Viability Of Dental Pulp Stem Cells Research Articles

EFFECT OF TRIPLE ANTIBIOTIC PASTE, CALCIUM HYDROXIDE, LEDERMIX® ON VIABILITY OF PULP MESENCHYMAL STEM CELLS

Objective: The goal of regenerative endodontic therapy is biological healing of the pulp tissue. It involves the disinfection of the canals with irrigantsand medicaments. The medicaments that are currently used for this purpose are a triple antibiotic paste (TAP), calcium hydroxide (Ca[OH]2), andLedermix®, a paste containing demeclocycline and triamcinolone. Therefore, the purpose of this study was to evaluate the effects of TAP, Ca(OH)2, andLedermix® on the viability of dental pulp stem cells (DPSC).Methods: Primary cultures of DPSC were obtained from immature third molars. Immunofluorescence assay using STRO-1 marker was performedto confirm the mesenchymal nature of the DPSC. The cells were exposed to TAP, Ca(OH)2, and Ledermix® at concentrations of 0.1 and 1 mg/mL. Cellviability was analyzed using the MTT assay.Results: Significant differences in viability were noted between the cells exposed to the medicaments and those in the control group (p<0.05).Conclusions: All three medicaments decreased the viability of DPSC, with the Ledermix® paste demonstrating the highest toxic effect.

Adhesive and oxidative response of stem cell and pre-osteoblasts on titanium and zirconia surfaces in vitro.

The aim of the present study was to investigate the initial stem cell and pre-osteoblast cell adhesion and oxidative response on zirconia in comparison with titanium. Human dental pulp stem cells (DPSC) and murine pre-osteoblasts (MC3T3-E1) cells were cultured on zirconia and titanium surfaces, and at 3-, 12-, and 24-hour intervals, cell viability and morphology were determined with tetrazolium based colorimetric assay, scanning electron microscopy, and immunofluorescence analysis. The in situ reactive oxygen species level of both cells on each material surface was examined after 24-hour culture. Both DPSC and MC3T3-E1 cells revealed comparable morphological features during 24-hour cell adhesion processes, with cells continued expanding of cell size and increasing of cell viability on titanium and zirconia surfaces during 24-hour culture. Zirconia demonstrated relatively higher mean cell viability compared to titanium within 24-hour culture, with significantly higher DPSC viability at 12hours after seeding (P<0.05). Relatively higher mean reactive oxygen species levels in both DPSC and MC3T3E1 were found on zirconia surfaces after 24-hour culture compared to titanium. From the results, zirconia as a potential dental implant substrate demonstrated equivalent or better initial cellular responses compared to titanium.

Graphene Oxide Foils as an Osteoinductive Stem Cell Substrate.

The hydrophilic graphene derivative, graphene oxide (GO), is used to synthesize free-standing GO foils characterized by cross-linked GO sheets with enhanced mechanical properties and no tendency to release GO flakes in aqueous solution. These GO foils do not evidence cytotoxic effects toward dental pulp stem cells (DPSC). Rather, DPSC viability is significantly increased for cells grown on GO foil and SEM analyses evidence the synthesis of a consistent extracellular matrix by DPSCs with respect to cells grown on polystyrene. Gene expression of osteogenic markers and alkaline phosphatase (ALP) activity tests demonstrate DPSC differentiation toward the osteoblastic lineage. Indeed RUNX2, a key transcriptor factor associated with osteogenic differentiation, as well as SP7, responsible for triggering bone matrix mineralization, are significantly augmented after 7 and 14 days of culture on GO foil with respect to the control, respectively, underlying the capability of GO foil to promote a potential faster and better DPSC differentiation with respect to cells grown on polystyrene. This increase of rate differentiation is confirmed by SEM analyses of DPSCs evidencing a consistent extracellular matrix synthesis at the earliest time of culture (i.e., 3 and 14 days).

