Preparation, Characterization, and Biological Testing of Novel Magnetic Nanocomposite Hydrogels.

To provide a novel approach for the clinical treatment of cartilage tissue defects, we prepared a new type of magnetic nanocomposite hydrogel with an optimal raw material ratio using FeO, polyvinyl alcohol (PVA), and type-II collagen (COLII). Briefly, five groups of PVA and collagen hydrogel matrices with different mass ratios were prepared by a combination of repeated thawing cycles and foam-frozen ice crystal separation methods. Microscopic characterization was conducted using electron microscopy, and the biomechanical properties of each group of hydrogels were then tested. The highest performing component hydrogel matrix was selected after which FeO with different mass ratios was introduced to construct a new FeO/PVA/COLII hydrogel. The prepared composite hydrogels were also microscopically characterized using electron microscopy along with scanning, measurements for porosity and moisture content, and biomechanical, infrared spectrum and degradation performance testing. CCK-8 detection and staining to determine the amount of living and dead cells were also performed. Collectively, these results showed that PVA/COLII,95:5 was the optimal hydrogel matrix. Using this hydrogel matrix, five groups of composite hydrogels with different FeO mass ratios were then prepared. There was no significant difference in the microscopic characteristics between these different hydrogels. FeO/PVA/COLII,5:95:5 had better physical properties as well as swelling performance and cell compatibility. The PVA/COLII,95:5 hydrogel matrix was determined to be the best, while the new magnetic nanocomposite hydrogel FeO/PVA/COLII,5:95:5 had good, comprehensive properties.