The purple sections in this image are the actin cytoskeleton of human mesenchymal stem cells, the blue spot in the upper left area is the nucleus of cells and the green spots represent 2D covalent organic framework nanoparticles. Image: Dr. Akhilesh K. Gaharwar/Texas A&M Engineering.Stem cells can develop into many different types of cells in the body. For instance, when a person is injured, stem cells migrate to the site of the injury and aid in healing damaged tissues. Now, novel nanotechnology developed by a team of researchers from Texas A&M University could leverage the body’s regenerative potential by directing stem cells to form bone tissue.
Led by Akhilesh Gaharwar, associate professor in the Department of Biomedical Engineering, the researchers have developed water-stable, 2D covalent organic framework (COF) nanoparticles that can direct the differentiation of human mesenchymal stem cells into bone cells. They report their advance in a paper in Advanced Healthcare Materials.
Significant research attention has been given to 2D COFs – porous organic polymers – due to their crystallinity, ordered and tunable porous structure, and high specific surface area. However, the difficulty of processing COFs into nanosized materials – along with their poor stability – has limited their application in regenerative medicine and drug delivery. There is a need for new approaches that can provide COFs with sufficient physiological stability while maintaining their biocompatibility.
Gaharwar’s team has now managed to enhance the hydrolytic (water) stability of COFs by integrating them with amphiphilic polymers, which are macromolecules that contain both hydrophobic and hydrophilic components. This approach, which has not been reported previously, confers water dispersibility on the COFs, allowing them to be used for biomedical applications.
“To the best of our knowledge, this is the first report demonstrating the ability of COFs to direct stem cells toward bone tissue,” Gaharwar said. “This new technology has the potential to impact the treatment of bone regeneration.”
The researchers found that their 2D COFs did not affect the viability and proliferation of cells, even at higher concentrations. They also observed that the COFs exhibit bioactivity and can direct stem cells towards bone cells. This preliminary study indicated that the shape and size of the nanoparticles can impart their bioactivity, and additional in-depth studies need to be carried out for mechanistic insights.
The nanoparticles are highly porous, and Gaharwar’s team showed they could leverage this unique characteristic for drug delivery. They were able to load an osteo-inducing drug called dexamethasone into the porous structure of the COF to further enhance bone formation.
“These nanoparticles could prolong delivery of drugs to human mesenchymal stem cells, which are commonly used in bone regeneration,” said Sukanya Bhunia, senior author of the paper and a postdoc associate in the biomedical engineering department. “The sustained delivery of the drug resulted in enhanced stem cell differentiation toward bone lineage, and this technique can be used for bone regeneration.”
Gaharwar noted that, having provided a proof-of-concept, the team’s next step will be to evaluate this nanotechnology in a diseased model. These findings are important for the future design of biomaterials that can give directions for tissue regeneration and drug delivery applications.
This story is adapted from material from Texas A&M University, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.