Liposomal Delivery of Demineralized Dentin Matrix for Dental Tissue Regeneration

Abstract

Current dental restorations have short longevity, and consequently, there is a need for novel tissue engineering strategies that aim to regenerate the dentin-pulp complex. Dentin matrix contains a myriad of bioactive growth factors and extracellular matrix proteins associated with the recruitment, proliferation, and differentiation of dental pulp progenitor cells. In this study, we show that demineralized dentin matrix (DDM), from noncarious dentine, can be encapsulated into liposomes for delivery to dental tissue to promote regeneration. Liposomes were formulated to encapsulate 0–100 μg/mL DDM, lysed with Triton X, and used in vascular endothelial growth factor (VEGF) and transforming growth factor-β1 (TGF-β1) enzyme-linked immunosorbent assays to quantify release. The encapsulation efficiencies were calculated to be 25.9% and 28.8% (VEGF/TGF-β1) for 50 μg/mL DDM liposomes and 39% and 146.7% (VEGF/TGF-β1) for 100 μg/mL DDM liposomes. All liposome formulations had no cytotoxic effects on a dental pulp stem cell (DPSC) clone, as shown by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltertrazolium bromide), Caspase 3/7 assays, and cell counts. The ability of the liposomes to stimulate DPSC chemotactic recruitment was tested by Boyden chamber chemotaxis assays. Unloaded liposomes alone stimulated significant progenitor cell recruitment, while DDM-loaded liposomes further promoted chemotactic recruitment in a dose-dependent manner. DDM liposomes promoted the upregulation of “osteodentin” markers osteocalcin and RUNX2 (Runt-related transcription factor 2) in DPSCs after 9 days of treatment, determined by real-time quantitative PCR. Furthermore, Alizarin Red S staining showed that unloaded liposomes alone induced biomineralization of DPSCs, and DDM liposomes further increased the amount of mineralization observed. DDM liposomes were more effective than free DDM (10 μg/mL) at activating recruitment and osteogenic differentiation of DPSC, which are key events in the endogenous repair of the dentin-pulp complex. The study has highlighted the therapeutic potential of bioactive DDM liposomes in activating dental tissue repair in vitro, suggesting that liposomal delivery from biomaterials could be a valuable tool for reparative dentistry and hard-tissue engineering applications.

Nano-Structured Demineralized Human Dentin Matrix to Enhance Bone and Dental Repair and Regeneration

“…In another study, dentin matrix was treated with 2% HNO 3 for 10 min, then transplanted into the tooth extraction pocket, and bone augmentation was observed [42]. Ethylene diamine tetra acetic acid (EDTA) was also used in demineralization [16,32,43,44]. The EDTA-demineralized dentin matrix is named treated dentin matrix (TDM) in some reports [32,44].…”

“…Ethylene diamine tetra acetic acid (EDTA) was also used in demineralization [16,32,43,44]. The EDTA-demineralized dentin matrix is named treated dentin matrix (TDM) in some reports [32,44]. Gradient EDTA (17%, 5%) was employed to demineralize dentin matrix, and dentin tubules were exposed [43].…”

“…Gradient EDTA (17%, 5%) was employed to demineralize dentin matrix, and dentin tubules were exposed [43]. The EDTA concentration and demineralization time were also varied in different reports [16,32,43,44]. Figure 2.…”

Advanced liposome-loaded scaffolds for therapeutic and tissue engineering applications

“…There are plenty of bioactive factors and extracellular matrix proteins that are related with the recruitment, proliferation and differentiation of pulp progenitor cells in dentin matrix. Therefore, Melling et al [130] fabricated decalcified dental matrix loaded liposomes (DDM-Lip) to repair the teeth tissues. As the results showed, more efficiency in recruiting and activating dental pulp stem cell (DPSC) could be found in samples treated with DDM-Lip, comparing to samples treated with DDM.…”

“…liposomes fused with different kind of cell membranes, according to the clinical demands, then combine with scaffolds to treat diseases and accelerate tissues repairment by taking the advantage of the immune therapy and tissues engineering; and (3) self-assembly drug delivery systems and staged responsive delivery systems fabricated by combining scaffolds and liposomes would provide promising prospects to disease treatment and tissue regeneration. Journal Pre-proof Demineralized dentin matrix [130]…”