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Tissue Characterization after a New Disaggregation Method for Skin Micro-Grafts Generation

Several new methods have been developed in the field of biotechnology to obtain autologous cellular suspensions during surgery, in order to provide one ...

Burns Centre and Emilia Romagna Regional Skin Bank

A multi-centre, open, within-patient controlled study was performed on 23 adult burnt patients to investigate the effectiveness, safety and tolerability of Veloderm in comparison with Algisite M and Jaloskin in split-thickness skin graft donor site care. The areas dressed with Veloderm completely healed within 10-13 days in a significant higher proportion than the other two dressings (47.6% for Veloderm versus 26.3% for Algisite M and 10% for Jaloskin, P<0.03), showing during the whole study less incidence of exudates and of peri-lesional erythema. The aesthetic outcome of the treated lesions after healing was significantly better for Veloderm (P=0.0016). Veloderm) and Jaloskin required very few renewals of the medication during the first week of treatment, while Algisite M needed several multiple re-dressings. Veloderm was judged better than the other two treatments as far as the acceptability (P<0.001), ease of use (P<0.001) and efficacy (P<0.00001). Both pain during application or at removal of dressings and local infections were negligible with all treatments. No scars were formed in any skin donor site. In conclusion Veloderm is a safe and effective dressing for the re-epithelialization of the skin graft donor sites: it showed higher activity than the other two compared dressings.

Use of a new hemicellulose dressing (Veloderm) for the treatment of split-thickness skin graft donor sites A within-patient controlled study.

Results of a national retrospective survey on Hyalomatrix PA in burn patients are reported.A total of 11 burn centers were contacted.A total of 57 patients were available. Hyalomatrix PA was used on young and adult patients, mainly in deep partial thickness and full thickness burns. In most cases, Hyalomatrix PA was applied immediately after the wound cleaning (wound debridement or escharectomy for adults, dermabrasion or debridement in young patients). After 7 days, reepithelization processes were more frequent in deep partial thickness burns. One-half of the patient population underwent grafting. After 29 days, complete closure was achieved in almost all patients. The Vancouver Scar Scale showed better values for adults, while no differences were observed for burn depth or patients undergoing grafting. No adverse reactions were recorded.Hyalomatrix PA is used in young and adults, in deep partial thickness and full thickness burns, as a temporary coverage before grafting or alone for wound healing.

Hyalomatrix PA in burn care practice: results from a national retrospective survey, 2005 to 2006.

Interest is increasing in biological scaffolds for tissue regeneration such as extracellular matrix membranes, developed through soft tissue decellularization. Extracellular matrix membranes were developed to heal different tendon and soft tissue lesions that are very frequent in the general population with high health-care costs and patient morbidity. The aim of this research was to evaluate a human dermal matrix (HDM) decellularized by a chemico-physical method. A primary culture of rat tenocytes was performed: tenocytes were seeded on HDM samples and on polystyrene wells as controls (CTR). Cell viability and synthetic activity were evaluated at 3 and 7 days. An in vitro microwound model was used to evaluate HDM bioactivity: after tenocyte expansion, artificial wounds were created, HDM extracts were added, and closure time and decorin synthesis were monitored histomorphometrically at 1, 4, 24, and 72 hr. A significant higher amount of collagen I was observed when cells were cultured on HDM in comparison with that on CTR (3 days: p < 0.0001; 7 days: p < 0.05). In HDM group, fibronectin synthesis was significantly higher at both experimental times (p < 0.0001). At 3 days, proteoglycans and transforming growth factor-β1 releases were significantly higher on HDM (p < 0.0001 and p < 0.005, respectively). The artificial microwound closure time and decorin expression were significantly enhanced by the addition of 50% HDM extract (p < 0.05). In vitro data showed that the decellularization technique enabled the development of a matrix with adequate biological and biomechanical properties.

Decellularized human dermis to treat massive rotator cuff tears: in vitro evaluations.

Interest is increasing in biological scaffolds for tissue regeneration, such as extracellular matrix (ECM) membranes, developed through soft tissue decellularization. The present study describes the development of a chemicophysical decellularization method applied to allogenic human-derived dermis (HDM). To evaluate the absence of viable cells and the maintenance of ECM structure, biological, histological and ultrastructural assessments were performed on the HDM membrane. Residual DNA content and glycosaminoglycan (GAG) and collagen contents were quantified. Growth factor (GF) release was directly measured on HDM extracts and indirectly measured by assessing cell proliferation after administering extract to cultures. Tensile tests were performed to measure the effect of the decellularization technique on the mechanical properties of tissue. Histocompatibility was investigated after subcutaneous implantation in rats. Residual DNA, GAG and collagen content measurements, vitality index, histology and electron microscopy showed the efficiency of the decellularization process and preservation of ECM matrix and bioactivity. In HDM extracts, among the tested GFs, transforming growth factor-β1 showed the highest concentration. HDM extracts significantly increased the proliferation rate of L929 fibroblasts in comparison with controls (p < 0.005, p < 0.05 and p < 0.0005). Maximum load and stiffness of HDM were significantly higher than those of cellularized dermis (p < 0.0005, p < 0.005). Histological and histomorphometric analysis of explanted samples showed that the membrane was integrated with host tissues in the absence of inflammatory reactions. Our results show that the decellularization method allowed the development of a human allograft dermal matrix that might be useful for soft tissue regeneration.

Development and evaluation of a decellularized membrane from human dermis.

Although progress has been made in the treatment of articular cartilage lesions, they are still a major challenge because current techniques do not provide satisfactory long-term outcomes. Tissue engineering and the use of functional biomaterials might be an alternative regenerative strategy and fulfill clinical needs. Decellularized extracellular matrices have generated interest as functional biologic scaffolds, but there are few studies on cartilage regeneration. The aim of this study was to evaluate in vitro the biological influence of a newly developed decellularized human dermal extracellular matrix on two human primary cultures.

Davide Melandri

Burns Centre and Emilia Romagna Regional Skin Bank

Tissue Characterization after a New Disaggregation Method for Skin Micro-Grafts Generation