Recapitulation of embryonic endochondral bone formation is a promising alternative approach to bone tissue engineering. However, the time-consuming process is one of the reasons the approach is unpractical. Here, we aimed at accelerating the in vitro endochondral ossification process of tissue engineering by using a pulsed electromagnetic field (PEMF). The rat bone marrow-derived stem cells wer...

BACKGROUND Cyclo-oxygenase-2 (Cox-2) is an inflammatory mediator that is necessary for the tissue repair, including bone fracture healing. Although the application of Cox-2 gene therapy to a murine closed femoral fracture has accelerated bony union, but the beneficial effect was not observed until the endochondral stage of bone repair that is well after the inflammatory stage normally subsides....

Although endochondral ossification of the limb and axial skeleton is relatively well-understood, the development of dermal (intramembranous) bone featured by many craniofacial skeletal elements is not nearly as well-characterized. We analyzed the expression domains of a number of markers that have previously been associated with endochondral skeleton development to define the cellular transitio...

BACKGROUND/AIMS Joint cartilage defects are difficult to treat due to the limited self-repair capacities of cartilage. Cartilage tissue engineering based on stem cells and gene enhancement is a potential alternative for cartilage repair. Bone morphogenetic protein 2 (BMP2) has been shown to induce chondrogenic differentiation in mesenchymal stem cells (MSCs); however, maintaining the phenotypes...

Differentiation is the cellular process that regulates development of long bones and joint surface cartilage of synovial cavities. Growth plate cartilage development is commonly referred to as endochondral ossification which is the end stage of long bone development. Endochondral ossification proceeds as a continuum of chondrocyte proliferation cycles followed by non-proliferative phases couple...

Mammals are remarkably diverse in limb lengths and proportions, but the number and kind of developmental mechanisms that contribute to length differences between limb bones remain largely unknown. Intra- and interspecific differences in bone length could result from variations in the cellular processes of endochondral bone growth, creating differences in rates of chondrocyte proliferation or hy...

Hedgehog (Hh) signaling has been implicated in the development of osteoblasts and osteoclasts whose balanced activities are critical for proper bone formation. Since many mouse mutants in the Hh pathway are embryonic lethal, questions on the exact effects of Hh signaling on osteogenesis remain. Using zebrafish larvae mutant in Indian Hedgehog, patched1, patched2 and suppressor of fused (dre), w...

Regeneration of amputated structures is severely limited in humans and mice, with complete regeneration restricted to the distal portion of the terminal phalanx (P3). Here, we investigate the dynamic tissue repair response of the second phalangeal element (P2) post amputation in the adult mouse, and show that the repair response of the amputated bone is similar to the proximal P2 bone fragment ...

The aim of this study is to clarify the effect of low intensity pulsed ultrasound (LIPUS) on shortening of the fracture healing period and endochondral ossification during the fracture healing process. We first established a model of aging-related delayed union fractures consisting of aged mouse (C57BL/6J; 40 weeks old) with closed femur fractures. We compared the healing process of 40-week-old...

INTRODUCTION: Previous reports indicated that nonsteroidal anti-inflammatory drugs (NSAIDs) suppress bone repair in vivo. Our previous study further found that ketorolac suppressed bone repair at the early stage of endochondral ossification. Furthermore, we also found that NSAIDs suppressed osteoblast proliferation in vitro, which may be one of the important factors contributing to their inhibi...