Preparation and Characterization of Alginate and Psyllium Beads Containing Lactobacillus acidophilus

This paper describes preparation and characterization of beads of alginate and psyllium containing probiotic bacteria of Lactobacillus acidophilus DMSZ20079. Twelve different formulations containing alginate (ALG) and alginate-psyllium (ALG-PSL) were prepared using extrusion technique. The prepared beads were characterized in terms of size, morphology and surface properties, encapsulation efficiency, viabilities in acid (pH 1.8, 2 hours) and bile (0.5% w/v, 2 hours) conditions, and release in simulated colon pH conditions. The results showed that spherical beads with narrow size distribution ranging from 1.59 ± 0.04 to 1.67 ± 0.09 mm for ALG and from 1.61 ± 0.06 to 1.80 ± 0.07 mm for ALG-PSL with encapsulation efficiency higher than 98% were achieved. Furthermore, addition of PSL into ALG enhanced the integrity of prepared beads in comparison with ALG formulations. The results indicated that incorporation of PSL into alginate beads improved viability of the bacteria in acidic conditions as well as bile conditions. Also, stimulating effect of PSL on the probiotic bacteria was observed through 20-hour incubation in simulated colonic pH solution. According to our in vitro studies, PSL can be a suitable polymer candidate for partial substitution with ALG for probiotic coating

Effect of two prophylaxis methods on adherence of Streptococcus mutans to microfilled composite resin and giomer surfaces

Objectives: Surface attributes of a restoration play an important role in adherence of plaque bacteria. Prophylaxis methods may be involved in modification of or damaging the restoration surface. The aim of the present study was to evaluate the effect of two prophylaxis methods on adherence of Streptococcus mutans to the surface of two restorative materials. Study design: A total of 60 specimens were prepared from each material; a microfilled composite resin (HelioProgress) and a giomer (Beautifil II). For each material, the specimens were randomly divided into three groups (n=20). Group 1: no prophylaxis treatment (control); Group 2: prophylaxis with pumice and rubber cup; Group 3: prophylaxis with air-powder polishing device (APD). The surfaces of selected specimens from each group were evaluated under a scanning electron microscope (SEM), and the surface topography formed by the two prophylaxis methods was determined by atomic force microscopy (AFM). Adherence of Streptococcus mutans to the surface of specimens was determined by the plate counting method following immersion in a bacterial innoculum for 4 hours, rinsing and sonication. Data were analyzed by two-way ANOVA and post hoc Tukey test for multiple comparisons. Statistical significance was set at P<0.05. Results: Bacterial adherence was significantly affected by both factors: restorative material type and prophylaxis method (P<0.0005). Mean bacterial adhesion was significantly higher in composite groups compared to corresponding giomer groups. Within each material, bacterial adherence was significantly lower in the control group compared to prophylaxis groups. Prophylaxis with pumice and rubber cup resulted in a significantly lower bacterial adherence compared to prophylaxis with APD. Conclusions: Based on the results of the present study, giomer specimens demonstrated lower bacterial adherence compared to composite resin specimens. In both materials, the highest bacterial adherence was observed with prophylaxis with APD, pumice and rubber cup and the control group, respectively. © Medicina Oral S. L

A study on enhanced intestinal permeability of clarithromycin nanoparticles

The main objective of the present study was to determine the permeability of clarithromycin (CLA)-PLGA nanoparticles using single-pass intestinal perfusion technique in rats. Clarithromycin nanoparticles were prepared by nano-precipitation according to the modified quasi emulsion solvent diffusion technique and evaluated for their physicochemical characteristics. Permeability coefficients (Peff) in anaesthetized rats were determined at 3 different concentrations. Drug solution or suspensions in PBS was perfused through a cannulated jejunal segment and samples were taken from outlet tubing at different time points up to 90 min. Microbiological assay of CLA and phenol red in the samples were analyzed using an agar well diffusion procedure and HPLC method respectively. The average particle size of prepared nanoparticles was 305 ± 134 nm. The mean Peff of CLA solution in concentrations of 150, 250 and 400 µg/mL was found to be 1.20 (±0.32) ×10-3, 9.62 (±0.46) ×10-4, and 1.36 (±0.95) ×10-3 cm/sec, respectively. The corresponding values for the same concentration of nanoparticles were found to be 2.74 (±0.73) ×10-3, 2.45 (±0.88) ×10-3, and 3.68 (±0.46) ×10-3 cm/s, respectively. The two-tailed Student’s t-test showed that the intestinal permeability of CLA nanoparticle suspensions in prepared concentrations were significantly increased in comparison with its solution.O objetivo principal do presente estudo foi determinar a permeabilidade de nanopartículas de claritromicina (CLA)-PLGA, utilizando a técnica de perfusão intestinal de passo único em ratos. As nanopartículas de claritromicina foram preparadas por nanoprecipitação, de acordo com a técnica modificada de difusão de solvente quase-emulsão, e suas características físico-químicas avaliadas. Os coeficientes de permeabilidade (Peff) em ratos anestesiados foram determinados em três concentrações diferentes. A solução, ou suspensões, do fármaco em PBS foi perfundida através do segmento de jejuno canulado e as amostras foram tomadas do tubo externo em diferentes tempos até 90 minutos. Os ensaios microbiológico de CLA e de vermelho de fenol das amostras foram realizados, utilizando-se o procedimento de difusão em poço de ágar e de CLAE, respectivamente. O tamanho médio das partículas das nanopartículas preparadas foi de 305 ± 134 nm. O Peff médio da solução de CLA em concentrações de 150, 250 and 400 µg/mL foi de 1.20(±0.32)×10-3, 9.62(±0.46)]×10-4 e de 1.36(±0.95)×10-3 cm/s, respectivamente. O valor correspondente para a mesma concentração de nanopartículas foi de 2.74 (±0.73)×10-3, 2.45(±0.88)×10-3 e de 3.68 (±0.46)×10-3 cm/s, respectivamente. O teste t de Student com duas variáveis mostrou que a permeabilidade intestinal das suspensões de nanopartículas de CLA nas concentrações preparadas foram significativamente aumentadas em comparação com sua solução

