Therapeutic effect of adipose-derived mesenchymal stem cells in a porcine model of abdominal sepsis.

BACKGROUND: The term sepsis refers to a complex and heterogeneous syndrome. Although great progress has been made in improving the diagnosis and treatment of this condition, it continues to have a huge impact on morbidity and mortality worldwide. Mesenchymal stem cells are a population of multipotent cells that have immunomodulatory properties, anti-apoptotic effects, and antimicrobial activity. We studied these capacities in a porcine model of peritoneal sepsis. METHODS: We infused human adipose-derived mesenchymal stem cells (ADSCs) into a porcine model of peritoneal sepsis. Twenty piglets were treated with antibiotics alone (control group) or antibiotics plus peritoneal infusion of ADSCs at a concentration of 2 × 106 cells/kg or 4 × 106 cells/kg (low- and high-dose experimental groups, respectively). The animals were evaluated at different time points to determine their clinical status, biochemical and hematologic parameters, presence of inflammatory cytokines and chemokines in blood and peritoneal fluid, and finally by histologic analysis of the organs of the peritoneal cavity. RESULTS: One day after sepsis induction, all animals presented peritonitis with bacterial infection as well as elevated C-reactive protein, haptoglobin, IL-1Ra, IL-6, and IL-1b. Xenogeneic ADSC infusion did not elicit an immune response, and peritoneal administration of the treatment was safe and feasible. One day after infusion, the two experimental groups showed a superior physical condition (e.g., mobility, feeding) and a significant increase of IL-10 and TGF-ß in blood and a decrease of IL-1Ra, IL-1b, and IL-6. After 7 days, all animals treated with ADSCs had better results concerning blood biomarkers, and histopathological analysis revealed a lower degree of inflammatory cell infiltration of the organs of the peritoneal cavity. CONCLUSIONS: Intraperitoneal administration of ADSCs as an adjuvant therapy for sepsis improves the outcome and diminishes the effects of peritonitis and associated organ damage by regulating the immune system and reducing intra-abdominal adhesions in a clinically relevant porcine model of abdominal sepsis.

Valoración de la grasa hepática y pancreática como biomarcadores de imagen en el síndrome metabólico / Hepatic and pancreatic fat as imaging biomarkers of metabolic syndrome

OBJETIVO: Valorar objetivamente la afectación hepática y pancreática en el síndrome metabólico mediante biomarcadores de resonancia magnética (RM). MATERIAL Y MÉTODOS: Serie retrospectiva inicial de 407 pacientes con diagnóstico de síndrome metabólico, estudiados con RM en un único centro durante 2 años. Se excluyeron 154 pacientes por falta de datos clínico-analíticos, alteraciones pancreáticas o inadecuada calidad de la RM. Para la medición de la grasa hepática y pancreática se utilizaron las imágenes con desplazamiento químico (en fase y fase opuesta), con medidas por regiones de interés de la fracción grasa (%) en el páncreas (FGP) e hígado (FGH). La asociación entre las variables clínico-analíticas seleccionadas y la fracción grasa se evaluó mediante modelos de regresión beta. RESULTADOS: Se incluyeron finalmente 253 pacientes. La FGH fue del 4,9% y la FGP del 7,9%. La FGH no presentó ninguna asociación estadística con las variables clínico-analíticas. Sin embargo, la FGP se asoció positivamente con la edad (odds ratio [OR]=1,025, p <0,001) y la glucosa basal (OR=1,005, p <0,001). Se observó que los pacientes con diabetes presentaban valores más altos de FGP (OR=2,64, p = 0,038). La FGP y la FGH estaban relacionadas de manera estadísticamente positiva (OR=69,44, p <0,001). CONCLUSIONES: La esteatosis pancreática puede considerarse un marcador del síndrome metabólico y la diabetes. La RM cuantitativa permite el diagnóstico y la gradación de pacientes con páncreas graso mediante técnicas sencillas de desplazamiento químico

