Early Osteogenic Differentiation Stimulation of Dental Pulp Stem Cells by Calcitriol and Curcumin

Dental pulp stem cells (DPSCs), stem cells from human exfoliated deciduous teeth (SHEDSCs), and periodontal ligament stem cells (PDLSCs) isolation, characterization and the effectiveness of allantoin as bioactive molecule for dental regeneration

INTRODUCTION

Dental stem cells are valuable tools in regenerative medicine due to their pluripotency and self-renewal properties. This study aimed to investigate the effects of allantoin (Al) on Dental pulp stem cells (DPSCs), stem cells from human exfoliated deciduous teeth (SHEDSCs), and periodontal ligament stem cells (PDLSCs) regarding cytotoxicity, proliferation, wound healing, and osteogenic differentiation.

METHODS

Human dental stem cells were isolated from three dental tissues using the explant culture method and cultured in DMEM-F12 medium supplemented with 15 % fetal bovine serum (FBS) and antibiotics. The cytotoxicity and proliferation of allantoin were assessed using the XTT cell viability assay at concentrations ranging from 0.25 to 5 mg/mL. Wound healing was evaluated through a scratch assay at 1 mg/mL, and osteogenic differentiation was assessed using Alizarin Red S staining at 0.5 mg/mL and 1 mg/mL.

RESULTS

Al exhibited no cytotoxic effects across the tested concentrations. It enhanced cell proliferation, particularly in SHEDSCs at 5 mg/mL. DPSCs also showed significant improvement in wound healing in the scratch assay. At 1 mg/mL, Al inhibited osteogenic differentiation in DPSCs and PDLSCs, as indicated by reduced mineralization.

CONCLUSION

Al shows potential as a non-cytotoxic agent for enhancing the proliferation of dental stem cells, especially SHEDSCs. However, its limited effect on wound healing of SHEDSCs and PDLSCs and inhibition of osteogenic differentiation at higher concentrations suggest that further optimization is required for its application in bone regeneration.

STATEMENT OF CLINICAL RELEVANCE

Evaluation of the effects of plant-based therapeutic compounds on various types of dental stem cells may have the potential to increase the success of stem cell-based therapies in clinical applications in regenerative dentistry.

Early osteogenic differentiation of human dental stem cells by gelatin/calcium phosphate- Punica granatum nanocomposite scaffold

BACKGROUND

Tissue engineering for bone regeneration aims to heal severe bone injuries. This study aimed to prepare and assess the early osteogenic differentiation effects of a gelatin/calcium phosphate- Punica granatum nanocomposite scaffold on stem cells from human exfoliated deciduous (SHED) and human dental pulp stem cells (HDPSCs).

METHODS

The electrospinning method was used to prepare a gelatin/calcium phosphate nanocomposite scaffold containing pomegranate (Punica granatum) extract. The physicochemical properties of the scaffold were evaluated. The effect of the scaffold on the selected cells was done by the cell viability evaluation. A special alkaline phosphatase (ALP) kit was utilized to investigate the early osteogenic differentiation effects of the prepared scaffold on HDPSCs and SHED.

RESULTS

The results showed that the scaffold had uniformly accumulated in the networked form. Besides, the prepared scaffold did not have beads (structural defects). No new interactions were observed in the spectroscopic spectra of the scaffold and these peaks showed the successful formation of the fibrous nanocomposite as well. Furthermore, cell viability percentage was significantly higher for the scaffold compared with the control group (cells without any material) for both HDPSCs and SHED. Early osteogenic differentiation results specified that the ALP activity was significantly higher for the scaffold compared with the control group (cells without any material) for both HDPSCs and SHED.

CONCLUSION

The appropriate physicochemical assay and cellular results (cell viability and early osteogenic differentiation) for the prepared fibrous nanocomposite showed that the use of this nanocomposite can be considered in the construction of various scaffolds in bone and dental tissue engineering.

Advances in the research of immunomodulatory mechanism of mesenchymal stromal/stem cells on periodontal tissue regeneration

Periodontal disease is a highly prevalent disease worldwide that seriously affects people's oral health, including gingivitis and periodontitis. Although the current treatment of periodontal disease can achieve good control of inflammation, it is difficult to regenerate the periodontal supporting tissues to achieve a satisfactory therapeutic effect. In recent years, due to the good tissue regeneration ability, the research on Mesenchymal stromal/stem cells (MSCs) and MSC-derived exosomes has been gradually deepened, especially its ability to interact with the microenvironment of the body in the complex immunoregulatory network, which has led to many new perspectives on the therapeutic strategies for many diseases. This paper systematically reviews the immunomodulatory (including bone immunomodulation) properties of MSCs and their role in the periodontal inflammatory microenvironment, summarizes the pathways and mechanisms by which MSCs and MSC-EVs have promoted periodontal regeneration in recent years, lists potential areas for future research, and describes the issues that should be considered in future basic research and the direction of development of "cell-free therapies" for periodontal regeneration.

