Which Culture System Is better for Chondrogenesis of Adipose-Derived Stem Cells ; Pellet or Micromass?

Background and Aims: The current study was conducted to compare the expression levels of collagen type Π and X during chondrogenesis of human adipose-derived mesenchymal stem cells (hADMSCs) pellet and micromass cultures. Materials and Methods: Extracted hADMSCs were cultured until three passages and then transferred to pellet and micromass cultures in the experimental groups of day 7 and day14. For pellet and micromass cultures, aliquots of 5×105 cells/ml were centrifuged and respectively cultured in the conical tubes and droplets (12.5 µl) of the 24-well plates containing chondrogenic medium. Realtime-polymerase chain reaction technique was performed for gene expression levels. Results: Increased expression of collagen type Π was shown in micromass day14 compared to micromass day 7, pellet day 14 (p<0.01) and pellet day 7 (p<0.001). Also, an increased expression of collagen type Π was seen in micromass day 7 and pellet day 14 compared to pellet day 7 (p< 0.05). Expression of collagen type X increased in pellet day 14 compared to micromass on days 7 and 14 (p<0.001, p<0.01) and pellet day14 compared to pellet day7 (p< 0.05). An increased expression of collagen type X was shown in pellet day 7 compared to micromass on days 7 and 14 (p<0.05). Conclusions: According to the results, higher expression of collagen type Π and lower expression of collagen type X in micromass cultures that are prepared by cell suspension play a better role during cellular condensation that leads to the formation of large nodules exhibiting cartilage-like morphology, suggests a higher efficiency for micromass cultures.

Individual cell-only bioink and photocurable supporting medium for 3D printing and generation of engineered tissues with complex geometries

Functional tissues with complex geometries can be engineered by 3D bioprinting individual cell-only bioinks into a photocrosslinkable microgel support bath, which permits structural control over cellular condensation formation and long-term culture.

TINJAUAN HISTOLOGIK TULANG RAWAN

Cartilage belongs to the suppportive tissue which is relatively dense. In an adult, this tissue is only found in two areas: extraskeletal cartilage and joints. During chondrogenesis in an embryo, messenchymal cells round up, retract their extensions, multiply rapidly, and form cellular condensation, cartilage formation area. The development of this ares occurs in two mechanisms: interstitial growth and apppositional growth. Injured cartilage will be repaired by the perichondrium. Its cells tend to fill spaces or deffects meanwhile chondrogenic cells of the perichondrium will undergone proliferation and differentiation to become chondroblast which produces new matrix.Keywords: cartilage, types of cartilageAbstrak: Tulang rawan merupakan jaringan ikat penahan berat yang relatif padat, tetapi tidak sekuat tulang. Dalam kehidupan pasca lahir, jaringan ini hanya ditemukan pada dua jenis tempat sesudah tidak tumbuh lagi, yaitu pada sejumlah bangunan tulang rawan ekstra-skeletal yang terdapat dalam tubuh dan pada persendian. Pada tempat pembentukan tulang rawan embrio, sel-sel mesenkim menyusutkan cabang-cabangnya dan mengumpul dalam agregasi padat yang dikenal sebagai pusat kondrifikasi. Pertumbuhan dalam perluasan pusat kondrifikasi terjadi melalui dua mekanisme berbeda, yaitu: pertumbuhan interstitial dan pertumbuhan aposisional. Cedera tulang rawan akibat trauma akan diperbaiki oleh perikondrium. Sel-sel perikondrium cenderung untuk mengisi kekosongan atau defek, sedangkan sel-sel kondrogenik dalam perikondrium akan berproliferasi dan berdiferensiasi menjadi kondroblas yang menghasilkan matriks baru.Kata kunci: kartilago, jenis kartilago

Chondrogenic differentiation of clonal mouse embryonic cell line ATDC5 in vitro: differentiation-dependent gene expression of parathyroid hormone (PTH)/PTH-related peptide receptor.

The regulatory role of parathyroid hormone (PTH)/PTH-related peptide (PTHrP) signaling has been implicated in embryonic skeletal development. Here, we studied chondrogenic differentiation of the mouse embryonal carcinoma-derived clonal cell line ATDC5 as a model of chondrogenesis in the early stages of endochondral bone development. ATDC5 cells retain the properties of chondroprogenitor cells, and rapidly proliferate in the presence of 5% FBS. Insulin (10 micrograms/ml) induced chondrogenic differentiation of the cells in a postconfluent phase through a cellular condensation process, resulting in the formation of cartilage nodules, as evidenced by expression of type II collagen and aggrecan genes. We found that differentiated cultures of ATDC5 cells abundantly expressed the high affinity receptor for PTH (Mr approximately 80 kD; Kd = 3.9 nM; 3.2 x 10(5) sites/cell). The receptors on differentiated cells were functionally active, as evidenced by a PTH-dependent activation of adenylate cyclase. Specific binding of PTH to cells markedly increased with the formation of cartilage nodules, while undifferentiated cells failed to show specific binding of PTH. Northern blot analysis indicated that expression of the PTH/PTHrP receptor gene became detectable at the early stage of chondrogenesis of ATDC5 cells, preceding induction of aggrecan gene expression. Expression of the PTH/PTHrP receptor gene was undetectable in undifferentiated cells. The level of PTH/PTHrP receptor mRNA was markedly elevated parallel to that of type II collagen mRNA. These lines of evidence suggest that the expression of functional PTH/PTHrP receptor is associated with the onset of chondrogenesis. In addition, activation of the receptor by exogenous PTH or PTHrP significantly interfered with cellular condensation and the subsequent formation of cartilage nodules, suggesting a novel site of PTHrP action.