Tideglusib enhances odontogenic differentiation in human dental pulp stem cells in vitro

Bioactive deproteinized bovine bone mineral based on self-assembled albumin nanoparticles promoted bone regeneration via activation of Wnt/β-catenin pathway

One of the major problems faced with pre-implant bone reconstruction therapy is that large bone defects do not heal over time. Artificial bone graft materials, such as deproteinized bovine bone mineral, are commonly used in clinics. However, the lack of osteoinductive capacity and risk of post-implantation infections remain key limitations. Bioactive materials with strong bone formation and a high degree of biocompatibility are still needed. In this study, we synthesised bovine serum albumin nanoparticles (BNP) loaded with Tideglusib (TD), TD and BNP were bound together by self-assembly, and mixed with deproteinized bovine bone mineral (DBBM) to form a bone substitute material (TD-BNP@DBBM) that had low cytotoxicity, promoted cell proliferation and migration, induced cell differentiation, and regulated osteogenesis. In vitro, experiments suggested that TD-BNP@DBBM could promote osteoblast differentiation of MC3T3-E1 cells. In vivo, experiments demonstrated that TD-BNP@DBBM significantly accelerated bone reconstruction and enhanced bone healing in a rat cranial defect model. Furthermore, this result suggested a link between the Wnt/β-catenin pathway and the osteogenic effect, providing a basis for subsequent investigations into the mechanism of bone regeneration induced by osteogenic biomaterials. TD-BNP@DBBM might be a promising new approach for treating bone defects.

Evaluation of the bone regenerative effect of glycogen synthase kinase 3 antagonist Tideglusib carried by different scaffolds on rat calvarial defects

The aim was to explore the efficiency of Tideglusib in bone tissue healing by carrying it with different scaffolds on rat calvarial lesions. Twentyfour male Dawley rats were utilized. Two bone defects of 5 mm in diameter were formed (n = 8). Groups constituted negative control, collagen sponge + Tideglusib (CT), bacterial cellulose carrier (BC), bacterial cellulose carrier + Tideglusib (BC + T), PCL/Gel nanocarrier (Nano) and PCL/Gel + Tideglusib (Nano+T). After four week, histomorphometric and immunohistochemistry investigations were performed. Pairwise comparisons by means of the new bone formation (NBF) effect of Tideglusib demonstrated a significant difference between the control and the Nano+T groups solely (p < 0.05). BC group demonstrated reduced NBF in comparison to the CT group (p < 0.05), Nano group (p < 0.01) and Nano+T group (p < 0.01). Similarly, the BC + T group exhibited a diminished rate of NBF in comparison to both the Nano (p < 0.01) and Nano+T groups (p < 0.01). Type I collagen expression decreased in the BC group (p < 0.05) and BC + T group (p < 0.05) relative to the control. Axin2 expression was increased in the Nano+T group (p < 0.05) compared to the control. Within the limits, Tideglusib delivered with a nanocarrier containing PCL/Gel may have favorable impact on bone regeneration. However, the impact may vary with different carrier.

In-vitro evaluation of the effect of okra (Abelmoschus esculentus L.) extract on periodontal cells: a comprehensive study of cellular and molecular impacts

BACKGROUND

This research assessed the potential role of okra (Abelmoschus esculentus L.) extract on periodontal tissue wound healing by evaluating its effects on human periodontal ligament fibroblast (hPDLF), human gingival fibroblast (hGF), and human osteoblast (hOB) cells in vitro.

METHODS

The viability effect of okra extract on hPDLF, hGF, and hOB cells was determined using the MTT assay protocol. The highest viability concentrations were applied to hPDLF and hOB cells, and the expression levels of on type 1 collagen (COL1), bone morphogenetic protein 2 (BMP2), axis inhibition protein 2 (AXIN2), and fibroblast growth factor 2 (FGF2) proteins were determined through ELISA. The extract was also tested for antioxidant (CUPRAC, DPPH, FCR, and FRAP tests), acetylcholinesterase (AChE) inhibition, and antimicrobial properties, and its content was determined by HPLC-DAD.

RESULTS

The viability results showed no significant difference between the okra extract-treated and control groups for all cell types. In hPDLF cells, higher expression levels of COL1 and AXIN2 in the okra extract-treated group compared to the control group, while BMP2 expression level was lower. In hOB cells, the extract-treated group had higher levels of COL1, BMP2, and AXIN2 expression than the control group.