Antibacterial Effect of Co-Loaded Curcumin and Rutin in Mesoporous Silica Nanoparticles Compared to their Loading Alone

AIMS

The present study aimed to assess the antibacterial effect of co-loaded rutin and curcumin in mesoporous silica nanoparticles (Cur-Rut-MSNs).

BACKGROUND

Rutin is a nontoxic phytochemical that is present expansively in vegetables and fruits. Curcumin is an active ingredient of Curcuma longa. Curcumin and rutin have a variety of therapeutic effects, essentially antimicrobial, anti-inflammatory, and antioxidant actions.

OBJECTIVE

Low aqueous solubility and poor bioavailability of rutin and curcumin limit their application in therapeutic goals. One of the advantageous routes to improve their bioavailability and solubility is nanoformulation. Co-delivery of therapeutic agents has been reported to have better therapeutic effects than monotherapy.

METHODS

The present study has evaluated the antibacterial properties of Cur-Rut-MSNs. The Minimum Inhibitory Concentration (MIC) of Cur-Rut-MSNs has been assessed against different bacteria.

RESULTS

Cur-Rut-MSNs exerted significantly higher antibacterial effect than curcumin-loaded MSNs (Cur-MSNs) and rutin-loaded MSNs (Rut-MSNs) against Acinetobacter baumannii, Escherichia coli, Staphylococcus aureus, and Enterococcus faecalis (p<0.05).

CONCLUSION

The antibacterial effect was enhanced by the co-loading of rutin and curcumin in MSNs. According to the findings of this study, Cur-Rut-MSNs exhibit an antibacterial effect and can be a favorable nanoformulation against planktonic bacteria.

The Effectiveness of Curcumin Nanoparticle-Coated Titanium Surfaces in Osteogenesis: A Systematic Review

(1) Background: This systematic review critically appraises and synthesizes evidence from in vitro studies investigating the effects of curcumin nanoparticles on titanium surface modification, focusing on cell adhesion, proliferation, osteogenic differentiation, and mineralization. (2) Methods: A comprehensive electronic search was conducted in PubMed, Cochrane Central Register of Controlled Trials, and Google Scholar databases, yielding six in vitro studies that met the inclusion criteria. The search strategy and study selection process followed PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. A qualitative methodological assessment was performed using the SciRAP (Science in Risk Assessment and Policy) method, which evaluated the reporting and methodological quality of the included studies. (3) Results: All six studies consistently demonstrated that curcumin-coated titanium surfaces inhibited osteoclastogenesis and promoted osteogenic activity, evidenced by enhanced cell adhesion, proliferation, osteogenic differentiation, and mineralization. The mean reporting quality score was 91.8 (SD = 5.7), and the mean methodological quality score was 85.8 (SD = 10.50), as assessed by the SciRAP method. Half of the studies used hydroxyapatite-coated titanium as a control, while the other half used uncoated titanium, introducing potential variability in baseline comparisons. (4) Conclusions: This systematic review provides compelling in vitro evidence supporting the osteogenic potential of curcumin nanoparticle-coated titanium surfaces. The findings suggest that this surface modification strategy may enhance titanium implants' biocompatibility and osteogenic properties, potentially improving dental and orthopedic implant outcomes. However, the review highlights significant heterogeneity in experimental designs and a concentration of studies from a single research group. Further research, particularly in vivo studies and clinical trials from diverse research teams, is essential to validate these findings and comprehensively understand the translational potential of this promising surface modification approach.

New Perspectives about Relevant Natural Compounds for Current Dentistry Research

Natural compounds have been used since the earliest civilizations and remain, to this day, a safer alternative for treating various dental problems. These present antimicrobial, anti-inflammatory, antioxidant, analgesic, and antimutagenic effects, making them useful in the prophylactic and curative treatment of various oral diseases such as infections, gingivitis, periodontitis, and even cancer. Due to the high incidence of unpleasant adverse reactions to synthetic compounds, natural products tend to gradually replace conventional treatment, as they can be just as potent and cause fewer, milder adverse effects. Researchers use several methods to measure the effectiveness and safety profile of these compounds, and employing standard techniques also contributes to progress across all medical disciplines.

Injectable and In Situ Formed Dual-Network Hydrogel Reinforced by Mesoporous Silica Nanoparticles and Loaded with BMP-4 for the Closure and Repair of Skull Defects

