Magnesium (Mg2 +), Strontium (Sr2 +), and Zinc (Zn2 +) Co-substituted Bone Cements Based on Nano-hydroxyapatite/Monetite for Bone Regeneration.

New bone cement type that combines Sr2 + /Mg2 + or Sr2 + /Zn2 + co-substituted nano-hydroxyapatite (n-HAs) with calcium phosphate dibasic and chitosan/gelatin polymers was developed to increase adhesion and cellular response. The cements were physicochemically described and tested in vitro using cell cultures. All cements exhibited quite hydrophilic and had high washout resistance. Cement releases Ca2 + , Mg2 + , Sr2 + , and Zn2 + in concentrations that are suitable for osteoblast proliferation and development. All of the cements stimulated cell proliferation in fibroblasts, endothelial cells, and osteoblasts, were non-cytotoxic, and produced apatite. Cements containing co-substituted n-HAs had excellent cytocompatibility, which improved osteoblast adhesion and cell proliferation. These cements had osteoinductive potential, stimulating extracellular matrix (ECM) mineralization and differentiation of MC3T3-E1 cells by increasing ALP and NO production. The ions Ca2 + , Mg2 + , Zn2 + , and Sr2 + appear to cooperate in promoting osteoblast function. The C3 cement (HA-SrMg5%), which was made up of n-HA co-substituted with 5 mol% Sr and 5 mol% Mg, showed exceptional osteoinductive capacity in terms of bone regeneration, indicating that this new bone cement could be a promising material for bone replacement.

Doxycycline encapsulated in ß-cyclodextrin for periodontitis: a clinical trial.

This clinical trial compared the efficacy of doxycycline (DOX) in ß-cyclodextrin (DOX)/ßCD) with DOX- alone in gel on thirty-three subjects with periodontitis. Patients were randomized to group 1 GI; 10% DOX + scaling and root planning (SRP); group 2 (GII (10% DOX /ß-CD + SRP), and group 3 (GIII; SRP). Gels were applied in GI and GII at baseline (T0) and 30 days later (T1). Periodontal Probing Depth (PPD), Clinical Attachment Level (CAL), Bleeding on Probing (BOP) and Visible Plaque Index (VPI) were evaluated at (T0), 30 days (T1) and 60 days after T0 (T2). Bone density was analyzed after 18 months (T3). GII showed the most significant reduction of PPD (2.62 mm; p <0.003), and greatest gain in CAL (2.54 mm p <0.003) at T2. BOP and the VPI had a strong reduction in all groups at T2 (p <0.05), both decreased by ≥5 times and 2 times, respectively, in all groups at T1. Bone density increased in all groups in radiographs (T3). The use of DOX encapsulated in ß-CD gel with SRP resulted in significant improvements in clinical periodontal parameters; such molecular inclusion of doxycycline into ß-CD in gel for local application is relatively simple and useful in dentistry.

Polycaprolactone nanofibers loaded oxytetracycline hydrochloride and zinc oxide for treatment of periodontal disease.

Periodontal diseases (PD) are mixed bacterial infections caused by microorganisms that colonize the tooth surface, leading to destructions at tooth-supporting tissues. Several local delivery systems, as nanofibers, have been developed for the treatment of PD. The purpose of the present study was developing polycaprolactone (PCL) nanofibers incorporating two antibacterial agents, OTC and ZnO, for use in the treatment of PD. Nanofibers were produced by electrospinning method: PCL loaded with ZnO (PCL-Z), PCL loaded with OTC (PCL-OTC), PCL loaded with OTC and ZnO (PCL-OTCz) and pristine PCL (PCL-P). The nanofibers were characterized physicochemically using different techniques. In addition, in vitro study of the OTC release from the nanofibers was performed. The PCL-OCT showed sustained release of the drug up to 10 h, releasing 100% of OTC. However, the PCL-OTCz nanofiber showed a slow release of OTC up to 120 h (5th day) with 54% of drug retention. The cytotoxicity assay showed that PCL-OTC nanofiber was slightly cytotoxic after 48 h and the other nanofibers were non-cytotoxic. The antibacterial activity of the nanofibers was evaluated by qualitative and quantitative analysis and against mixed bacterial culture, composed of four Gram-negative anaerobic bacteria involved in periodontal diseases. The disk diffusion method showed that the PCL-OTC displayed higher inhibition zone than PCL-OTCz (p < 0.001). The quantitative analysis, evaluated by broth culture, showed that the PCL-OTC and PCL-OTCz exhibited excellent activity against a mixed bacterial culture with growth inhibition of 98.0% and 97.5%, respectively. Based on these results, the PCL-OTCz nanofibers developed have great potential as a drug delivery system for the PD treatment.

