Effects of Ciprofloxacin-containing Scaffolds on Enterococcus faecalis Biofilms

Introduction: Antibiotic-containing polymer-based nanofibers (hereafter referred to as scaffolds) have demonstrated great potential for their use in regenerative endodontics from both an antimicrobial and cytocompatibility perspective. This study sought to evaluate in vitro the effects of ciprofloxacin (CIP)-containing polymer scaffolds against Enterococcus faecalis biofilms. Methods: Human mandibular incisors were longitudinally sectioned to prepare radicular dentin specimens. Sterile dentin specimens were distributed in 24-well plates and inoculated with E. faecalisfor biofilm formation. Infected dentin specimens were exposed to 3 groups of scaffolds, namely polydioxanone (PDS) (control), PDS + 5 wt% CIP, and PDS + 25 wt% CIP for 2 days. Colony-forming units (CFU/mL) (n = 10) and scanning electron microscopy (SEM) (n -= 2) were performed to quantitatively and qualitatively assess the antimicrobial effectiveness, respectively. Results: PDS scaffold containing CIP at 25 wt% showed maximum bacteria elimination with no microbial growth, differing statistically (P < .05) from the control (PDS) and from PDS scaffold containing CIP at 5 wt%. Statistical differences (P < .05) were also seen for the CFU/mL data between pure PDS (5.92-6.02 log CFU/mL) and the PDS scaffold containing CIP at 5 wt% (5.39 5.87 log CFU/mL). SEM images revealed a greater concentration of bacteria on the middle third of the dentin specimen. after 5 days of biofilm formation. On scaffold exposures, SEM images showed similar results when compared with the CFU/mL data. Dentin specimens exposed to PDS + 25 wt% CIP scaffolds displayed a practically bacteria-free surface. Conclusions: On the basis of the data presented, newly developed antibiotic-containing electrospun scaffolds hold promise as an intracanal medicament to eliminate biofilm/infection before regenerative procedures.

Electromyographic study of the trapezius muscle in free movements of the arm

The trapezius muscle (superior, middle and inferior portions) was analyzed in 20 volunteers. The electromyographic tests were carried out using a four-channel TECA TE 2-7 electromyograph with surface- and single coaxial needle electrodes. In abduction, adduction and flexion-extension, the 3 portions show increasing and decreasing activity, respectively, from the beginning until the end of these movements. In hyperextension, the 3 portions show increasing activity from the beginning until the end of the movement, with greater participation of the middle portion. Significant differences were not observed in the electromyographic profile of the trapezius, using surface and needle electrodes.

Electromyographic study of the trapezius muscle in free movements of the shoulder

The objective of this study is to analyze the simultaneity of the actions of the three portions of the trapezius (superior portion = TS; middle portion = TM and inferior portion = TI) in elevation, lowering, retraction and protraction of the shoulders. The electromyographic tests were carried out in 20 volunteers using a 4-channel TECA TE 2-7 electromyograph and surface and single coaxial needle electrodes. The electromyographs, obtained with the two types of electrodes, show that in elevation and lowering of the shoulders, TS and TM present increasing and decreasing activity, respectively, from the beginning until the end of these movements. In retraction of the shoulders, TM and TI present increasing activity from the beginning to the end of the movement. In protraction, TS, TM and TI do not show any activity.

Efeito de scaffolds de nanofibras incorporados com antibióticos sobre biofilmes formados por bactérias presentes nos canais radiculares

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Obtenção e caracterização de nanofibras eletrofiadas via solução de quitosana com e sem inclusão de hidroxiapatita

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Eletrofiação de fibras de borracha natural com adição de polianilina

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Efeito de diferentes cargas orgânicas em cimentos resinosos experimentais

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Obtenção de nanofibras de carbono a partir do processo de eletrofiação

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Influência da incorporação de nanofibras de poliamida 6 com e sem nanotubos de carbono como reforço de prótese parcial fixa adesiva