The effect of Malaysian stingless bee, Trigona spp. honey in promoting proliferation of the undifferentiated stem cell

Stem cells provide various potential applications in regenerative medicine through its ability of self-renewal and differentiation. Among the various stem cells, dental pulp stem cells (DPSCs) have shown encouraging results in their ability to regenerate. Honey has been used in traditional culture as a natural medicine in supporting wound healing. Yet, very few studies on honey were conducted for its potential as a proliferative agent for stem cells. The aim of this study is to evaluate the stability of two Trigona spp. honeys (1 and 2) added in culture media and its proliferative effect on DPSCs. Both honeys were diluted with standard culture medium through dilution process to prepare the concentrations of 0.01%, 0.04%, 0.10% and 0.25%. DPSCs were treated with the diluted honeys for 24 hours. The proliferative activity was determined through the images taken using an inverted microscope for every six hours. In addition, the MTT assay was conducted to determine the cell viability of DPSCs when treated with both honey 1 and 2 at various concentrations. The results showed a stable culture media added with honey for three days and a dose-dependent proliferative effect of both Trigona spp. honey samples on DPSCs. Optimum proliferative effects were observed at 24 hours for both Trigona spp. honey 1 and 2 on DPSCs. The optimum concentration of Trigona spp. honey 1 was from 0.04% to 0.10% and Trigona spp. honey 2 was below 0.01%. It is concluded that Trigona spp. honey has a promising proliferative effect on DPSCs.

Pluripotent Stem Cell Markers and microRNA Expression May Correlate with Dental Pulp Stem Cell Viability and Proliferation Rates

Pluripotent Stem Cell Markers and microRNA Expression May Correlate with Dental Pulp Stem Cell Viability and Proliferation Rates

Evaluation of the effects of low intensity laser in proliferation of dental pulp stem cells

Objective: In this study, the effects of the low intensity laser were evaluated in the proliferation of human dental pulp stem cells (DPSCs). Design: These cells were irradiated every 12 hours for 72 hours or at 0 and 48 hours only, with a Red-InGaAlP laser (660nm, 30mW and 0.5 or 1J/cm2) for 16 or 33 seconds and their proliferation was assessed by the MTT assay. In addition, the Trypan Blue assay was used to analyze the viability of DPSCs in the best parameter recorded by MTT. Results: It was observed that the lowest dose of the laser (0.5J/cm2) in applications at 0 and 48 hours obtained the higher proliferation rates then all the other groups. Finally, through the Trypan Blue assay, we observed that the viability of the stem cells was not affected by the low intensity laser (0.5J/cm2). Conclusions: Our data corroborate with other data from the literature and therefore suggest that the low intensity laser can be used in order to improve cell proliferation. However, further studies should be carried out in order to evaluate if these parameters can be used in other cell lines.

In vitro performance of a nanobiocomposite scaffold containing boron-modified bioactive glass nanoparticles for dentin regeneration.

Every year, many dental restoration methods are carried out in the world and most of them do not succeed. High cost of these restorations and rejection possibility of the implants are main drawbacks. For this reason, a regenerative approach for repairing the damaged dentin-pulp complex or generating a new tissue is needed. In this study, the potential of three-dimensional cellulose acetate/oxidized pullulan/gelatin-based dentin-like constructs containing 10 or 20% bioactive glass nanoparticles was studied to explore their potential for dentin regeneration. Three-dimensional nano biocomposite structures were prepared by freeze-drying/metal mold pressing methods and characterized by in vitro degradation analysis, water absorption capacity and porosity measurements, scanning electron microscopy, in vitro biomineralization analysis. During one-month incubation in phosphate buffered saline solution at 37°C, scaffolds lost about 25-30% of their weight and water absorption capacity gradually decreased with time. Scanning electron microscopy examinations showed that mean diameter of the tubular structures was about 420 µm and the distance between walls of the tubules was around 560 µm. Calcium phosphate precipitates were formed on scaffolds surfaces treated with simulated body fluid, which was enhanced by boron-modified bioactive glass addition. For cell culture studies human dental pulp stem cells were isolated from patient teeth. An improvement in cellular viability was observed for different groups over the incubation period with the highest human dental pulp stem cells viability on B7-20 scaffolds. ICP-OES analysis revealed that concentration of boron ion released from the scaffolds was between 0.2 and 1.1 mM, which was below toxic levels. Alkaline phosphatase activity and intracellular calcium amounts significantly increased 14 days after incubation with highest values in B14-10 group. Von Kossa staining revealed higher levels of mineral deposition in these groups. In this work, results indicated that developed dentin-like constructs are promising for dentin regeneration owing to presence of boron-modified bioactive glass nanoparticles.

MicroRNA let-7c-5p Suppressed Lipopolysaccharide-Induced Dental Pulp Inflammation by Inhibiting Dentin Matrix Protein-1-Mediated Nuclear Factor kappa B (NF-κB) Pathway In Vitro and In Vivo.

