology. The amniotic membrane is obtained from the plancenta delivered by Caesarean section. Informed consent and blood tests for HIV, syphilis and hepatitis are obtained. The amnion is separated from the chorion and the amniotic membrane can be stored in a special preparatory medium. Laboratory studies have established some of the properties of this tissue. It can reduce inflammation and promote healing. Clinical studies have established the use of amniotic membranes for ocular surface reconstruction in chemical burns, and autoimmune diseases such as ocular cicatricial pemphigold and Stevens Johnson Syndrome. It has also been shown to be effective in decreasing the discomfort associated with bullous keratopathy and it promotes healing. It also reduces recurrence after removal of band keratopathy. It is used to replace conjunctiva after extensive resection in pterygium surgery. The membrane provides a matrix for growth of cells such as epithelial stem cells. Future studies will determine the best use of the membrane in ophthalmology. (Au)