Bone defects are a common and challenging orthopedic problem with poor self-healing ability and long treatment cycles. The difficult-to-heal bone defects cause a significant burden of medical expenses on patients. Currently, biomaterials with mechanical stability, long-lasting action, and osteogenic activity are considered as a suitable way to effectively heal bone defects. Here, an injectable double network (DN) hydrogel prepared using physical and chemical cross-linking methods is designed. The first rigid network is constructed using methylpropenylated hyaluronic acid (HAMA), while the addition of chitosan oligosaccharide (COS) forms a second flexible network by physical cross-linking. The mesoporous silica nanoparticles (MSN) loaded with bone morphogenetic protein-4 (BMP-4) were embedded into DN hydrogel, which not only enhanced the mechanical stability of the hydrogel, but also slowly released BMP-4 to achieve long-term skull repair. The designed composite hydrogel showed an excellent compression property and deformation resistance. In vitro studies confirmed that the HAMA/COS/MSN@BMP-4 hydrogel had good biocompatibility and showed great potential in supporting proliferation and osteogenic differentiation of mouse embryo osteoblast precursor (MC3T3-E1) cells. Furthermore, in vivo studies confirmed that the DN hydrogel successfully filled and closed irregular skull defect wounds, effectively promoted bone regeneration, and significantly promoted bone repair compared with the control group. In addition, HAMA/COS/MSN@BMP-4 hydrogel precursor solution can quickly form hydrogel in situ at the wound by ultraviolet light, which can be applied to the closure and repair of wounds of different shapes, which provides the new way for the treatment of bone defects.

A review of the therapeutic potential of dental stem cells as scaffold-free models for tissue engineering application

In the realm of regenerative medicine, tissue engineering has introduced innovative approaches to facilitate tissue regeneration. Specifically, in pulp tissue engineering, both scaffold-based and scaffold-free techniques have been applied. Relevant articles were meticulously chosen from PubMed, Scopus, and Google Scholar databases through a comprehensive search spanning from October 2022 to December 2022. Despite the inherent limitations of scaffolding, including inadequate mechanical strength for hard tissues, insufficient vents for vessel penetration, immunogenicity, and suboptimal reproducibility-especially with natural polymeric scaffolds-scaffold-free tissue engineering has garnered significant attention. This methodology employs three-dimensional (3D) cell aggregates such as spheroids and cell sheets with extracellular matrix, facilitating precise regeneration of target tissues. The choice of technique aside, stem cells play a pivotal role in tissue engineering, with dental stem cells emerging as particularly promising resources. Their pluripotent nature, non-invasive extraction process, and unique properties render them highly suitable for scaffold-free tissue engineering. This study delves into the latest advancements in leveraging dental stem cells and scaffold-free techniques for the regeneration of various tissues. This paper offers a comprehensive summary of recent developments in the utilization of dental stem cells and scaffold-free methods for tissue generation. It explores the potential of these approaches to advance tissue engineering and their effectiveness in therapies aimed at tissue regeneration.

Effect of Curcumin-containing Nanofibrous Gelatin-hydroxyapatite Scaffold on Proliferation and Early Osteogenic Differentiation of Dental Pulp Stem Cells

BACKGROUND

In recent years, the electrospinning method has received attention because of its usage in producing a mimetic nanocomposite scaffold for tissue regeneration. Hydroxyapatite and gelatin are suitable materials for producing scaffolds, and curcumin has the osteogenesis induction effect.

AIMS

This study aimed to evaluate the toxicity and early osteogenic differentiation stimulation of nanofibrous gelatin-hydroxyapatite scaffold containing curcumin on dental pulp stem cells (DPSCs).

OBJECTIVE

The objective of the present investigation was the evaluation of the proliferative effect and primary osteogenic stimulation of DPSCs with a nanofibrous gelatin-hydroxyapatite scaffold containing curcumin. Hydroxyapatite and gelatin were used as suitable and biocompatible materials to make a scaffold suitable for stimulating osteogenesis. Curcumin was added to the scaffold as an osteogenic differentiation- enhancing agent.

METHODS

The effect of nano-scaffold on the proliferation of DPSCs was evaluated. The activity of alkaline phosphatase (ALP) as the early osteogenic marker was considered to assess primary osteogenesis stimulation in DPSCs.

RESULTS

The nanofibrous gelatin-hydroxyapatite scaffold containing curcumin significantly increased the proliferation and the ALP activity of DPSCs (P<0.05). The proliferative effect was insignificant in the first 2 days, but the scaffold increased cell proliferation by more than 40% in the fourth and sixth days. The prepared scaffold increased the activity of the ALP of DPSCs by 60% compared with the control after 14 days (p<0.05).

CONCLUSION

The produced nanofibrous gelatin-hydroxyapatite scaffold containing curcumin can be utilized as a potential candidate in tissue engineering and regeneration of bone and tooth.

FUTURE PROSPECTS

The prepared scaffold in the present study could be a beneficial biomaterial for tissue engineering and the regeneration of bone and tooth soon.

Curcumin attenuates replicative senescence in human dental follicle cells and restores their osteogenic differentiation

OBJECTIVE

This study aimed to examine the therapeutic effects of curcumin against replicative senescence in dental follicle cells (DFCs).

METHODS

Human DFCs were cultured in Dulbecco's Modified Eagle Medium with growth supplements. Replicative senescence in DFCs at different passages was assessed using β-galactosidase activity assay. Cell proliferation and size of DFCs at different passages were determined by CCK-8 kit and microscopy method, respectively. In addition, curcumin's effect on replicative senescence, cell proliferation, and size of DFCs at different passages was analyzed. Using western-blot analysis and siRNA-mediated gene silencing, we determined the molecular mechanisms involved in curcumin's effect against replicative senescence and osteogenic differentiation in DFCs at different passages.

