B. Azzena

Active Silver Nanoparticles for Wound Healing

In this preliminary study, the silver nanoparticle (Ag NP)-based dressing, Acticoat™ Flex 3, has been applied to a 3D fibroblast cell culture in vitro and to a real partial thickness burn patient. The in vitro results show that Ag NPs greatly reduce mitochondrial activity, while cellular staining techniques show that nuclear integrity is maintained, with no signs of cell death. For the first time, transmission electron microscopy (TEM) and inductively coupled plasma mass spectrometry (ICP-MS) analyses were carried out on skin biopsies taken from a single patient during treatment. The results show that Ag NPs are released as aggregates and are localized in the cytoplasm of fibroblasts. No signs of cell death were observed, and the nanoparticles had different distributions within the cells of the upper and lower dermis. Depth profiles of the Ag concentrations were determined along the skin biopsies. In the healed sample, most of the silver remained in the surface layers, whereas in the unhealed sample, the silver penetrated more deeply. The Ag concentrations in the cell cultures were also determined. Clinical observations and experimental data collected here are consistent with previously published articles and support the safety of Ag NP-based dressing in wound treatment.

Histotopographic study of the fibroadipose connective cheek system.

The purpose of this study was to investigate the morphology of the superficial musculoaponeurotic system (SMAS). Eight embalmed cadavers were analyzed: one side of the face was macroscopically dissected; on the other side, full-thickness samples of the parotid, zygomatic, nasolabial fold and buccal regions were taken. In all specimens, a laminar connective tissue layer (SMAS) bounding two different fibroadipose connective layers was identified. The superficial fibroadipose layer presented vertically oriented fibrous septa, connecting the dermis with the superficial aspect of the SMAS. In the deep fibroadipose connective layer, the fibrous septa were obliquely oriented, connecting the deep aspect of the SMAS to the parotid-masseteric fascia. This basic arrangement shows progressive thinning of the SMAS from the preauricular district to the nasolabial fold (p < 0.05). In the parotid region, the mean thicknesses of the superficial and deep fibroadipose connective tissues were 1.63 and 0.8 mm, respectively, whereas in the region of the nasolabial fold the superficial layer is not recognizable and the mean thickness of the deep fibroadipose connective layer was 2.9 mm. The connective subcutaneous tissue of the face forms a three-dimensional network connecting the SMAS to the dermis and deep muscles. These connective laminae connect adipose lobules of various sizes within the superficial and deep fibroadipose tissues, creating a three-dimensional network which modulates transmission of muscle contractions to the skin. Changes in the quantitative and qualitative characteristics of the fibroadipose connective system, reducing its viscoelastic properties, may contribute to ptosis of facial soft tissues during aging.

Characterization and evaluation of silver release from four different dressings used in burns care

For centuries silver and silver compounds have been in use to control infection and avoid septicaemia in the care of burns and chronic wounds. Renewed interest has resulted in a number of Ag based dressings that are now widely used in burns centres. Despite extensive use, a systematic study of the chemical composition, release kinetics and biochemical action of these products has yet to be published. In this work we have characterized the morphology of four commercial Ag dressings by scanning electron microscopy and the silver content was determined to range between 1.39 mg/cm(2) and 0.03 mg/cm(2). Release kinetics in three different matrices (ultra pure water, normal saline solution and a human serum substitute) were determined. The highest rates were found in serum substitute, with a maximum of 4099 μg/(hcm(2)) to a minimum of 0.0001 μg/(hcm(2)). Our results show that the mean inhibitory concentrations are exceeded for most common pathogens in serum substitute and sterile water, but the presence of high Cl(-) concentrations tend to inactivate the dressings.

