Effects Of Gold Nanoparticles And Carbon Nanotubes On Osteogenic And Adipogenic Differentiation Of Bone Marrow Stromal Cells

Recently, due to the unique physical properies, nanomaterials have evoked a great amount of attention for improving diease prevention, diagnosis, treatment, and especially, tissue engineering. Since nature tissues or organs are nometer in dimension, the biomimetic features and excellent physiochemical properties of nanomaterials play a key role in stimulating cell growth as well as guide tissue regeneration. Even though it was a field in its infancy, currently, numerous researchers fabricate nanomaterials scaffolds encapsulating cells (such as stem cells, chondrocytes and osteoblasts, etc.) for tissue engineering applications.However, due to the ultra-small size, nanomaterials enter the body through variety ways, such as bone marrow. Whether the balance of bone metabolism and bone tissue function would be affected when nanoparticles entered bone marrow, still required further study. By using models of primary mouse bone marrow stromal cells (MSCs) and osteoblasts (OB) and methods of MTT, ALP activity assay, red O stain and assay, we study the effect of gold nanoparticle (Au NPs) and carbon nanotubes (CNTs) on osteogenic and adipogenic differentiation of MSCs and on adipogenic trans-differentiation of osteoblasts. Then we study the expression of osteogenic and adipogenic differentiation related genes by using western blot and real-time PCR.And the results show that:1.At cell level, Au NPs can promote osteogenic differentiation and inhibite adipogenic differentiation and adipogenic trans-differentiation of MSCs and OB;2. At cell level, CNTs can inhibit osteogenic and adipogenic differentiaiton of MSCs;3.Au NPs up-regulated the expression of osteogenic differentiation related genes (such as Runx2, BMP-2, OCN, ALP, etc.) and down-regulated the expression of adipogenic differentiation related genes (such as PPARγ2, E/CBPα, E/CBPβ和E/CBPδ);4.CNTs down-regulated the expression of osteogenic and adipogenic differentiation genes of MSCs;5.Au NPs up-regulated the expression of Runx2 and BMP-2 proteins, and down-regulated the expression of PPARy2 of MSCs.In conclusion, Au NPs promoted the osteogenic differentiation and inhibited the adipogenic and trans-differentiation. While, CNTs inhibited the osteogenic and adipogenic differentiation of MSCs.