Olena Kravchuk

Vitronectin: Growth Factor Complexes Hold Potential as a Wound Therapy Approach

Topical administration of growth factors has displayed some potential in wound healing, but variable efficacy, high doses, and costs have hampered their implementation. Moreover, this approach ignores the fact that wound repair is driven by interactions between multiple growth factors and extracellular matrix (ECM) proteins. We report herein that complexes comprising IGF and IGF-binding proteins bound to the ECM protein vitronectin (VN) significantly enhance cellular functions relevant to wound repair in human skin keratinocytes in two- and three-dimensional in vitro cell models and are active, even in the presence of wound fluid. Moreover, these responses require activation of both the IGF receptor and the VN-binding alpha(v) integrins. Further, we assessed the complexes as a topical agent in the treatment of deep dermal partial thickness burns in a porcine model. This pilot study revealed that the complexes may hold promise as a wound healing therapy. Critically, the significant responses observed in vitro and the encouraging preliminary data in vivo were obtained with nanogram doses of growth factors. This suggests that coupling delivery of growth factors to ECM proteins such as VN may ultimately prove to be a more effective strategy for developing a wound healing therapy.

An Audit of First-Aid Treatment of Pediatric Burns Patients and Their Clinical Outcome

This study describes the first aid used and clinical outcomes of all patients who presented to the Royal Children’s Hospital, Brisbane, Australia in 2005 with an acute burn injury. A retrospective audit was performed with the charts of 459 patients and information concerning burn injury, first-aid treatment, and clinical outcomes was collected. First aid was used on 86.1% of patients, with 8.7% receiving no first aid and unknown treatment in 5.2% of cases. A majority of patients had cold water as first aid (80.2%), however, only 12.1% applied the cold water for the recommended 20 minutes or longer. Recommended first aid (cold water for ≥20 minutes) was associated with significantly reduced reepithelialization time for children with contact injuries (P = .011). Superficial depth burns were significantly more likely to be associated with the use of recommended first aid (P = .03). Suboptimal treatment was more common for children younger than 3.5 years (P < .001) and for children with friction burns. This report is one of the few publications to relate first-aid treatment to clinical outcomes. Some positive clinical outcomes were associated with recommended first-aid use; however, wound outcomes were more strongly associated with burn depth and mechanism of injury. There is also a need for more public awareness of recommended first-aid treatment.

The optimal duration and delay of first aid treatment for deep partial thickness burn injuries.

Using our porcine model of deep dermal partial thickness burn injury, various durations (10min, 20min, 30min or 1h) and delays (immediate, 10min, 1h, 3h) of 15 degrees C running water first aid were applied to burns and compared to untreated controls. The subdermal temperatures were monitored during the treatment and wounds observed weekly for 6 weeks, for re-epithelialisation, wound surface area and cosmetic appearance. At 6 weeks after the burn, tissue biopsies were taken of the scar for histological analysis. Results showed that immediate application of cold running water for 20min duration is associated with an improvement in re-epithelialisation over the first 2 weeks post-burn and decreased scar tissue at 6 weeks. First aid application of cold water for as little as 10min duration or up to 1h delay still provides benefit.

Silver deposits in cutaneous burn scar tissue is a common phenomenon following application of a silver dressing

Background:  Silver dressings have been widely and successfully used to prevent cutaneous wounds, including burns, chronic ulcers, dermatitis and other cutaneous conditions, from infection. However, in a few cases, skin discolouration or argyria‐like appearances have been reported. This study investigated the level of silver in scar tissue post‐burn injury following application of Acticoat™, a silver dressing.

Toward a full characterization of native starch: Separation and detection by size-exclusion chromatography

The structure of starch molecules is relevant to nutrition and industrial applications. Size-exclusion chromatography (SEC, also known as GPC) of native starch generally suffers non-satisfactory repeatability and reproducibility of the dissolution and separation. This work combines two polar organic solvents: dimethylsulfoxide for complete dissolution and dimethylacetamide to limit shear degradation. The separation is as repeatable as that of polystyrene standards performing dissolution and separation at 80 degrees C. Successful covalent-labeling on the glucose unit is claimed to be published here for the first time in non-degradative conditions and allows the use of UV detector with significantly higher sensitivity than with a refractometer.

Silver absorption on burns after the application of Acticoat: data from pediatric patients and a porcine burn model.

