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Objective Fibrin has been used as a standard material for scaffold fixation during cartilage repair surgery. Most of the commercially available fibrin preparations need an additional method for scaffold fixation, most often with sutures, thus damaging the surrounding healthy cartilage. There is therefore a need to find alternatives to this method. In our study, we have investigated the potential possibility to use mussel adhesive protein as such an alternative. Methods In this study, hydrophobic plastic was coated with the mussel adhesive protein Mefp-1 as well as with other cell adhesives (poly-lysine, fibronectin, and collagen). Human keratinocytes and chondrocytes were seeded on these substrates at 37°C in culture medium, followed by analysis of attachment and proliferation by crystal violet staining and metabolic labelling. Performance of Mefp-1 and fibrin as tissue glues were estimated by tensional force resistance measurement of moist porcine dermis (as a correlate to scaffold) glued to dermis, cartilage, or bone at 37°C. Results Mefp-1 supported maximal cell attachment at a coating density of approximately 1 µg/cm2. This was at least as good as the other adhesives tested. In addition, it supported cell proliferation at least as good as regular tissue culture plastic over a 7-day period. Measurement of tensional force resistance showed that Mefp-1 performed equally well as fibrin when porcine dermis was glued to cartilage and bone at the same concentration. Separation of the moist tissues after 15-minute incubation required a force of approximately 1 N/cm2 for both compounds. Conclusions Mefp-1 show properties that qualify it as a compound that potentially could replace fibrin as a tissue glue for scaffold fixation. Given the possibilities to modify this protein by bioengineering, it is likely that the properties can be further improved.

BackgroundCommercially available fibrin is routinely being used as both a matrix in certain cartilage repair techniques and a method for scaffold fixation. Chondrocytes from non-digested particulated cartilage fragments are proposed as a possible source for new cartilage tissue formation in some operative techniques. The goal of this study was to test that chondrocytes from particulated articular cartilage embedded in fibrin have an active role in the process of cartilage repair, as well as if commercially available fibrin should be used as a suitable matrix.MethodsArticular cartilage was obtained from patients undergoing total knee replacement surgery. The biopsies were particulated in small, 1–2-mm3 pieces and embedded in fibrin. Two groups were compared in our study, particulated articular cartilage with and without collagenase treatment. The specimens were analyzed by optical microscopy after 2–5 weeks of cultivation in a special construct embedded in a cell culture medium containing particulated cartilage embedded in fibrin in the upper phase and cancellous bone in the lower phase under the perforated nylon membrane.ResultsNone of the biopsies taken from four different patients showed the outgrowth of chondrocytes or bone marrow-originated cells into the fibrin matrix in our experimental model.ConclusionsIt has been shown in our experimental model in vitro little to support the theory that articular chondrocytes from particulated articular cartilage embedded in fibrin have an active role in cartilage repair in its early stage.

Objective:Isolated cases of osteoarthritis of the knee represent a major clinical problem. A particular challenge is a case in which both articular surfaces are affected. Such is the case with the isolated form of patellofemoral osteoarthritis. Studies that describe methods for treating such conditions are few, and the results are not too promising.Methods:In this article, we present one such case of isolated patellofemoral osteoarthritis in which we used a new approach combining periosteal transplantation on one side and the autologous matrix-induced chondrogenesis (AMIC) technique on the other side.Results:The patient has improved, measured by the Knee injury and Osteoarthritis Outcome Score (KOOS) from 48 preoperatively to 77 at 1 year postoperatively (mean improvement) and measured by the Lysholm score from 45 preoperatively to 90 at 1 year postoperatively.Conclusion:This original approach has shown promising results in this patient and could be tested in a larger group of patients with the same type of osteoarthritis in order to estimate its real clinical value.