CONCLUSION

It can be posited that okra extract may activate the Wnt/β-catenin signalling pathway and may have a beneficial impact on wound healing in periodontal tissues. However, extensive long-term in-vivo research on the activation of signalling pathways by okra extract in periodontal wound healing is required.

Odontogenic differentiation of dental pulp stem cells by glycogen synthase kinase-3β inhibitory peptides

BACKGROUND

To investigate the effects of peptide-based substrate competitive inhibitors of GSK-3β (GSK-3βi) on promoting odontogenic differentiation of human dental pulp stem cells (hDPSCs).

METHODS

The biocompatibility and proliferation of hDPSCs treated with GSK-3βi peptides (pS9, LRP 6a, L803, and L803-mts) were evaluated using the tetrazolium reduction assay and cell counting kit-8 assay, respectively. The differentiation of hDPSCs following peptide treatment was determined using the alkaline phosphatase assay (ALP), calcium mineralization (alizarin red staining), and quantification of mRNA expression of differentiation markers via quantitative real-time polymerase chain reaction. The accumulation of β-catenin in the nucleus of GSK3-βi-treated hDPSCs was determined using immunofluorescence staining. The effect of peptide treatment on hDPSC migration was characterized using the transwell assay.

RESULTS

All tested concentrations of the peptides were found to be biocompatible with the hDPSCs, with no significant difference compared to the control (p > 0.05). The peptides had no effect on the proliferation of hDPSCs compared to the control (p > 0.05). However, all the tested peptides significantly increased ALP activity and calcium deposition in a dose-dependent manner (p < 0.05). Specifically, L803-mts showed significantly greater ALP activity and mineralization compared to the other peptides and the controls (p < 0.05). Additionally, L803-mts showed a significant increase (p < 0.05) in the expression of DSPP, DMP-1, Runx-2, along with increased protein expression of DSPP and DMP-1 compared to the control. Furthermore, it enhanced the nuclear translocation of β-catenin and increased the chemotactic migratory potential of hDPSCs.

CONCLUSIONS

L803-mts, a peptide-based substrate competitive inhibitor of GSK-3β, enhanced the odontogenic differentiation of hDPSCs by activating the Wnt signaling pathway.

Effect of the anti-Alzheimer drug GSK-3β antagonist on numerical modeling of the energy dissipation through the resin-dentin interface

OBJECTIVES

The aim of this study was to determine the viscoelastic performance and energy dissipation of conditioned dentin infiltrated with polymeric nanoparticles (NPs) doped with tideglusib (TDg) (TDg-NPs).

METHODS

Dentin conditioned surfaces were infiltrated with NPs and TDg-NPs. Bonded interfaces were created, stored for 24 h and submitted to mechanical and thermal challenging. Resin-dentin interfaces were evaluated through nano-DMA/complex-loss-storage moduli-tan delta assessment and atomic force microscopy (AFM) analysis.

RESULTS

Dentin infiltrated with NPs and load cycled attained the highest complex modulus at hybrid layer and bottom of hybrid layer. Intertubular dentin treated with undoped NPs showed higher complex modulus than peritubular dentin, after load cycling, provoking energy concentration and breakdown at the interface. After infiltrating with TDg-NPs, complex modulus was similar between peri-intertubular dentin and energy dissipated homogeneously. Tan delta at intertubular dentin was higher than at peritubular dentin, after using TDg-NPs and load cycling. This generated the widest bandwidth of the collagen fibrils and bridge-like mineral structures that, as sight of energy dissipation, fastened active dentin remodeling. TDg-NPs inducted scarce mineralization after thermo-cycling, but these bridging processes limited breakdown zones at the interface.

SIGNIFICANCE

TDg-based NPs are then proposed for effective dentin remineralization and tubular seal, from a viscoelastic approach.

Mitigating lipopolysaccharide-induced impairment in human dental pulp stem cells with tideglusib-doped nanoparticles: Enhancing osteogenic differentiation and mineralization

OBJECTIVE

Drug-loaded non-resorbable polymeric nanoparticles (NPs) are proposed as an adjunctive treatment for pulp regenerative strategies. The present in vitro investigation aimed to evaluate the effectiveness of tideglusib-doped nanoparticles (TDg-NPs) in mitigating the adverse effects of bacterial lipopolysaccharide endotoxin (LPS) on the viability, morphology, migration, differentiation and mineralization potential of human dental pulp stem cells (hDPSCs).

