Chitosan sponges loaded with metformin and microalgae as dressing for wound healing: A study in diabetic bio-models.

Among the conditions caused by diabetes, the diabetic foot is a significant public health problem due to its delayed healing process. That makes it essential to design, manufacture, and apply auxiliary dressings during healing. In this work, chitosan sponges were developed and evaluated as wound dressings. Metformin, fucoidan, and exopolysaccharide from Porphyridium purpureum algae were loaded into the sponges and studied as healing promoters. The composite sponges were physicochemically, morphologically, and thermally characterized, allowing us to determine the chemical mechanisms involved in the sponge formation. The mechanical analysis demonstrated that sponge composites have shape memory and good mechanical performance under compression stress, showing a compressive strength above 30 kPa. These results correlated with the materials' porosity, influencing the swelling capacity that reached a maximum of 70 %. The morphology of materials was observed by SEM, resulting in folded films with surface porosity. The results of the biocompatibility tests confirmed that the materials are not cytotoxic or hemolytic and have good antibacterial activity. In vivo wound healing evaluation showed that metformin-loaded chitosan sponges regenerated skin tissue after 21 days of treatment, highlighting the rate of healing provided when exopolysaccharide was added to promote tissue regeneration, which can be corroborated by histological analysis. These results make chitosan sponge compounds promising dressings for diabetic foot wound treatment.

Morphological changes and Mitochondrial alterations on Cardiomyocytes exposed to Fluoride.

OBJECTIVE: To evaluate the morphological changes of cardiomyocytes exposed to different sodium fluoride (NaF) concentrations, as well as to evaluate the behavior of the mitochondria. METHODS: Rat H9c2 cardiomyocytes were exposed to NaF at concentrations of 0.5 to 5 mmol/L. The morphology and number of mitochondria in these cells were monitored, and the calcium ion (Ca2+) concentration was determined. RESULTS: Morphological changes were evident in the cells treated with different NaF concentrations, and both the number of mitochondria and the Ca2+ concentration decreased in a dose-dependent manner. CONCLUSION: Sodium fluoride induced morphological damage in cardiomyocytes, decreases the Ca2+ concentration and mitochondrial number.

Evaluation of the sealing capability and morphological fit of prefabricated dowels and fiber-reinforced composite resin: An in vitro study.

STATEMENT OF PROBLEM: Prefabricated dowels do not always provide intraradicular sealing in the root canal dentin, and the lack of sealing predisposes the dowel to adhesive failure and debonding. It is unclear if fiber-reinforced composite resin dowels provide better sealing. PURPOSE: The purpose of this in vitro study was to evaluate the intraradicular sealing and morphological fit of prefabricated dowels and fiber-reinforced composite resin dowels in root canal dentin. The thickness of the resin cement layer and push-out bond strength were determined to assess their effects on the sealing of the dowels. MATERIAL AND METHODS: A total of 50 permanent maxillary central incisors were endodontically treated and divided into 2 subgroups (n=25). In one group, prefabricated dowels were cemented; in the second group, fiber-reinforced composite resin dowels were placed. The thickness of the resin cement layer was assessed in 3 different locations: coronal, middle, and apical of the root canal dentin with fluorescence confocal laser microscopy. The push-out bond strength was then determined, and intraradicular sealing observed by using scanning electron microscopy. RESULTS: Fiber-reinforced composite resin dowels showed a closer intraradicular fit and seal in the root canal dentin, and the morphology of the apical portion of the fiber-reinforced composite resin dowels showed a sealing area with the gutta percha in the apical portion. The mean thickness of the resin cement layer was significantly reduced for the fiber-reinforced composite resin dowels compared with the prefabricated dowels (P<.05) in the cervical area (197.0 µm versus 311.0 µm) and in the apical portion of the root canal (57.3 µm versus 131.6 µm). The mean push-out strength was higher for the fiber-reinforced composite resin dowels (22.98 N/mm2) than that for the prefabricated dowels (16.49 N/mm2) (P<.05). CONCLUSIONS: The morphological fit of fiber-reinforced composite resin dowels provides better intraradicular sealing in the cervical and apical portions, reducing the resin cement thickness. The increased push-out strength can therefore be assumed to result from increased frictional retention compared with prefabricated dowels.

