Evaluation of synergistic osteogenesis between icariin and BMP2 through a micro/meso hierarchical porous delivery system

Abstract

BMP2 is well known as an outstanding growth factor for inducing new bone formation. However, improvements are still required to use BMP2 effectively and expand its clinical application due to the potential side effects at high doses. In this study, icariin (IC), a type of traditional Chinese medicine, was originally proposed to be a cooperative factor for BMP2. An alkaline phosphatase (ALP) activity assay showed that IC promoted BMP2 osteogenesis in a concentration-dependent manner with significant enhancement at 38.4 µM versus that for BMP2 at 0.8 µg/mL. Furthermore, we developed a composite hierarchical porous scaffold (SF/SBA15; composed of micropores of silk fibroin [SF] scaffold and mesopores of SBA15) for the controlled delivery of BMP2 and IC. This composite scaffold was investigated by a series of physical characterizations and displayed good in vitro cell biocompatibility. In addition, the composite scaffold also showed the degradation rate of 12% dry weight loss and a slight change in the microstructures within 10 days. Moreover, BMP2 and IC were loaded into the SF and SBA15 structures, respectively, of the SF/SBA15 scaffold. This protein/drug loading system (SF BMP2 /SBA15 IC ) provided delivery of BMP2 with an initial burst release of 60.9%±0.9% in the first 24 hours and a gradual release over the subsequent 6 days to 97.9%±0.8%, whereas IC exhibited a burst release of 64.2%±0.7% in the first 24 hours, followed by a sustained release to 92.4%±0.8% over 10 days. With the prolonged local retention and interaction duration of BMP2 and IC, the SF BMP2 /SBA15 IC scaffold provided better osteogenic differentiation than other groups with different loading modes of BMP2 or IC, as determined by ALP staining and quantitation and Alizarin red staining. Finally, the results of quantitative real-time polymerase chain reaction analysis indicated that the SF BMP2 /SBA15 IC scaffold induced a significantly higher increase in the RUNX2, ALP, COL I , and OCN expression levels of cocultured bone marrow mesenchymal stem cells than other payload composite scaffolds. This study suggests that a micro/meso hierarchical porous delivery system of BMP2 and IC ensures osteogenic synergy and demonstrates promise for bone tissue engineering.

The emerging role of cell senescence in atherosclerosis

“…BMPs are prominent growth factors that induce new bone formation [62]. BMP-2 is a member of the BMP family and enhances the migration and proliferation of HVSMCs via the actin/CD44/MMP-2 molecular pathway [63].…”

Icariin induces the growth, migration and osteoblastic differentiation of human periodontal ligament fibroblasts by inhibiting Toll-like receptor�4 and NF-κB p65 phosphorylation

“…Arising studies have demonstrated that icarrin play a vital role in regulating these genes. Wang et al used ALP activity assay to observe that icariin stimulate BMP2 osteogenesis in a concentration-dependent manner ( 29 ). Besides, the expression of osteogenic genes (Col I, Runx2, osteopotin and DLX5) were significantly elevated by icariin in rat bone marrow stromal cells ( 30 ).…”

<p>Delivery vehicle of muscle-derived irisin based on silk/calcium silicate/sodium alginate composite scaffold for bone regeneration</p>

“…[1][2][3][4] Conditions such as trauma, tumors, and inflammation will impair the structure and functions of bone, thus resulting in bone defects that, in turn, significantly impact psychological health and the quality of life. 5 To overcome the limitations of traditional bone grafting, tissue engineering has become the strategy with the most potential for the clinical treatment of bone defects. 6 Tissue engineering approaches are mainly based on the use of scaffolding biomaterials, seed cells and growth factors/molecules.…”