Magnesium-Containing Nanostructured Hybrid Scaffolds for Enhanced Dentin Regeneration

Abstract

Dental caries is one of the most prevalent chronic diseases in the United States, affecting 92% of adults aged 20-64 years. Scaffold-based tissue engineering represents a promising strategy to replace damaged dental structures and restore their biological functions. Current single-component scaffolding materials used for dental tissue regeneration, however, cannot provide the proper microenvironment for dental stem/progenitor cell adhesion, proliferation, and differentiation; new biomimetic hybrid scaffolds are needed to promote better dental tissue formation. In this work, we developed a biomimetic approach to prepare three-dimensional (3D) nanofibrous gelatin/magnesium phosphate (NF-gelatin/MgP) hybrid scaffolds. These scaffolds not only mimic the nanostructured architecture and the chemical composition of natural dentin matrices but also constantly present favorable chemical signals (Mg ions) to dental pulp stem cells (DPSCs), thus providing a desirable microenvironment to facilitate DPSC proliferation, differentiation, and biomineralization. Synthesized hybrid NF-gelatin/MgP possesses natural extracellular matrix (ECM)-like architecture, high porosity, high pore interconnectivity, well-defined pore size, and controlled Mg ion release from the scaffold. Adding MgP into NF-gelatin also increased the mechanical strength of the hybrid scaffold. The sustained release of Mg ions from the NF-gelatin/MgP (MgP = 10% wt/wt) scaffold significantly enhanced the proliferation, differentiation, and biomineralization of human DPSCs in vitro. The alkaline phosphatase (ALP) activity and the gene expressions for odontogenic differentiation (collagen I [Col I], ALP, osteocalcin [OCN], dentin sialophosphoprotein [DSPP], and dentin matrix protein 1 [DMP1]) were all significantly higher ( p < 0.05) in the NF-gelatin/MgP group than in the NF-gelatin group. Those results were further confirmed by hematoxylin and eosin (H&E) and von Kossa staining, as shown by greater ECM secretion and mineral deposition in the hybrid scaffold. Consistent with the in vitro study, the DPSCs/NF-gelatin/MgP constructs produced greater ECM deposition, hard tissue formation, and expression of marker proteins (DSPP, DMP1, Col I) for odontogenic differentiation than did the DPSCs/NF-gelatin after 5 weeks of ectopic implantation in rude mice. The controlled release of metallic ions from biomimetic nanostructured hybrid scaffolds, therefore, is a promising approach to enhancing the biological capability of the scaffolds for dental tissue regeneration.

Human treated dentin matrices combined with Zn-doped, Mg-based bioceramic scaffolds and human dental pulp stem cells towards targeted dentin regeneration

“…The hTDMs/scaffold constructs were first placed into each well of 24-well plates and incubated with CCM for 2 h at 37 • C and 5% CO 2 , to mimic the effect of tissue fluids, allowing initial wetting of DENTAL-2769; No. of Pages 17 d e n t a l m a t e r i a l s x x x ( 2 0 1 6 ) xxx.e1-xxx.e17 xxx.e5 the scaffolds with the serum containing medium, optimizing the conditions for protein absorption and therefore initial cell attachment, as previously supported [19,20]. Each scaffold was then spotted with 100 l CCM containing 10 6 DPSCs.…”

Complete pulpodentin complex regeneration by modulating the stiffness of biomimetic matrix

“…To test this hypothesis, we used a nanofibrous gelatin (NF-gelatin) matrix as the scaffolding material and developed a 3D model to explore how DPSCs interact with matrices of varying stiffness in a 3D environment. NF-gelatin matrix was selected in this study because (1) NF-gelatin matrix mimics the chemical composition and physical architecture of the collagen in dental matrices and provides an excellent microenvironment to support DPSC adhesion, proliferation, differentiation, and neo tissue formation [32,33]; (2) NF-gelatin can be readily fabricated into 3D scaffolds with well-defined macro-, micro-, and nano-structures, offering a unique platform to exploit cell-scaffold interaction in 3D [34][35][36]; and (3) The stiffness of NF-gelatin can be readily modulated via the crosslinking density without changing other properties of the scaffold. In this study, we first seeded DPSCs into the 3D gelatin scaffold and examined the effect of the scaffolding stiffness on the adhesion, proliferation, differentiation, and biomineralization of the DPSCs.…”

Demineralized Dentin Matrix Induces Odontoblastic Differentiation of Dental Pulp Stem Cells

“…Tissue engineering technology may yield methods of dentin regeneration for clinical applications for replacing wounded dental tissues caused by caries, trauma or clini-cal accident [Zheng et al, 2012;Jiao et al, 2014;Qu et al, 2014]. The use of tissue scaffolding, cells and growth factors, alone or in combination, enables the generation of complex, multilayered tissues and tissue structures including dentin, root structures and the dentin-pulp complex, based on the basic principles of biology and engineering.…”