ABSTRACT
During skin repair, leukocyte infiltration is the principal inflammatory response which is instrumental in triggering growth factor and cytokine signals that orchestrate together to recruit cells necessary for healing. In severe wounds like burn, when acute inflammation becomes chronic, intervention is required to control inflammation so as to hasten the process of healing. Heparin, a known anticoagulant also possesses anti-inflammatory activity by its ability to interfere with the adhesion of leukocytes to the endothelium. Desulfated heparins (DSH) have subdued anticoagulant activity while possessing increased anti-inflammatory activity. Among which 2,3 DSH is found to have marked potency as an anti-inflammatory agent and has been utilized for this study. In this investigation, a controlled delivery system was designed by incorporating 2,3 DSH in microspheres and embedding in collagen matrix which could serve as a wound dressing in burns. In vivo evaluation of healing process was ascertained in rat burn wound model by qualitative and quantitative estimation of proinflammatory cytokines in serum and granulation tissue and collagen turnover was also assessed as healing progressed. The results of this study suggests that 2,3 DSH could be delivered in a controlled manner to regulate inflammatory events to hasten healing of burn wounds.
Subject(s)
Burns/drug therapy , Burns/pathology , Heparin/chemistry , Heparin/pharmacology , Heparin/therapeutic use , Inflammation/drug therapy , Wound Healing/drug effects , Animals , Burns/immunology , Collagen/metabolism , Cytokines/immunology , Female , Granulation Tissue/cytology , Granulation Tissue/metabolism , Inflammation/immunology , Rats , Rats, Wistar , Wound Healing/immunology , Wound Healing/physiologyABSTRACT
OBJECTIVES: A novel collagen-based dressing consisting of 2,3-dihydroxybenzoic-acid-modified gelatin microspheres loaded with doxycycline has previously been reported to address both infection and matrix degradation. In the present study the potential benefits of the dressing were investigated in an excisional wound model in rats challenged with Pseudomonas aeruginosa. METHODS: A full-thick excisional wound (1.5 x 1.5 cm) was created on the dorsum of the rats and infection induced by injecting 10(5) colony-forming units (CFU) of P. aeruginosa. The healing pattern was assessed from wound reduction, matrix metalloprotease (MMP) levels, CFU reduction and histological and biochemical analysis. KEY FINDINGS: The treated group exhibited complete healing by day 15, compared with day 24 in the control group. Early subsidence of infection (99.9% by day 9) resulted in faster epidermal resurfacing and fibroplasias, whereas the microbial load exceeded 10(3) CFU even on day 15 in the control group and caused severe inflammation. Biochemical analysis showed that the expression of both collagen and hexosamine was significantly increased in the treated group. Gelatin zymography revealed prolonged expression of MMPs 2, 8 and 9 in the control group compared with the treated group. CONCLUSIONS: The study indicates that the developed dressing attenuated both infection and metalloprotease levels, and may therefore have potential application in wound healing.
Subject(s)
Anti-Bacterial Agents/therapeutic use , Collagen , Doxycycline/therapeutic use , Drug Delivery Systems/methods , Skin/drug effects , Wound Healing/drug effects , Wound Infection/drug therapy , Animals , Anti-Bacterial Agents/pharmacology , Bandages, Hydrocolloid , Collagen/metabolism , Colony Count, Microbial , Disease Models, Animal , Doxycycline/pharmacology , Female , Gels , Hexosamines/metabolism , Hydroxybenzoates , Inflammation/prevention & control , Matrix Metalloproteinases, Secreted/metabolism , Microspheres , Pseudomonas Infections/drug therapy , Pseudomonas aeruginosa/drug effects , Rats , Rats, Wistar , Skin/microbiology , Skin/pathologyABSTRACT
Collagen from different sources was isolated and designed as scaffolds to act as a three-dimensional substrate for culturing human skin fibroblasts, which can be used as dermal substitutes. The thermodynamic behavior of the scaffolds developed was analyzed through Differential Scanning Calorimetric (DSC) and Thermogravimetric analysis (TGA). Analysis by Fourier Transform Infrared Spectroscopy (FTIR) revealed the functional groups in the scaffolds and the mechanical stability of various scaffolds was assessed through tensile strength analysis. Human skin fibroblasts were cultured on the developed scaffolds to assess their cellular interaction and behavior, and the morphological characteristics of the cultured fibroblasts were evaluated using Scanning Electron Microscopy (SEM). The collagen scaffold exhibited unique features when developed from various sources and it was observed that cells could grow and proliferate well and spread as a monolayer in the reconstituted collagen scaffold.
