Gold nanoparticles that have functional surfaces and act on osteogenic differentiation of stem cells have been successfully developed by Tissue Regeneration Materials Unit at the International Center for Materials Nanoarchitectonics (MANA). This research result had been published online version of journal Biomaterials.
In regenerative medicine, the technology to control stem cell functions such as differentiation and proliferation is indispensable. It the past, researches have showed that nanosized gold particles promote the differentiation of human mesenchymal stem cells into osteoblasts. Other studies suggested that various functional groups such as amino, carboxyl and hydroxyl groups can promote or inhibit stem cell differentiation. Inspired by those reports and the team started this project to test their assumption that gold nanoparticles with surface modified with functional groups could be a promising candidate to control stem cell functions.
The researchers synthesized gold nanoparticles with surface modified with three functional groups: a positively-charged amino group (-NH2), a negatively-charged carboxyl group (-COOH) or a neutral hydroxyl group (-OH), and identified how they affect the osteogenic differentiation of mesenchymal stem cells that were derived from human bone marrow. Results showes that among these three types of nanoparticles, those with the carboxyl groups were uptaken by cells and exhibited a strong bone differentiation-inhibitory effect.
In the following research, they investigated the effect of gold nanoparticles with carboxyl groups on the gene expression profile of mesenchymal stem cell from human bone marrow. The results demonstrated that the nanoparticles could inhibit several gene expressions related to osteogenic differentiation. And the influence of the gold nanoparticles on promoting or inhibiting osteogenic differentiation varied depending on the types of functional groups.
In regenerative medicine, it is crucial to develop technology enabling controlling stem cell functions as well as their safety and high-quality. In the present study, researchers attempted to control stem cell functions through material manipulation, and their findings contribute a lot to the creation of novel nanomaterials that facilitate the advancement of stem cell manipulation. It is expected that based on these results , more breakthrough discoveries and technology will be made in developing regenerative medicine.