RESULTS

We observed decreased proliferation and increased cell size and replicative senescence in cultured human DFCs at higher passages. Intriguingly, despite not showing any effect on cell size, curcumin (50 μM) significantly restored proliferation ability in DFCs and inhibited their replicative senescence. Concerning mechanisms, we found that curcumin inhibits replicative senescence in DFCs via down-regulation of senescence markers (P16 & P21) and restoration of proliferation markers (E2F1 & P53). Additionally, curcumin also rescued the osteogenic differentiation potential in higher-passage DFCs via restoration of osteogenic markers RUNX2 and OPN.

CONCLUSION

Our findings reveal for the first time that curcumin could act as a potential anti-senescence therapeutic for DFCs via regulation of proliferation, senescence, and osteogenic differentiation markers.

Micelle encapsulated curcumin and piperine-laden 3D printed calcium phosphate scaffolds enhance in vitro biological properties

Limitations in the current clinical management of critical-sized osseous defects have driven the need for multifunctional bone constructs. The ideal bone scaffold should possess advanced microarchitecture, well-defined pore interconnectivity, and supply biological signals, which actively guide and control tissue regeneration while simultaneously preventing post-implantation complications. Here, a natural medicine-based localized drug delivery from 3D printed scaffold is presented, which offers controlled release of curcumin, piperine from nano-sized polymeric micelles, and burst release of antibacterial carvacrol from the coating endowing the scaffold with their distinct, individual biological properties. This functionalized scaffold exhibits improved osteoblast (hFOB) cell attachment, 4-folds higher hFOB proliferation, and 73% increased hFOB differentiation while simultaneously providing cytotoxicity towards osteosarcoma cells with 61% lesser viability compared to control. In vitro, early tube formation (p < 0.001) indicates that the scaffolds can modulate the endothelial cellular network, critical for faster wound healing. The scaffold also exhibits 94% enhanced antibacterial efficacy (p < 0.001) against gram-positive Staphylococcus aureus, the main causative bacteria for osteomyelitis. Together, the multifunctional scaffolds provide controlled delivery of natural biomolecules from the nano-sized micelle-loaded 3D printed matrix for significant improvement in osteoblast proliferation, endothelial formation, osteosarcoma, and bacterial inhibition, guiding better bone regeneration for post-traumatic defect repair.

Periplaneta americana extract promotes osteoblast differentiation of human alveolar bone marrow mesenchymal stem cells

OBJECTIVES

This study aims to investigate the effects of Traditional Chinese medicine, Periplaneta americana extract (PAE), on osteoblast differentiation of human alveolar bone marrow-derived mesenchymal stem cells (hABMMSCs).

MATERIALS AND METHODS

Human alveolar bone marrow-derived mesenchymal stem cells were treated with different concentrations of PAE. Cell Counting Kit-8 (CCK-8) assay and transwell migration assay were conducted to evaluate cell proliferation and migration, respectively. Alkaline phosphatase (ALP) staining, ALP activity assay, and Alizarin red S staining were performed to detect osteogenesis in hABMMSCs. In addition, real-time quantitative polymerase chain reaction (RT-qPCR) and western blot (WB) assay were performed to evaluate expression levels of osteogenic markers. Finally, RNA sequencing analysis and WB were carried out to elucidate the underlying mechanism.

RESULTS

A total of 0.1 mg/ml PAE promoted cell proliferation and migration. PAE also increased ALP activity and mineralized nodule formation of hABMMSCs. In addition, PAE upregulated the expression of osteogenesis-related genes (RUNX2, COL1A1, and BGLAP). RNA-sequencing analysis revealed that PAE activated the focal adhesion signaling pathway. Treatment with Defactinib, an inhibitor of FAK, attenuated the effects induced by PAE.

CONCLUSIONS

PAE could enhance osteoblast differentiation of hABMMSCs through focal adhesion signaling pathway, suggesting a therapeutic potential for the alveolar bone defect.

Potential applications of medicinal herbs and phytochemicals in oral and dental health: Status quo and future perspectives

OBJECTIVE

Herbal therapies are utilized to treat a broad diversity of diseases all over the globe. Although no clinical studies have been conducted to demonstrate the antibacterial, antimicrobial, and antiplaque characteristics of these plants, this does not imply that they are ineffectual as periodontal treatments or anti-cariogenic drugs. However, there is a scarcity of research confirming their efficacy and worth.

SUBJECT

Herbs are utilized in dentistry as antimicrobial, antineoplastic, antiseptic, antioxidant, and analgesics agents as well as for the elimination of bad breath. In addition, the application of herbal agents in tissue engineering improved the regeneration of oral and dental tissues. This study reviews the application of medicinal herbs for the treatment of dental and oral diseases in different aspects.