OBJECTIVE: To objectively evaluate hepatic and pancreatic involvement in metabolic syndrome through magnetic resonance imaging (MRI) biomarkers. MATERIAL AND METHODS: From an initial retrospective sample of 407 patients diagnosed with metabolic syndrome studied by MRI in a single center during a 2-year period, 154 were excluded because of a lack of clinical and/or laboratory data, pancreatic abnormalities, or inadequate quality of MRI studies. To measure hepatic and pancreatic fat, we used chemical shift imaging (in-phase and out-of-phase), measuring the fat fraction (%) in regions of interest in the pancreas and liver. Associations between the fat fraction and selected clinical and laboratory variables were assessed with beta regression models. RESULTS: In the end, 253 patients were included. The hepatic fat fraction was 4.9% and the pancreatic fat fraction was 7.9%. We found no significant associations between the hepatic fat fraction and any of the clinical or laboratory variables. However, the pancreatic fat fraction was positively associated with age (OR=1.025, p < 0.001) and baseline glucose (OR=1.005, p < 0.001). Patients with diabetes had higher values of pancreatic fat fraction (OR=2.64, p = 0.038). Pancreatic fat fraction and hepatic fat fraction were positively associated (OR=69.44, p < 0.001). CONCLUSIONS: Pancreatic steatosis can be considered a marker of metabolic syndrome and diabetes. Quantitative MRI enables the diagnosis and grading of fatty pancreas through simple chemical shift techniques

Hepatic and pancreatic fat as imaging biomarkers of metabolic syndrome. / Valoración de la grasa hepática y pancreática como biomarcadores de imagen en el síndrome metabólico.

OBJECTIVE: To objectively evaluate hepatic and pancreatic involvement in metabolic syndrome through magnetic resonance imaging (MRI) biomarkers. MATERIAL AND METHODS: From an initial retrospective sample of 407 patients diagnosed with metabolic syndrome studied by MRI in a single center during a 2-year period, 154 were excluded because of a lack of clinical and/or laboratory data, pancreatic abnormalities, or inadequate quality of MRI studies. To measure hepatic and pancreatic fat, we used chemical shift imaging (in-phase and out-of-phase), measuring the fat fraction (%) in regions of interest in the pancreas and liver. Associations between the fat fraction and selected clinical and laboratory variables were assessed with beta regression models. RESULTS: In the end, 253 patients were included. The hepatic fat fraction was 4.9% and the pancreatic fat fraction was 7.9%. We found no significant associations between the hepatic fat fraction and any of the clinical or laboratory variables. However, the pancreatic fat fraction was positively associated with age (OR=1.025, p<0.001) and baseline glucose (OR=1.005, p<0.001). Patients with diabetes had higher values of pancreatic fat fraction (OR=2.64, p=0.038). Pancreatic fat fraction and hepatic fat fraction were positively associated (OR=69.44, p<0.001). CONCLUSIONS: Pancreatic steatosis can be considered a marker of metabolic syndrome and diabetes. Quantitative MRI enables the diagnosis and grading of fatty pancreas through simple chemical shift techniques.

Soft-tissue outcomes following implantation of different types of bone conduction hearing devices in a single centre.

OBJECTIVE: To compare soft-tissue complications following implantation of different bone conduction hearing devices. METHODS: Adults who underwent implantation of different bone conduction hearing devices, between January 2008 and December 2016, were included in the study. Five groups were identified depending on the soft-tissue approach: (1) split-thickness skin flap with use of dermatome; (2) Sheffield 'S'-shaped incision with skin thinning; (3) linear incision without skin thinning (hydroxyapatite-coated abutment); (4) 'C'-shaped full-thickness incision for passive transcutaneous bone conduction hearing devices; and (5) post-aural incision for active transcutaneous bone conduction hearing devices. The main outcome measures were different soft-tissue complications. RESULTS: The study comprised 120 patients (group 1 = 20 patients, group 2 = 35, group 3 = 35, group 4 = 20, and group 5 = 10). Soft tissue related problems were encountered in 55 per cent of patients from group 1, 26 per cent in group 2, 3 per cent in group 3, and 0 per cent in groups 4 and 5. CONCLUSION: There was a reduction in soft tissue related complications with reduced soft-tissue handling. In addition, there was a shift from an initial skin-penetrating (percutaneous) approach to a non-skin-penetrating (transcutaneous) approach.