BackgroundLet-7c-5p is down-regulated in dental pulp tissues in inflammatory disorders. The microRNA (miR) molecule shows an anti-inflammation potential due to its direct regulation of dentin matrix protein-1 (DMP1), which promotes inflammation changes in dental pulp tissues. In the present study, the effect of let-7c-5p on lipopolysaccharide (LPS)-induced pulpitis was detected and the associated mechanism was explored.Material/MethodsDental pulp stem cells (DPSCs) were isolated from rat dental tissues, infected with let-7c-5p lentivirus particles, and subjected to LPS administration to induce inflammation. Then, the effect of let-7c-5p overexpression on LPS-induced impairments on DPSCs were detected and the mechanism was explained by focusing on the DMP1 expression and NF-κB pathway. The role of DMP1 in the anti-inflammation effect of let-7c-5p was assessed by incubating let-7c-5p-expressed DPSCs with DMP1 protein. The results of in vitro assays were verified in LPS-induced rat pulpitis models.ResultsLPS administration increased the production of IL-1β and TNF-α and decreased DPSCs viability by increasing the expression of DMP1 and activating NF-κB pathway. However, the induced expression of let-7c-5p relieved DPSCs from LPS-induced inflammation and suppressed DMP1 as well as NF-κB pathway. The incubation of let-7c-5p-expressed DPSCs with DMP1 protein blocked the effect of let-7c-5p. In in vivo experiments, the injection of let-7c-5p attenuated LPS-induced pulpitis by inhibiting DMP1-mediated NF-κB pathway.ConclusionsFindings outlined in the current study demonstrated the dental pulp protecting function of let-7c-5p during LPS-induced inflammation, which was exerted by inhibiting the DMP1-mediated NF-κB pathway.

Simvastatin increases cell viability and suppresses the expression of cytokines and vascular endothelial growth factor in inflamed human dental pulp stem cells in vitro.

In recent years, simvastatin has been demonstrated to be capable of inducing odontogenic differentiation in human dental pulp stem cells (DPSCs), which makes it a promising source for endodontic treatment in pulpitis. However, a comprehensive understanding of how simvastatin affects the behavior of DPSCs and its potential in pulpitis is still lacking. In this study, we investigated the effects of simvastatin on the viability of inflamed DPSCs. The expression of cytokines and vascular endothelial growth factor (VEGF) was also studied in response to simvastatin treatment. We characterized the cell viability, inflammatory reactions and the production of VEGF in inflamed DPSCs, induced by lipopolysaccharides (LPS). The methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay, cell cycle, apoptosis analysis, quantitative reverse transcription polymerase chain reaction (RT-PCR), enzyme-linked immunosorbent assay (ELISA), and western blot analyses were performed. We observed that a low dosage of simvastatin accelerated cell proliferation , whereas its high dosage (>15 μg/mL) suppressed propagation. A simvastatin dose of 8 μg/mL was sufficient to promote cell growth and cell cycle progression in DPSCs treated with LPS. Meanwhile, simvastatin induced apoptosis. The expression of multiple cytokines, including interleukins (IL)-1, IL-4 and IL-1β, and especially interferon-gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α), was significantly suppressed. Moreover, the protein secretion and mRNA transcription of VEGF was observed to be markedly inhibited by simvastatin by inactivating mitogen-activated protein kinase (MAPK) signaling. Taken together, these results suggested that simvastatin might be a potent ingredient to enhance cell proliferation, alleviate inflammation response and attune vasculogenesis in pulpitis.

Neurogenic Differentiation of Human Dental Pulp Stem Cells on Graphene-Polycaprolactone Hybrid Nanofibers.