METHODS

This article focuses on current developments in the use of medicinal herbs and phytochemicals in oral and dental health. An extensive literature review was conducted via an Internet database, mostly PubMed. The articles included full-text publications written in English without any restrictions on a date.

CONCLUSION

Plants have been suggested, as an alternate remedy for oral-dental problems, and this vocation needs long-term dependability. More research on herbal medicine potential as pharmaceutical sources and/or therapies is needed.

Molecules Inducing Dental Stem Cells Differentiation and Bone Regeneration: State of the Art

Teeth include mesenchymal stem cells (MSCs), which are multipotent cells that promote tooth growth and repair. Dental tissues, specifically the dental pulp and the dental bud, constitute a relevant source of multipotent stem cells, known as dental-derived stem cells (d-DSCs): dental pulp stem cells (DPSCs) and dental bud stem cells (DBSCs). Cell treatment with bone-associated factors and stimulation with small molecule compounds are, among the available methods, the ones who show excellent advantages promoting stem cell differentiation and osteogenesis. Recently, attention has been paid to studies on natural and non-natural compounds. Many fruits, vegetables, and some drugs contain molecules that can enhance MSC osteogenic differentiation and therefore bone formation. The purpose of this review is to examine research work over the past 10 years that has investigated two different types of MSCs from dental tissues that are attractive targets for bone tissue engineering: DPSCs and DBSCs. The reconstruction of bone defects, in fact, is still a challenge and therefore more research is needed; the articles reviewed are meant to identify compounds useful to stimulate d-DSC proliferation and osteogenic differentiation. We only consider the results of the research which is encouraging, assuming that the mentioned compounds are of some importance for bone regeneration.

Incorporation of synthetic water-soluble curcumin polymeric drug within calcium phosphate cements for bone defect repairing

Modified macroporous structures and active osteogenic substances are necessary to overcome the limited bone regeneration capacity and low degradability of self-curing calcium phosphate cement (CPC). Curcumin (CUR), which possesses strong osteogenic activity and poor aqueous solubility/bioavailability, esterifies the side chains in hyaluronic acid (HA) to form a water-soluble CUR-HA macromolecule. In this study, we incorporated the CUR-HA and glucose microparticles (GMPs) into the CPC powder to fabricate the CUR-HA/GMP/CPC composite, which not only retained the good injectability and mechanical strength of bone cements, but also significantly increased the cement porosity and sustained release property of CUR-HA in vitro. CUR-HA incorporation greatly improved the differentiation ability of bone marrow mesenchymal stem cells (BMSCs) to osteoblasts by activating the RUNX family transcription factor 2/fibroblast growth factor 18 (RUNX2/FGF18) signaling pathway, increasing the expression of osteocalcin and enhancing the alkaline phosphatase activity. In addition, in vivo implantation of CUR-HA/GMP/CPC into femoral condyle defects dramatically accelerated the degradation rate of cement and boosted local vascularization and osteopontin protein expression, and consequently promoted rapid bone regeneration. Therefore, macroporous CPC based composite cement with CUR-HA shows a remarkable ability to repair bone defects and is a promising translational application of modified CPC in clinical practice.

Tooth Discoloration and Solubility of Zinc Oxide Eugenol Combined with Different Concentrations of Nano-Curcumin: An in vitro Study

Statement of the Problem

Due to the unfavorable properties of eugenol, the eugenol content can be reduced to improve the properties of zinc oxide eugenol (ZOE) by making a new combination of nanocurcumin called curcumin pulpal paste (CPP).

Purpose

The aim of this in vitro study was to evaluate the solubility and tooth discoloration of three concentrations of CPP compared to ZOE, and Metapex.

Materials and Method

In this in vitro study for evaluating of the solubility, five groups including ZOE, Metapex, and three concentrations of CPP (5%, 10%, and 20%) were tested. For evaluating the solubility, the changes in of the weight of samples were measured at 1, 3, 7 and 30 days after initial setting. In order to evaluate the tooth discoloration, 75 bovine maxillary anterior teeth were filled with one of five pulpal pastes. The changes in tooth color were evaluated at 1 hour, 1 week, 1 and 3 months after material placement.

Results

The solubility increased by increasing the nano-curcumin percentage in CPPs. After 30 days, the solubility of the 5%CPP, and ZOE was not significantly different (p= 1.000). According to the colorimetric test, after 3 months, the highest discoloration was recorded for 20% CPP (8.45), and the smallest discoloration was registered for Metapex (4.06). The discoloration of 5% CPP, and 10% CPP was similar to ZOE's color change (p> 0.05).

Conclusion

The results of the present study showed that the solubility of pulpal paste has increased with increasing curcumin concentrations. Therefore, pulpal paste with different nanocurcumin concentrations can be used considering the patient's age and the desired time of deciduous tooth loss, and dissolution of pulpal paste. Concerning the discoloration after 3 months, Metapex was the best material and the most discoloration rate was related to 20% CPP, and there was no difference between the 5% CPP, and 10% CPP with ZOE.

