4 research outputs found
A clinical feasibility study to evaluate the safety and efficacy of PEOT/PBT implants for human donor site filling during mosaicplasty
Mosaicplasty has become a well-accepted treatment modality for articular cartilage lesions in the knee. Postoperative bleeding remains potentially concerning. This study evaluates the porous poly(ethylene oxide)terephthalate/poly(butylene terephthalate) (PEOT/PBT) implants used for donor site filling. Empty donor sites were the controls. After 9 months, MRI, macroscopical and histological analysis were carried out. Treated defects did not cause postoperative bleeding. No adverse events or inflammatory response was observed. PEOT/PBT implants were well integrated. Empty controls occasionally showed protrusion of repair tissue at the defect margins. Surface stiffness was minimally improved compared to controls. Existing polymer fragments indicated considerable biodegradation. Histological evaluation of the filled donor sites revealed congruent fibrocartilaginous surface repair with proteoglycan-rich domains and subchondral cancellous bone formation with interspersed fibrous tissue in all implanted sites. The PEOT/PBT implants successfully reduce donor site morbidity and postoperative bleeding after mosaicplasty
Cell adhesion molecules in stromal corneal dystrophies
The aim of the present study was to
investigate the expression pattern of different cell
adhesion molecules in corneal stromal dystrophies.
Fifteen corneal buttons from patients diagnosed with
three different types of stromal corneal dystrophies and
healthy corneas were investigated. Paraffin embedded
sections were stained immunohistochemically with
monoclonal antibodies against human intercellular
adhesion molecule-1 (ICAM-1), endothelial selectin (Eselectin)
and endothelial cadherin (E-cadherin) using the
avidin-biotin-peroxidase-complex technique. The
sections were compared to normal eye bank controls.
In corneas from granular dystrophy patients ICAM-1
was expressed focally in epithelial cells and in
keratocytes, and expressed diffusely in endothelial cells.
In corneas from macular dystrophy patients diffuse
epithelial staining was observed and the stromal and
endothelial expression was found to be similar to that of
granular dystrophy. In lattice dystrophy, only the
epithelial cells and endothelium were intensively
positive for ICAM-1. E-selectin was not present on any layer of the corneal specimens. E-cadherin was observed
only in the epithelium of all three types of corneal
dystrophies. Normal corneas did not express any of the
investigated adhesion molecules.
We found different expression patterns of adhesion
molecules in corneas from stromal dystrophies. Our
results suggest that adhesion molecules may be involved
in the pathogenesis of corneal stromal dystrophies
A computer-assisted microscopic analysis of bone tissue developed inside a polyactive polymer implanted into an equine articular surface
One of the most promising applications for the restoration of small or moderately sized focal articular lesions is mosaicplasty (MP). Although recurrent hemarthrosis is a rare complication after MP, recently, various strategies have been designed to find an effective filling material to prevent postoperative bleeding from the donor site. The porous biodegradable polymer Polyactive (PA; a polyethylene glycol terephthalate - polybutylene terephthalate copolymer) represents a promising solution in this respect. A histological evaluation of the longterm PA-filled donor sites obtained from 10 experimental horses was performed. In this study, attention was primarily focused on the bone tissue developed in the plug. A computer-assisted image analysis and quantitative polarized light microscopic measurements of decalcified, longitudinally sectioned, dimethylmethylene blue (DMMB)- and picrosirius red (PS) stained sections revealed that the coverage area of the bone trabecules in the PA-filled donor tunnels was substantially (25%) enlarged compared to the neighboring cancellous bone. For this quantification, identical ROIs (regions of interest) were used and compared. The birefringence retardation values were also measured with a polarized light microscope using monochromatic light. Identical retardation values could be recorded from the bone trabeculae developed in the PA and in the neighboring bone, which indicates that the collagen orientation pattern does not differ significantly among these bone trabecules. Based on our new data, we speculate that PA promotes bone formation, and some of the currently identified degradation products of PA may enhance osteo-conduction and osteoinduction inside the donor cana