Biocidal effects of organometallic materials supported on ZSM-5 Zeolite: Influence of the physicochemical and surface properties.

Antifouling coatings containing biocidal agents can be used to prevent the accumulation of biotic deposits on submerged surfaces; however, several commercial biocides can negatively affect the ecosystem. In this study, various formulations of a potential biocide product comprising copper nanoparticles and capsaicin supported on zeolite ZSM-5 were analyzed to determine the influence of the concentration of each component. The incorporation of copper was evidenced by scanning electron microscopy and energy dispersive spectroscopy. Similarly, Fourier-transform infrared spectroscopy confirmed that capsaicin was supported on the zeolite surface. The presence of capsaicin on the external zeolite surface significantly reduced the surface area of the zeolite. Finally, bacterial growth inhibition analysis showed that copper nanoparticles inhibited the growth of strains Idiomarina loihiensis UCO25, Pseudoalteromonas sp. UCO92, and Halomonas boliviensis UCO24 while the organic component acted as a reinforcing biocide.

Dual antifungal activity against Candida albicans of copper metallic nanostructures and hierarchical copper oxide marigold-like nanostructures grown in situ in the culture medium.

AIMS: This study aimed to determine in vitro activity of copper nanoparticles and copper nanowires against Candida albicans strains and to assess their effects on morphology and submicron structure. METHODS AND RESULTS: The microdilution method determined the minimal inhibitory concentration (MIC) of copper nanoparticles (CuNPs) and copper nanowires (CuNWs) against three strains of C. albicans: ATCC 10231 and two clinical strains (C and E). Effects on the morphology and ultrastructure of C. albicans strains were examined by scanning electron microscopy and transmission electron microscopy. MIC for CuNPs was 129·7 µg ml-1 for strain ATCC 10231, 1037·5 µg ml-1 for strain C and 518·8 µg ml-1 for strain E. MIC for CuNWs was similar for all strains tested (260·3 µg ml-1 ). SEM and TEM studies showed alterations in morphology, cell wall and the complete collapse of the yeast after incubation with CuNPs. In contrast, most of the yeast cells maintained their structure with an intact cell wall, and only decreased the number and size of fimbriae when C. albicans was exposed to CuNWs. CuNPs and CuNWs formed hierarchical copper oxide nanostructures growing in situ in the culture medium. Results suggest a dual mechanism for antifungal activity: (i) free Cu2+ ions act as a biocide, (ii) sharp edges of marigold-like petal nanostructures could injure the cellular wall and membrane and cause the death of the yeast. CONCLUSIONS: CuNPs and CuNWs inhibited the growth of the three strains of C. albicans tested. Moreover, CuNPs disrupted cell wall with leakage of the cytoplasmic content. Each concentration of the series used for the determination of the activity of CuNPs and nanowires against C. albicans formed copper oxide marigold-like nanostructures. SIGNIFICANCE AND IMPACT OF THE STUDY: This study suggests that CuNPs and CuNWs are good candidates for formulating new therapeutic agents for candidiasis.

Comparative Study of the Antimicrobial Effect of Nanocomposites and Composite Based on Poly(butylene adipate-co-terephthalate) Using Cu and Cu/Cu2O Nanoparticles and CuSO4.

Nanocomposites and a composite based on poly(butylene adipate-co-terephthalate) (PBAT) were synthesized using commercial copper nanoparticles (Cu-NPs), copper/cuprous oxide nanoparticles (Cu|Cu2O-NPs), and copper sulfate (CuSO4), respectively. The Cu|Cu2O-NPs were synthesized using chemical reduction and characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The synthesis of Cu|Cu2O-NPs yielded a mixture of Cu and Cu2O, with metal Cu having a spherical morphology of approximately 40 nm in diameter and Cu2O with a diameter of 150 nm. To prepare the nanocomposites (NCs) and the composite material (MC), the NPs and the CuSO4 salt were incorporated into the PBAT matrix in concentrations of 1, 3, and 5% p/p via an ex situ method. Fourier transform infrared spectroscopy (FTIR), a tensile test, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and agar diffusion assays were used for structural, thermomechanical, and antimicrobial characterization. Results showed that the reinforcements did not modify the chemical structure of the PBAT and only slightly increased the percentage of crystallization. The mechanical and thermal properties of the PBAT did not change much with the addition of fillers, except for a slight increase in tensile strength and thermal stability, respectively. The agar diffusion antimicrobial assays showed that the NCs and MCs had good inhibitory responses against the nonresistant strains Enterococcus faecalis, Streptococcus mutans, and Staphylococcus aureus. The MCs based on CuSO4 had the highest biocidal effect, even against the resistant bacteria Acinetobacter baumannii.

Metagenomic study of bacterial microbiota in persistent endodontic infections using Next-generation sequencing.

