Preparation and Osteogenic Efficacy of Emodin-loaded Hydroxyapatite Electrospun Fibers

Biological scaffolds have been the focus of bone tissue engineering research in recent years. In this paper, emodin (EM), macromolecular compound polycaprolactone (PCL), and hydroxyapatite (HA) were used as raw materials to prepare EM/PCL/HA fibers containing different EM ratios by electrospinning, and the properties and osteogenic efficacy of EM/PCL/HA were studied. Scanning electron microscopy, transmission electron microscopy, and atomic force microscopy were used to characterize the structures of HA and the electrospun fibers. Results showed that HA has high crystallinity and loose porous structure, and the electrospun fibers have a smooth and flat surface. In vitro release results showed that EM was slowly released from EM/PCL/HA within 216 h. Cell proliferation assay in mouse embryonic osteoblast precursor cells (MC3T3-E1) exhibited that 5% EM/PCL/HA had the best effect on promoting cell proliferation. Alkaline phosphatase (ALP) and mineralized nodules staining results also showed that 5% EM/PCL/HA had the best effect on promoting osteogenic differentiation. qRT-PCR results showed that the mRNA expression level of osteoblast differentiation markers, namely, bone morphogenetic protein (BMP)-2, BMP-9, and osteocalcin were significantly upregulated by 5% EM/PCL/HA treatment. These results indicate that EM/PCL/HA is a potential osteogenic material, which can provide a reference for the development of bone injury repair materials.