Surface degradation and biofilm formation on hybrid and nanohybrid composites after immersion in different liquids.

PURPOSE: This study evaluated the association of surface degradation and formation of Streptococcus mutans (S. mutans) biofilm in resin-based composites (RBCs) after storage in different acidic liquids. METHODS: To evaluate microhardness and surface micromorphology, hybrid and nanohybrid RBC discs were stored in artificial gastric acid, cola drink, orange juice, artificial saliva, and distilled water for three intervals of 15 min per day for 7, 15, and 30 days. After 30 days of storage, surface roughness was analyzed, and the RBC discs were placed in a biofilm reactor inoculated with S. mutans to evaluate surface biofilm formation. RESULTS: As compared with nanohybrid RBCs, roughness and surface microhardness values were significantly lower (P < 0.05) for hybrid RBCs stored in artificial gastric acid, followed by specimens stored in cola drink and orange juice. Artificial gastric acid caused greater surface degradation, which increased the biomass of S. mutans on the surface of both RBC types. CONCLUSION: Surface degradation of hybrid and nanohybrid RBCs correlated with the pH of the liquid, while S. mutans biofilm formation was associated with increased surface roughness in hybrid RBCs.

MTA-Based Cements: Biocompatibility and Effects on the Gene Expression of Collagen Type 1 and TGF-ß1.

Objective: This study sought to evaluate the biocompatibility of Neomineral Trioxide Aggregate (Neo-MTA), MTA Repair High Plasticity (MTA-HP), and Mineral Trioxide Aggregate-Angelus white (MTA-Ang) in fibroblasts of human dental pulp. Materials and Methods: Morphology was evaluated after 24 h of incubation. LIVE/DEAD assay and cell adhesion tests were performed at 24 h of treatment. Cell proliferation assays (MTSs) and Annexin V were performed at 48 h incubation with different treatments. The expression of Col-1 and TGF-ß1 was tested by endpoint PCR at 5 days of treatment. Results: Morphological changes were observed in all groups. Neo-MTA and MTA-Ang were associated with increased cell viability, and all materials induced apoptosis, with a higher percentage in the MTA-HP group than in the other groups. In the LIVE/DEAD assay, there was more damage to the cell membrane in the group of cells treated with MTA-HP than in the other groups. Conclusion: Neo-MTA and MTA-Ang presented similar biocompatibility, and both showed greater biocompatibility than MTA-HP. MTA-HP and MTA-Ang increased Col-1A gene expression, and Neo-MTA and MTA-Ang increased TGF-ß1 gene expression in a similar way.

Effect of 4-Allyl-1-hydroxy-2-methoxybenzene (eugenol) in the expression of genes involved in cellular cycle and apoptotic process in dental pulp fibroblasts.

OBJECTIVE: This study sought to evaluate the effect of eugenol on the cell morphology and expression of genes involved in the apoptotic process in human dental pulp fibroblasts (hDPFs) from deciduous teeth. MATERIALS AND METHODS: hDPFs were cultured with 4 concentrations of eugenol (0.06 nM, 0.6 nM, 6 nM, 12 nM) and compared with a control group. After a 72 h incubation period, the cytotoxic effect on cell morphology by optical microscopy and gene expression by RT-PCR were evaluated. RESULTS: At 0.06 nM and 0.6 nM eugenol concentrations, vacuolisation of the cytoplasm was observed with atypical granulation of the hDPFs, and, at 6 nM and 12 nM cytoplasmic extensions disappeared almost completely. Casp-3, Casp-9, and telomerase genes were not expressed at the concentrations evaluated nor in the control group. The relative expression responses of Bcl-2 and TGF-ß genes were overexpressed at the 4 concentrations. MAKP's 0.06 nM (p < .001), 0.6 nM (p < .05) and 12 nM (p < .05) and Cyclin 1 at 12 nM showed significant difference versus the control group (p < .05). CONCLUSION: Eugenol is capable of causing morphological changes in hDPFs in a dose-dependent manner, higher concentrations may promote overexpression of apoptotic genes.