Guaiacol/ß-cyclodextrin for rapid healing of dry socket: antibacterial activity, cytotoxicity, and bone repair-an animal study.

PURPOSE: Dry socket (DS) is one the most common and symptomatic post-extraction complications; however, no consensus on its treatment has been reached. This study aimed to develop a novel dressing material for DS containing the phenolic agent guaiacol and evaluate its biological properties. METHODS: An inclusion complex of guaiacol and ß-cyclodextrin (Gu/ßcd) was prepared by freeze-drying. Its antibacterial activity over six oral bacteria was analyzed using the microdilution method, and its cytotoxicity in osteoblasts was assessed with the MTT assay. The alveolar healing process induced by Gu/ßcd was evaluated histologically after the treatment of DS in rats. RESULTS: ßcd complexation potentiated Gu's antibacterial effect and reduced its cytotoxicity in osteoblasts. Bone trabeculae were formed in the alveolar apices of rats treated with Gu/ßcd by day 7. On day 14, woven bone occupied the apical and middle thirds of the sockets; on day 21, the entire alveolus was filled by newly formed bone, which was in a more advanced stage of repair than the positive control (Alvogyl™). CONCLUSION: The improvement in Gu's biological properties in vitro and the rapid alveolar repair in comparison with Alvogyl™ in vivo demonstrated the benefits of the Gu/ßcd complex as a future alternative for the treatment of DS.

Evidence of hypoglycemic, lipid-lowering and hepatoprotective effects of the Bixin and Bixin: ß-CD inclusion compound in high-fat-fed obese mice.

Associations between obesity, diabetes type II, and steatosis have long been recognized. However, a pharmacotherapy that acts in a multifactorial manner controlling the interactions between these conditions is not available. A variety of natural plants, functional fatty acids, and other natural dietary compounds have been used in various anti-obesity products. We investigated the effects of oral administration of an antioxidant carotenoid pigment Bixin and Bixin: ß-Cyclodextrin in an obese murine model. C57BL/6 male mice (4-5 weeks) received standard diet (2.18 kcal per 1 g) (CT) and high-fat diet (4.38 kcal per 1 g) (CT/OB, BIX and BIX/ßCD) (n = 10 per group). After 16 weeks, the BIX and BIX/ßCD were treated by gavage (100 µL day-1) for six weeks, with water (CT and CT/OB groups) and (50 mg kg-1 day-1), Bixin (BIX group) or Bix: ß-CD (BIX/ßCD). Body weight, Lee's Index, adiposity, CHT, TG, CHT/HDL-c, glucose levels (metabolic markers) and, liver markers (AST and ALT) were determined. All metabolic and liver parameters exhibited down-regulation after oral administration of BIX and BIX/ßCD. Particularly relevant was Lee's Index and adiposity in BIX- and BIX/ßCD-treated groups (339.18 g/cm -BIX and 327.58 g/cm -BIX/ßCD vs. 360.68 g/cm -CT/OB animals), this finds associated with the insulin sensitivity test, showed a clear association between reduction of adipose tissue and decrease of peripherical insulin resistant. In conclusion, our study suggested that the oral administration of the Bixin and Bix: ß-CD inclusion compound improved the metabolic parameters evaluate in obese mice, being more palatable and hepatoprotective.

