chondroitin-sulfates and Wounds--Penetrating

The fabrication of new dermal substitutes providing mechanical support and cellular cues is urgently needed in dermal reconstruction. Silk fibroin (SF)/chondroitin sulfate (CS)/hyaluronic acid (HA) ternary scaffolds (95-248μm in pore diameter, 88-93% in porosity) were prepared by freeze-drying. By the incorporation of CS and HA with the SF solution, the chemical potential and quantity of free water around ice crystals could be controlled to form smaller pores in the SF/CS/HA ternary scaffold main pores and improve scaffold equilibrium swelling. This feature offers benefits for cell adhesion, survival and proliferation. In vivo SF, SF/HA and SF/CS/HA (80/5/15) scaffolds as dermal equivalents were implanted onto dorsal full-thickness wounds of Sprague-Dawley rats to evaluate wound healing. Compared to SF and SF/HA scaffolds, the SF/CS/HA (80/5/15) scaffolds promoted dermis regeneration, related to improved angiogenesis and collagen deposition. Further, vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF) and basic fibroblast growth factor (bFGF) expression in the SF/CS/HA (80/5/15) groups were investigated by immunohistochemistry to assess the mechanisms involved in the stimulation of secretion of VEGF, PDGF and bFGF and accumulation of these growth factors related to accelerated wound process. These new three-dimensional ternary scaffolds offer potential for dermal tissue regeneration.

Topics: Animals; Biocompatible Materials; Chondroitin Sulfates; Dermatologic Surgical Procedures; Equipment Design; Equipment Failure Analysis; Fibroins; Hyaluronic Acid; Male; Materials Testing; Plastic Surgery Procedures; Rats; Rats, Sprague-Dawley; Skin; Skin, Artificial; Tissue Scaffolds; Treatment Outcome; Wound Healing; Wounds, Penetrating

To report our institutional experience with the use of a bioartificial dermal substitute (Integra) combined with subatmospheric pressure [vacuum-assisted closure (VAC)] dressings followed by delayed split-thickness skin grafting for management of complex combat-related soft tissue wounds secondary to blast injuries.. Retrospective review of patients treated December 2004 through November 2005.. Military treatment facility.. Integra grafting was performed 18 times in 16 wounds at our institution. Indications for Integra placement were wounds not amenable to simple split-thickness skin grafting, specifically those with substantial exposed bone and/or tendon.. Patients underwent an average of 8.5 irrigation and debridement procedures and concurrent VAC dressings prior to placement of the Integra. Following Integra grafting, all patients were managed with VAC dressings, changed every 3 to 4 days at the bedside or in clinic, with subsequent split-thickness skin grafting an average of 19 days later.. The mechanism and date of injury, size of residual soft tissue deficit, indication for Integra placement, number of irrigation and debridement procedures prior to Integra placement, days from injury to Integra placement, days from Integra placement to split-thickness skin grafting, and clinical outcome were recorded.. Integra placement and subsequent skin grafting was successful in achieving durable and cosmetic definitive coverage in 15 of 16 wounds with two of these patients requiring repeat Integra application. Two patients with difficult VAC dressing placement had early Integra graft failure but successfully healed following repeated Integra application and skin grafting.. Bioartificial dermal substitute grafting, when coupled with subatmospheric dressing management and delayed split-thickness skin grafting, is an effective technique for managing complex combat-related soft tissue wounds with exposed tendon. This can potentially lessen the need for local rotational or free flap coverage.

Topics: Chondroitin Sulfates; Collagen; Debridement; Dermis; Humans; Skin Transplantation; Skin, Artificial; Soft Tissue Injuries; Treatment Outcome; Vacuum; Warfare; Wound Healing; Wounds, Penetrating

Current use of Integra, the collagen-based dermal analogue, requires a two-step grafting procedure to achieve wound closure with an "ultrathin" autograft.. A one-step operative procedure of meshed composite skin graft (MCSG) using Integra as a dermal template for a meshed split thickness autograft was developed in rats. The silicon layer of Integra was removed, the resulting dermal analogue was meshed (1:1.5), expanded, and placed on excised full thickness wound and covered with a meshed (1:1.5 or 1:6) split thickness autograft. Grafted wounds were dressed with BioBrane, Vaseline gauze, silver-impregnated nylon, or silver-nylon and direct current (SNDC). At scheduled intervals up to 3 months postgrafting, wounds were examined for epithelialization, collagen deposition and fibrosis, hair growth, and contraction. The results of wound closure and healing following the one-step procedure were compared with the outcome of the two-step grafting procedure where application of meshed Integra (step one) was followed in 14 days by removal of the silicon layer and application of the meshed autograft (step two).. The one-step procedure applied to meshed autograft/Integra (1:1.5/1:1.5) composite graft accelerated wound closure by 6-19 days when compared with the two-step procedure. At 3 months postgrafting, the contraction of the healed wound dressed with SNDC, BioBrane, or Vaseline gauze was reduced by 13-16% following the one-step procedure compared with the two-step procedure (p < 0.05). The one-step procedure allowed the expansion of the autograft layer to 1:6 while achieving wound healing results similar to grafting with 1:1.5 meshed autograft layer using the two-step grafting procedure.. Single-step application of meshed, thin, split thickness autograft over meshed Integra-derived dermal substitute allows more rapid wound closure with less contraction and more efficient use of graft donor skin than can be obtained with the commonly used two-step grafting procedure.

Topics: Analysis of Variance; Animals; Biocompatible Materials; Chondroitin Sulfates; Collagen; Dermis; Disease Models, Animal; Female; Occlusive Dressings; Outcome and Process Assessment, Health Care; Rats; Rats, Inbred Lew; Skin Transplantation; Skin, Artificial; Surgical Mesh; Time Factors; Transplantation, Autologous; Wound Healing; Wounds, Penetrating

In vitro, chondroitin sulfate (CS) proteoglycans (PGs) bind with high-affinity lipoproteins (LPs) containing apolipoprotein B (apo B), and cultured monocytes incubated with LP-PG complexes transform into foam cells (FCs). Consequently, arterial PGs are thought to contribute to the accumulation of LPs in atherosclerotic lesions, but their in vivo interaction has yet to be demonstrated. Balloon catheterization of rabbit aorta modifies the normal aortic distribution of endogenous LPs containing apo B, and determines their accumulation in normocholesterolemic conditions. The distribution of aortic CS-PGs parallels that of apoB within the neointima of injured aortas and might contribute to a favorable environment for LP sequestration within the lesions. To visualize the in situ relationship between apo B and CS-PG, we performed experiments for double detection by immunofluorescence and by post-embedding electron microscope immunogold. The results indicated that the colocalization of endogenous LPs containing apo B and of the large intimal CS-PGs in advanced lesions developed under the regenerated endothelium. At the ultrastructural level, frequent associations were visualized in the extracellular space and in relation to FCs. The close spatial relation between CS-PG and apo B inside the aortic lesions seems to support the hypothesis of their in situ interaction and of a simultaneous cellular uptake, and may be related to the development of both extracellular lipid deposits and the formation of FCs in atherogenesis.

Topics: Animals; Aorta; Apolipoproteins B; Arteriosclerosis; Chondroitin Sulfates; Endothelium, Vascular; Extracellular Space; Fluorescent Antibody Technique; Microscopy, Electron; Proteoglycans; Rabbits; Tissue Distribution; Wounds, Penetrating