Autologous Platelet-Rich Plasma as an Adipocyte In Vivo Delivery System: Case Report

Tissue engineering has emerged as a promising alternative to current clinical treatments for restoration of soft tissue defects. A key element in the process of tissue engineering is an ideal implant that provides structural support and a favorable environment for growing cells. The authors hypothesized that autologous platelet-rich plasma (APRP) could be used as an in vivo adipocyte delivery system to favor cell survival and to stimulate early recruitment of microcapillaries to the site of implantation. Autologous fat was included in APRP and injected as a gel into a subcutaneous pocket created to correct a painful, adherent scar at the shoulder level in a 75-year-old woman. The surgical outcome was evaluated by histologic and immunohistochemical analysis as well as by ecography before and after surgery. The results were satisfactory, showing fat survival 1 year after surgery. The characteristics of this new material should stimulate research into future clinical applications for such cell constructs in plastic and reconstructive surgery.

Reversed gracilis pedicle flap for coverage of a total knee prosthesis.

BACKGROUNDnPoor wound-healing and skin necrosis are potentially devastating complications after total knee arthroplasty. Primary soft-tissue coverage with a medial or lateral gastrocnemius transposition flap is typically the first choice for reconstruction. The aim of this study was to evaluate the use of a distally based secondary-pedicle flap of the gracilis muscle for reconstruction of a soft-tissue defect.nnnMETHODSnThe characteristics of the distally based (secondary) pedicles of the gracilis muscle were studied with use of dissection (ten cadavers) and computed tomographic angiograms (fifty patients). On the basis of the anatomical features, an extended reversed gracilis flap based on the secondary pedicles was used in three patients with severe soft-tissue complications of total knee arthroplasty.nnnRESULTSnThe mean number of secondary pedicles was 1.8 (range, one to four). The pedicles originated from the superficial femoral or popliteal artery. The most proximal pedicle was often the largest (mean caliber, 2.0 mm), and its point of entry into the gracilis muscle was an average (and standard deviation) of 21 +/- 3.6 cm (range, 16 to 28 cm) from the ischiopubic branch. A significant positive association (p = 0.001; r(2) = 0.49) was found between the caliber of the proximal secondary pedicle and the number of other secondary pedicles. In all three patients, the adequate caliber of the secondary pedicles (as shown on preoperative computed tomographic angiograms) and good muscle vascularization confirmed the utility of the gracilis as a distally based pedicle flap.nnnCONCLUSIONSnFor the treatment of large soft-tissue defects of the patella or the proximal part of the knee, or for soft-tissue reconstruction over an exposed total knee prosthesis, the reversed gracilis pedicle flap may be an alternative to, or may be integrated with, a lateral or medial gastrocnemius flap.

Blood Levels, Apoptosis, and Homing of the Endothelial Progenitor Cells After Skin Burns and Escharectomy

BACKGROUNDnSkin burns are an acute trauma involving an extensive vascular damage and an intense inflammatory response. Bone marrow-derived circulating endothelial progenitor cells (EPC) are known to migrate to sites of neovascularization in response to mediators (vascular endothelial growth factor and stromal cell-derived factor-1) released after trauma and ischemia, to contribute to wound healing, and to increase neovascularization of animal prefabricated flaps. Recent data showed an increase in EPC number in burned patients and a positive correlation between EPC number and total body surface area (TBSA) burnt, but data were limited to the first 5 days after thermal injury.nnnMETHODSnBy using flow cytometry, we studied EPC (CD34, CD133, CD45, and KDR cells) blood levels, apoptosis, and homing (stromal cell-derived factor-1 receptor expression and CXC chemokine receptor 4) in a 1-month follow-up postburn in 25 patients with ≥15% TBSA burnt, at least grade II burns and escharectomy performed at days 5 to 6, with respect to 31 controls.nnnRESULTSnEPC count at admission showed a positive linear correlation with TBSA burnt. The EPC blood levels of the patients were low (50.7 cells/mL±61.8 cells/mL) immediately after thermal injury, then increased with two peaks, at day 1 (188.3 cells/mL±223.2 cells/mL) and day 12 (253.1 cells/mL±430.7 cells/mL) with respect to controls (95.2 cells/mL±28.5 cells/mL, p<0.05), and then returned to normal levels in 1 month. EPC apoptotic rate and inflammatory parameters paralleled EPC blood count. No significant variations were found in CXC chemokine receptor 4 expression.nnnCONCLUSIONSnThermal injury and escharectomy seem to induce an intense response in EPC production. In particular, escharectomy could improve physiologic wound repair by increasing EPC levels.