Comparison of diffusion, cytotoxicity and tissue inflammatory reactions of four commercial bleaching products against human dental pulp stem cells.

Multiple side effects related to bleaching were found to occur in the dental pulp tissue, including decreased cell metabolism and viability. In this work we evaluated the in vitro diffusion capacity, cytotoxicity and biocompatibility of four commercial bleaching products on stem cells from human dental pulp (hDPSCs). Two commercial bleaching gels hydrogen peroxide-based (HP), Norblanc Office 37.5% (Nor-HP) and Opalescence Boost 40% (Opal-HP) were applied for 30 min to enamel/dentine discs. Another two gels from the same manufacturers, 16% carbamide peroxide-based (CP), Norblanc Home (Nor-CP) and Opalescence CP 16% (Opal-CP), were applied for 90 min. The diffusion of HP was analysed by fluorometry. Cytotoxicity was determined using the MTT assays, the determination of apoptosis, immunofluorescence assays and intracellular reactive oxygen species (ROS) level. Tissue inflammatory reactions were evaluated histopathologically in rats. Statistical differences were performed by one-way ANOVA and Bonferroni post-test (α < 0.05). Normon products showed lower cytotoxicity and diffusion capacity than the Ultradent products. A high intracellular ROS level was measured in hDPSCs after exposure to Opal-HP. Finally, a severe necrosis of both coronal and radicular pulp was observed with Opal-HP. Similar concentrations of hydrogen peroxide and carbamide peroxide in a variety of bleaching products exhibited different responses in cells and dental pulp tissue, suggesting that bleaching products contain unknown agents that could influence their toxicity.

Evaluation of changes in ion release and biological properties of NeoMTA-Plus and Endocem-MTA exposed to an acidic environment.

AIM: To analyse in vitro changes in ion release and biological properties of Endocem-MTA (Maruchi, Wonju, Korea) and NeoMTA-Plus (Avalon Biomed Inc, Bradenton, FL, USA) exposed to acidic or neutral environment on human dental periodontal ligament stem cells (hPDLSCs). METHODOLOGY: Cell viability and wound healing assays were performed using eluates of each material. Cell death and changes in phenotype induced by the set endodontic sealer eluates were evaluated through flow cytometry. To evaluate cell attachment to the different materials, hPDLSCs were directly seeded onto the material surfaces and analysed by scanning electron microscopy. The chemical composition of the materials was determined by energy-dispersive X-ray (EDX), and ion release was evaluated by inductively coupled plasma-mass spectrometry. Statistical analysis was performed with analysis of variance and a Bonferroni or Tukey post-test (α < 0.05). RESULTS: The MTT assay revealed non-cytotoxic effects of NeoMTA-Plus and Endocem-MTA at pH 5.2 and 7.4. However, there were minor differences compared with the control, especially at pH 5.2, where both materials were associated with significantly greater cell viability (P < 0.05). In both environments, the materials stimulated hPDLSCs to migrate. hPDLSCs were attached to the bioactive cements, with multiple prolongations proliferated on the surface of the samples. Moreover, there were no changes to cell phenotype or apoptosis/necrosis rates, indicating that the acidic environment did not induce cell death. Prismatic crystalline structures were seen on the surface of the cements exposed to butyric acid and EDX analysis identified a marked peak of Ca2+ from NeoMTA-Plus and Endocem-MTA in acidic and physiological environments. CONCLUSIONS: An acidic environment favoured the release of Ca2+ ions from both bioactive cements, and the cytotoxicity of these bioactive cements was low in both environments studied.

GuttaFlow Bioseal promotes spontaneous differentiation of human periodontal ligament stem cells into cementoblast-like cells.

