The Promise of Cytokines

these high amounts of BMP, a thousand times the natural concentration, are known to trigger ectopic bone growth in susceptible patients, just as found by Urist, 1965 in his rabbit experiments. 

Proteins such as rhBMP can be incorporated into calcium phosphate layers when biomimetically co-precipitated with the inorganic components (Liu et al., 2004). For example, rhBMP-2 (0.1-10pgml-1) retains its osseoinductive potential when incorporated into the crystal lattice of hydroxyapatite in a dose-dependent manner as ascertained by protein blot staining and enzyme-linked immunosorbent assay (ELISA). The positive osseogenicity of rhBMP-2 was assessed quantitatively by monitoring ALP activity (see Section 7.10.3.1) on rat BMSCs grown directly on the calcium phosphate coatings. 

A similar route was taken by Wang et al. (2014), using polydopamine films to induce the growth of hydroxyapatite on titanium alloy to enhance osteoconductiv-ity. BMP-2 was absorbed onto hydroxyapatite for improved osteoinductivity. The results showed that the conjunction of HAp and BMP-2 increases cell adhesion, 

ALP activity and gene expression of osteogenic markers. Hence, this treatment is potentially useful to develop orthopaedic devices with enhanced properties. 

Anderson, H.C. (1969) Vesicles associated with calcification in the matrix of epiphyseal cartilage. J. Cell Biol., 41, 59-72. 

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