Ocellatin peptides from the skin secretion of the South American frog Leptodactylus labyrinthicus (Leptodactylidae): characterization, antimicrobial activities and membrane interactions.

BACKGROUND: The availability of antimicrobial peptides from several different natural sources has opened an avenue for the discovery of new biologically active molecules. To the best of our knowledge, only two peptides isolated from the frog Leptodactylus labyrinthicus, namely pentadactylin and ocellatin-F1, have shown antimicrobial activities. Therefore, in order to explore the antimicrobial potential of this species, we have investigated the biological activities and membrane interactions of three peptides isolated from the anuran skin secretion. METHODS: Three peptide primary structures were determined by automated Edman degradation. These sequences were prepared by solid-phase synthesis and submitted to activity assays against gram-positive and gram-negative bacteria and against two fungal strains. The hemolytic properties of the peptides were also investigated in assays with rabbit blood erythrocytes. The conformational preferences of the peptides and their membrane interactions have been investigated by circular dichroism spectroscopy and liposome dye release assays. RESULTS: The amino acid compositions of three ocellatins were determined and the sequences exhibit 100% homology for the first 22 residues (ocellatin-LB1 sequence). Ocellatin-LB2 carries an extra Asn residue and ocellatin-F1 extra Asn-Lys-Leu residues at C-terminus. Ocellatin-F1 presents a stronger antibiotic potential and a broader spectrum of activities compared to the other peptides. The membrane interactions and pore formation capacities of the peptides correlate directly with their antimicrobial activities, i.e., ocellatin-F1 > ocellatin-LB1 > ocellatin-LB2. All peptides acquire high helical contents in membrane environments. However, ocellatin-F1 shows in average stronger helical propensities. CONCLUSIONS: The obtained results indicate that the three extra amino acid residues at the ocellatin-F1 C-terminus play an important role in promoting stronger peptide-membrane interactions and antimicrobial properties. The extra Asn-23 residue present in ocellatin-LB2 sequence seems to decrease its antimicrobial potential and the strength of the peptide-membrane interactions.

Efficient cutaneous wound healing using bixin-loaded PCL nanofibers in diabetic mice.

The present work demonstrated an efficient cutaneous wound healing using Bixin-loaded polycaprolactone (PCL) nanofibers as a controlled delivery system. The influence of Bixin (Bix) content on PCL nanofiber, Bix-PCL1(2.5% w/w bix) and Bix-PCL2 (12.5% w/w bix) formation was investigated using electrical conductivity, attenuated total reflectance infrared spectroscopy, X-ray diffraction, thermal analysis, and scanning electronic microscopy. The results showed that a greater bixin concentration resulted in higher polymeric solution electrical conductivity. Moreover, higher polymeric solution electrical conductivity provides lower nanofibers in terms of average diameter than pure PCL nanofibers. In vitro release was largely governed by a diffusion-controlled mechanism. The initial Bixin release domain showed a burst release over the first 10 hours where approximately 30% and 40% of Bixin was released from Bix-PCL1 and Bix-PCL2 nanofibers, respectively. The second kinetic domain was comprised of a continuous and slow Bixin release that led to almost 100% of the Bixin being released within 14 days. The results on excisional wound model in induced diabetic mice indicated that the low concentration of Bixin released from loaded Bix-PCL nanofibers maintain the biological activity of Bixin and is efficient in accelerating the wound healing as well as in reducing the scar tissue area compared with pure PCL nanofibers. Therefore, soft material Bixin-loaded PCL nanofibers are a promising candidate for use in wound dressing. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1938-1949, 2017.