Silver dressings have been widely used to successfully prevent burn wound infection and sepsis. However, a few case studies have reported the functional abnormality and failure of vital organs, possibly caused by silver deposits. The aim of this study was to investigate the serum silver level in the pediatric burn population and also in several internal organs in a porcine burn model after the application of Acticoat™. A total of 125 blood samples were collected from 46 pediatric burn patients. Thirty-six patients with a mean of 13.4% TBSA burns had a mean peak serum silver level of 114 &mgr;g/L, whereas 10 patients with a mean of 1.85% TBSA burns had an undetectable level of silver (<5.4 &mgr;g/L). Overall, serum silver levels were closely related to burn sizes. However, the highest serum silver was 735 &mgr;g/L in a 15-month-old toddler with 10% TBSA burns and the second highest was 367 &mgr;g/L in a 3-year old with 28% TBSA burns. In a porcine model with 2% TBSA burns, the mean peak silver level was 38 &mgr;g/L at 2 to 3 weeks after application of Acticoat™ and was then significantly reduced to an almost undetectable level at 6 weeks. Of a total of four pigs, silver was detected in all four livers (1.413 &mgr;g/g) and all four hearts (0.342 &mgr;g/g), three of four kidneys (1.113 &mgr;g/g), and two of four brains (0.402 &mgr;g/g). This result demonstrated that although variable, the level of serum silver was positively associated with the size of burns, and significant amounts of silver were deposited in internal organs in pigs with only 2% TBSA burns, after application of Acticoat™.

The efficacy of Aloe vera, tea tree oil and saliva as first aid treatment for partial thickness burn injuries.

Many alternative therapies are used as first aid treatment for burns, despite limited evidence supporting their use. In this study, Aloe vera, saliva and a tea tree oil impregnated dressing (Burnaid) were applied as first aid to a porcine deep dermal contact burn, compared to a control of nothing. After burn creation, the treatments were applied for 20 min and the wounds observed at weekly dressing changes for 6 weeks. Results showed that the alternative treatments did significantly decrease subdermal temperature within the skin during the treatment period. However, they did not decrease the microflora or improve re-epithelialisation, scar strength, scar depth or cosmetic appearance of the scar and cannot be recommended for the first aid treatment of partial thickness burns.

Influence of Dryer Type on Surface Characteristics of Milk Powders

Reconstituted milk powders (skim milk, whole milk, and milk protein concentrate powders) were spray dried using research-scale (laboratory- and pilot-scale) spray dryers to investigate the influence of type on the dryer on the surface composition (protein, fat, lactose) and morphological characteristics (size and surface structure) of the powder particles. Milk powders produced by these research-scale dryers were compared to commercially produced and freeze-dried powders. The powders produced by the laboratory- and pilot-scale dryers were significantly different from the commercially dried powders in both surface composition and morphology. The milk powders produced by laboratory- and pilot-scale dryers provided reproducible results with similar surface morphologies between dryer types, despite varying surface compositions. The surface composition of the freeze-dried powder was also significantly different from than that of the spray-dried powders. The freeze-dried skim milk powder (SMP) was similar in surface protein to its bulk protein composition, indicating relative homogeneity of particle composition of the freeze-dried powder.

Ultrasound assessed thickness of burn scars in association with laser Doppler imaging determined depth of burns in paediatric patients

This study describes the ultrasound assessment of burn scars in paediatric patients and the association of these scar thickness with laser Doppler imaging (LDI) determined burn depth. A total of 60 ultrasound scar assessments were conducted on 33 scars from 21 paediatric burn patients at 3, 6 and 9 months after-burn. The mean of peak scar thickness was 0.39±0.032 cm, with the thickest at 6 months (0.40±0.036 cm). There were 17 scald burn scars (0.34±0.045 cm), 4 contact burn scars (0.61±0.092 cm), and 10 flame burn scars (0.42±0.058 cm). Each group of scars followed normal distributions. Twenty-three scars had original burns successfully scanned by LDI and various depths of burns were presented by different colours according to blood perfusion units (PU), with dark blue <125, light blue 125-250, and green 250-440 PU. The thickness of these scars was significantly different between the predominant colours of burns, with the thinnest scars for green coloured burns and the thickest for dark blue coloured burns. Within light blue burns, grafted burns healed with significantly thinner scars than non-grafted burns. This study indicates that LDI can be used for predicting the risk of hypertrophic scarring and for guiding burn care. To our knowledge, this is the first study to correlate the thickness of burns scars by ultrasound scan with burn depth determined by LDI.

Burn healing is dependent on burn site : A quantitative analysis from a porcine burn model

This retrospective review examines healing in different sites on a porcine burn model; 24 pairs of burns on 18 pigs from other animal trials were selected for analysis. Each pair of burns was located on the either the cranial or the caudal part of the thoracic ribs region, on the same side of the animal. The burns were 40-50 cm(2) in size and of uniform deep-dermal partial thickness. Caudal burns healed significantly better than cranial burns, demonstrated by earlier closure of wounds, less scar formation and better cosmesis. To our knowledge, this is the first detailed study reporting that burn healing is affected by location on a porcine burn model. We recommend that similar symmetrical burns should be used for future comparative assessments of burn healing.