Effect of tricalcium silicate cements in gene expression of COL1A1, MAPK's, and NF-kB, and cell adhesion in primary teeth' pulp fibroblasts.

Tricalcium silicate cements (TSCs) regulate gene expression and cell responses from dental tissues surrounding the repair site. The study aimed to evaluate the gene expression levels of Collagen Type I Alpha 1 Chain (COL1A1), Mitogen-Activated Protein Kinases (MAPK's), Nuclear Factor-Kappa B (NF-κB), cell adhesion, and morphology of human dental pulp fibroblasts (hDPFs) from primary teeth treated with eluates obtained from Mineral Trioxide Aggregate (MTA) and Biodentine. hDPFs were treated with eluates from Biodentine and MTA (2.5 mg/mL in culture medium). The control group was a culture without the eluates. Gene expressions of COL1A1, MAPK's, and NF-κB were evaluated using Polymerase Chain Reaction (PCR) and cell adhesion by immunocytochemistry for Vinculin and Integrin ß1 expression. Gene expression of MAPK's and NF-κB in hDPFs with the eluates from MTA and Biodentine showed no significant difference versus the control group (p > 0.05), but COL1A1 exhibited a significant difference (p < 0.05). The expression of COL1A1, MAPK's, and NF-κB was lower in cultures with MTA and Biodentine eluates regarding the control group, with no significant difference between MTA and Biodentine (p > 0.05). After 72 h of incubation, the hDPFs cultured with MTA and Biodentine eluates showed an elongated morphology; after 7 d, a loss or/and reduction of the cytoplasmic processes, and smaller nuclei were observed. Vinculin and Integrin ß1 were expressed in hDPFs treated with MTA and Biodentine eluates. MTA and Biodentine did not inhibit or generate a significant difference in the expression levels of COL1A1, MAPK's, and NF-κB in hDPFs.

Morphological and biological properties of silica nanoparticles for CRTC3-siRNA delivery and downregulation of the RGS2 expression in preadipocytes.

The aim of this study was to characterize the morphological properties of amorphous silica nanoparticles (SiO2 NPs), their cytotoxicity and intracellular location within Human Osteoblasts (HOB). Additionally, SiO2 NPs were explored for their effectivity as carriers of CRTC3-siRNA on Human Preadipocytes (HPAd), and thus downregulate RGS2 gene expression. SiO2 NPs were synthesized using the method of Stöber at 45 °C, 56 °C, and 62 °C. These were characterized via TEM with EDS, Zeta Potential and FT-IR. Cytotoxicity was evaluated by XTT at three concentrations 50, 100 and 500 µg/mL; SiO2 NPs intracellular localization was observed through Confocal Laser Scanning Microscope. Delivering siRNA effectivity was measured by RT-qPCR. Morphology of SiO2 NPs was spherical with a range size from 64 to 119 nm; their surface charge was negative. Confocal images demonstrated that SiO2 NPs were located within cellular cytoplasm. At a SiO2 NPs concentration of 500 µg/mL HOB viability decreased, while at 50 µg/mL and 100 µg/mL cell viability was not affected regardless SiO2 NPs size. SiO2 NPs-CRTC3-siRNA are effective to down-regulate RGS2 gene expression in HPAd without cytotoxic effects. The developed SiO2 NPs-CRTC3-siRNA are a promising tool as a delivery vehicle to control obesity.

Calcium hydroxide/iodoform nanoparticles as an intracanal filling medication: synthesis, characterization, and in vitro study using a bovine primary tooth model.

