Repair of Osteonecrosis of the Femoral Head with Adipose‐Derived Stem Cell Composite with New Nanomaterial

Abstract

This study was aimed at researching the effect of adipose-derived stem cell (ADSC) composite with new nanomaterials on repairing osteonecrosis of the femoral head (ONFH). Nanophase hydroxyapatite/collagen bone material was composited with ADSCs to form a new nanobone material. 24 bone defect rabbits were divided into S1 group (implanted with ADSC composite with nanophase hydroxyapatite/collagen bone material 14 days after modelling), S2 group (implanted with nanophase hydroxyapatite/collagen bone material), and S3 group (simple models). HE staining was used to measure the percentage area of trabecular bone and bone mineral density in rabbit femoral tissue, the load strength of femoral head was measured by orthopedic biomechanical tester, and the number of FVII-Ag-positive cells was detected by immunohistochemistry. There were 8 rabbit models in each group. ADSCs showed black nodules after alkaline phosphatase staining, which was a positive reaction. The OD value of ADSC cells showed a trend of increasing first and then decreasing. The growth rate of ADSC cells was relatively slow in 1-4 days, the growth rate was significantly accelerated in 4-6 days, and the growth inhibition period was entered after 6 days. After hematoxylin-eosin (HE) staining, many scattered bone trabecular structures and bone marrow tissues were found in the rabbits in the S1 group. The nanomaterials were still observed in the rabbits in the S2 group after surgery, and large sheets of bone trabecula appeared with the formation of medullary cavity partially. The bone marrow tissues of the rabbits in the S3 group disappeared partially after surgery, and undifferentiated mesenchymal stem cells and capillaries appeared with many scattered bone trabeculae. The rabbits in the S1 group had significantly higher trabecular bone percentage area and bone mineral density ( 59.76 ± 6.23 ; 0.141 ± 0.015 g/cm2) than the S2 group ( 42.51 ± 7.03 ; 0.113 ± 0.008 g/cm2), and the differences were statistically significant ( P < 0.05 ). The postoperative load strength of rabbits in group S1 was significantly higher than that in group S2, and the difference was statistically significant ( P < 0.05 ). ADSC composite with the new nanomaterial had a good repairing effect on ONFH.