chondroitin-sulfates and Tympanic-Membrane-Perforation

To provide a less expensive and more convenient protocol for the treatment of tympanic membrane perforations (TMPs).. Several materials were prepared and compared for TMP repair including Carbylan-SX, Gelatin-DTPH-PEGDA (GX), Carbylan-S/Gelatin-DTPH (Carbylan-GSX) (injectable and sponge), Gelfoam, Epifilm, and crosslinked thiolated chondroitin sulfate (CS-DTPH-PEGDA [CS-SX]). Hartley pigmented guinea pigs (Elm Hill) underwent bilateral myringotomy with 1 ear left as a control and the other treated with one of the previously mentioned materials.. Carbylan-GSX (injectable and sponge), Gelfoam with saline, and CS-SX had the shortest time for TMP closure. Epifilm, Carbylan, and gelatin preparations resulted in closure rates similar to controls. CS-SX showed a marked inflammatory reaction compared with controls and other materials based on neutrophil, lymphocyte, epitheloid counts, and degree of fibrosis.. This study shows the validity of Carbylan-GSX compared with Gelfoam as a material to promote TMP closure in an acute TMP guinea pig model.

Topics: Animals; Chondroitin Sulfates; Disease Models, Animal; Extracellular Matrix; Gelatin; Gelatin Sponge, Absorbable; Guinea Pigs; Humans; Hyaluronic Acid; Hydrogels; Polyethylene Glycols; Tympanic Membrane Perforation

Extracellular matrix components have hitherto been sparsely studied in tissue repair processes. In this study, the distribution of hyaluronan (HYA), fibronectin, and five chondroitin sulfate glycosaminoglycans (GAGs) was analysed in healing tympanic membrane (TM) perforations of rats, at different time points, using a HYA-binding protein probe and six monoclonal antibodies (MAbs). Hyaluronan appeared, the first day, around migrating squamous epithelial and inflammatory cells in the perforation borders and close to dilated vessels at the malleus handle. Accumulated HYA persisted in the thickened perforation rim until closure of the perforation, then it slowly disappeared from the healed TM area. Fibronectin immunoreactivity occurred around proliferating cells in the perforation edge and around collagen bundles in the connective tissue. The MAbs for chondroitin sulfate GAGs rendered specific, constant immunostaining patterns throughout the healing process. Unsulfated chondroitin, chondroitin-4-sulfate and chondroitin-6-sulfate were present in small amounts in the connective tissue surrounding collagen fibres and fibroblasts. The staining for native chondroitin and dermatan sulfate was most pronounced in the epithelial layers, in particular the squamous epithelium and its keratin layer, whereas the loose connective tissue was left unstained. After closure of the TM perforations, the immunoreactivity for unsulfated chondroitin, native chondroitin and dermatan sulfate increased in the scar tissue. It is concluded that HYA is abundant in early stages of healing of TM perforations, whereas fibronectin, unsulfated chondroitin, chondroitin-4 and 6-sulfate are constantly present in small amounts during the healing process. Unsulfated chondroitin, native chondroitin and dermatan sulfate increase in the healed TM area.

Topics: Animals; Chondroitin Sulfates; Dermatan Sulfate; Extracellular Matrix; Fibronectins; Hyaluronic Acid; Immunohistochemistry; Male; Rats; Rats, Sprague-Dawley; Time Factors; Tympanic Membrane Perforation; Wound Healing