Biomimetic Nucleation of Hydroxyapatite Crystals Mediated by Antheraea pernyi Silk Sericin Promotes Osteogenic Differentiation of Human Bone Marrow Derived Mesenchymal Stem Cells

Abstract

Biomacromolecules have been used as templates to grow hydroxyapatite crystals (HAps) by biomineralization to fabricate mineralized materials for potential application in bone tissue engineering. Silk sericin is a protein with features desirable as a biomaterial, such as increased hydrophilicity and biodegradation. Mineralization of the silk sericin from Antheraea pernyi (A. pernyi) silkworm has rarely been reported. Here, for the first time, nucleation of HAps on A. pernyi silk sericin (AS) was attempted through a wet precipitation method and consequently the cell viability and osteogenic differentiation of BMSCs on mineralized AS were investigated. It was found that AS mediated the nucleation of HAps in the form of nanoneedles while self-assembling into β-sheet conformation, leading to the formation of a biomineralized protein based biomaterial. The cell viability assay of BMSCs showed that the mineralization of AS stimulated cell adhesion and proliferation, showing that the resultant AS biomaterial is biocompatible. The differentiation assay confirmed that the mineralized AS significantly promoted the osteogenic differentiation of BMSCs when compared to nonmineralized AS as well as other types of sericin (B. mori sericin), suggesting that the resultant mineralized AS biomaterial has potential in promoting bone formation. This result represented the first work proving the osteogenic differentiation of BMSCs directed by silk sericin. Therefore, the biomineralization of A. pernyi silk sericin coupled with seeding BMSCs on the resultant mineralized biomaterials is a useful strategy to develop the potential application of this unexplored silk sericin in the field of bone tissue engineering. This study lays the foundation for the use of A. pernyi silk sericin as a potential scaffold for tissue engineering.

Bio-inspired mineralization of hydroxyapatite in 3D silk fibroin hydrogel for bone tissue engineering

“…The prominent peak at 2 of 31.8° is assigned to the (211) planes of hydroxyapatite (HAP) according to the standard card of HAP (JCPDS09-0432)[30]. The peak became shaper with increasing mineralization time, indicating enhanced crystallinity of HAP with time and corroborated with the findings of Yang et al,[31,32]. They reported the similar nucleation behavior of HAP in presence of another silk protein sericin.…”

Biomineralization of Natural Collagenous Nanofibrous Membranes and Their Potential Use in Bone Tissue Engineering

“…44,48 To further understand the osteogenic differentiation of MSCs at late stage, real-time polymerase chain reaction (PCR) analysis was used to profile the gene expression of a late-stage osteogenic differentiation marker, osteocalcin (OCN), by following our published protocol. 44,49 …”

A review of the application of reinforced hydrogels and silk as biomaterials for intervertebral disc repair

“…Another way to process silk is to use electrospinning to allow the fibre networks to produce an extracellular collagen-like matrix, composed of fibres with diameters in the nano-to micron-scale range, with high specific surface area and high porosity, thus being predestined candidates for enhanced cell attachment (Catto et al, 2015;Meinel et al, 2009;Min et al, 2004;Sheikh et al, 2015;Zhang et al, 2009). Moreover, silk composite fibres can be realised with collagen proteins (Zhu et al, 2015) or nanoparticles such as hydroxyapatite for bone tissue engineering Yang et al, 2014) silver (Sheikh et al, 2014), or fibres incorporating specific growth factors for sustained drug delivery (Li et al, 2006). Additionally, liquid silk can be directly injected into the NP (Boyd and Carter, 2006;Hu et al, 2012;Murab et al, 2015).…”