Delivery of demineralized bone matrix powder using a salt-leached silk fibroin carrier for bone regeneration

Abstract

Demineralized bone matrix (DBM) has been widely used for bone regeneration due to its osteoinductivity and osteoconductivity. However, the use of DBM powder is limited due to the difficulties in handling, the tendency to migrate from graft sites and the lack of stability after surgery. In this study, a mechanically stable, salt-leached porous silk fibroin carrier was used to improve the handling properties of DBM powder and to support the attachment, proliferation and osteogenic differentiation of rat bone marrow derived mesenchymal stem cells (rBMSCs). The DBM-silk fibroin (DBM/SF) scaffolds were fabricated with different contents of DBM powder (0%, 10%, 20%, 40% and 80% DBM/SF scaffolds). It was found that the DBM/SF scaffolds could form a stable composite preventing the migration of DBM powder. Moreover, the microarchitecture and mechanical properties of the scaffolds were influenced by the DBM powder. rBMSCs were seeded on the DBM/SF scaffolds and cultured for 14 days. Cell proliferation assays and cell morphology observations indicated that 20% DBM/SF scaffolds exhibited good cell attachment and proliferation. In addition, compared with the other groups, the cellular function was more actively exhibited on 20% DBM/SF scaffolds, as evident by the real-time reverse transcriptase-polymerase chain reaction (RT-PCR) analysis for osteoblast-related gene markers (e.g. COL1A1, ALP and cbfa1), the immunocytochemical evaluations of osteoblast-related extracellular matrix components (e.g. COL1A1, OCN and ONN) and the ALP activities. All the data suggested that DBM powder could be delivered using a silk fibroin carrier with improved handling characteristics and that 20% DBM/SF scaffolds had great potential as osteogenesis promoting scaffolds for successful applications in bone regeneration. † Electronic supplementary information (ESI) available: Immunocytochemistry staining video (10Â objective) of rBMSCs cultured on 20% DBM/SF scaffolds for 7 (Video S1) and 14 days (Video S2). The confocal images were captured from the surface to a depth of 165 mm with increments of 3 mm. The videos were created by the 3D projections module of LAS AF to observe the 3D morphologies of the cellscaffold constructs. See

Hybrid scaffolds of Mg alloy mesh reinforced polymer/extracellular matrix composite for critical-sized calvarial defect reconstruction

“…Though no specific, isolated biological agents inducing osteogenic differentiation, such as plasmid DNA, PDGF, or BMP‐2, were added in this study, DBM has been shown to retain some BMP proteins and collagens (Wildemann, Kadow‐Romacker, Haas, & Schmidmaier, ). For prior studies in the rat model with DBM inclusion (Ding et al, ; Dozza et al, ), correlations between osteogenic gene expression and ALP/calcium deposition have shown, specifically that DBM was associated with osteogenic gene expression, including COL1A1, ALP, OCN, and ONN. The effect of adding Mg to the polymer/DBM scaffold is consistent with earlier reports with Mg‐containing materials (Liu et al, ).…”

“…The rotating target holding the Mg mesh ensured the Mg mesh was encapsulated by the PLGA fibres (as shown in Figure c) as well as DBM particles being distributed into the scaffold. It has been shown that the loading strategy of DBM into composite materials can have a large effect on the delivery and release of its bioactive components and thus the resulting bone regenerative efficacy (Ding et al, ). In this study, viscous hyaluronic acid (HA) was used to suspend DBM particles, which made the electrospraying process easier to accomplish.…”

Silk scaffolds for musculoskeletal tissue engineering

“…A salt-leached 3D porous SF scaffold was produced to improve the characteristics of DBM powders and to enhance the adhesion, proliferation, and osteoblastic differentiation of BMSCs. 59 …”

Assessments for bone regeneration using the polycaprolactone SLUP (salt‐leaching using powder) scaffold

“…To address these requirements, conventional fabrication methods and solid freeform fabrication (SFF) methods have been developed. There are various conventional methods for preparing scaffolds, including salt‐leaching, gas‐forming, solvent‐casting (SC), phase separation, and freeze‐drying techniques . Similarly, SFF methods encompass a wide range of procedures, including the use of a stereo lithography apparatus, selective laser sintering, and three dimensional (3D) plotting .…”

“…There are various conventional methods for preparing scaffolds, including salt-leaching, gas-forming, solvent-casting (SC), phase separation, and freeze-drying techniques. [11][12][13][14][15] Similarly, SFF methods encompass a wide range of procedures, including the use of a stereo lithography apparatus, selective laser sintering, and three dimensional (3D) plotting. [16][17][18] Commonly, SFF techniques can be used to fabricate scaffolds with well-defined pore structures and interconnected pores compared with conventional methods.…”