Antibacterial Effect of Synthetic Peptide LyeTxI and LyeTxI/ß-Cyclodextrin Association Compound Against Planktonic and Multispecies Biofilms of Periodontal Pathogens.

BACKGROUND: Antimicrobial peptides (AMPs) have shown rapid and potent effect against planktonic bacteria. However, control of periodontopathic biofilms is a challenge even for AMPs. Thus, the present study evaluates in vitro antimicrobial activity of synthetic peptide LyeTxI and association compound LyeTxI/ß-cyclodextrin (ßCD) against multispecies biofilms. METHODS: Sensibility to LyeTxI and LyeTxI/ßCD was determined for planktonic Gram-negative periodontopathogens. Time-kill kinetic assay was performed at minimum inhibitory concentrations (MICs) in all planktonic strains. Multispecies biofilms were grown on pegs using a biofilm device and studied by scanning electron microscopy at 2, 5, and 10 days. Minimal biofilm eradication concentration (MBEC) was determined for 2- and 4-day multispecies biofilms. Metabolic activity of biofilms was determined by fluorometry study. RESULTS: Biofilms showed reproducible cell density on pegs of the biofilm device. LyeTxI and LyeTxI/ßCD were active against all strains tested at concentrations ≤62.5 µg/mL. Kinetic assays showed rapid bactericidal effect of LyeTxI against all periodontopathogens. MBECs of LyeTxI and LyeTxI/ßCD against multispecies 2-day biofilms were two-fold higher than MICs of cells shed from biofilms. LyeTxI was able to reduce multispecies 2-day metabolic activity by 90%. Multispecies 4-day biofilms were tolerant to all agents tested. CONCLUSIONS: LyeTxI and LyeTxI/ßCD are active against periodontopathic bacteria, showing rapid bactericidal effect and may be used to prevent biofilm development. In the future, AMPs could be therapeutic tools for treatment of periodontitis.

Ocellatin peptides from the skin secretion of the South American frog Leptodactylus labyrinthicus (Leptodactylidae): characterization, antimicrobial activities and membrane interactions

Background The availability of antimicrobial peptides from several different natural sources has opened an avenue for the discovery of new biologically active molecules. To the best of our knowledge, only two peptides isolated from the frog Leptodactylus labyrinthicus, namely pentadactylin and ocellatin-F1, have shown antimicrobial activities. Therefore, in order to explore the antimicrobial potential of this species, we have investigated the biological activities and membrane interactions of three peptides isolated from the anuran skin secretion. Methods Three peptide primary structures were determined by automated Edman degradation. These sequences were prepared by solid-phase synthesis and submitted to activity assays against gram-positive and gram-negative bacteria and against two fungal strains. The hemolytic properties of the peptides were also investigated in assays with rabbit blood erythrocytes. The conformational preferences of the peptides and their membrane interactions have been investigated by circular dichroism spectroscopy and liposome dye release assays. Results The amino acid compositions of three ocellatins were determined and the sequences exhibit 100% homology for the first 22 residues (ocellatin-LB1 sequence). Ocellatin-LB2 carries an extra Asn residue and ocellatin-F1 extra Asn-Lys-Leu residues at C-terminus. Ocellatin-F1 presents a stronger antibiotic potential and a broader spectrum of activities compared to the other peptides. The membrane interactions and pore formation capacities of the peptides correlate directly with their antimicrobial activities, i.e., ocellatin-F1 > ocellatin-LB1 > ocellatin-LB2. All peptides acquire high helical contents in membrane environments. However, ocellatin-F1 shows in average stronger helical propensities. Conclusions The obtained results indicate that the three extra amino acid residues at the ocellatin-F1 C-terminus play an important role in promoting stronger peptide-membrane interactions and antimicrobial properties. The extra Asn-23 residue present in ocellatin-LB2 sequence seems to decrease its antimicrobial potential and the strength of the peptide-membrane interactions.(AU)

