Preparation and characterization of human keratinocyte-fibroblast cell sheets constructed using PNIAM-co-AM grafted surfaces for burn wound healing.

Autologous skin grafting, the standard treatment for severe burns, is sometimes not possible due to the limited available skin surfaces for the procedure. With advances in tissue engineering, various cell-based skin substitutes have been developed to serve as skin replacements and to promote tissue regeneration and healing. In this work, we propose the use of cell sheet technology to fabricate keratinocyte-fibroblast tissue constructs from the temperature-responsive poly(N-isoproprylacrylamide-co-acrylamide) (PNIAM-co-AM) grafted surfaces for the treatment of burn wounds. The characteristics of the human keratinocyte and fibroblast cell sheets harvested using PNIAM-co-AM grafted surfaces were similar to those cell sheets detached from the commercially-available UpCellTM plates. Upon lowering the incubation temperature, confluent keratinocytes and fibroblasts could be detached as intact sheets, consisting of biologically active cells, as indicated by their high cell viability and their reattachment, migratory, and proliferative activities. A histological analysis of the stratified keratinocyte-fibroblast cell sheets revealed the evidence of cell migration and tissue reorganization to form two distinct epidermal and dermal layers, quite similar to the skin tissue's structure. In addition, the keratinocyte-fibroblast sheets could synthesize and release significant amounts of essential cytokines and growth factors involved in regulating the wound healing process, including IL-1α, IL-6, TNF-α, VEGF, and bFGF, implying the therapeutic effect of these cell sheets, which could be beneficial to accelerate tissue repair and regeneration, leading to faster wound healing.

Clinical effectiveness of alginate silver dressing in outpatient management of partial-thickness burns.

Askina Calgitrol Ag(®) (B. Braun Hospicare Ltd, Collooney Co. Sligo, Ireland), alginate silver wound dressing, is an advanced wound dressing which combines the potent broad-spectrum antimicrobial action of silver with enhanced exudate management properties of calcium alginate and polyurethane foam. The purpose of this study was to compare the efficacy of Askina Calgitrol Ag(®) and 1% silver sulfadiazine (1% AgSD) in the outpatient management of partial-thickness burn wounds at Burn Unit, Siriraj Hospital. A prospective descriptive study was conducted between January 2008 and January 2009 in Burn Unit, Division of Trauma Surgery, Siriraj Hospital, Mahidol University, Thailand. The 65 patients with partial-thickness burn wounds, less than 24 hours post-burn injury, had a total body surface area (TBSA%) less than 15% were treated at Siriraj Outpatient Burn Clinic. All patients were divided into Askina Calgitrol Ag(®) treated group (30 patients) and 1% AgSD treated group (35 patients). The data were compared by the demographics including age, gender, % TBSA burn, pain score, number of wound dressing change, nursing time and time of wound healing. Patients included in both groups were comparable with no significant differences in demographic data of age, gender, location of burn and type of burn injury (P > 0·05 evaluated by paired Student's t-test) between both group. The present results showed that average pain scores in the Askina Calgitrol Ag(®) treated group were significantly lower than the 1% AgSD treated group (2·23 ± 1·87 versus 6·08 ± 2·33, respectively) between both groups (P < 0·02). Patients treated with Askina Calgitrol Ag(®) had significantly lower number of wound dressing change (P < 0·02) and nursing time (P < 0·02) compared with 1% AgSD treated group. The Askina Calgitrol Ag(®) group needed less frequent wound dressing. Healing time was 7 ± 3·51 days after the application of Askina Calgitrol Ag(®). This was significantly shorter than that of control wounds (14 ± 4·18 days). Application of Askina Calgitrol Ag(®) leads to a good burn wound outcome. The present study confirms the effectiveness of Askina Calgitrol Ag(®) in the outpatient management of partial-thickness burn wounds.

Polyurethane-biomacromolecule combined foam dressing containing asiaticoside: fabrication, characterization and clinical efficacy for traumatic dermal wound treatment.

Polyurethane combined (PUC) foam dressings with various biomacromolecules were fabricated with the adsorption of asiaticoside and silver nanoparticles for traumatic wound treatment. Biomacromolecules had varying effects on physicochemical and mechanical properties of PU foam. With 2% incorporation, starches, high molecular weight chitosan and gelatin provided stiffer and more porous foams while carboxymethylcellulose had the highest compression strength but the lowest water vapor transmission. High water absorption was from foams with carboxymethylcellulose, alginate, hydroxypropyl methylcellulose and low molecular weight chitosan. Increasing the concentrations up to 12% had more prominent effect. However, powdery surface was noticed with poorer tensile properties that 6% incorporation was selected. FTIR spectra and DSC thermograms suggested interaction of PU formulation with biomacromolecules. EDS analysis confirmed existence of active compounds while acceptable stability was from sterilized PUC foam with alginate. On healthy volunteers, this selected foam dressing caused no skin irritation and retained moisture comparable to commercial product. In patients with traumatic dermal wounds, healing improvement with shorter wound closure time, higher reepithelialization and less pain score were from the selected foam dressing compared to standard gauze soaked with chlorhexidine. This PU-alginate combined foam dressing adsorbed with asiaticoside and silver nanoparticles proved advantages for traumatic dermal wound management.