Comparison of the effect of NaOCL, curcumin, and EDTA on differentiation, proliferation, and adhesion of dental pulp stem cells

Introduction

This study examined the effect of 1.5% NaOCl, 17% EDTA, and curcumin on the proliferation, attachment, and differentiation of dental pulp stem cells (DPSCs) placed on the dentin specimens.

Methods

MTT assay was performed to evaluate the proliferation of DPSCs on the dentin specimens treated with different concentrations of NaOCl, 17% EDTA, and curcumin (0.97-250 μM). Cell-adhering ability of DPSCs was tested via the LDH assay to calculate the attached DPSCs. In addition, the western blotting assay was performed to investigate the expression levels of fibronectin as a cell-adhesion marker and analyze the expressions level of differentiation markers, including DMP-1, OCN, ALP, and DSPP, to detect the odontogenic potential of hDPCs.

Results

NaOCl had lower toxicity on DPSCs at lower concentrations (P < 0.001). The cytotoxicity of irrigants increased with increased dosage. The difference between the cell-adhesion ability of NaOCl and curcumin was not significant (∼4.4 MU/mL), whereas EDTA (∼3.8 MU/mL) exhibited the lowest release of LDH and less damage to hDPSCs. Regarding fibronectin expression, the pattern differed between irrigants in inducing cell adhesion. NaOCl increased fibronectin expression more than EDTA and curcumin. All the treated groups upregulated the expression of DSPP, DMP-1, OCN, and ALP compared to the control group, in which NaOCl showed a higher effect on the overexpression of differentiation markers.

Conclusion

The results showed that all the tested irrigants could be used in regenerative endodontic treatment. However, as an herbal-based and biocompatible irrigant, curcumin exhibited fewer adverse effects than NaOCl and EDTA.

The protective role of curcumin in human dental pulp stem cells stimulated by lipopolysaccharide via inhibiting NF-κB p65 phosphorylation to suppress NLRP3 inflammasome activation

OBJECTIVES

This study aims to investigate the anti-inflammatory effect of curcumin and underlying mechanisms regarding the modulation of the nod-like receptor pyrin domain containing 3 (NLRP3) inflammasome in human dental pulp stem cells (hDPSCs).

MATERIALS AND METHODS

The impact of curcumin on the viability of hDPSCs was evaluated. The effect of curcumin on the expression of IL-1β and NLRP3 in hDPSCs stimulated by lipopolysaccharide (LPS) was assessed. Then, LPS-primed hDPSCs were pre-treated with curcumin before ATP triggering NLRP3 inflammasome activation, and NLRP3 inflammasome-related mediators were assessed. The mechanism of curcumin inactivation of LPS plus ATP-induced inflammasome associated with NF-κB pathway was explored. The NF-κB pathway related pro-inflammatory mediators at mRNA and protein levels were evaluated. The expression of NF-κB p65 and phosphorylation p65 was visualized after curcumin or NF-κB inhibitor administrating respectively in hDPSCs with an activated NLRP3 inflammasome. Statistical analysis was performed.

RESULTS

While curcumin at the concentration of 0.5-5 μM showed no obvious impact on the viability of hDPSCs, it significantly decreased IL-1β and NLRP3 mRNA expression in LPS-induced hDPSCs in a dose-dependent manner. Curcumin significantly inhibited the LPS plus ATP-primed NLRP3 inflammasome activation in hDPSCs (NLRP3, ASC, caspase-1, and IL-1β). Curcumin evidently attenuated the LPS plus ATP-induced expression of NF-κB pathway-related pro-inflammatory mediators (IL-6, IL-8, TNF-α, and COX-2). Furthermore, curcumin effectively reduced p65 phosphorylation, which acts as an NF-κB inhibitor in hDPSCs with an activated NLRP3 inflammasome.

CONCLUSIONS

Curcumin pre-treatment may exert an anti-inflammatory role via inactivation of the NLRP3 inflammasome by inhibiting NF-κB p65 phosphorylation in cultured hDPSCs.

CLINICAL RELEVANCE

Curcumin may have therapeutic potential in pulp inflammation.

Preparation of rutin-loaded mesoporous silica nanoparticles and evaluation of its physicochemical, anticancer, and antibacterial properties

BACKGROUND

The studies have shown that rutin has great potential as an anticancer and antimicrobial plant base agent; nevertheless, poor bioavailability and low aqueous solubility of rutin limit its application. One of the beneficial routes to increase the solubility and bioavailability of rutin is the development of nanoparticulate material. This study aimed to assess the anticancer and antibacterial effects of rutin-loaded mesoporous silica nanoparticles (RUT-MSNs).

METHODS

RUT-MSNs were prepared and physicochemically characterized. The cytotoxicity of RUT-MSNs on the HN5 cells as head and neck cancer cells was evaluated. The expression level of apoptosis-related genes such as Bcl-2 and Bax genes were evaluated. In addition, ROS production of RUT-MSNs treated cells was assessed. In addition, minimum inhibitory concentration (MIC), biofilm, and attachment inhibitory effects of RUT-MSNs compared with free rutin were assessed against different bacterial strains.