OBJECTIVES: To evaluate in vitro the cementogenic potential and the biological effects of GuttaFlow Bioseal, GuttaFlow 2, MTA Fillapex and AH Plus on human periodontal ligament stem cells (hPDLSCs). METHODS: Cell viability, cell migration and cell morphology assays were performed using eluates of each material. To evaluate cell attachment, hPDLSCs were directly seeded onto the material surfaces and analyzed by scanning electron microscopy (SEM). The effects of endodontic sealers on cementum protein 1 (CEMP1), cementum-derived attachment protein (CAP), bone sialoprotein (BSP), ameloblastin (AMBN), amelogenin (AMELX) and alkaline phosphatase (ALP) gene expression on hPDLSCs were investigated by qPCR and immunofluorescence (IF). Statistical analysis was performed with analysis of variance and Bonferroni or Tukey post-test (α<0.05). RESULTS: More than 90% of viable cells were obtained using extracts of GuttaFlow Bioseal and GuttaFlow2 after 72h of culture. By contrast, AH Plus and MTA Fillapex induced significantly lower levels of cell viability. GuttaFlow2 and GuttaFlow Bioseal promoted wound closure in a concentration-dependent manner, comparable to that observed with control extracts (*p<0.05). However, with AH Plus and MTA Fillapex, cell migration was significantly lower than in the control (***p<0.0001). SEM analysis pointed to an organized stress fiber assembly and high degree of cell adhesion on GuttaFlow Bioseal disks but low rates on GuttaFlow2, MTA Fillapex and AH Plus. When hPDLSCs were cultured with GuttaFlow Bioseal-conditioned media, qPCR assays and IF showed a higher level of AMELX, AMBN, CEMP1 and CAP expression than the control (*p<0.05)), whereas no such expression was observed in the other sealers. SIGNIFICANCE: Our results showed that GuttaFlow sealers were more cytocompatible than AH Plus and MTA Fillapex, while GuttaFlow Bioseal favored cementoblast differentiation of hPDLSCs in the absence of any growth factors.

Biological effects of silk fibroin 3D scaffolds on stem cells from human exfoliated deciduous teeth (SHEDs).

The aim is to investigate in vitro biological effects of silk fibroin 3D scaffolds on stem cells from human exfoliated deciduous teeth (SHEDs) in terms of proliferation, morphological appearance, cell viability, and expression of mesenchymal stem cell markers. Silk fibroin 3D scaffolding materials may represent promising suitable scaffolds for their application in regenerative endodontic therapy approaches. SHEDs were cultured in silk fibroin 3D scaffolds. Then, cell numbers were counted and the Alamar blue colorimetric assay was used to analyse cell proliferation after 24, 48, 72, and 168 h of culture. The morphological features of SHEDs cultured on silk fibroin scaffolds were evaluated by scanning electron microscopy (SEM). Finally, cell viability and the expression of mesenchymal stem cell markers were analysed by flow cytometry. One-way analysis of variance (ANOVA) followed by a Bonferroni post-test was performed (P < 0.05). At 24 and 48 h of culture, SHED proliferation on scaffolds was modest compared to the control although still significant (p < 0.05). However, cell proliferation progressively increased from 72 to 168 h compared with the control (p < 0.001; p < 0.01). In addition, flow cytometry analysis showed that the culture of SHEDs on silk fibroin scaffolds did not significantly alter the level of expression of the mesenchymal markers CD73, CD90, or CD105 up to 168 h; in addition, cell viability in silk fibroin was similar to than obtained in plastic. Moreover, SEM studies revealed a suitable degree of proliferation, cell spreading, and attachment, especially after 168 h of culture. The findings from the current study suggest that silk fibroin 3D scaffolds had a favourable effect on the biological responses of SHEDs. Further in vivo investigations are required to confirm these results.

Comparative analysis of the biological effects of the endodontic bioactive cements MTA-Angelus, MTA Repair HP and NeoMTA Plus on human dental pulp stem cells.

