Icariin controlled release on a silk fibroin/mesoporous bioactive glass nanoparticles scaffold for promoting stem cell osteogenic differentiation

Abstract

The treatment of bone defects caused by various reasons is still a major problem in orthopedic clinical work. Many studies on osteogenic implant materials have used various biologically active factors such as osteogenic inducers, but these biologically active factors have various side effects. Therefore, in this study, silk fibroin (SF) was used as a scaffold material, mesoporous bioactive glass nanoparticles (MBGNs) as a sustained release carrier, and the traditional Chinese drug icariin (ICA) was loaded to promote bone formation. The experiments in this study have proven that SF/MBGNs-ICA scaffolds can successfully load and release ICA for a long time, and the sustained-release ICA can promote the proliferation and differentiation of BMSCs for a long time. This controlled-release ICA organic/inorganic two-component scaffold material is expected to become a new bone grafting solution.

Fig. 1. (A) General morphology of MBGNs and ICA, (B) SEM images of SF scaffold (scale bar = 200 μm) and high magnification (scale bar = 50 μm) with ratio of MBGNs 1% wt, (C) FTIR spectra of ICA, SF, MBGNs and SF/MBGNs-ICA, (D) ICA releasing from SF-ICA and SF/MBGNs-ICA.

Fig. 2. Cell adhesion, cytotoxicity assays and proliferation: (A) the SEM images of cells on the scaffold after seeding for 7 d, (B) the live-dead staining of cells cultured after 14 d, (C) CCK-8.

Fig. 3. Osteogenesis of BMSCs measured by (A) ALP staining at 7 d and Alizarin Red staining at 21 d. Scale bar = 400 μm. (B) Immunofluorescence assays for OCN expression at 14 d, with the nucleus stained in blue (DAPI) and OCN stained in red. Scale bar = 100 μm.

Fig. 4. Detection of mRNA from selected osteogenic markers in BMSCs after 3 d, 7 d, and 14 d of incubation. The mRNA levels of Alp, Runx2, Opn, and Ocn were quantified (*p < 0.05 and **p < 0.01 compared with control).