The Influence of MgO Nanoparticles on the Osseointegration of Polycaprolactone - Sodium Alginate Hydrogel Interfaces

Aims: The aims of this study were to evaluate the influence of magnesium oxide (MgO) nanoparticles on the cell viability of a sodium alginate (SA) hydrogel and to evaluate the influence of MgO nanoparticles on the interface tensile strength between polycaprolactone (PCL) and SA hydrogel scaffolds after two weeks of cell culture.
Study Design: Mouse osteoblast cells (MT3T3E1) were cultured on two groups of scaffolds: SA hydrogel and SA hydrogel with 22 nm MgO particles. Quantitative cell viability tests were conducted on each of the samples to compare the influence of magnesium oxide (MgO) nanoparticles on cell viability between the two groups. MT3T3E1 cells were cultured on two groups of coupled PCL-SA hydrogel scaffolds: PCL-SA hydrogel scaffold and PCL-SA hydrogel scaffold with 22 nm MgO particles. Tension tests were conducted on the coupled samples to compare the interface tensile strength between the two groups.
Place and Duration of Study: The studies were carried out in the Stephenson Research and Technology Center at University of Oklahoma, the Interface Tissue Engineering Laboratory at the University of Central Oklahoma, and the Cell Biology Research Laboratory at the University of Central Oklahoma between June 2009 and May 2011.
Methodology: Standard cell culture protocols were used to culture cells on SA hydrogel scaffolds with and without MgO nanoparticles for 4 and 24 hours. Absorbance and fluorescent intensity tests were conducted for quantitative measurements of cell viability. Cells were cultured on PCL-SA coupled scaffolds for 2 weeks. A custom tension setup was designed and fabricated to conduct tension tests on the coupled scaffolds to quantify the mechanical strength of the osseointegration.
Results: This research found that SA hydrogel scaffolds containing MgO nanoparticles demonstrated higher osteoblast cell activity compared to SA hydrogel without MgO. The study also found reduced interface tensile strength when PCL-SA coupled scaffolds contained MgO nanoparticles.
Conclusion: This study thus suggested that MgO nanoparticle improves the cell viability of SA hydrogel, but it is detrimental for the osseointegration of PCL-SA hydrogel constructs.