AIM: To evaluate the biological effects in vitro of MTA-Angelus (MTA-Ang; Angelus, Londrina, PR, Brazil), MTA Repair HP (MTA-HP; Angelus) and NeoMTA Plus (NeoMTA-P; Avalon Biomed Inc, Bradenton, FL, USA) on human dental pulp stem cells (hDPSCs). METHODOLOGY: Cell viability and cell migration assays were performed using eluates of each material. To evaluate cell morphology and cell attachment to the different materials, hDPSCs were directly seeded onto the material surfaces and analysed by immunocytofluorescence and scanning electron microscopy, respectively. The chemical composition of the materials was determined by energy-dispersive X-ray (EDX), and eluates were analysed by inductively coupled plasma-mass spectrometry (ICP-MS). Statistical analysis was performed with the analysis of variance and Bonferroni or Tukey post-test (α < 0.05). RESULTS: Undiluted MTA-Ang, MTA-HP and NeoMTA-P displayed a significant increase in cell viability greater than that obtained using complete medium alone (control) (*P < 0.05; **P < 0.01; ***P < 0.001). Moreover, a cell migration assay revealed cell migration rates after incubation with extracts of MTA-Ang, MTA-HP and NeoMTA-P that were similar to levels obtained in the control group. In addition, stretched cytoskeletal F-actin fibres were detected in the cells treated with the three material extracts. SEM studies revealed a high degree of cell proliferation and attachment on all three materials. EDX analysis demonstrated similar weight percentages of C, O and Ca in all three materials, whilst other elements such as Al, Si and S were also found. CONCLUSIONS: MTA-Ang, MTA-HP and NeoMTA-P were associated with biological effects on hDPSCs in terms of cell proliferation, morphology, migration and attachment.

A comparison study of complications and initial follow-up costs of transcutaneous and percutaneous bone conduction devices.

BACKGROUND: The percutaneous osseointegrated bone conduction device can be associated with more soft tissue complications when compared to the magnetic transcutaneous osseointegrated bone conduction device. This study aimed to determine whether fewer soft tissue complications may result in the transcutaneous osseointegrated bone conduction device being a lower cost option in hearing rehabilitation. METHODS: This retrospective case note review included adult patients who underwent implantation with the transcutaneous Cochlear Attract (n = 22) or percutaneous Cochlear DermaLock (n = 25) bone-anchored hearing aids between September 2013 and December 2014. The number of post-operative clinic appointments, complications and treatments undertaken, and calculated cost average, were compared between the two groups. RESULTS: Although the transcutaneous device was slightly more expensive than the percutaneous device, the percutaneous device was associated with a greater number of soft tissue complications and, as a result, the percutaneous device had significantly higher follow-up costs in the first six months following surgery. CONCLUSION: The transcutaneous osseointegrated bone conduction device may represent a more cost-effective method of hearing rehabilitation compared to the percutaneous osseointegrated bone conduction device.

Cytotoxicity and bioactivity of various pulpotomy materials on stem cells from human exfoliated primary teeth.

AIMS: To investigate the cytotoxicity and bioactivity of several pulpotomy materials: Biodentine (Septodont, Saint-Maur-des-Fosses, France) MTA (Angelus, Londrina, PR, Brazil), Theracal LC (Bisco Inc., Schamburg, IL, USA) and IRM (Dentsply DeTrey GmbH, Konstanz, Germany), after contact with stem cells isolated from human exfoliated primary teeth (SHEDs). METHODOLOGY: SHEDs were cultured in the presence of the eluates of various pulpotomy materials for 24, 48 and 72 h. Cell viability was determined by mitochondrial dehydrogenase enzymatic (MTT) assay. Apoptosis and changes in cell phenotype were evaluated by flow cytometry. Also, an in vitro scratch wound-healing assay was used to determine their effects on cell migration. To assess cell morphology and attachment to the different pulpotomy materials, SHEDs were directly seeded onto the material surfaces and analysed by scanning electron microscopy (SEM). Finally, the deposition of a calcified matrix in presence of these materials was verified by Alizarin Red staining. Statistical analysis was performed with analysis of variance and Bonferroni or Tukey post-test (α = 0.05). RESULTS: Cell viability in the presence of Biodentine eluates was significantly higher to that obtained using complete medium alone (control; P < 0.01) and was also significantly higher than using MTA Angelus from 48 h of incubation (P < 0.01). However, Theracal LC and IRM were associated with low rates of cell viability (P < 0.001). Similar results were obtained in an apoptosis assay. In addition, SHEDs maintained their mesenchymal phenotype in all conditions although their capacity to migrate was higher in the presence of Biodentine. SEM studies revealed a suitable proliferation rate, cell spreading and attachment, especially when using Biodentine and MTA Angelus discs. Finally, Biodentine eluates significantly induced calcified matrix deposition from 7 days of culture (P < 0.01). CONCLUSIONS: Biodentine exhibited better cytocompatibility and bioactivity than MTA Angelus, Theracal LC and IRM.