The aims of this in vitro study were to synthesize, characterize, and evaluate the efficacy of a Calcium Hydroxide/Iodoform nanoparticles (CHIN) paste compared with Ultrapex as intracanal filling medication using an experimental model of bovine primary teeth. CH nanoparticle synthesis was performed via the simple hydrolysis technique of reacting calcium nitrate with sodium hydroxide. SEM-EDS and FT-IR analyses were used to characterize the obtained product. 30% of CH nanoparticles were combined with 40% of iodoform and 30% silicone oil to prepare an intracanal filling paste (CHIN). All endodontic procedures were performed on 34 uniradicular primary bovine teeth. Every root canal was instrumented with K files (up to #35) and obturated with the nanoparticle paste (experimental) or Ultrapex® (control). Three outcome variables were studied: penetration depth through the root dentinal tubules, Ca2+ ion release, and filling paste dissolution rate. The obtained data were analyzed by Student's t test. The X-ray diffraction pattern of CH nanoparticles showed characteristic peaks at CH, as confirmed by FT-IR analyses in which an intense signal was observed at 3643 cm-1, characteristic of CH. In the morphological characterization, CH particles could be detected at the nanosize scale. When applied as intracanal filling, the CHIN paste exhibited a higher level of penetration through the root dentin tubules. The global mean penetration measures were 500 µm for the experimental paste and 380 µm for the control paste (p < 0.05). The release of Ca2+ ions (up to the seventh day) and the dissolution rate were significantly higher in the experimental paste group than in the control group. No significant differences were observed between the groups regarding pH levels. The findings of this study suggest the potential suitability of CHI nanoparticles as an alternative intracanal filling medication for infected or devitalized primary teeth.

Gene expression profile involved in signaling and apoptosis of osteoblasts in contact with cellulose/MWCNTs scaffolds.

The aim of this work was to evaluate the expression profile of genes involved in signaling, intracellular and extracellular Ca+2 concentration and apoptosis pathways of osteoblasts in contact with a scaffold made of a composite of BCN/MWCNTs. Osteoblasts were cultivated on BCN, MWCNTs and their mixtures. Osteoblast RNA was extracted for sintering cDNA to amplify genes of interest by PCR; intra- and extracellular calcium (Ca2+) was also quantified. Regarding the genes that participate in the regulation paths (MAPK and NF-KB), it was found that only the expression of NF-KB was affected in all treatments. The expression of VEGFA increased, except in the treatment of high concentration of MWCNTs, where remained unchanged. The expression of genes Apaf-1 and Bcl-2/Bax and TP53 increased as compared to the control (except for TP53 in BC and C1/MWCNTs) indicating that cells are responding to the presence of BCN-MWCNTs composites scaffolds. The results suggest that osteoblast developed a modification in the expression profile of genes that actively participate in cellular processes such as proliferation, vasculogenesis and apoptosis, which may be modulated by the increase of intra- and extracellular Ca2+ concentration.

Evaluation of the Bond Strength and Marginal Seal of Indirect Restorations of Composites Bonded with Preheating Resin.

OBJECTIVE: Preheated resins (PR) are considered a cementing agent option for indirect adhesive restorations of composite inlays and onlays. The objective of this in vitro study was to evaluate the marginal sealing, adhesive interface, and microtensile bond strength of indirect adhesive restorations of composites in terms of dentin cemented with PR. MATERIALS AND METHODS: Standardized Class II preparations were performed on 30 extracted human premolars, impressions were taken, and indirect composite restorations were manufactured. In total, 15 restorations were cemented with PR (ENA HRi, SYNCA), and 15 restorations were cemented with self-adhesive resinous cement (RC) (Relyx U200, 3M ESPE), followed by a thermocycling regime. After that, these were segmented sagittally and longitudinally to evaluate the marginal sealing and the adhesive interface with scanning electron microscopy and confocal microscopy. Microtensile bond strength was assessed with a mechanical device (TA. XT Plus C, Stable Micro System). STATISTICAL ANALYSIS: Statistical analysis was conducted using the two-sample Student's t-test. RESULTS: The results showed that there is no statistically significant difference in the degree of microfiltration using PR or RC; however, microtensile bond strength is greater when the restoration is cemented with RC (278.75 N/cm3) than with PR (144.49 N/cm3), and better adjustment and sealing were observed for composite restorations with PR. CONCLUSION: PR comprise an alternative cementing agent for indirect composite restorations in Class II cavities in premolars.

Synergistic interaction between 4-allyl-1-hydroxy-2-methoxybenzene (eugenol) and diclofenac: An isobolograpic analysis in Wistar rats.

