title: Fibrous wound repair associated with biodegradable poly-L/D-lactide copolymer implants: study of the expression of tenascin and cellular fibronectin.
abstract: Extracellular matrix (ECM) proteins are known to play a role in inflammatory and hyperplastic processes. Our aim in the present study was to study the distribution of tenascin (Tn), cellular fibronectins (cFn) and myofibroblasts around biodegradable poly-L/D-lactide (PLA) implants with monoclonal antibodies (MAb). Ethylene-oxide and gamma-irradiation sterilized PLA plate-type implants were inserted into the dorsal subcutaneous tissue of ten adult rabbits. Follow-up times were 4, 12, 16, 36 and 48 wk. Only some inflammatory cells were observed. In electron microscopy, a close coherence between the implant and the stromal tissue was seen. Immunoreactivity for Tn, cFn and alpha-actin was detected as a distinct layer bordering the implant, regardless of the sterilization method for the first 36 wk. From week 36 onwards, Tn immunoreactivity was downregulated while cFn immunoreactivity still persisted. A moderate upregulation for myofibroblasts was seen on the week 48 specimens, when hydrolysation of PLA implant had started. The persistent content of myofibroblasts, Tn and cFn suggests a prolonged wound healing produced by PLA implants. The absence of Tn at the week 48 specimens suggests that cFn, rather than Tn may be needed for alpha-actin-mediated contraction by myofibroblasts.
authors.affiliation: Department of Maxillofacial Surgery, Helsinki University Central Hospital, Kasarminkatu 11-13, 00130 Helsinki, Finland. risto.kontio@medius.inet.fi
authors.forename: R
authors.initials: R
authors.lastname: Kontio
authors.forename: A
authors.initials: A
authors.lastname: Salo
authors.forename: R
authors.initials: R
authors.lastname: Suuronen
authors.forename: C
authors.initials: C
authors.lastname: Lindqvist
authors.forename: J H
authors.initials: JH
authors.lastname: Meurman
authors.forename: I
authors.initials: I
authors.lastname: Virtanen