By recruiting stem cells into scaffolds and differentiating
them
into osteoblasts, stem cells can be mobilized to directly repair bone
defects, which avoids a series of disadvantages of exogenous stem
cell implantation. In this study, a microsphere-composite hydrogel
for the recruitment and osteogenic differentiation of stem cells was
constructed. Methacrylic anhydride modified gelatin (GelMA) and heparin
(HepMA), as well as nanohydroxyapatite (nHAP), were used to prepare
microspheres followed by adsorbing platelet-derived growth factor
BB (PDGF-BB) whose loading efficiency was 53.7 ± 2.2%. Then the
microspheres were compounded to the GelMA hydrogel encapsulated with
simvastatin (SIM) to obtain microsphere-composite hydrogel GHnH-P@GS.
GHnH-P@GS hydrogel could slowly release SIM and PDGF-BB, and the extents
of release within 7 days were 44.1 ± 2.0% and 32.8 ± 1.1%.
The synergistic effect of small molecule drugs and growth factors
not only induced the recruitment of rabbit bone marrow-derived mesenchymal
stem cells, but also promoted the osteogenic differentiation of stem
cells, which was confirmed by experiments of cell migration, alkaline
phosphatase, and alizarin red staining. Collectively, the microsphere-composite
hydrogel GHnH-P@GS has a certain reference significance for the design
of scaffolds for alveolar bone repair and regeneration.