RESULTS

Transmission electron microscopy (TEM) showed mesoporous rod-shaped nanoparticles with an average particle size of less than 100 nm. RUT-MSNs displayed the cytotoxic effect with IC₅₀ of 20.23 µM in 48 h of incubation time (p < 0.05). The elevation in the ratio of Bax/Bcl-2 was displayed within the IC₅₀ concentration of RUT-MSNs in 48 h (p < 0.05). The antibacterial action of rutin was improved by loading rutin in MSNs to the nano-sized range in the MIC test.

CONCLUSION

The anticancer and antibacterial effects of RUT-MSNs were considerably more than rutin. RUT-MSNs inhibited the growth of HN5 cells by inducing apoptosis and producing ROS. These results suggest that RUT-MSNs may be useful in the treatment of cancers and infections.

A Novel Perspective on Tissue Engineering Potentials of Periodontal Ligament Stem Cells

It is challenging to completely and predictably regenerate the missing periodontal tissues caused by the trauma or disease. To regenerate the periodontium, there is a need to consider several aspects that co-occur with periodontal development. This study provides an overview of the most up-to-date investigations on the characteristics and immunomodulatory features of Periodontal Ligament Stem Cells (PDLSCs) and the recent interventions performed using these cells, focusing on cell survival, proliferation, and differentiation. Keeping in mind the relationship between age and potency of PDLSCs, this work also demonstrates the necessity of establishing dental-derived stem cell banks for tissue regeneration applications. The data were collected from Pubmed and Google Scholar databases with the keywords of periodontal ligament stem cells, tissue engineering, characteristics, and stem cell therapy. The results showed the presence of wide-ranging research reports supporting the usability of PDLSCs for periodontal reconstruction. However, a better understanding of self-restoration for adequate regulation of adult stem cell growth is needed for various applied purposes.

Effect of Curcumin-Loaded Mesoporous Silica Nanoparticles on the Head and Neck Cancer Cell Line, HN5

Curcumin is an active ingredient isolated from Curcuma longa. It has several pharmacological effects, including anticancer, anti-inflammatory, and antioxidant effects. Due to its low bioavailability, chemical structure instability, and easy oxidation, the application of curcumin has been limited. In this study, to overcome these limitations, curcumin-loaded mesoporous silica nanoparticles (Cur-MSN) were prepared, and the anticancerous effect of Cur-MSNs on head and neck cancer cells, HN5, was investigated. Transmission electron microscopy (TEM) revealed rod-shaped mesoporous nanoparticles with average particle size smaller than 100 nm. Higher cytotoxicity of Cur-MSNs was seen in treated cancer cells compared with free curcumin. The expression of Bcl-2 was significantly reduced in the presence of Cur-MSNs compared to the control (untreated HN5 cells) (p < 0.05). A 3.43-fold increase in the Bax/Bcl-2 ratio was seen in Cur-MSNs treated HN5 cells at the IC50. Cur-MSNs increased intracellular reactive oxygen species (ROS) production. Based on these novel results, we suggest that Cur-MSNs offer efficacy for cancer treatment and future studies should further characterize their properties in various experimental cancer models.

Curcumin-Loaded Silica Nanoparticles: Applications in Infectious Disease and Food Industry

Curcumin has multiple properties that are used to cure different diseases such as cancer, infections, inflammatory, arthritic disease, etc. Despite having many effects, the inherent physicochemical properties-such as poor water solubility, chemical instability, low bioavailability, photodegradation, fast metabolism, and short half-life-of curcumin's derivatives have limited its medical importance. Recently, unprecedented advances in biomedical nanotechnology have led to the development of nanomaterial-based drug delivery systems in the treatment of diseases and diagnostic goals that simultaneously enhance therapeutic outcomes and avoid side effects. Mesoporous silica nanoparticles (MSNs) are promising drug delivery systems for more effective and safer treatment of several diseases, such as infections, cancers, and osteoporosis. Achieving a high drug loading in MSNs is critical to the success of this type of treatment. Their notable inherent properties-such as adjustable size and porosity, high pore volume, large surface area, functionality of versatile surfaces, as well as biocompatibility-have prompted extraordinary research on MSNs as multi-purpose delivery platforms. In this review, we focused on curcumin-loaded silica nanoparticles and their effects on the diagnosis and treatment of infections as well as their use in food packaging.

