Matrix production was characterized in terms of surface concentrations of calcium and phosphorous, components of bone matrix, using X-ray photoelectron spectroscopy (XPS).
Next we tested the degradation of bone matrix using a fluorescent bone resorption assay, where the release of a fluorescent dye into the cell culture supernatant is used to quantify the resorptive activity of osteoclasts on fluoresceinated calcium phosphate plates (Fig. 5c).
Bisphosphonates are the most widely used and effective agents against resorption of bone matrix by osteoclasts and have become an essential part of treatment in patients with established osteoporosis and in patients with risk factors for developing osteoporosis [ 1– 3].
We used MLO-A5 cells to develop a system for studying the mechanical modulation of bone matrix formation in 3D using a cyclic compressive loading stimulus.
Using nanoindentation, material properties such as the elastic modulus and hardness of bone matrix can be determined independently of changes in bone mass or structure [35], [36].
Here we used nanoindentation methods to characterize the effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin 2,3,7,8-tetrachlorodibenzo-p-dioxin 2,3,7,8-tetrachlorodibenzo-p-dioxin 2,3,7,8-tetrachlorodibenzo-p-dioxin
Enhancing osteogenic capabilities of bone matrix for the treatment of fractures and segmental defects using growth factors is an active area of research.
Calcium phosphate (CaP) has traditionally been used for the repair of bone defects because of its strong resemblance to the inorganic phase of bone matrix.
We have previously used this approach to demonstrate that TGF-β signaling in osteoblasts regulates the elastic modulus and hardness of bone matrix in genetically-modified mice [10].
We used 3-point bending to estimate whole bone elastic modulus, quantitative backscattered electron microscopy (qBSEM) to quantify the amount of bone matrix mineral, nanoindentation to measure the bone matrix elastic and plastic properties, and transmission electron microscopy (TEM) to examine the apatite crystals size and organization.
