| 1. |
- Pulliainen, Outi, et al.
(författare)
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Poly-L-D-lactic acid scaffold in the repair of porcine knee cartilage lesions.
- 2007
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Ingår i: Tissue engineering. - : Mary Ann Liebert Inc. - 1076-3279 .- 1557-8690. ; 13:6, s. 1347-55
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Tidskriftsartikel (refereegranskat)abstract
- Articular cartilage injuries cause a major clinical problem because of the negligible repair capacity of cartilage. Autologous chondrocyte transplantation is a surgical method developed to repair cartilage lesions. In the operation, cartilage defect is covered with a periosteal patch and the suspension of cultured autologous chondrocytes is injected into the lesion site. The method can form good repair tissue, but new techniques are needed to make the operation easier and to increase the postoperative biomechanical properties of the repair tissue. In this study, we investigated poly-L,D-lactic acid (PLDLA) scaffolds alone or seeded with autologous chondrocytes in the repair of circular 6-mm cartilage lesions in immature porcine knee joints. Spontaneous repair was used as a reference. Histologic evaluation of the repair tissue showed that spontaneous repair exhibited higher scores than either PLDLA scaffold group (with or without seeded chondrocytes). The scaffold material was most often seen embedded in the subchondral bone underneath the defect area, probably because of the hardness of the PLDLA material. However, some of the cell-seeded and nonseeded scaffolds contained cartilaginous tissue, suggesting that invasion of mesenchymal cells inside nonseeded scaffolds had occurred. Hyaluronan deposited in the scaffold had possibly acted as a chemoattractant for the cell recruitment. In conclusion, the PLDLA scaffold material used in this study was obviously mechanically too hard to be used for cartilage repair in immature animals.
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| 2. |
- Tiitu, Virpi, et al.
(författare)
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Bioreactor improves the growth and viability of chondrocytes in the knitted poly-L,D-lactide scaffold.
- 2008
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Ingår i: Biorheology. - : IOS Press. - 0006-355X .- 1878-5034. ; 45:3-4, s. 539-546
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Tidskriftsartikel (refereegranskat)abstract
- In the present study bovine chondrocytes were cultured in two different environments (static flasks and bioreactor) in knitted poly-L,D-lactide (PLDLA) scaffolds up to 4 weeks. Chondrocyte viability was assessed by employing cell viability fluorescence markers. The cells were visualized using confocal laser scanning microscopy and scanning electron microscopy. The mechanical properties and uronic acid contents of the scaffolds were tested. Our results showed that cultivation in a bioreactor improved the growth and viability of the chondrocytes in the PLDLA scaffolds. Cells were observed both on and in between the fibrils of scaffold. Furthermore, chondrocytes cultured in the bioreactor, regained their original round phenotypes, whereas those in the static flask culture were flattened in shape. Confocal microscopy revealed that chondrocytes from the bioreactor were attached on both sides of the scaffold and sustained viability better during the culture period. Uronic acid contents of the scaffolds, cultured in bioreactor, were significantly higher than in those cultured in static flasks for 4 weeks. In summary, our data suggests that the bioreactor is superior over the static flask culture when culturing chondrocytes in knitted PLDLA scaffold.
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