Clinical and preclinical research that contributes pain palliation has suggested that drugs favor the expected effects and minimize the adverse effects. Among the most widely used strategies is the combination of analgesic drugs among those in the same group, with those in another group of analgesics or with co-adjuvants (nonanalgesic drugs or elements of traditional medicine). This work aims to evaluate the interaction between eugenol (EUG) and diclofenac (DFC) on nociception in the presence of a noxious stimulus through the formalin test and isobolographic analysis. The results indicate that EUG, DFC, or the combination of both produce an antinociceptive effect in rodents (p ≤ 0.05). Local co-administration of EUG and DFC gave a theoretical effective dose (Zadd ) 2,936.27 ± 155.33 µg/kg (p ≤ 0.05) significantly higher as compared to the effective experimental doses (Zmix ) of 866.89 ± 0.02 µg/kg in phase 1 and 292.88 ± 0.05 µg/kg in phase 2, with an interaction index of 0.29 and 0.09, respectively. These data allow concluding that the interaction derived from the joint administration of EUG and DFC, in the rodent at a local level, is synergistic.

The Effect of PEGDE Concentration and Temperature on Physicochemical and Biological Properties of Chitosan.

Chitosan (CHT) is a polysaccharide with multiple claimed properties and outstanding biocompatibility, generally attributed to the presence of protonable amino groups rendering a cationic natural polymer. However, the effect of changes in CHT structure due to hydration is not considered in its performance. This study compares the effects on biocompatibility after drying at 25 °C and 150 °C scaffolds of chitosan, polyethylene glycol diglycidyl ether (PEGDE) crosslinked CHT (low, medium and high concentration) and glutaraldehyde (GA) crosslinked CHT. PEGDE crosslinked CHT showed a reduction in free amino groups and the amide I/II ratio, which exhaustive drying reduced further. In X-ray diffraction (DRX) analysis, PEGDE crosslinked CHT showed multiple peaks, whereas the crystallinity percentage was reduced with an increase in PEGDE concentration and thermal treatments at 150 °C. In a direct contact cell assay, high osteoblast viability was achieved at low and medium PEDGE concentrations, which was improved when the crosslinked scaffolds were thermally treated at 150 °C. This was attributed to its partial hydrophilicity, low crystallinity and low surface roughness; this in spite of the small reduction in the amount of free amino groups on the surface induced during drying at 150 °C. Furthermore, PEGDE crosslinked CHT scaffolds showed strong vinculin and integrin 1ß expression, which render them suitable for bone contact applications.

Quantification of TNF-α in Patients with Periodontitis and Type 2 Diabetes.

OBJECTIVE: The present study aimed to compare variations in quantified tumor necrosis factor-alpha (TNF-α) levels in patients with periodontitis stage 2 grade B (POD2B) and/or type 2 diabetes (T2D) and to identify any relationships between this cytokine and these diseases. METHODS: Levels of the cytokine TNF-α in gingival crevicular fluid in patients with POD2B and/or T2D were evaluated. A total of 160 subjects were distributed into four groups: those with POD2B (n=44); those with T2D (n=37); those with POD2B/T2D (n=40); and healthy subjects (n=39). Glycosylated hemoglobin (HbA1c) and blood glucose (BG) levels were quantified in each subject. Data were collected on body mass index (BMI), loss of insertion (LI), and probe depth (PD). Gingival crevicular fluid samples were collected from the most acutely affected periodontal pocket and gingival sulcus in each subject, and TNF-α was quantified by multiplex analysis. RESULTS: Kruskal Wallis tests was used to identify differences in TNF-α levels, LI, PD, BMI, BG, and HbA1c by group. Differences (p<0.001) were found for LI, PD, BG, and HbA1c. A Spearman test was used to calculate possible correlations between TNF-α levels and LI or PD identified a weak but significant negative correlation of TNF-α with LI (Rho=-0199; p=0.012), and a moderately positive correlation of LI with PD (Rho=0.509; p < 0.001). CONCLUSIONS: No variation was found between TNF-α levels and the presence of POD2B, POD2B/T2D, or T2D, suggesting the absence of any direct relationship between progression of these diseases and TNF-α levels. However, a correlation was present between low TNF-α concentrations and greater LI.

