Silicate nanoplatelets cause stem cells to become bone cells (increasing formation of red color).
Credit: A. Gaharwar, Khademhosseini lab.
As the US population ages, more than a million Americans a year are undergoing hip or knee replacement surgery, according to the National Institutes of Health. Add to that orthopedic injuries incurred by military veterans, plus diseases such as osteoporosis and arthritis, and the importance of research in ways to help the body regenerate human bone becomes clear.
Now, scientists studying that topic are looking to modified clay materials as crucial foundations for bone ingrowth and regeneration.
One team at North Dakota State University (Fargo) has developed a 3D mesh scaffold based on degradable, biocompatible nanoclay materials. The clay improves mechanical properties of the scaffold, allowing it to bear loads while bone regenerates, according to team leader Kalpana Katti, Distinguished Professor of Civil Engineering.
“The biomineralized nanoclays also impart osteogenic or bone-forming abilities to the scaffold to enable birth of bone,” Katti says in a press release. In an article in the Journal of Biomedical Materials Research Part A (subscription required), the workers reported using modified, amino acid containing nanoclays to facilitate new bone growth in bioreactors designed to simulate flow of fluid and blood in the body during bone regeneration.
Another research group working at Brigham and Women’s Hospital (Boston), MA recently reported that layered clay can transform stem cells to bone cells without additional bone-inducing factors.
Writing in Advanced Materials (subscription required), the group, led by Ali Khademhosseini, PhD, BWH Division of Biomedical Engineering, says synthetic silicates it has pioneered can “direct stem cell differentiation and facilitate functional tissue formation.” The materials are simple or complex salts of silicic acids that have been widely used as food additives, fillers for glasses and ceramics, and other industrial applications.
“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 fillers, or therapeutic agents for stimulating specific cellular responses in bone-related tissue engineering,” study coauthor Akhilesh Gaharwar, PhD, BWH Division of Biomedical Engineering, says in a news release. Future research will focus on developing a better understanding of the mechanisms involved and how biomaterials can ultimately shorten patient recovery time, he adds.