Stem cells derived from dental tissues—dental stem cells—are favored due to their easy acquisition. Among them, dental pulp stem cells (DPSCs) extracted from the dental pulp have many advantages, such as high proliferation and a highly purified population. Although their ability for neurogenic differentiation has been highlighted and neurogenic differentiation using electrospun nanofibers (NFs) has been performed, graphene-incorporated NFs have never been applied for DPSC neurogenic differentiation. Here, reduced graphene oxide (RGO)-polycaprolactone (PCL) hybrid electrospun NFs were developed and applied for enhanced neurogenesis of DPSCs. First, RGO-PCL NFs were fabricated by electrospinning with incorporation of RGO and alignments, and their chemical and morphological characteristics were evaluated. Furthermore, in vitro NF properties, such as influence on the cellular alignments and cell viability of DPSCs, were also analyzed. The influences of NFs on DPSCs neurogenesis were also analyzed. The results confirmed that an appropriate concentration of RGO promoted better DPSC neurogenesis. Furthermore, the use of random NFs facilitated contiguous junctions of differentiated cells, whereas the use of aligned NFs facilitated an aligned junction of differentiated cells along the direction of NF alignments. Our findings showed that RGO-PCL NFs can be a useful tool for DPSC neurogenesis, which will help regeneration in neurodegenerative and neurodefective diseases.

Antibacterial effects and cytotoxicity of an adhesive containing low concentration of silver nanoparticles

ObjectivesTo evaluate the antibacterial effects, cytotoxicity and microtensile bond strength of an adhesive containing low concentrations of silver nanoparticles (NAg). MethodsVarious concentrations of NAg (50, 100, 150, 200 and 250 ppm) were incorporated into the primer of the Scotchbond Multi-Purpose adhesive system (SBMP). Antibacterial activity was examined using a broth microdilution assay to determine minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC), agar diffusion assay and the MTT assay was used to examine the biofilm metabolic activity (S. mutans). The Microtensile Bond Test (μTBS) was performed after 24 h, followed by 6-months storage in distilled water. Cytotoxicity was assessed with an MTT reduction assay in human dental pulp stem cells viability after exposure to Nag-conditioned culture media during 0, 24, 48, and 72 h. The results were statistically analyzed (α ≤ 0.05). ResultsMIC was found between NAg 25 and 50 ppm MBC was determined at 50 ppm of NAg. Bacterial activity inhibition was higher than control in all NAg groups compared to control in agar diffusion assay. Biofilm inhibition was statistically higher in 250 ppm NAg than control. All NAg groups and SBMP presented similar cytotoxicity in each period. Adhesives with NAg 200 and 250 ppm and SBMP (control) presented the highest μTBS values, similar to that of SBMP control, in both instances (24 h and 6 months) (p > 0.05). ConclusionsThe commercial primer containing NAg 250 ppm showed both antibacterial effect and reliable bond strength with no cytotoxicity increase. The addition of NAg to primers seems promising for the improvement of conventional dental adhesives efficacy.Clinical Significance: The addition of low concentrations of NAg (250 ppm) to primers were effective to improve antibacterial effect preserving the bond strength and the biocompatibility of the commercial product. NAg/primer association could protect the tooth-adhesive interface increasing dental restoration longevity.

The antimicrobial properties, cytotoxicity, and differentiation potential of double antibiotic intracanal medicaments loaded into hydrogel system.

This study evaluated the antimicrobial properties, cytotoxicity, and mineralization potential of methylcellulose hydrogels loaded with low concentrations of double antibiotic pastes (DAP). The direct and residual antibacterial effects of 1, 5, and 10mg/mL of DAP loaded into hydrogels as well as calcium hydroxide (Ca(OH)2) were tested against single-species biofilms of Enterococcus faecalis and dual-species biofilms (Enterococcus faecalis and Prevotella intermedia). The effects of DAP hydrogels on proliferation and mineralization of dental pulp stem cells (DPSC) were tested using MTT assays, alkaline phosphate activity (ALP), and alizarin red staining. Fisher's exact tests, Wilcoxon rank sum tests, and one-way ANOVA were used for statistical analyses (α = 0.05). All tested concentrations of DAP hydrogels as well as Ca(OH)2 demonstrated significant direct antibacterial effects against single- and dual-species biofilms. However, only 5 and 10mg/mL of DAP hydrogels exhibited significant residual antibacterial effects against both types of tested biofilms. Only 1mg/mL of DAP hydrogels did not have significant negative effects on DPSC viability, ALP activity, and mineralization nodule formation. However, 5 and 10mg/mL of DAP hydrogels caused significant negative effects on cytotoxicity and mineralization nodule formation of DPSC. Hydrogels containing 1mg/mL DAP offered significant direct antibacterial effects against single- and dual-species biofilms without causing significant negative effects on viability, ALP activity, and mineralization nodule formation of DPSC. The methylcellulose-based hydrogel proposed in this study can be used clinically as a biocompatible system to deliver controlled low concentrations of DAP.