RGD-functionalization of PLA/starch scaffolds obtained by electrospinning and evaluated in vitro for potential bone regeneration.

The engineering of bone tissues represents an area of opportunity for the development of new polymeric compounds. In this context, the objective of this work is the generation and evaluation in vitro of supports obtained from mixtures of starch with poly (lactic acid) (PLA), treated with arginine-glycine-aspartic acid peptides (RGD). For this, non-woven fibers of PLA with different starch content (0.0, 2.5, 5.0 and 10.0%wt) were obtained using the electrospinning technique. Then the physical absorption of RGD was carried out, with the aim of increasing the cellular adhesion of the polymeric material. Subsequently, in vitro biocompatibility tests were performed, and viability (LIFE/DEAD), proliferation (MTS assay) and cell adhesion were carried out with osteoblasts incubated for 48 h. Regarding biocompatibility results, only viable cells were found for all the compositions, and the biocompatibility of the materials was validated by the morphological analysis of the cultured cells, where extended cells were observed. Proliferation assays show that osteoblasts proliferate better on the surfaces of PLA and PLA with 5.0% starch scaffolds. Therefore, it is concluded that the scaffolds obtained by electrospinning of PLA with starch and functionalized with RGD are promising for its use in the regeneration of bone tissue.

Calcium sustained release, pH changes and cell viability induced by chitosan-based pastes for apexification.

We explored chitosan-based sustained release pastes for apexification. The study aimed to formulate chitosan-based pastes loaded with calcium hydroxide (CH) or with calcium chloride (CC), and to evaluate the sustained release of Ca2+ and pH changes in deionized water as well as the effect of the pastes on cell viability. The pastes were formulated by dissolution of the chitosan in 1% or 2% acetic acid (AAC) plus the addition of CH or CC, then were suspended in deionized water for 50 days; the released Ca(II) and pH were measured with an electrode probe. The effect of the pastes on viability of human dental pulp cells was evaluated with a MTS assay. The results showed that the pastes prepared with 1% and 2% AAC and loaded with CH released a 74.9% and a 76.1% of the Ca2+ content, respectively, while the pastes prepared with 1% and 2% AAC loaded with CC released a content of Ca2+ of 90.8% and 76.6%, respectively. A control paste (CH and polyethylene glycol) released a 95.4%; significant statistical differences were found between the percentage of the experimental pastes and the control. The CH-loaded pastes caused an alkaline pH at the starting of the study, but the pH became neutral at the ending. The pH of the CC-loaded pastes was neutral at the starting and was acid at the ending. The pastes no affected on the cell viability. The chitosan-based pastes showed a suitable sustained release profile and cytocompatibility.

Cytotoxicity, Cell Adhesion, and Apoptotic Gene Expression in Periodontal Ligament Fibroblasts treated with Endodontic Sealers.

OBJECTIVE: The present study assessed cytotoxicity, cell adhesion, and apoptotic gene expression in periodontal ligament fibroblasts (PLF) treated with 2 endodontic sealers. METHODS: PLF cells were obtained from nonerupted third molars and cultured. MTS and LIVE/DEAD assays were performed using different treatments and time periods. Cellular adhesion was evaluated using immunocytochemistry for integrin ß1 and vinculin expression, and the gene expressions of nuclear factor kB (NF-кB), P53, and apoptotic protease-activating factor 1 (Apaf-1) were evaluated using PCR. RESULTS: Cell proliferation at 12, 24, and 48 h was statistically significant in the control and PLF groups receiving different treatments; PLF treated with culture medium containing non-hardened (NH) sealers showed a decrease in the number of cells. PLF treated with culture medium containing hardened (H) sealers also exhibited a decreased cell population. Integrin ß1 and vinculin were expressed in both cell cultures treated with Acroseal (NH and H); however, the cell morphology changed and the cell population decreased. The gene expression of NF-kB and that of P53 were significantly different between the control group and the groups treated with the different sealers; mineral trioxide aggregate (MTA) (NH and H) inhibited Apaf-1, and PLF treated with Acroseal H exhibited increased Apaf-1 expression. CONCLUSION: Both sealers showed a certain level of cytotoxicity. The gene expression of NF-κB and P53 in PLF treated with the sealers showed significant changes compared to that of the control group, and MTA inhibited Apaf-1.