Burn care in relation to burn epidemiology in Italy.

AIMnBurn centres are hubs of referral for large areas and should be organised in a network optimised for the needs of their area. Burn centres organisation and activity in Italy are analysed with reference to burn epidemiology in the country.nnnMETHODSnA questionnaire was submitted to Italian burn centres concerning organisation, activity and epidemiology of burns treated in 2008.nnnRESULTSnA total of 2067 patients were admitted to a burn centre in 2008; 50% of burns were due to flames (21% alcohol); and 25% of patients were <14 years old. Overall mortality was 5.3%. 144 beds in 15 burn centres were available (seven reserved for children; bed/inhabitants ratio, 1/414, .023). However, distribution is not uniform in the country. Bed rotation was 14.4 patients/bed, and hospital stay varied from 11.7 days for <20% total body surface area (TBSA) burns to >120 days for burns >70%. About half (57%) of patients admitted had less than 20% TBSA burns, 32% had 20-50% TBSA burns, 7% from 50% to 70% and 4% over 70% TBSA. A national network coordinating burn centre activity is lacking.nnnCONCLUSIONSnItaly seems to have less availability of beds for burn care than other countries, and distribution and organisation of the network may be improved. The high prevalence of child burns should be noticed and this makes prevention campaigns advisable.

Accident proneness and impulsiveness in an Italian group of burn patients

There is controversy about the existence of a predisposition to burn incidents (accident proneness). Our objective was to examine, in a group of burn patients, the conditions or unconscious subjective predisposition, the presence of impulsiveness that may have contributed to bringing about the burn event, and to assess the presence of psychiatric diagnoses and specific characteristics of temperament. 25 consecutive burn patients were interviewed by using specific psychometric tests. The sample was divided into two groups: control group (N=10), composed of subjects who had accidentally been involved in the incident and case group (N=15) composed of subjects who had very likely and more or less knowingly put themselves at risk of injury. We observed a marked statistically significant difference with case group subjects appearing to be more impulsive than the ones in control group. Higher levels of impulsiveness may predispose case group patients to a greater risk of burn. Our survey also seems to reveal a relationship between impulsiveness and the proneness of some subjects to burns.

Development and application of methods for the determination of silver in polymeric dressings used for the care of burns

Open vessel and microwave digestion methods have been developed for the determination of total silver in six commercial dressing used for the treatment of skin burns. An extraction method using TMAH has also been developed to determine the amount of silver present in the exudates found on the surface after dressing removal so an estimation of the patient dose can be made. All microwave methods had a quantitative recovery, whereas the open vessel had recoveries that ranged from 80 to 100%. The silver concentrations were determined by inductively coupled plasma mass spectrometry using an external calibration. In the absence of suitable reference materials, isotope dilution analysis was applied to validate the accuracy of results obtained by external calibration. All the products had a total Ag content that agreed with the values declared by the producer, which ranged from 10 to 0.2% Ag by weight. One of the methods was applied to the indirect determination of Ag released in vivo by Acticoat™ Flex 3, a dressing composed of silver nanoparticles on a polymer net. Silver levels were determined in used dressings after application to patients with partial thickness skin burns. A maximum of 62% of the silver was found to have been released onto the patient where hemopurulent exudate occurred, indicating that the dressing was virtually exhausted after 3 days of use. We conclude that the Ag released into the patients tissues is closely correlated with the local severity of the wound.

Geometric Reconstruction of the Right Hemi-Trunk After Resection of Giant Chondrosarcoma

We present a case of a giant chondrosarcoma arising from the right anterolateral chest wall and extending to the abdomen. An extensive resection of the right lower chest wall, most of the right hemidiaphragm, and most of the anterior abdominal wall on the right side was carried out. A long titanium plate was used to reconstruct the right costal margin. This plate gave attachment to two polytetrafluoroethylene meshes that were used to cover the abdominal and chest wall defects. The patches were covered with pedicled muscles and omental flaps and subsequently with rotational skin flap.