Ocellatin peptides from the skin secretion of the South American frog Leptodactylus labyrinthicus (Leptodactylidae): characterization, antimicrobial activities and membrane interactions

Abstract Background The availability of antimicrobial peptides from several different natural sources has opened an avenue for the discovery of new biologically active molecules. To the best of our knowledge, only two peptides isolated from the frog Leptodactylus labyrinthicus, namely pentadactylin and ocellatin-F1, have shown antimicrobial activities. Therefore, in order to explore the antimicrobial potential of this species, we have investigated the biological activities and membrane interactions of three peptides isolated from the anuran skin secretion. Methods Three peptide primary structures were determined by automated Edman degradation. These sequences were prepared by solid-phase synthesis and submitted to activity assays against gram-positive and gram-negative bacteria and against two fungal strains. The hemolytic properties of the peptides were also investigated in assays with rabbit blood erythrocytes. The conformational preferences of the peptides and their membrane interactions have been investigated by circular dichroism spectroscopy and liposome dye release assays. Results The amino acid compositions of three ocellatins were determined and the sequences exhibit 100% homology for the first 22 residues (ocellatin-LB1 sequence). Ocellatin-LB2 carries an extra Asn residue and ocellatin-F1 extra Asn-Lys-Leu residues at C-terminus. Ocellatin-F1 presents a stronger antibiotic potential and a broader spectrum of activities compared to the other peptides. The membrane interactions and pore formation capacities of the peptides correlate directly with their antimicrobial activities, i.e., ocellatin-F1 > ocellatin-LB1 > ocellatin-LB2. All peptides acquire high helical contents in membrane environments. However, ocellatin-F1 shows in average stronger helical propensities. Conclusions The obtained results indicate that the three extra amino acid residues at the ocellatin-F1 C-terminus play an important role in promoting stronger peptide-membrane interactions and antimicrobial properties. The extra Asn-23 residue present in ocellatin-LB2 sequence seems to decrease its antimicrobial potential and the strength of the peptide-membrane interactions.

Oral management of Marfan syndrome: an overview and case report.

Marfan syndrome is an autosomal-dominant genetic disorder that affects connective tissues. Diagnosis is based on genetic history as well as major and minor clinical criteria. This article presents a case of Marfan syndrome, emphasizing the clinical manifestations of the disease, and provides an overview of oral management. Knowledge of the etiopathologic and clinical aspects of this condition is essential to providing dental treatment aimed at improving the quality of life of affected individuals.

Antimicrobial effect of photodynamic therapy in carious lesions in vivo, using culture and real-time PCR methods.

BACKGROUND: The aim of this study was to evaluate the antimicrobial effect of photodynamic therapy (PDT) in carious lesions in vivo by culture and real-time PCR methods. METHODS: Ten teeth with deep active carious lesions were selected and five portions of carious dentin were removed for each tooth. Two increments were used as control, to represent the superficial and deep dentin, respectively. Methylene blue at 100mg/L was placed in contact with the cavity for 5min, before being irradiated with a halogen light source for 1min. Then, after PDT, other three portions were removed. The samples were processed in laboratory and the number of viable cfu was obtained. The real-time PCR analyses were performed in two increments of carious dentin, removed before and after PDT. The Streptococcus mutans DNA was isolated from carious dentin samples and amplification and detection of DNA were performed with real-time PCR. The cavities were then restored with glass-ionomer cement. RESULTS: Using conventional culture methods, the results demonstrated that viable bacteria were significantly reduced in all of the agar plates following photosensitization. No difference was found between both groups regarding S. mutans DNA quantification by real-time PCR. CONCLUSION: Although PDT may not affect the number of S. mutans DNA copies immediately after the treatment, clear reduction of the number of cfu was found. Despite its promising use for eliminating bacteria in dental caries treatment, further studies are necessary to establish an effective clinical protocol for the PDT.