The aim of this study was to evaluate the behavior of reinforced composites with polyamide 6 fibers aligned (6000 rpm) and alignment (120 rpm) with or without CNT using the flexural strength test. After preparation of nanofibers aligned nylon 6 (6000 rpm) and alignment (120 rpm) with and without incorporation of nanotube carbon by the method of electrospinning, were performed one control group (n = 10) and 4 experimental groups (n = 40) G1: Control (just resin Charisma - Heraeus Kulzer) ;G2 Resin + N6 aligned (6000 rpm) + CNT; G3:Resin + N6 alignment (120 rpm) + CNT; G4: Resin + aligned ( 6000 rpm) N6. G5: Resin + N6 alignment (120 rpm). The fibers were cut to the dimensions of 0,3 x 15 mm and were applied an adhesive at the surface (Single Bond 2) for 5 min and cured. In the matrix, was added resin in the proximal box (Charisma A2, Heraeus Kulzer) and cured for 40 s. (power 1100 mW / cm²). A first layer of resin and on the resin was deposited. The resin layers specimens were light irradiated with three overlapping exposures delivered. For each resin layer were light irradiated for 40 sec. The samples were tested with a cross-speed of 1 mm / min, and a 50 Kgf at Universal testing machine (EMIC mod.DL2000). The Dunnet test showed that only the nanotube group was significantly different from the control group. The ANOVA two-way indicates that the nanotube factor was statistically significant (p < 0.05) and there is no interaction between factors and orientation nanotube. The presence of nanotube showed lower fracture resistance values for aligned and unaligned groups. The results of this study showed that the orientation of the fibers does not influence the strength of composite resins and the incorporation of nylon nanofibers with carbon nanotubes decreased the fracture resistance values. The presence of the fibers has not been able to improve the strength of the material in any of the...

Preparation and evaluation of the electrospun chitosan/PEO fibers for potential applications in cartilage tissue engineering

Fibrous materials have morphological similarities to natural cartilage extracellular matrix and have been considered as candidate for bone tissue engineering scaffolds. In this study, we have evaluated a novel electrospun chitosan mat composed of oriented sub-micron fibers for its tensile property and biocompatibility with chondrocytes (cell attachment, proliferation and viability). Scanning electronic microscope images showed the fibers in the electrospun chitosan mats were indeed aligned and there was a slight cross-linking between the parent fibers. The electrospun mats have significantly higher elastic modulus (2.25 MPa) than the cast films (1.19 MPa). Viability of cells on the electrospun mat was 69% of the cells on tissue-culture polystyrene (TCP control) after three days in culture, which was slightly higher than that on the cast films (63% of the TCP control). Cells on the electrospun mat grew slowly the first week but the growth rate increased after that. By day 10, cell number on the electrospun mat was almost 82% that of TCP control, which was higher than that of cast films (56% of TCP). The electrospun chitosan mats have a higher Young’s modulus (P <0.01) than cast films and provide good chondrocyte biocompatibility. The electrospun chitosan mats, thus, have the potential to be further processed into three-dimensional scaffolds for cartilage tissue repair.

Influência da incorporação de nanofibras de poliamida 6 com e sem nanotubos de carbono como reforço de prótese parcial fixa adesiva

The aim of this study was to evaluate the behavior of reinforced composites with polyamide 6 fibers aligned (6000 rpm) and alignment (120 rpm) with or without CNT using the flexural strength test. After preparation of nanofibers aligned nylon 6 (6000 rpm) and alignment (120 rpm) with and without incorporation of nanotube carbon by the method of electrospinning, were performed one control group (n = 10) and 4 experimental groups (n = 40) G1: Control (just resin Charisma - Heraeus Kulzer) ;G2 Resin + N6 aligned (6000 rpm) + CNT; G3:Resin + N6 alignment (120 rpm) + CNT; G4: Resin + aligned ( 6000 rpm) N6. G5: Resin + N6 alignment (120 rpm). The fibers were cut to the dimensions of 0,3 x 15 mm and were applied an adhesive at the surface (Single Bond 2) for 5 min and cured. In the matrix, was added resin in the proximal box (Charisma A2, Heraeus Kulzer) and cured for 40 s. (power 1100 mW / cm²). A first layer of resin and on the resin was deposited. The resin layers specimens were light irradiated with three overlapping exposures delivered. For each resin layer were light irradiated for 40 sec. The samples were tested with a cross-speed of 1 mm / min, and a 50 Kgf at Universal testing machine (EMIC mod.DL2000). The Dunnet test showed that only the nanotube group was significantly different from the control group. The ANOVA two-way indicates that the nanotube factor was statistically significant (p < 0.05) and there is no interaction between factors and orientation nanotube. The presence of nanotube showed lower fracture resistance values for aligned and unaligned groups. The results of this study showed that the orientation of the fibers does not influence the strength of composite resins and the incorporation of nylon nanofibers with carbon nanotubes decreased the fracture resistance values. The presence of the fibers has not been able to improve the strength of the material in any of the...