METHODS

Cell viability, proliferation, and differentiation were assessed using a MTT assay, cell migration evaluation, cell cytoskeleton staining analysis, Alizarin Red S staining and expression of the odontogenic related genes by a real-time quantitative polymerase chain reaction (RT-qPCR) were also performed. Cells were tested both with and without stimulation with LPS at various time points. One-way ANOVA and Tukey's test were employed for statistical analysis (p < 0.05).

RESULTS

Adequate cell viability was encountered in all groups and at every tested time point (24, 48, 72 and 168 h), without differences among the groups (p > 0.05). The analysis of cell cytoskeleton showed nuclear alteration in cultures with undoped NPs after LPS stimulation. These cells exhibited an in blue diffuse and multifocal appearance. Some nuclei looked fragmented and condensed. hDPSCs after LPS stimulation but in the presence of TDg-NPs exhibited less nuclei changes. LPS induced down-regulation of Alkaline phosphatase, Osteonectin and Collagen1 gene markers, after 21d. LPS half-reduced the cells production of calcium deposits in all groups (p < 0.05), except in the group with TDg-NPs (decrease about 10 %).

SIGNIFICANCE

LPS induced lower mineral deposition and cytoskeletal disorganization in hDPSCs. These effects were counteracted by TDg-NPs, enhancing osteogenic differentiation and mineralization.

The Effect of Tideglusib Application on Type 1 and Type 3 Collagen Expressions by Human Dental-Pulp Derived Stem Cells: A Preliminary Study

BACKGROUND

Although Tideglusib cytotoxicity studies and its effects on human dental pulp-derived stem cells (DPSCs) have been examined in previous studies, there is no study investigating the expression of type 1 collagen and type 3 collagen by Tideglusib.

AIM

The purpose of this study is to examine the effect of Wnt signaling activation using Tideglusib execution on human DPSC to determine its potential efficacy in collagen expression.

METHODS

Stem cell isolation was performed from five human third molar wisdom tooth pulps. DPSCs identified in only one sample were treated with 50 nM Tideglusib for 24 h and 1 week. Axin-2, type 1 and type 3 collagen expressions were evaluated by Western blot analysis. DPSCs without treatment served as a negative control. The Mann-Whitney U test was used for statistical analysis.

RESULTS

The levels of type 1 collagen and Axin-2 in the test group were significantly higher than those in the control group at 24 h (P = 0.000, P = 0.001, respectively). Compared to the control group, a slight increase in type 3 collagen expression was observed in the test group at 24 h (P value = 0.063). Application of 50 nM Tideglusib for 1 week revealed marked decreases in type 1 and type 3 collagen expressions (P = 0.029, P = 0.038, respectively). In contrast, there was a significant increase in the level of Axin-2 (P = 0.000) compared to the control group.

CONCLUSION

The fact that Wnt signaling pathway activation obtained by Tideglusib application on DPSCs confirmed by the finding in the increase of Axin-2 at short and long-term evaluation periods which is resulted in the increase in the type 1 collagen expression at 24 h and decrease at 1 week together with the decrease in type 3 collagen expression at 1 week warrants further studies to evaluate the effect of Tideglusib on extracellular matrix expression.

NP-12 peptide functionalized nanoparticles counteract the effect of bacterial lipopolysaccharide on cultured osteoblasts

OBJECTIVE

To evaluate whether nanoparticles (NPs) functionalized with Tideglusib (TDg, NP-12), and deposited on titanium surfaces, would counteract the effect of bacterial lipopolysaccharide (LPS) on osteoblasts.