Development of sulfadiazine-decorated PLGA nanoparticles loaded with 5-fluorouracil and cell viability.

The aim of this work was to synthesize sulfadiazine-poly(lactide-co-glycolide) (SUL-PLGA) nanoparticles (NPs) for the efficient delivery of 5-fluorouracil to cancer cells. The SUL-PLGA conjugation was assessed using FTIR, 1H-NMR, 13C-NMR, elemental analysis and TG and DTA analysis. The SUL-PLGA NPs were characterized using transmission and scanning electron microscopy and dynamic light scattering. Additionally, the zeta potential, drug content, and in vitro 5-FU release were evaluated. We found that for the SUL-PLGA NPs, Dh = 114.0 nm, ZP = -32.1 mV and the encapsulation efficiency was 49%. The 5-FU was released for up to 7 days from the NPs. Cytotoxicity evaluations of 5-FU-loaded NPs (5-FU-SUL-PLGA and 5-FU-PLGA) on two cancer cell lines (Caco-2, A431) and two normal cell lines (fibroblast, osteoblast) were compared. Higher cytotoxicity of 5-FU-SUL-PLGA NPs were found to both cancer cell lines when compared to normal cell lines, demonstrating that the presence of SUL could significantly enhance the cytotoxicity of the 5-FU-SUL-PLGA NPs when compared with 5-FU-PLGA NPs. Thus, the development of 5-FU-SUL-PLGA NPs to cancer cells is a promising strategy for the 5-FU antitumor formulation in the future.

Propolis varnish: antimicrobial properties against cariogenic bacteria, cytotoxicity, and sustained-release profile.

Varnishes are preparations that differ in the polymeric matrix and therapeutical agents. In dentistry they are used to prevent caries. In this study we developed a propolis varnish, considering propolis properties against cariogenic bacteria. To a chitosan polymeric base (CHV) was added ethanolic propolis extract in different concentrations: PV1 (5%), PV2 (10%), and PV3 (15%). Antimicrobial activity was carried out against Streptococcus mutans (SM), Streptococcus sanguinis (SG), Streptococcus salivarius (SS), and Lactobacillus casei (LC) through agar diffusion method. The three propolis concentrations incorporated were effective in inhibiting the growth of all microorganisms, but without significant difference between the zones of inhibition observed. Cytotoxicity assay was done by MTT method. Data were analyzed by one-way ANOVA and Bonferroni test. None of the varnishes were cytotoxic, keeping 80% of viable cells, while CHV allowed cellular proliferation (120%). Sustained-release test was carried out by applying 40 µ L of each varnish in the buccal surface of bovine teeth and kept in an ethanol/water solution removed in regular times. According to the "independent model approach," the release profiles were distinct from each varnish and the most prolonged was PV3 (8 weeks). Varnish formulations had satisfactory antimicrobial activity against cariogenic bacteria and have a low cytotoxicity (<50%).

Evaluation of antibacterial photodynamic therapy effects on human dental pulp cell cultures.

BACKGROUND: The antibacterial photodynamic therapy (aPDT) has been used in dentistry against oral microorganisms because of its excellent biocide effect. However, for carious lesions applications, there is little evidence that this therapy is safe for the pulp tissue. OBJECTIVE: This study evaluates the effects of an aPDT protocol on human pulp cells in vitro. METHODS: Pulp cells isolated from dental pulp were exposed to an aPDT protocol associating methylene blue (MB) at concentrations of 0.0125, 0.025 and 0.050mg/ml and red laser irradiation using a continuous-wave indium-gallium-aluminum-phosphide (InGaAlP) diode laser (λ=660nm, 40mW, 2.4J, 60J/cm(2) for 1min). Pre-irradiation time was 5min for each MB concentration. Cell viability was determined by MTT assay and activity of alkaline phosphatase was assessed by BCIP-NBT assay. Type of aPDT-induced cell death was assessed by flow cytometry. Data was statistically compared (ANOVA followed by Tukey' or Bonferroni's post hoc tests). RESULTS: aPDT was able to kill pulp cells in a dye concentration-dependent manner. The cellular viability was significantly reduced when used MB at 0.025 or 0.050mg/ml concentrations (p<0.0001). At these concentrations, aPDT-induced cell death occurred mostly by necrosis. Alkaline phosphatase activity was significantly reduced in all experimental groups (p<0.001). Pulp cells showed suitable viability when MB at 0.0125mg/ml was exposed to laser irradiation. CONCLUSIONS: aPDT with MB at 0.0125mg/ml may represent a low-risk therapy for restorative dentistry applications. aPDT protocol using concentrations above 0.025mg/ml of MB associating red laser irradiation may be harmful for dental pulp cells.