Magnetic fabrics and their relationship with the emplacement of the Piracaia pluton, SE Brazil

Magnetic fabric and rock-magnetism studies were performed on the four units of the 578 +/- 3-Ma-old Piracaia pluton (NW of Sao Paulo State, southern Brazil). This intrusion is roughly elliptical (similar to 32 km(2)), composed of (i) coarse-grained monzodiorite (MZD-c), (ii) fine-grained monzodiorite (MZD-f), which is predominant in the pluton, (iii) monzonite heterogeneous (MZN-het), and (iv) quartz syenite (Qz-Sy). Magnetic fabrics were determined by applying both anisotropy of low-field magnetic susceptibility (AMS) and anisotropy of anhysteretic remanent magnetization (AARM). The two fabrics are coaxial. The parallelism between AMS and AARM tensors excludes the presence of a single domain (SD) effect on the AMS fabric of the units. Several rock-magnetism experiments performed in one specimen from each sampled units show that for all of them, the magnetic susceptibility and magnetic fabrics are carried by magnetite grains, which was also observed in the thin sections. Foliations and lineations in the units were successfully determined by applying magnetic methods. Most of the magnetic foliations are steeply dipping or vertical in all units and are roughly parallel to the foliation measured in the field and in the country rocks. In contrast, the magnetic lineations present mostly low plunges for the whole pluton. However, for eight sites, they are steep up to vertical. Thin-section analyses show that rocks from the Piracaia pluton were affected by the regional strain during and after emplacement since magmatic foliation evolves to solid-state fabric in the north of the pluton, indicating that magnetic fabrics in this area of the pluton are related to this strain. Otherwise, the lack of solid-state deformation at outcrop scale and in thin sections precludes deformation in the SW of the pluton. This evidence allows us to interpret the observed magnetic fabrics as primary in origin (magmatic) acquired when the rocks were solidified as a result of magma flow, in which steeply plunging magnetic lineation suggests that a feeder zone could underlie this area.

Hybrid Scaffolds Built From PET and Collagen as a Model For Vascular Graft Architecture

A hybrid material with excellent mechanical and biological properties is produced by electrospinning a co-solution of PET and collagen. The fibers are mapped using SEM, confocal Raman microscopy and collagenase digestion assays. Fibers of different compositions and morphologies are intermingled within the same membrane, resulting in a heterogeneous scaffold. The collagen distribution and exposure are found to depend on the PET/collagen ratio. The materials are chemically and mechanically characterized and biologically tested with fibroblasts (3T3-L1) and a HUVEC culture in vitro. All of the hybrid scaffolds show better cell attachment and proliferation than PET. These materials are potential candidates to be used as vascular grafts.

Magnetic fabric of Araguainha complex impact structure (Central Brazil): Implications for deformation mechanisms and central uplift formation

The weakening mechanisms involved in the collapse of complex impact craters are controversial. The Araguainha impact crater, in Brazil, exposes a complex structure of 40 km in diameter, and is an excellent object to address this issue. Its core is dominated by granite. In addition to microstructural observations, magnetic studies reveal its internal fabric acquired during the collapse phase. All granite samples exhibit impact-related planar deformation features (PDFs) and planar fractures (PFs), which were overprinted by cataclasis. Cataclastic deformation has evolved from incipient brittle fracturing to the development of discrete shear bands in the center of the structure. Fracture planes are systematically decorated by tiny grains (<10 mu m) of magnetite and hematite, and the orientation of magnetic lineation and magnetic foliation obtained by the anisotropies of magnetic susceptibility (AMS) and anhysteretic remanence (AAR) are perfectly coaxial in all studied sites. Therefore, we could track the orientation of deformation features which are decorated by iron oxides using the AMS and AAR. The magnetic fabrics show a regular pattern at the borders of the central peak, with orientations consistent with the fabric of sediments at the crater's inner collar and complex in the center of the structure. Both the cataclastic flow revealed from microstructural observations and the structural pattern of the magnetic anisotropy match the predictions from numerical models of complex impact structures. The widespread occurrence of cataclasis in the central peak, and its orientations revealed by magnetic studies indicate that acoustic fluidization likely operates at all scales, including the mineral scales. The cataclastic flow made possible by acoustic fluidization results in an apparent plastic deformation at the macroscopic scale in the core. (C) 2012 Elsevier B.V. All rights reserved.

Formation and Characterization of Oriented Micro-and Nanofibers Containing Poly (ethylene oxide) and Pectin

Formation of oriented or aligned micro- and nanofibers using biocompatible materials opens the possibility to obtain engineered tissues that can be used in medicine, environmental engineering, security and defense, among other applications. Pectin, a heteropolysaccharide, is a promising material to be incorporated into the fibers because, besides being biocompatible, this material is also biodegradable and bioactive. In this work, the formation of oriented fibers using solutions containing pectin and polyethylene oxide (biocompatible polymers), and chloroform (as the solvent) is investigated. The injection of solution into an intense electric field defined between two parallel electrodes was used to obtain oriented fibers. This novel approach is a modification of the conventional electrospinning process. The presence of pectin in the fibers was confirmed by FTIR analysis. Fibers with diameters of hundreds of nanometers and several centimeters long can be collected. The incorporation of pectin leads to a higher variation of the diameter of the fibers, and a trend to larger fiber diameters. This behavior can be related to the presence of pectin clusters in the fibers. (C) 2012 The Electrochemical Society. [DOI: 10.1149/2.057203jes] All rights reserved.