AIM: To determine the bacterial microbiota in root canals associated with persistent apical periodontitis and their relationship with the clinical characteristics of patients using next-generation sequencing (NGS). METHODOLOGY: Bacterial samples from root canals associated with teeth having persistent apical periodontitis were taken from 24 patients undergoing root canal retreatment. Bacterial DNA was extracted, and V3-V4 variable regions of the 16S rRNA gene were amplified. The amplification was deep sequenced by Illumina technology to establish the metagenetic relationships among the bacterial species identified. The composition and diversity of microbial communities in the root canal and their relationships with clinical features were analysed. Parametric and nonparametric tests were used to analyse differences between patient characteristics and microbial data. RESULTS: A total of 86 different operational taxonomic units (OTUs) were identified and Good's nonparametric coverage estimator method indicated that 99.9 ± 0.00001% diversity was recovered per sample. The largest number of bacteria belonged to the phylum Proteobacteria. According to the medical history from the American Society of Anesthesiologists (ASA) Classification System, ASA II-III had higher richness estimates and distinct phylogenetic relationships compared to ASA I individuals (P < 0.05). Periapical index (PAI) score 5 was associated with increased microbiota diversity in comparison to PAI score 4, and this index was reduced in symptomatic patients. CONCLUSIONS: Based on the findings of this study, it is possible to suggest a close relationship between several clinical features and greater microbiota diversity with persistent endodontic infections. This work provides a better understanding on how microbial communities interact with their host and vice versa.

Synthesis of Copper Nanowires and Their Antimicrobial Activity on Strains Isolated Persistent Endodontic Infections.

Copper nanowires, Cu-NWs may have a good antimicrobial effect in endodontic treatment. The objective of this work was to synthesize, characterize and evaluate the antibacterial activity of Cu-NWs on strains obtained from human root canal. A wide distribution of Cu-NWs diameters from 30 to 90 nm was obtained with lengths ranging from 5 to 40 µm. Structural analysis of Cu-NWs showed crystalline planes, which corresponded to Cu, with preferential growth in the direction [110]. The geometric mean MICs was of 289.30 µg/mL, with a MIC50 of 256 µg/mL and a MIC90 of 512 µg/mL for Cu-NWs. Cellular viability of 28 a biofilm tends to decrease the longer it is exposed to Cu-NWs. Synthesized and characterized Cu-NWs have a good antimicrobial effect against clinical strains used in the present study and has a potential to be used for disinfection of the root canal system.

Células madre mesenquimales orales: estado del arte en Odontología / Oral mesenchymal stem cells: state of the art in dentistry

Desde la organogénesis y hasta estadios adultos, las células madre mesenquimales participan activamente dando origen y manteniendo la homeostasis del organismo. En la cavidad oral han sido aisladas desde variadas estructuras del órgano dental tales como el ligamento periodontal, pulpa dental, tejido gingival, folículo dental y papila apical significando una prometedora fuente de células madre mesenquimales las que pueden ser caracterizadas de acuerdo a los criterios mínimos establecidos por 'The International Society for Cellular Therapy' que son: a) La adherencia al plástico; b) La expresión de marcadores CD73, CD90, CD105 y la carencia de CD34,CD45, CD14, CD11, CD79, CD19 y HLA-DR (clase II); c) Capacidad multipotencial de diferenciación hacia linajeosteogénico, condrogénico y adipogénico. El objetivo de esta revisión consiste en realizar un levantamiento de la situación actual de este tema efectuando una revisión comprensiva de la literatura en los campos de; identificación a través de marcadores de superficie, aislamiento por medio de mecanismos de digestión enzimática o explante, almacenamiento atendiendo a la necesidad de suprimir el uso de suero fetal bovino como medio de cultivo en un esfuerzo por avanzar hacia aplicaciones terapéuticas, banca o criopreservación destacando nuevas experiencia en este campo como lo es la criopreservación de piezas dentales completas gracias a la tecnología láser Nd:YAG. Y, finalmente, las aplicaciones clínicas que promete este grupo de células a través de la medicina regenerativa y la ingeniería tisular tanto en el campo de la odontología como la medicina general (AU)

Since organogenesis and even adult stages, mesenchymal stem cells actively participate starting and maintaining body homeostasis. In the oral cavity they have been isolated from various structures dental organ such as the periodontal ligament, dental pulp, gingiva, dental follicle and apical papilla meaning a promising source of mesenchymal stem cells which can be characterized according to the minimum criteria set by The International Society for Cellular Therapy that are: a) the adherence to plastic, b) expression of markers CD73, CD90, CD105 and the absence of CD34, CD45, CD14, CD11, CD79, CD19 and HLA-DR (class II ) c) multipotent differentiation capacity to osteogenic lineage, chondrogenic and adipogenic. The objective of this review is to conduct a survey of the current status of this issue by a comprehensive review of the literature in the fields; identification through surface markers, isolation through mechanisms of enzymatic or explant, storage digestion with the need to eliminate the use of fetal bovine serum as the culture medium in an effort to move towards therapeutic applications, highlighting new banking and cryopreservation experience in this field such as the cryopreservation of whole teeth thanks to the NdYAG laser technology. And finally promising clinical applications this group of cells through regenerative medicine and tissue engineering both in the field of dentistry and general medicine (AU)