Thermoplasmonic Regulation of the Mitochondrial Metabolic State for Promoting Directed Differentiation of Dental Pulp Stem Cells

Regulating stem cell differentiation in a controllable way is significant for regeneration of tissues. Herein, we report a simple and highly efficient method for accelerating the stem cell differentiation of dental pulp stem cells (DPSCs) based on the synergy of the electromagnetic field and the photothermal (thermoplasmonic) effect of plasmonic nanoparticles. By simple laser irradiation at 50 mW/cm² (10 min per day, totally for 5 days), the thermoplasmonic effect of Au nanoparticles (AuNPs) can effectively regulate mitochondrial metabolism to induce the increase of mitochondrial membrane potential and further drive energy increase during the DPSC differentiation process. The proposed method can specifically regulate DPSCs' cell differentiation toward odontoblasts, with the differentiation time reduced to only 5 days. Simultaneously, the molecular profiling change of mitochondria within DPSCs during the cell differentiation process is revealed by in situ surface-enhanced Raman spectroscopy. It clearly demonstrates that the expression of hydroxyproline and glutamate gradually increases with prolonging of the differentiation days. The developed method is simple, robust, and rapid for stem cell differentiation of DPSCs, which would be beneficial to tissue engineering and regenerative medicine.

Identification of Di/Tripeptide(s) With Osteoblasts Proliferation Stimulation Abilities of Yak Bone Collagen by in silico Screening and Molecular Docking

Endothelial protein C receptor (EPCR), cannabinoid receptor 2 (CBR2), and estrogen receptor α (ERα) play vital roles in osteoblasts proliferation. Also, collagen peptides have osteoblasts proliferation stimulation abilities, and di/tri-peptides could be absorbed by the intestine more easily. This study obtained three di/tripeptides with potential osteoblasts proliferation stimulation abilities of yak bone collagen, namely, MGF, CF, and MF, by in silico screening. Results suggested that these three peptides exhibited good absorption, distribution, metabolism, excretion, and toxicity (ADMET) properties. They also had strong affinities with EPCR, CBR2, and ERα, and the total -CDOCKER energy (-CE) values were 150.9469, 113.1835, and 115.3714 kcal/mol, respectively. However, further Cell Counting Kit-8 (CCK-8) assays indicated that only MGF could significantly (P < 0.05) stimulate osteoblasts proliferation at 0.3 mg/ml. At the same time, the proliferating index (PI) of the osteoblasts treated with MGF increased significantly (P < 0.05), and the alkaline phosphatase (ALP) activity decreased highly significantly (P < 0.01). In summary, MGF exhibited the potential to be an effective treatment for osteoporosis.

Curcumin nanoformulations: Beneficial nanomedicine against cancer

Curcumin is a phytochemical achieved from the plant turmeric. It is extensively utilized for the treatment of several types of diseases such as cancers. Nevertheless, its efficiency has been limited because of rapid metabolism, low bioavailability, poor water solubility, and systemic elimination. Scientists have tried to solve these problems by exploring novel drug delivery systems such as lipid-based nanoparticles (NPs) (e.g., solid lipid NPs, nanostructured lipid carriers, and liposomes), polymeric NPs, micelles, nanogels, cyclodextrin, gold, and mesoporous silica NPs. Among these, liposomes have been the most expansively studied. This review mainly focuses on the different curcumin nanoformulations and their use in cancer therapy in vitro, in vivo, and clinical studies. Despite the development of curcumin-containing NPs for the treatment of cancer, potentially serious side effects, including interactions with other drugs, some toxicity aspects of NPs may occur that require more high-quality investigations to firmly establish the clinical efficacy.

The Antimicrobial, Antioxidative, and Anti-Inflammatory Effects of Polycaprolactone/Gelatin Scaffolds Containing Chrysin for Regenerative Endodontic Purposes

The appropriate endodontic material should eliminate the infection and inflammation to provide a situation for regeneration and healing of pulp tissue besides biomineralization. Chrysin is one of the active ingredients of plant flavonoids, which has significant anti-inflammatory and antimicrobial properties. In the present study, this natural substance was evaluated for antioxidant, anti-inflammatory, and mineralization properties on dental pulp stem cells (DPSCs). SEM, FTIR, and TGA tests were used to determine the successful synthesize of chrysin-loaded scaffolds. The antimicrobial effects of the synthesized scaffold against Acinetobacter baumannii, Pseudomonas aeruginosa, Staphylococcus aureus, and Enterococcus faecalis were assessed by the agar diffusion test and live/dead assay. The proliferation of DPSCs on these scaffolds was determined by the MTT assay, DAPI staining, and DNA extraction. Moreover, the antioxidant and anti-inflammation activity of chrysin-loaded scaffolds on inflamed DPSCs was evaluated. Alkaline phosphatase activity and Alizarin Red S Stain tests were done to evaluate the mineralization of DPSCs seeded on these scaffolds. The chrysin-loaded scaffolds reported antimicrobial effects against evaluated bacterial strains. The proliferation of DPSCs seeded on these scaffolds was increased significantly (p < 0.05). The TNFα and DCF levels in inflamed DPSCs showed a significant decrease in the presence of chrysin-loaded scaffolds (p < 0.05). The ALP activity and formation of mineralized nodules of DPSCs on these scaffolds were significantly increased compared with the control group (p < 0.05). These results indicated that chrysin as an ancient therapeutic agent can accelerate the healing and regeneration of damaged pulp tissue, and this active ingredient can be a potential natural substance for regenerative endodontic procedures.