High expression of TRAIL by osteoblastic differentiated dental pulp stem cells affects myeloma cell viability.

Cells from dental tissues have a mesenchymal stem cell (MSC) phenotype, are multipotent and can differentiate into osteoblastic cells, as we have previously found. MSCs, due to their tumor‑homing ability, are currently being used as cell‑based delivery systems for cancer protein therapeutics, such as the TNF‑related apoptosis‑inducing ligand (TRAIL). In the present study we revealed that dental pulp stem cells (DPSCs) expressed TRAIL to a greater extent when they were differentiated into the osteoblastic lineage. TRAIL affected the viability of undifferentiated DPSCs, while osteoblastic differentiated DPSCs were not sensitive to TRAIL. The expression trend of TRAIL receptors underwent changes during the osteoblastic differentiation of DPSCs exhibiting low DcR2 and high DR5 levels in the undifferentiated DPSCs and an opposite scenario was presented in the differentiated cells. The sensitivity of the undifferentiated DPSCs to the TRAIL‑apoptotic effect was also associated with low levels of intracellular anti‑apoptotic proteins, such as c‑FLIP, XIAP and the activation of caspase‑8 and ‑3. DPSC‑differentiated osteoblasts expressing high TRAIL levels were capable to affect the cell viability of the human myeloma cell line H929, thus representing an effective anticancer therapeutic method.

Dental pulp stem cell-derived chondrogenic cells demonstrate differential cell motility in type I and type II collagen hydrogels

Background ContextAdvances in the development of biomaterials and stem cell therapy provide a promising approach to regenerating degenerated discs. The normal nucleus pulposus (NP) cells exhibit similar phenotype to chondrocytes. Because dental pulp stem cells (DPSCs) can be differentiated into chondrogenic cells, the DPSCs and DPSCs-derived chondrogenic cells encapsulated in type I and type II collagen hydrogels can potentially be transplanted into degenerated NP to repair damaged tissue. The motility of transplanted cells is critical because the cells need to migrate away from the hydrogels containing the cells of high density and disperse through the NP tissue after implantation. PurposeThe purpose of this study was to determine the motility of DPSC and DPSC-derived chondrogenic cells in type I and type II collagen hydrogels. Study Design/SettingThe time lapse imaging that recorded cell migration was analyzed to quantify the cell migration velocity and distance. MethodsThe cell viability of DPSCs in native or poly(ethylene glycol) ether tetrasuccinimidyl glutarate (4S-StarPEG)-crosslinked type I and type II collagen hydrogels was determined using LIVE/DEAD cell viability assay and AlamarBlue assay. DPSCs were differentiated into chondrogenic cells. The migration of DPSCs and DPSC-derived chondrogenic cells in these hydrogels was recorded using a time lapse imaging system. This study was funded by the Regional Institute on Aging and Wichita Medical Research and Education Foundation, and the authors declare no competing interest. ResultDPSCs showed high cell viability in non-crosslinked and crosslinked collagen hydrogels. DPSCs migrated in collagen hydrogels, and the cell migration speed was not significantly different in either type I collagen or type II collagen hydrogels. The migration speed of DPSC-derived chondrogenic cells was higher in type I collagen hydrogel than in type II collagen hydrogel. Crosslinking of type I collagen with 4S-StarPEG significantly reduced the cell migration speed of DPSC-derived chondrogenic cells. ConclusionsAfter implantation of collagen hydrogels encapsulating DPSCs or DPSC-derived chondrogenic cells, the cells can potentially migrate from the hydrogels and migrate into the NP tissue. This study also explored the differential cell motility of DPSCs and DPSC-derived chondrogenic cells in these collagen hydrogels.

A biocompatible decellularized pulp scaffold for regenerative endodontics.

To investigate the feasibility of decellularizing the entire dental pulp using a mild treatment protocol to develop a decellularized biological extracellular matrix scaffold for use in regenerative endodontic procedures. Decellularized human dental pulps were assessed using histological and immunohistochemical methods, scanning electron microscope and DNA quantification assay. Cytotoxicity assays to determine decellularized scaffold biocompatibility were also performed. Decellularized scaffolds were seeded with human dental pulp stem cells and cell viability assessed using Live/Dead® stain. Quantitative data were analysed statistically using Student's t-test and one-way analysis of variance to compare mean values between groups depending on group numbers. Assessment of decellularized tissues revealed an acellular matrix with preservation of native tissue histoarchitecture and composition. Decellularized tissues showed no evidence of cytotoxicity, with cell growth in direct contact with the scaffold and no reduction in cellular activity following extract incubation. Furthermore, the scaffold was able to support human dental pulp stem cell viability and attachment following recellularization. Promising results were observed in developing a decellularized biological scaffold derived from the dental pulp with the perseveration of extracellular structural components which are required for tissue-specific regeneration.

