Fibronectin has been localized by indirect immunofluorescence during the various phases of endochondral bone formation in response to subcutaneously implanted demineralized bone matrix. Its histologic appearance has been correlated with results of biosynthetic experiments. (a) The implanted collagenous bone matrix was coated with fibronectin before and during mesenchymal cell proliferation. (b)...

Long bones develop by a process called endochondral bone formation, in which a cartilage model is generated and then is replaced with bone (Erlebacher et al., 1995; Cancedda et al., 1995). Endochondral development begins with condensation of undifferentiated mesenchymal cells that prefigure the future skeletal elements. In the core of these condensations, cells differentiate into chondroblasts,...

Bone repair and regeneration is one of the most extensively studied areas in the field of tissue engineering. All of the current tissue engineering approaches to create bone focus on intramembranous ossification, ignoring the other mechanism of bone formation, endochondral ossification. We propose to create a transient cartilage template in vitro, which could serve as an intermediate for bone f...

Explanted mouse limb buds aged 12, 13 or 14 days cultured for 9 days in vitro failed to develop a marrow cavity or show endochondral ossification. Explants aged 15 days developed a marrow cavity and showed signs of endochondral ossification. The periosteum in these limbs was perforated and laminated and cells appeared to be passing between the laminae to populate the marrow cavity. This suggest...

Subcutaneous implantation of coarse powders (74-420 micron) of demineralized diaphyseal bone matrix resulted in the local differentiation of endochondral bone. However, implantation of matrix with particle size of 44-74 micron (Fine matrix) did not induce bone. We have recently reported that the dissociative extraction of coarse matrix with 4 M guanidine HCl resulted in a complete loss of the a...

Many bony features of the face develop from endochondral ossification preexisting collagen-rich cartilage structures. The proper development these structures is essential to morphological formation face. developmental programs governing pre-bone facial cartilages are sensitive chemical compounds that disturb histone acetylation patterns and chromatin structure. We have taken advantage this fact...

The Growth/Differentiation Factors (GDFs) are a subgroup of the Bone Morphogenetic Proteins (BMPs) well known for their role in joint formation and chondrogenesis. Mice deficient in one of these signaling molecules, GDF-5, have recently been shown to exhibit a decreased rate of endochondral bone growth in the proximal tibia due to a significantly longer hypertrophic phase duration. GDF-7 is a r...

Many studies have reported on the effects of cyclooxygenase-2 (COX-2) inhibition on osteogenesis. However, far less is known about the effects of COX-2 inhibition on chondrogenic differentiation. Previous studies conducted by our group show that COX-2 inhibition influences in vitro chondrogenic differentiation. Importantly, this might have consequences on endochondral ossification processes occ...

Endochondral ossification is a developmental process by which cartilage is replaced by bone. Terminally differentiated hypertrophic chondrocytes are calcified, vascularized, and removed by chondroclasts before bone matrix is laid down by osteoblasts. In mammals, the malleus is one of three auditory ossicles that transmit vibrations of the tympanic membrane to the inner ear. The malleus is forme...

Endochondral bone development is a fascinating story of proliferation, maturation, and death. An understanding of this process at the molecular level is emerging. In particular, significant advances have been made in understanding the role of parathyroid-hormone-related peptide (PTHrP), parathyroid hormone (PTH), and the PTH/PTHrP receptor in endochondral bone development. Mutations of the PTH/...