Synthetic Silicate Stimulates Stem Cells to Form Bone Cells

Researchers from Boston, MA have used synthetic silicate nanoplatelest or layered clay to induce bone cell formation from stem cells in the absence of other bone-inducing factors.

Synthetic silicates are composed of either simple or complex salts of silicic acid (SiH4O4).  Silicic acids have been used extensively in commercial and industrial applications that include food additives, glass and ceramic filler materials, and anti-caking agents.

In this study, novel silicate nanoplatelets were constructed that stimulated human mesenchymal stem cells to differentiate into bone-making cells in the absence of any bone-inducing growth factors or cytokines.  The presence of the silicate triggers a set of events inside the mesenchymal stem cells that re-enacts the steps cell normally take during development when they form become bone cells.  These exciting findings illustrate how the use of these silicate nanoplatelets in designing bioactive scaffolds for tissue engineering can lead to the formation of clinically useful bone tissues.

The lead author of this work, Ali Khademhosseini from the division of biomedical engineering at Brigham and Woman’s Hospital, thinks that silicic acid derivatives might be useful in engineering bone. “With an aging population in the U.S., injuries and degenerative conditions are subsequently on the rise,” said Khademhosseini. This means that there is also an increased demand for therapies to repair damaged tissues. Forming such tissues requires protocols to direct stem cell differentiation so that the cells can form new tissues and biomaterials. According to Khademhosseini, “Silicate nanoplatelets have the potential to address this need in medicine and biotechnology.”

“Based on the strong preliminary studies, we believe that these highly bioactive nanoplatelets may be utilized to develop devices such as injectable tissue repair matrixes, bioactive filters, or therapeutic agents for stimulating specific cellular responses in bone-related tissue engineering,” said Akhilesh Gaharwar, first author of this present study.

Future mechanistic studies are necessary to elucidate those underlying pathways that govern the induction of bone differentiation by materials like silicates. Such studies should lead to a better understanding of how particular strategies can be adjusted to improve the performance of lab constructed biomaterials, and accelerate patient recovery time.