Evaluation of cytocompatibility of calcium silicate-based endodontic sealers and their effects on the biological responses of mesenchymal dental stem cells.

AIM: To investigate in vitro the cytocompatibility of the calcium silicate-containing endodontic sealers MTA Fillapex and TotalFill BC Sealer on human periodontal ligament stem cells (hPDLSCs) by assaying their biological responses and compare them with that observed when using an epoxy resin-based sealer (AH Plus). METHODOLOGY: Specimens from the three different endodontic sealers were eluated with culture medium for 24 h. The cytotoxicity of these eluates was evaluated using the MTT assay. In addition, an in vitro scratch wound healing model was used to determine their effects on cell migration. Cell adhesion to collagen type I after treatment with the different sealer eluates was also measured, whereas cytotoxicity was determined using the DNA-specific fluorochrome Hoechst 33342. Finally, to assess cell morphology and attachment to the different sealers, hPDLSCs were directly seeded onto the material surfaces and analysed by scanning electron microscopy (SEM). One-way analysis of variance (anova) followed by a Bonferroni post-test were performed (P < 0.05). RESULTS: hPDLSCs exposed to different dilutions of TotalFill BC Sealer eluates had significantly higher cell proliferation compared with that observed when cells were treated with AH Plus and MTA Fillapex eluates (P < 0.001). In addition, TotalFill eluates were associated with significantly increased cell adhesion to collagen type I and migration of hPDLSCs in a concentration-dependent manner than displayed after treatment with MTA Fillapex or AH Plus eluates (P < 0.001). Moreover, TotalFill BC Sealer-induced cytotoxicity was significantly lower than observed using AH Plus and MTA Fillapex eluates (P < 0.001). Finally, SEM studies revealed suitable proliferation, cell spreading and attachment, especially when using TotalFill BC Sealer discs. CONCLUSION: TotalFill BC Sealer exhibited a higher cytocompatibility than AH Plus and MTA Fillapex. Further investigations using in vivo animal models are required to validate the potential biological responses of TotalFill BC Sealer on hPDLSCs.

Toxicity and efficacy of busulfan and fludarabine myeloablative conditioning for HLA-identical sibling allogeneic hematopoietic cell transplantation in AML and MDS.

The safety and efficacy of a 4-day myeloablative conditioning (MAC) regimen consisting of Bu 3.2 mg/kg and fludarabine 40 mg/m(2)/day for HLA-identical sibling allogeneic hematopoietic cell transplantation (HCT) in myeloid malignancies was investigated in 133 patients (median age, 47 years; range 19-74 years) with de novo AML (60%), secondary AML (20%) or myelodysplastic syndrome (20%). All patients engrafted. Hepatic veno-occlusive disease occurred in five patients (4%), and severe toxicities, mostly mucositis, occurred in twenty-three (17%) patients. The non-relapse mortality (NRM) at 100 days was 1.5%. The incidences of acute GVHD grade 2-4 and grade 3-4 were 32 and 13%, respectively. At a median follow-up of 38 months, the cumulative incidence of chronic GVHD was 67%. The relapse incidence was 30% (27 and 31%, respectively, in patients with early- and late-stage disease), and the overall NRM was 15%. The actuarial 4-year disease-free survival (DFS) and overall survival (OS) were 54 and 62%, respectively. Patients aged <50 years had better outcomes compared with older patients (DFS 64 vs 42%, P=0.006; OS 73 vs 47%, P<0.001, respectively).

Effects of composite films of silk fibroin and graphene oxide on the proliferation, cell viability and mesenchymal phenotype of periodontal ligament stem cells.