Comparison of efficacy of 1% silver sulfadiazine and Acticoat for treatment of partial-thickness burn wounds.

BACKGROUND: Acticoat (Smith & Nephew, Hull, UK) is a silver-coated dressing reported to reduce infection and exhibit antimicrobial activity in wounds. OBJECTIVE: The purpose of the present study was to compare the efficacy ofacticoat and 1% silver sulfadiazine (1% AgSD) for treatment of partial thickness burn wounds. MATERIAL AND METHOD: The authors reviewed 50 patients who had partial thickness burn wounds less than 25% admitted to Siriraj Burn Unit from May 2002 to September 2005. All patients were divided into 2 groups: the acticoat treated group (25 patients) and the 1% silver sulfadiazine treated group (25 patients). The 2 groups were compared for the etiology of burn wound, demographic data including age, sex, % Total Body Surface Area burn (TBSA%), cultured organisms, wound infection and outcome of Length Of hospital Stay (LOS) and level of pain. RESULTS: The authors found no significant differences in age, TBSA (%) between both groups. 7 patients (28%) developed wound infection. There were no differences in wound infection and LOS between both groups (p > 0.05). All of the patients who developed wound infection responded well to targeted topical and systemic antibiotic treatment. The 1% AgSD treated group (6 of 25, 24%) obtained more split thickness skin graft to close the granulation defects compared to patients who were treated with acticoat (4 of 25, 16%) but no statistical significance, p = 0.32). Average pain scores in the acticoat treated groups were significantly lower than the 1% AgSD treated group (4 +/- 0.6 versus 5 +/- 0.7, respectively). CONCLUSION: The present study confirms the efficacy of acticoat treatment in partial thickness burn wound. The authors conclude that acticoat has an advantage of limiting the frequency of replacement of the dressing and provides a less painful alternative to wound care with 1% AgSD with comparable incidence of burn wound infection. This is due to its long wear time and the ease of application and removal.

Clinical Efficacy Test of Polyester Containing Herbal Extract Dressings in Burn Wound Healing.

Technological advancement has assisted in developing various availabilities of wound products that help in not only in healing and preventing infection but also in providing patients' comfort and pain reduction during application. However, most of advanced wound healing products in Thailand were imported at high costs to patients. Nowadays, there are increased numbers of local researches of herbs that could provide healing environment for successful wound care. Herbal wound products are currently being introduced as alternatives to those imported dressings. The aim of this study was to report the clinical efficacy of using polyester containing herbal extract dressings in healing of second-degree burns. The volunteers were divided by simply randomized method into the study group of patient using polyester containing herbal extract dressing and the control group of patients treating with dressings that are commercially available and common use. The standard treatment protocols were performed at every 3 days of dressing change. Comparative evaluation consisted of time of healing, length of hospital stays, pain analog score assessment, percentage of infection, and descriptive notification of unfavorable clinical symptoms or signs or side effects.

Correlation of clinical outcome of integra application with microbiologic and pathological biopsies.

BACKGROUND: Integra, a dermal replacement template consisting of bovine collagen, chondroitin-6-sulfate, and a silastic sheet is a postexcisional treatment for deep partial to full thickness burns where autograft is limited. This study correlates Integra histology and quantitative microbiology cultures with clinical outcomes after autografting. METHODS: Charts of 29 burn patients who underwent Integra treatment and neodermis biopsy at the time of ultra thin autografting were reviewed. We analyzed microbial contamination, inflammatory reaction, and autograft take. RESULTS: The mean burn size and age were 43% total body surface area and 39 years old, respectively. In quantitative neodermis cultures, 90% of samples had bacterial growth; nine samples (31%) had > 10(5) colony forming units per gram. The most common organism was Staphylococcus aureus (31%). Patients with quantitative bacterial counts >10(5) CFU/g received targeted systemic antibiotics. Integra take (83%) and autograft take (92%) were acceptable even in patients with high bacterial counts (78% Integra take; 86% autograft take). More than 50% of biopsies had dermal regeneration similar to normal dermis; foreign body reactions were unusual. Histologic evidence of inflammation, especially polymorphonuclear cells, was increased in biopsies with high bacterial counts. CONCLUSION: Integra and autograft take can be acceptable even with high bacterial counts if wounds are treated with appropriate targeted topical and systemic antibiotics in the presence of microbial contamination. Neodermis biopsies showed fibrous in-growth congruent with existing Integra fibers with minimal foreign body reaction. These data support Integra use as a safe and effective treatment modality in patients with major burns.