RESUMEN
Objective To explore biological characteristics of chondrogenic differentiation of human periosteum-derived cells and the role of BMP4 in chondrogenic differentiation of these cells.Methods From October 2009 to September 2012,periosteum was obtained from tibia of patients undergoing leg amputation surgery,and isolated periosteum-derived cells by tissue culture method.Cells were cultured in DMEM/F12 containing 10％ fetal bovine serum,and morphology of cells were observed under inverted microscope.Periosteum-derived cells growth and the effect of BMP4 on cells growth examined by cell count using trypan blue,and cells growth curve was made.Experiment was divided into control group,chondrogenic differentiation group and BMP4 group,cells were expanded and differentiated in the presence or absence of BMP4 and complete medium.Then toluidine and immunohistochemical staining analyzed proteoglycan and collagenⅡ expression of these cells after 14 and 21 days.The expression of aggrecan,collagen Ⅱ and SOX9 mRNA of these cells using real-time PCR.Results (1) Periosteumderived cells adhered to growth in vitro,the shape of cell presented fibroblast-like morphology changing into polygonal after 1 week and round cell formation after 2 weeks chondrrogenic differemtiation.Growth curve showed that the passage 3 and 9 cells had similar reproductive activity.The passage 3 cells were positive for CD90 (21.07％) and CD105 (25.84％).(2)Toluidine bule staining and type Ⅱ collagen immunohistochemical staining showed BMP4 group (40.29 ± 4.29,56.74 ± 5.12) and chondrogenic differentiated group (19.27 ± 3.71,38.31 ± 4.25) ccould secrete proteoglycan and collagen Ⅱ,control group were negative (10.24 ± 1.21,15.28 ± 2.23),BMP4 group were significantly than chondrogenic differentiated group.(3) The expression of aggrecan,collagen Ⅱ and SOX9 mRNA of BMP4 group(25.76 ±0.57,6.48 ±0.48,2.91 ±0.18)were significantly higher than that of control group(2.37 ±0.24,1.12 ± 0.31,1.07 ± 0.22)and chondrogenic differentiated group(11.12 ± 0.38,2.24 ± 0.41,1.54 ± 0.35)using real-time PCR.Conclusion Periosteum-derived cells have strong proliferative,and have good potentials of differentiating into chondroblasts like mesenchymal stem cells.BMP4 can promote chondrogenic differentiation of periosteum-derived cells in vitro cultures.
RESUMEN
The aim of this study was to evaluate the bone repair using autogenous periosteum-derived cells (PDC) and bovine anorganic apatite and collagen (HA-COL). PDC from Wistar rats (n=10) were seeded on HA-COL discs and subjected to osteoinduction during 6 days. Critical-size defects in rat calvarias were treated with blood clot (G1), autogenous bone (G2), HA-COL (G3) and HA-COL combined with PDC (G4) (n=40), and then analyzed 1 and 3 months after surgeries. Radiographic analysis exhibited no significant temporal change. G1 and G2 had discrete new marginal bone, but the radiopacity of graft materials in G2, G3 and G4 impaired the detection of osteogenesis. At 3 months, histopathological analysis showed the presence of ossification islets in G1, which was more evident in G2, homogeneous new bone around HA-COL in G3 and heterogeneous new bone around HA-COL in G4 in addition to moderate presence of foreign body cells in G3 and G4. Histomorphometric analysis showed no change in the volume density of xenograft (p>0.05) and bone volume density in G2 was twice greater than in G1 and G4 after 3 months (p<0.05), but similar to G3. The PDC did not increase bone formation in vivo, although the biomaterial alone showed biocompatibility and osteoconduction capacity.
O objetivo deste estudo foi avaliar o reparo ósseo usando células derivadas de periósteo (PDC) e apatita inorgânica e colágeno bovinos (HA-COL). PDC de ratos Wistar (n=10) foram semeadas sobre discos de HA-COL e osteoinduzidas por 6 dias. Defeitos de tamanho crítico em calvárias de ratos foram tratados com coágulo sanguíneo (G1), osso autógeno (G2), HA-COL (G3) ou HA-COL associado a PDC (G4) (n=40) e analisados em 1 e 3 meses após as cirurgias. Análise radiográfica não exibiu mudança temporal significante, G1 e G2 tiveram aumento discreto de novo osso marginal, entretanto a radiopacidade dos materiais de enxerto em G2, G3 e G4 prejudicou a detecção de osteogênese. Análise histopatológica mostrou em 3 meses ilhotas de ossificação em G1 que foi maior em G2, novo osso homogêneo ao redor de HA-COL em G3 e novo osso heterogêneo ao redor de HA-COL em G4 além da presença moderada de células gigantes de corpo estranho em G3 e G4. Análise histomorfométrica mostrou a densidade de volume inalterada do xenoenxerto (p>0,05) e a densidade de volume de novo osso em G2 duas vezes maior que G1 e G4 após 3 meses (p<0,05), mas similar a G3. PDC não aumentaram a formação óssea in vivo apesar do biomaterial sozinho ter apresentado biocompatibilidade e capacidade osteocondutora.