In regenerative dentistry, stem cell-based therapy often requires a scaffold to deliver cells and/or growth factors to the injured site. Graphene oxide (GO) and silk fibroin (SF) are promising biomaterials for tissue engineering as they are both non toxic and promote cell proliferation. On the other hand, periodontal ligament stem cells (PDLSCs) are mesenchymal stem cells readily accessible with a promising use in cell therapy. The purpose of this study was to investigate the effects of composite films of GO, SF and GO combined with fibroin in the mesenchymal phenotype, viability, adhesion and proliferation rate of PDLSCs. PDLSCs obtained from healthy extracted teeth were cultured on GO, SF or combination of GO and SF films up to 10 days. Adhesion level of PDSCs on the different biomaterials were evaluated after 12 h of culture, whereas proliferation rate of cells was assessed using the MTT assay. Level of apoptosis was determined using Annexin-V and 7-AAD and mesenchymal markers expression of PDLSCs were analyzed by flow cytometry. At day 7 of culture, MTT experiments showed a high rate of proliferation of PDLSCs growing on GO films compared to the other tested biomaterials, although it was slightly lower than in plastic (control). However PDLSCs growing in fibroin or GO plus fibroin films showed a discrete proliferation. Importantly, at day 10 of culture it was observed a significant increase in PDLSCs proliferation rate in GO films compared to plastic (P < 0.05), as well as in GO plus fibroin compared to fibroin alone (P < 0.001). Flow cytometry analysis showed that culture of PDLSCs in fibroin, GO or GO plus fibroin films did not significantly alter the level of expression of the mesenchymal markers CD73, CD90 or CD105 up to 168 h, being the cell viability in GO even better than obtained in plastic. Our findings suggest that the combination of human dental stem cells/fibroin/GO based-bioengineered constructs have strong potential for their therapeutic use in regenerative dentistry.

Effects of two low-shrinkage composites on dental stem cells (viability, cell damaged or apoptosis and mesenchymal markers expression).

To investigate the effects of new two low-shrinkage composites SDR(®) and Venus(®)Bulk Fill on the cell viability, cellular damage and expression of mesenchymal markers on dental stem cells. Specimens from two low-shrinkage composites were eluted with culture medium for 24 h. After 24 h of incubation, cytotoxicity of elutes were evaluated by MTT assay; apoptosis was determined using the DNA-specific fluorochrome Hoechst 33342 and the mesenchymal stem cells markers expression was analyzed by immunofluorescence staining. After 24 h of cell exposure to each extract media, dental stem cells expressed MSCs markers. The interaction among the material and cell line was not significantly correlated [F(1,60) = 2.251, P = 0.39], whereas statistically significant differences among cells lines were observed [F(1,60) = 9.157, P = 0.004], being dental pulp stem cells more resistant that periodontal ligament stem cells. Also, we did not find any significant effect between the tested materials [F(1,60) = 0.090, P = 0.765]. Furthermore, a very low proportion of exposed cells showed condensed or fragmented nuclei, typical of apoptotic cells at 24 h. The results suggest that SDR(®) and Venus(®) Bulk fill and should be considered when selecting an appropriate resin-based dental restorative material.

Tissue engineering with dental pulp stem cells: isolation, characterization, and osteogenic differentiation.

INTRODUCTION: Dental pulp stem cells (DPSCs) are adult mesenchymal stem cells that have the ability to differentiate into osteoblasts, a fact that is very interesting in the context of tissue engineering. Our purpose was to isolate and characterize DPSCs and to compare the differentiation potential of 3 different osteogenic media. PATIENTS AND METHODS: Human dental pulp extracted from healthy young adults was placed in flasks with a mesenchymal expansion medium. At passage 4 DPSCs were analyzed for cell-cycle stage, proliferation, viability, and immunophenotype. DPSCs were grown in 3 different osteogenic media for 40 days. Flasks were incubated at 37 °C in 5% CO2, and the medium was changed twice a week. At day 40, the mineralization of the matrix was determined with Alizarin Red S dye. RESULTS: After osteogenic induction, DPSCs developed mineralization nodules (clusters), as revealed by Alizarin Red staining. This staining was stronger in the Osteodiff (Miltenyi) medium when compared to the other osteogenic media. CONCLUSIONS: This study demonstrates the ability of DPSC to differentiate into osteoblasts, especially in the presence of Osteodiff (Miltenyi). DPSCs are therefore a good candidate model for the study of hard-tissue mineralization.