AMPA receptors modulate the reorganization of F-actin in Bergmann glia cells through the activation of RhoA.

Alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid glutamate receptors have been shown to modulate the morphology of the lamelar processes of Bergmann glia cells in the molecular layer of the cerebellum. Here we suggest that reorganization of F-actin may underlay the changes in the morphology of the lamelar processes. Using the fluorescent staining of F-actin with Phalloidin and the quantification of RhoA activation through immunoprecipitation or pull-down assays, we show that RhoA is activated after stimulation of alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptors and leads to the reorganization of the actin cytoskeleton of Bergmann fibers. This reorganization of the actin cytoskeleton is reflected in the form of an increase in the intensity of the F-actin staining as well as in the loss of the number of Bergmann fibers stained with Phalloidin. Moreover, using a pharmacological approach, we show that activation of RhoA and the change in the intensity of the F-actin staining depends on the activation of PI3-K, focal adhesion kinase, and protein kinase C, whereas changes in the number of Bergmann fibers depend on external calcium in a RhoA independent manner. Our findings show that glutamate may induce a form of structural plasticity in Bergmann glia cells through the reorganization of the actin cytoskeleton. This may have implications in the way the synaptic transmission is processed in the cerebellum.

Bioactive Tricalcium Silicate-based Dentin Substitute as an Indirect Pulp Capping Material for Primary Teeth: A 12-month Follow-up.

PURPOSE: The purpose of this study was to evaluate the clinical and radiographic outcomes of a bioactive tricalcium silicate [Ca3SiO5]-based dentin substitute and a light-activated calcium hydroxide [Ca(OH)2]-based liner as indirect pulp treatment (IPT) interventions for vital primary molars with carious lesions approaching the pulp. METHODS: Eighty children, aged four to eight years old, with 160 bilateral primary teeth without signs or symptoms of irreversibly inflamed or degenerative pulp tissue were treated in a split-mouth design trial comparing IPT using Ca3SiO5 or Ca(OH)2. The teeth were treated and restored with a preformed crown in a single session and assessed clinically and radiographically for one, three, six, and 12 months. RESULTS: Sixty patients with 120 treated molars completed the 12-month evaluations. The combined clinical and radiographic success rates were 98.3 percent (59 out of 60) for Ca3SiO5 and 95 percent for Ca(OH)2 (57 out of 60). No significant differences were found for success rates between the two study groups (P>0.05). The combined success rates for both groups was 96.7 percent. CONCLUSIONS: These results suggest that the indirect pulp treatment procedure with either a bioactive Ca3SiO5-based dentin substitute or a Ca(OH)2-based material may be considered a suitable treatment to achieve acceptable therapeutic results when applied on deeply carious primary teeth without degenerative symptoms.

In vitro evaluation of osteoblastic cells on bacterial cellulose modified with multi-walled carbon nanotubes as scaffold for bone regeneration.

In this paper we explore the use of native bacterial cellulose (BC) in combination with functionalized multi-walled carbon nanotubes (MWNTs) as an original biomaterial, suitable three-dimensional (3D) scaffold for osteoblastic cell culture. Functionalized MWNTs were mixed with native BC (secreted by Gluconacetobacter xylinus) with the aim of reinforcing the mechanical properties of BC. The results indicate that BC-MWNTs scaffolds support osteoblast viability, adhesion and proliferation at higher levels as compared to traditional culture substrates. Chemically functionalized MWNTs are also an excellent material to be used as scaffold because these did not affect cell viability and showed an enhanced osteoblast adhesion. These results suggest the potential for this combination of biomaterials, i.e. BC and carbon nanomaterials, as scaffolds for bone regeneration.