Peptides: ß-cyclodextrin inclusion compounds as highly effective antimicrobial and anti-epithelial proliferation agents.

BACKGROUND: The use of antimicrobial peptides (AMPs) as therapeutic agents for periodontal infections has great advantages, such as broad spectrum of action, low toxicity, and limited bacterial resistance. However, their practical use is limited because of the large amount of peptide required to exercise the microbicidal function. METHODS: LyeTxI, LL37f, and KR12 cationic peptides were prepared with ß-cyclodextrin (ßCD) at 1:1 molar ratios. The susceptibility of Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, and Fusobacterium nucleatum were assessed in anaerobic conditions. Cytotoxicity assays were performed using osteoblast and Caco-2 epithelial cells, and hemolytic activity was assessed on rabbit erythrocytes at an absorbance of 414 nm. Parameters of surface roughness and electrical charge were established by atomic force microscopy and zeta (ζ) potential, respectively. RESULTS: AMP/ßCDs drastically decreased the peptide concentration required for activity against the bacteria tested. Moreover, AMPs associated with ßCD were able to modify cell-surface parameters, such as roughness and ζ potential. On the other hand, AMP/ßCD did not alter the degree of hemolysis induced by the pure AMPs. The effective concentration at half-maximum values of the peptides and compounds on osteoblasts were greater than the concentrations required to achieve inhibition of bacterial growth in all the species tested. AMP/ßCDs inhibited the proliferation of Caco-2 epithelial cells in a more efficient manner than AMPs alone. CONCLUSION: AMP/ßCD compounds more effectively inhibit periodontopathogenic bacteria than AMPs alone, with the additional ability of inhibiting the proliferation of epithelial cells at concentrations that are non-cytotoxic for osteoblasts and erythrocytes.

Evaluation of antimicrobial activity and cell viability of Aloe vera sponges

Background: Aloe vera L., member of the Liliaceae family, has been shown to stimulate cell proliferation and contribute to healing and angiogenesis, has anti-bacterial, anti-fungal and anti-inflammatory activity. In addition, Aloe vera can be used as a support for drug transport. Our objective is to evaluate antimicrobial activity and cytotoxicity of sponges of Aloe vera L. for use as a carrying support of drugs. Results: In this work, sponge of free Aloe vera (AV) loaded with amoxicillin (AMX) or nystatin (NYS) at 1% w/w, were prepared and physico-chemically characterized via X-ray diffraction, Fourier Transform Infrared Spectroscopy and thermal analysis. Antimicrobial potency of AV sponge alone, loaded with AMX or NYS, against strains of Streptococcus mutans, Staphylococcus aureus, Aggregatibacter actinomycetemcomitans, Enterococcus faecalis and Candida albicans was determined. Osteoblasts and human gingival fibroblasts were cultivated on AV, Aloe vera loaded with amoxicillin (AV/AMX) and Aloe vera loaded with nystatin (AV/NYS) and cellular viability was assessed. The physico-chemical characterization performed suggested that the loaded drugs were dispersed in the sponge and those interactions between the AV sponge and the loaded drugs were weak. Furthermore, AV loaded with AMX or NYS demonstrated antimicrobial potency and osteoblasts and fibroblasts were viable after 24 hrs on free AV, and AV loaded with AMX or NYS. Conclusions: Our results indicate that sponges of free AV, loaded with AMX or NYS, are biocompatible and exhibit antimicrobial activity.