Clindamycin-modified Triple Antibiotic Nanofibers: A Stain-free Antimicrobial Intracanal Drug Delivery System

IntroductionA biocompatible strategy to promote bacterial eradication within the root canal system after pulpal necrosis of immature permanent teeth is critical to the success of regenerative endodontic procedures. This study sought to synthesize clindamycin-modified triple antibiotic (metronidazole, ciprofloxacin, and clindamycin [CLIN]) polymer (polydioxanone [PDS]) nanofibers and determine in vitro their antimicrobial properties, cell compatibility, and dentin discoloration. MethodsCLIN-only and triple antibiotic CLIN-modified (CLIN-m, minocycline-free) nanofibers were processed via electrospinning. Scanning electron microscopy, Fourier-transform infrared spectroscopy (FTIR), and tensile testing were performed to investigate fiber morphology, antibiotic incorporation, and mechanical strength, respectively. Antimicrobial properties of CLIN-only and CLIN-m nanofibers were assessed against several bacterial species by direct nanofiber/bacteria contact and over time based on aliquot collection up to 21 days. Cytocompatibility was measured against human dental pulp stem cells. Dentin discoloration upon nanofiber exposure was qualitatively recorded over time. The data were statistically analyzed (P < .05). ResultsThe mean fiber diameter of CLIN-containing nanofibers ranged between 352 ± 128 nm and 349 ± 128 nm and was significantly smaller than PDS fibers. FTIR analysis confirmed the presence of antibiotics in the nanofibers. Hydrated CLIN-m nanofibers showed similar tensile strength to antibiotic-free (PDS) nanofibers. All CLIN-containing nanofibers and aliquots demonstrated pronounced antimicrobial activity against all bacteria. Antibiotic-containing aliquots led to a slight reduction in dental pulp stem cell viability but were not considered toxic. No visible dentin discoloration upon CLIN-containing nanofiber exposure was observed. ConclusionsCollectively, based on the remarkable antimicrobial effects, cell-friendly, and stain-free properties, our data suggest that CLIN-m triple antibiotic nanofibers might be a viable alternative to minocycline-based antibiotic pastes.

The effect of Aloe vera gel on viability of dental pulp stem cells

Dental pulp stem cells (DPSCs) can play a prominent role in tissue regeneration. Aloe vera L. (Liliaceae) contains the polysaccharide of acemannan that was shown to be a trigger factor for cell proliferation, differentiation, mineralization, and dentin formation. This study sought to determine the viability of DPSCs in Aloe vera in comparison with Hank's balanced salt solution (HBSS). Twelve rabbits underwent anesthesia, and their incisor teeth were extracted; the pulp tissue was removed, chopped, treated with collagenase and plated in culture flasks. DPSCs from passage 3 were cultured in 24-well plates, and after 3 days, the culture media changed to 10, 25, 50, and 100% concentrations of Aloe vera at intervals of 45 and 90 min and 3 and 6 h. Distilled water was used as negative and HBSS as positive control for comparison. The cell morphology, viability, population doubling time (PDT), and growth kinetics were evaluated. RT-PCR was carried out for characterization and karyotyping for chromosomal stability. Aloe vera showed a significant higher viability than HBSS (74.74%). The 50% Aloe vera showed higher viability (97.73%) than other concentrations. PDT in 50% concentration was 35.1 h and for HBSS was 49.5 h. DPSCs were spindle shaped and were positive for CD73 and negative for CD34 and CD45. Karyotyping was normal. Aloe vera as an inexpensive and available herb can improve survival of avulsed or broken teeth in emergency cases as a transfer media.

An Optimized Injectable Hydrogel Scaffold Supports Human Dental Pulp Stem Cell Viability and Spreading.