METHODS

Experimental groups were: (a) Titanium discs (TiD), (b) TiD covered with undoped NPs (Un-NPs) and (c) TiD covered with TDg-doped NPs (TDg-NPs). Human primary osteoblasts were cultured onto these discs, in the presence or absence of bacterial LPS. Cell proliferation was assessed by MTT-assay and differentiation by measuring the alkaline phosphatase activity. Mineral nodule formation was assessed by the alizarin red test. Real-time quantitative polymerase chain reaction was used to study the expression of Runx-2, OSX, ALP, OSC, OPG, RANKL, Col-I, BMP-2, BMP-7, TGF-β1, VEGF, TGF-βR1, TGF-βR2, and TGF-βR3 genes. Osteoblasts morphology was studied by Scanning Electron Microscopy. One-way ANOVA or Kruskal-Wallis and Bonferroni multiple comparisons tests were carried out (p < 0.05).

RESULTS

TDg-NPs enhanced osteoblasts proliferation. Similarly, this group increased ALP production and mineral nodules formation. TDg-NPs on titanium discs resulted in overexpression of the proliferative genes, OSC and OSX, regardless of LPS activity. In the absence of LPS, TDg-NPs up-regulated Runx2, COL-I, ALP, BMP2 and BMP7 genes. OPG/RANKL gene ratios were increased about 2500 and 4,000-fold by TDg-NPs, when LPS was added or not, respectively. In contact with the TDg-NPs osteoblasts demonstrated an elongated spindle-shaped morphology with extracellular matrix production.

SIGNIFICANCE

TDg-NPs on titanium discs counteracted the detrimental effect of LPS by preventing the decrease on osteoblasts proliferation and mineralization, and produced an overexpression of proliferative and bone-promoting genes on human primary osteoblasts.

Human dental pulp stem cells derived extracellular matrix promotes mineralization via Hippo and Wnt pathways

Extracellular matrix (ECM) is an intricate structure providing the microenvironment niche that influences stem cell differentiation. This study aimed to investigate the efficacy of decellularized ECM derived from human dental pulp stem cells (dECM_DPSCs) and gingival-derived mesenchymal stem cells (dECM_GSCs) as an inductive scaffold for osteogenic differentiation of GSCs. The proteomic analysis demonstrated that common and signature matrisome proteins from dECM_DPSCs and dECM_GSCs were related to osteogenesis/osteogenic differentiation. RNA sequencing data from GSCs reseeded on dECM_DPSCs revealed that dECM_DPSCs upregulated genes related to the Hippo and Wnt signaling pathways in GSCs. In the inhibitor experiments, results revealed that dECM_DPSCs superiorly promoted GSCs osteogenic differentiation, mainly mediated through Hippo and Wnt signaling. The present study emphasizes the promising translational application of dECM_DPSCs as a bio-scaffold rich in favorable regenerative microenvironment for tissue engineering.

Dentin remineralization using a stimuli-responsive engineered small molecule GSK3 antagonists-functionalized adhesive

OBJECTIVES

Tideglusib has shown great performance in terms of dentin regenerative properties. This study aims to evaluate bonding ability, of demineralized dentin infiltrated with polymeric nanoparticles (NPs) doped with tideglusib (TG) (TG-NPs).

METHODS

Dentin conditioned surfaces were infiltrated with NPs and TG-NPs. Bonded interfaces were created and stored for 24 h and then submitted to mechanical, chemical and thermal challenging. The resin-dentin interface was evaluated through a doubled dye fluorescent technique and a calcium chelator fluorophore under a confocal laser scanning microscopy, and by field emission scanning electron microscopy.

RESULTS

Dentin surfaces treated with TG-NPs and load cycled produced higher bond strength than the rest of the groups. Immersion of dentin specimens treated with undoped-NPs in collagenase solution attained the lowest microtensile bond strength (MTBS) values. Both porosity and nanoleakage decreased when dentin was infiltrated with TG-NPs, that revealed strong signals of xylenol orange stain at both hybrid layer and dentinal tubules. The presence of NPs, in general, inducted the presence of mineralized interfaces after mechanical loading and thermocycling.

CONCLUSIONS

Nanoparticles doped with tideglusib promoted the highest dentin bonding efficacy among groups, as they facilitated the maximum bond strength values with creation of mineral deposits at the hybrid layer and dentinal walls. Tideglusib enabled scarce porosity, nanoleakage and advanced sealing among dentin groups.

SIGNIFICANCE

Doping hydrophilic polymeric NPs with tideglusib, infiltrated in etched dentin represents a reproducible technique to create reparative dentin at the resin-dentin interface, by inducing therapeutic bioactivity.