<unk>  <unk>  is allograft<unk>  that has had the inorganic mineral removed, leaving behind the organic "collagen"<unk> . It was first discovered by Marshall Urist in 1965 that the removal of the<unk>  mineral exposes more biologically active<unk>  morphogenetic proteins. These growth factors modulate the differentiation of progenitor cells into osteoprogenitor cells, which are responsible for<unk>  and cartilage formation. As a result of the demineralization process,<unk>  is more biologically active than undemineralized<unk>  grafts; conversely the mechanical properties are significantly diminished.
Demineralized bone matrix
Fibrocartilage callus
Hydroxyapatite
Neurite
Calculus 
Erdosteine
Fibrous cap
Polysulfated glycosaminoglycan