fibrin and Burns--Chemical

The purpose of this work is to describe the use of Fibrin-Plasma Rich in Growth Factors (PRGF) membranes for the treatment of a rabbit alkali-burn lesion. For this purpose, an alkali-burn lesion was induced in 15 rabbits. A week later, clinical events were evaluated and rabbits were divided into five treatment groups: rabbits treated with medical treatment, with a fibrin-PRGF membrane cultured with autologous or heterologous rabbit Limbal Epithelial Progenitor Cells (LEPCs), with a fibrin-PRGF membrane in a Simple Limbal Epithelial Transplantation and with a fibrin-PRGF membrane without cultured LEPCs. After 40 days of follow-up, corneas were subjected to histochemical examination and immunostaining against corneal or conjunctival markers. Seven days after alkali-burn lesion, it was observed that rabbits showed opaque cornea, new blood vessels across the limbus penetrating the cornea and epithelial defects. At the end of the follow-up period, an improvement of the clinical parameters analyzed was observed in transplanted rabbits. However, only rabbits transplanted with cultured LEPCs were positive for corneal markers. Otherwise, rabbits in the other three groups showed positive staining against conjunctival markers. In conclusion, fibrin-PRGF membrane improved the chemically induced lesions. Nonetheless, only fibrin-PRGF membranes cultured with rabbit LEPCs were able to restore the corneal surface.

Topics: Animals; Autografts; Burns, Chemical; Epithelial Cells; Eye Burns; Fibrin; Limbus Corneae; Plasma; Rabbits; Stem Cell Transplantation; Stem Cells

Topics: Aged; Alkalies; Burns, Chemical; Cells, Cultured; Combined Modality Therapy; Corneal Diseases; Corneal Topography; Eye Burns; Fibrin; Humans; Lasers, Excimer; Limbus Corneae; Male; Photorefractive Keratectomy; Stem Cell Transplantation; Stem Cells; Transplantation, Autologous

Although ulceration of the corneal stroma after alkali burns is known to be correlated with persistent epithelial defects, the relationship between a defect and the mediators thought to contribute to stromal destruction (plasminogen activator, plasmin, collagenase) has not been understood. This report demonstrates that fibrin and fibronectin appear on the stromal surface after an alkali burn, and that those substratum, matrix components disappear in correlation with the appearance of plasminogen activator on the stromal surface, re-surfacing by the epithelium and a persistent epithelial defect. The facts that epithelium releases plasminogen activator and that plasmin, generated from plasminogen by an activator, can degrade both fibrin and fibronectin, as well as the laminin component of the subepithelial basement membrane, would suggest that the plasminogen activator-plasmin system effect degradation of those macromolecules, thus initiating the events that lead to eventual, frank stromal ulceration. It is hypothesized that stromal ulceration is initiated by the chronic secretion from an epithelium with a persistent defect of a protease (plasminogen activator) involved in wound healing.

Topics: Animals; Basement Membrane; Burns, Chemical; Cornea; Corneal Ulcer; Fibrin; Fibrinolysin; Fibronectins; Male; Neutrophils; Plasminogen Activators; Rabbits; Wound Healing

The study includes 43 cases of conjunctival grafting in chemical burns and traumatic pterygium. Resorbable Bioplast fibrin film was used as a readily available, biocompatible conjunctival subsitute. The implant was absorbed and the site occupied by fresh conjunctival tissue in a few weeks. The composition of tear proteins was restored to normal as fast as after free conjunctival grafting. The results were also satisfactory in terms of cosmetics.

Topics: Biocompatible Materials; Bioprosthesis; Burns, Chemical; Conjunctiva; Eye Burns; Female; Fibrin; Follow-Up Studies; Humans; Male; Proteins; Pterygium; Tears

Topics: Burns, Chemical; Burns, Electric; Eye Burns; Fibrin; Fibrin Foam; Humans