Artikel
Matrix-assisted autologous cartilage regeneration of the hip joint
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Autoren
Veröffentlicht: | 13. Oktober 2014 |
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Gliederung
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Objective: Acetabular chondral lesions are common in patients suffering from femoroacetabular impingement (FAI) syndrome. However, unlike for the knee joint, cell-based concepts for in situ regeneration of circumscribed cartilage defects have not reached the clinical stage. The aim of this study was therefore i) to evaluate the proliferation potential of primary human chondrocytes derived from both acetabular and femoral site and ii) to validate cellular differentiation during hydrogel-based three-dimensional (3D) cultivation as a prerequisite for autologous matrix-assisted cartilage regeneration of the hip joint.
Method: Chondrocytes were isolated from two different cartilage samples obtained during arthroscopically assisted offset reconstruction in 6 patients: the first sample was taken from the bump area at the anterior head-neck junction and the second from damaged articular cartilage at the acetabular roof (carpet lesion). Proteoglycan content was assessed by Safranin-O staining. Chondrocytes were isolated from the chondral samples using combined collagenase and proteinase digestion and were kept for 19 days in primary culture. Proliferation was then assessed by microscopic cell counting. Cell viability was quantified using Trypan Blue exclusion prior to inoculation of the cells in an in situ polymerizable albumin and hyaluronan-based hydrogel. Chondrogenic differentiation was assessed using quantitative real-time reverse transcriptase polymerase chain reaction analysis for the marker genes collagen types I and II, aggrecan, and interleukin-1β upon monolayer cultivation, 48 hours/4-10 °C transport simulation and 14 days of 3D hydrogel-based cultivation. Statistical analysis was performed on quantified data using One-way ANOVA. A p-value <0.05 was considered significant.
Results and conclusion: Harvest yield from both acetabular and femoral cartilage samples were comparable to that known from knee joints after monolayer cultivation (mean ±SD, 13.4x106 ±5x106 cells per culture versus approximately 20x106 cells). No significant differences were observed concerning cell viability (>95%) and transport simulation. Monolayer cultivation caused a dedifferentiation of chondrocytes. Redifferentiation was induced during 3D hydrogel cultivation as observed by increased levels of both collagen II (1000-fold) and aggrecan (10-fold) gene compared with monolayer cultivation (p<0.001).
Human chondrocytes derived from both damaged acetabular cartilage as well as from the bump area on the femoral side appear to be qualified for autologous matrix-assisted cartilage transplantation paving the way for cell-based cartilage regeneration in FAI patients.