Introduction. HyStem-C™ is a commercially available injectable hydrogel composed of polyethylene glycol diacrylate (PEGDA), hyaluronan (HA), and gelatin (Gn). These components can be mechanically tuned to enhance cell viability and spreading. Methods. The concentration of PEGDA with an added disulfide bond (PEGSSDA) was varied from 0.5 to 8.0% (w/v) to determine the optimal concentration for injectable clinical application. We evaluated the cell viability of human dental pulp stem cells (hDPSCs) embedded in 2% (w/v) PEGSSDA-HA-Gn hydrogels. Volume ratios of HA : Gn from 100 : 0 to 25 : 75 were varied to encourage hDPSC spreading. Fibronectin (Fn) was added to our model to determine the effect of extracellular matrix protein concentration on hDPSC behavior. Results. Our preliminary data suggests that the hydrogel gelation time decreased as the PEGSSDA cross-linker concentration increased. The PEGSSDA-HA-Gn was biocompatible with hDPSCs, and increased ratios of HA : Gn enhanced cell viability for 14 days. Additionally, cell proliferation with added fibronectin increased significantly over time at concentrations of 1.0 and 10.0 μg/mL in PEGDA-HA-Gn hydrogels, while cell spreading significantly increased at Fn concentrations of 0.1 μg/mL. Conclusions. This study demonstrates that PEG-based injectable hydrogels maintain hDPSC viability and facilitate cell spreading, mainly in the presence of extracellular matrix (ECM) proteins.

Effects of ciprofloxacin-containing antimicrobial scaffolds on dental pulp stem cell viability—In vitro studies

ObjectiveA combination of antibiotics, including but not limited to metronidazole (MET) and ciprofloxacin (CIP), has been indicated to eradicate bacteria in necrotic immature permanent teeth prior to regenerative procedures. It has been shown clinically that antibiotic pastes may lead to substantial stem cell death. The aim of this study was to synthesise scaffolds containing various concentrations of CIP to enhance cell viability while preserving antimicrobial properties. DesignPolydioxanone (PDS)-based electrospun scaffolds were processed with decreasing CIP concentrations (25–1wt.%) and morphologically evaluated using scanning electron microscopy (SEM). Cytotoxicity assays were performed to determine whether the amount of CIP released from the scaffolds would lead to human dental pulp stem cell (hDPSC) toxicity. Similarly, WST-1 assays were performed to evaluate the impact of CIP release on hDPSC proliferation. Pure PDS scaffolds and saturated double antibiotic solution MET/CIP (DAP) served as both positive and negative controls, respectively. Antibacterial efficacy against E. faecalis (Ef) was tested. ResultsA significant decrease in hDPSC’ viability at concentrations 5–25wt.% was observed. However, concentrations below 5wt.% did not impair cell viability. Data from the WST-1 assays indicated no detrimental impact on cell proliferation for scaffolds containing 2.5wt.% CIP or less. Significant antimicrobial properties were seen for CIP-scaffolds at lower concentrations (i.e., 1 and 2.5wt.%). ConclusionThe obtained data demonstrated that a reduced concentration of CIP incorporated into PDS-based scaffolds maintains its antimicrobial properties while enhancing viability and proliferation of dental pulp stem cells.

Collagen/fibrin microbeads as a delivery system for Ag-doped bioactive glass and DPSCs for potential applications in dentistry

Silver doped bioactive glass (Ag-BG) and Dental Pulp Stem Cells (DPSCs) have shown promising properties for dental tissue regeneration. This study presents the fabrication and characterization of composite collagen/fibrin microbeads that aimed to incorporate and successfully deliver both Ag-BG and DPSC. Cell viability, cell differentiation in vitro and in vivo, and antibacterial properties of the systems against Escherichia coli (E. coli), Streptococcus mutans (S. mutans) and Enterococcus faecalis (E. faecalis) were evaluated. Cell viability and proliferation of DPSCs within the delivery system were found unaltered in both combinations (Beads/DPSCs and Beads/DPSCs/Ag-BG). Our results show that Ag-BG and DPSCs were successfully incorporated and proliferated within the collagen/fibrin microbeads. DPSCs continued to proliferate up to 6-weeks in cell culture but cell differentiation into odontoblast-like cells was observed only in vivo. The beads containing Ag-BG strongly inhibit bacterial growth in the experimental groups (beads alone, Beads/Ag-BG and Beads/DPSCs/Ag-BG). Our data suggests that collagen/fibrin microbead paste could have clinical applicability in the regenerative dentistry field.