Glycosaminoglycans accelerate biomimetic collagen mineralization in a tissue-based in vitro model

Significance Collagen mineralization is required for bone and dentin formation, but the molecular mechanism of that process is not completely understood. Using an in vitro model based on mouse dental tissues, we show that glycosaminoglycans (GAGs) promote collagen mineralization in mineralized tissues, rather than inhibiting mineralization of the ligament. Moreover, the mineralization promoting effect of GAGs is larger than for phosphoproteins, the most frequently studied controlling factor in crystal nucleation and growth. Our model enabled the study of molecular factors on collagen mineralization independently, without changing the expression pattern of other factors, and under conditions as close to native tissue as possible. Evidence that matrix GAGs promote collagen biomineralization has important implications for understanding control of mineralization in connective tissue more generally.