Evaluation of Antibacterial Efficacy of Photodynamic Therapy vs. 2.5% NaOCl against E. faecalis-infected Root Canals Using Real-time PCR Technique

Bacteria like E. faecalis can produce intra- and extra-radicular biofilms. Theoretically, the adjustable penetration ability of lasers enables better access to root canal system. Therefore the aim of the present study was to compare the ability of photoactivated laser and 2.5% NaOCl irrigation solution to eliminate E. faecalis from the root canals by real-time PCR technique. Sixty extracted human upper central incisors were selected and sterilized in an autoclave. The root canals were infected with E. faecalis (PTCC 1237, Persian Type Culture Collection, Iran) and then incubated for 24 hours. The samples were randomly divided into 3 groups. No intervention was made in the control group (group 1). In group 2, laser therapy was performed with a power of 100 mW by diode laser for 120 seconds. In group 3, the canals were irrigated with 5 mL of 2.5% NaOCl; then all the samples were sonicated in 15 mL of normal saline in test tubes in order to isolate the bacteria. DNA extraction was performed followed by real-time PCR technique for all the samples. Inhibition of bacterial growth in all the experimental samples was significantly more than that in the control group. There was a significant difference between photodynamic therapy and 2.5% NaOCl. The effect of NaOCl in all the samples was better than photodynamic therapy. The results of the mean CT (cyclic threshold) were 40, 30.2 and 15.35 for 2.5% NaOCl, photodynamic therapy and control group, respectively. Based on the results of this experimental study, 2.5% NaOCl eliminated E. faecalis from infected root canals more effectively compared to photodynamic therapy

Development and Validation of A Spectrofluorimetric Determination of Calf Thymus DNA Using a Terbium-Danofloxacin Probe

Background: Analysis of biomolecules is required in many biomedical research areas. A spectrofluorimetric method is proposed for determination of calf thymus DNA (ctDNA) based on the fluorescence enhancement of terbium-danofloxacin (Tb3+-Dano) in the presence of ctDNA. Methods: A probe with maximum excitation and emission wavelengths of 347 nm and 545 nm, respectively, was developed. The enhanced fluorescence intensity of Tb3+-Dano system was proportional to the concentration of ctDNA. The effective factors and the optimum conditions for the determination of ctDNA were studied. Under the optimum conditions of [Tris buffer]= 0.01 mol L-1 (pH 7.8), [ Tb3+]= 1×10-5 mol L-1 and [Dano]= 5×10-5 mol L-1, the maximum response was achieved. The developed method was evaluated in terms of accuracy, precision and limit of detection. Results: The linear concentration range for quantification of ctDNA was 36-3289 ng mL-1 and the detection limit (S/N=3) was 8 ng mL-1. The concentration of DNA extracted from Escherichia coli as an extracted sample was also determined using the developed probe. The concentration of DNA in extracted sample was determined using UV assay and developed method, the results were satisfactory. Conclusion: The proposed method is a simple, practical and relatively interference free method to follow up the concentrations of ctDNA

Intraperitoneal delivery of nanoparticles for cancer gene therapy

Nanoparticle-based gene delivery systems may be more efficient for administration of therapeutic genes to solid tumors and cancer metastases, owing to the numerous advantages in terms of enhanced tissue penetrability, improved cellular uptake and targeted gene delivery to the cells of interest compared with other gene delivery systems. Intraperitoneal (IP) delivery of therapeutic agents offers special merits because of the anatomical situation of peritoneum for local cancer therapy. Via the IP administration route, it is possible to target the therapeutic agents exactly to the target cells and protect healthy tissues outside the peritoneal cavity from side effects. IP delivery could be applicable for the treatment of disorders of organs in the peritoneal cavity covered with peritoneum and subperitoneal connective tissue, including cancers such as ovarian and gastric. The goal of this article is to review the current state of IP delivery of nanoparticles for cancer gene therapy

Determination of comparative minimum inhibitory concentration (MIC) of bacteriocins produced by enterococci for selected isolates of multi-antibiotic resistant Enterococcus spp.

Introduction: The occurrence of multi-antibiotic resistance among enterococci is a prevalent clinical problem worldwide and continues to get serious due to the lack of efficient therapeutic options by the time. In this regards, prokaryotic antimicrobial peptides with bactericidal or bacteriostatic activity which are directed against bacterial strains closely related to producer strains looks one of the promising alternative to conventional antibiotics. Methods: The antibiotic susceptibility pattern of 20 clinical isolates of enterococci was evaluated and subsequently the isolates were screened for antibacterial activity against three different indicator strains. The efficacy of potential bacteriocinogenic isolates were assayed against multi-antibiotic resistant Enterococcus spp. by comparative minimum inhibitory concentration (MIC). Results: Antibiotic resistant pattern of enterococcal isolates demonstrated that multi-antibiotic resistant to conventional antibiotics were significantly high and the prevalent pattern of resistance was combination of gentamicin, streptomycin, chloramphenicol and vancomycin. In addition, the data from comparative MIC showed the noticeable activity of selected potential bacteriocinogenic strains against pathogenic enterococci. Conclusion: The present survey may address the potential applicability of antimicrobial peptides in alleviating the problems of antibiotic resistance