Ultrastructural changes in bacterial membranes induced by nano-assemblies ß-cyclodextrin chlorhexidine: SEM, AFM, and TEM evaluation.

Chemical hosts bind their guests by the same physical mechanisms as biomolecules and often display similarly subtle structure activity relationships. The cyclodextrins have found increasing application as inert, nontoxic carriers of active compounds in drug formulations. The present study was conducted to prepare inclusion complexes of chlorhexidine:ß-cyclodextrin (Cx:ß-cd), and evaluate their interactions with bacterial membrane through: scanning electron microscopy (SEM) and transmission electron microscopy (TEM); and measuring morphology alterations, roughness values, and cell weights by atomic force microscopy (AFM). It was found that the antimicrobial activity was significantly enhanced by cyclodextrin encapsulation. SEM analysis images demonstrated recognizable cell membrane structural changes and ultrastructural membrane swelling. By TEM, cellular alterations such as vacuolization, cellular leakage, and membrane defects were observed; these effects were enhanced at 1:3 and 1:4 Cx:ß-cd. In addition, AFM analysis at these ratios showed substantially more membrane disruption and large aggregates mixing with microorganism remains. In conclusion, nanoaggregates formed by cyclodextrin inclusion compounds create cluster-like structures with the cell membrane, possibly due to a hydrogen rich bonding interaction system with increasing surface roughness and possibly increasing the electrostatic interaction between cationic chlorhexidine with the lipopolysaccharides of Gram negative bacteria.

Effect of testosterone incorporation on cell proliferation and differentiation for polymer-bioceramic composites.

In the current study, we characterized the polycaprolactone (PCL), poly(lactic acid-co-glycolic acid) (PLGA), and biphasic calcium phosphate (BCP) composites coated with testosterone propionate (T) using Fourier transform infrared spectroscopy (FTIR) and powder X-ray diffraction (XRD). Osteoblastic cells were seeded with PCL/BCP, PCL/BCP/T, PLGA/PCL/BCP and PLGA/PCL/BCP/T scaffolds, and cell viability, proliferation, differentiation and adhesion were analyzed. The results of physic-chemical experiments showed no displacements or suppression of bands in the FTIR spectra of scaffolds. The XRD patterns of the scaffolds showed an amorphous profile. The osteoblastic cells viability and proliferation increased in the presence of composites with testosterone over 72 h, and were significantly greater when PLGA/PCL/BCP/T scaffold was tested against PCL/BCP/T. Furthermore alkaline phosphatase production was significantly greater in the same group. In conclusion, the PLGA/PCL/BCP scaffold with testosterone could be a promising option for bone tissue applications due to its biocompatibility and its stimulatory effect on cell proliferation.

Condensation silicones: do new materials really presents better dimensional stability?

The aim of this study was evaluate the dimensional stability of some condensation silicones. The following materials were studied: Coltex/Coltoflax - Coltène, Speedex - Coltène, and Optosil Comfort/Xantopren VL Plus - Kulzer. They were evaluated by dimensional analysis and gas chromatography (GC) performed at the following times: T0, T1, T2, T3, T4, and T5 (immediately after setting, thirty minutes, two hours, twenty four hours, seventy two hours, and seven days after setting, respectively). The dimensional changes were measured directly in the molds using a Mitutoyo microscope. The Coltex fine/Coltoflax and Optosil Comfort/Xantopren VL Plus materials presented dimensional stability for up to thirty minutes after molding, while the Speedex material remained stable for up to two hours after molding. The gas chromatography experiment demonstrated that these materials release ethanol even after clinical setting.