Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

El diagnóstico reciente en diferentes puntos  de la geografía mundial de casos de niños con hepatitis agudas graves de etiología desconocida, activa los sistemas de vigilancia de los organismos de salud mundiales y regionales,  en la búsqueda de las causas,  tratamiento oportuno, eficaz  y  lo más importante, la forma de prevenirla.

To carry out a systematic review of the literature to identify the types of nanoparticles and the effect they have on periodontal regeneration, a systematic review of the literature was carried out in the ScienceDirect, PubMed and SciELO databases. As inclusion criteria, the full-text original articles that included the use of nanoparticles (0-100 nm) for periodontal regeneration purposes published between 2016 and 2022 were taken into account. The search terms were “Periodontal regeneration AND nanoparticles AND dental materials”. 13 articles that met the inclusion and exclusion criteria were obtained and analyzed. nHA was found to have a high regenerative effect, followed by TiO2NPs, gold, calcium phosphate, chitosan, and iron oxide, among others. These NPs showed a periodontal regeneration effect for one to four weeks, mainly promoting osteoinduction, cytocompatibility, cell adherence, degradability, analgesia and biomineralization properties. Nanotechnology in the dental field is emerging as an attractive platform for advanced therapy in conjunction with dental biomaterials. In this review, it was found that nHA and TiO2NPs showed the best cellular response and in the shortest time to obtain regenerative results in periodontics in comparison to other NPs. There are still very few NPs analyzed for periodontal regeneration purposes, so their study is an emerging area. It is essential to recognize the possible limitations, consequences and adverse effects in short and long term, which must be studied in greater depth.

Nobel-metal based bimetallic nanoparticles (BNPs) are composed of two different metals presenting heteroatom interactions. In these nanomaterials it is possible to tune the relative composition that allows for the modulation of electronic and catalytic properties. They are of great interest for their technological and industrial applications due to their catalytic properties which may exceed those of their monometallic analogue structures. A theoretical perspective on the electronic, stability and reactivity related properties of gold, ruthenium and Au-Ru nanoparticles is presented herein. This analysis considered the use of first-principles methods and the cluster approach to get a physical insight into the novel properties that arise from the combination of two metals in the nano and sub-nano scale. Au-Ru BNPs may present a higher catalytic efficiency than the monometallic structures due to the synergy between the metals in the CO oxidation reaction. However, the effect of Ru over the Au-based NPs on their enhanced catalytic activity is not well understood. A density functional theory (DFT) study of one Au-Ru cluster model was performed to analyze its electronic properties and to gain a better understanding in the stability of structures with various metal compositions. Based on the computed mixing enthalpy, the Au-Ru cluster with a core-shell type morphology and a relative composition close to 1:0.75 was determined as the most stable one. Finally, a CO oxidation reaction pathway different from that determined for Au-NPs was presented for the free particle occurring in the Au-Ru interface. O2 may undergo adsorption on a Ru site through a dissociative process. The computed CO oxidation barrier height is lower than that found for the monometallic Ru clusters but is higher than that determined for Au clusters. This study will guide further research on this kind of model nanostructures in heterogeneous catalysis.  

The recent developments made in the field of nanotechnology have brought new opportunities for innovation and advancement in a substantial number of disciplines, amongst which agriculture prominently stands out. The current percentages of starvation across the globe, along with the estimated growth of population, combined with the environmental problems caused by erosion and usage of chemical products, have highlighted the need for better, greener customs, that may be resolved using nanomaterials. These materials at nanometric scale (called NMs from now on) present themselves as an attractive replacement to conventional materials, due to their attributes and the improvement they may represent. Pesticides and fertilizers are two of many products that have shown to be great prospects when produced at nano-level, with targeted and controlled release of agrochemical, which translates to an augmented biological effectiveness, overall achieving an increase in crop yield and productivity. However, just as the full potential of nanotechnology remains unknown; there is limited knowledge regarding the biosafety, adverse effects, fate, and biological reactivity of nanomaterials once they are introduced into the environment. The harm they may cause, not only to agroecosystems, but to human health and the environment, is not yet fully understood, despite the numerous scientific efforts that are being made to evaluate the intrinsic hazard NMs may cause. Therefore, this review strives to serve as a framework regarding the status of nanotechnology in agriculture: developments, applications and known risks. The characteristics of NMs applied in agriculture are reviewed, along with the results obtained from behavior and fate tests regarding plant species. In addition, the reported interactions between the biotic and abiotic components of exposed ecosystems are analyzed, to present a comprehensive study regarding the state and direction of nanoagriculture.

A QSAR study was carried out, by considering common quinolone to develop new chemical structures with possible antibacterial action. Furthermore, it has been performed a docking assay to get insight into the molecular interactions of the studied molecules herein with the biological target Staphylococcus aureus (S. aureus). On the other hand, a TiO2 cluster was used as a nanocarrier model and was coupled to quinolones through a molecular docking assay. All the molecules were optimized using the density functional theory (DFT), with the functional M06L and a basis set 6-311+G(d,p); the molecular docking assay between isolated quinolone and the TiO2-quinolone complex with DNA gyrase-topoisomerase IV (like biological target), was performed with Molegro Virtual Docker Software. The results show that the designed molecules present MIC (minimum inhibitory concentrations) values better than those of commercial drugs, especially when isatine and azole substituents were added. The molecular coupling of the designed structures mimics the linkage mechanism with the biological target, as has been reported in the literature. The addition of TiO2 as a nanocarrier confers a better interaction than free drugs or free molecules due to the many target-ligand interactions. Finally, we can conclude that four potential antibiotics were designed, showing lower MIC values. Likewise, the TiO2 nanocarrier promotes a better molecular coupling with the biological target, being our molecules a solid proposal to be synthesized and in vitro tested.

Nanomaterials (NM) synthesized from metal oxides, such as zinc oxide nanoparticles (ZnO NPs), are one of the most widely used in the food industry in coatings for food packaging and excipients and in the cosmetics industry for the manufacture of creams, sunscreens, makeup, and other beauty products. As their use increases, so do the exposure scenarios, thus the interest in studying their possible toxic effects on health and the environment. The route of exposure and the physicochemical properties of NMs define their molecular interactions and toxicity. NMs entering the cell interact with different organelles, inducing oxidative stress and increasing the production of highly reactive oxygen species (ROS), one of the most common mechanisms of nanotoxicity. Furthermore, although there are many studies on the generation of ROS by NPs, little attention has been devoted to whether NPs can alter the antioxidant system of the cell. In this work, we show some examples of how ZnO and CuO NPs alter the antioxidant functions of hepatocytes to provide elements to help explain the molecular mechanisms of NPs-induced cellular toxicity.

The environmental lack awareness of agricultural producers and poor government policies for waste management is one of the challenges faced by agroindustrial companies. The nanobiocomposites production has been recognized recently with the obtaining of cellulose. Therefore, the objective of this work is the obtaining and characterization of nanocellulose from polluting residues of rice (Oryza sativa L.) Var. “Morelos A-2010”, in the state of Morelos. The rice husk was sieved and processed by alkaline extraction, blanching, followed by an acid pretreatment. The cellulose was treated with acid hydrolysis (H2SO4) and sonication to produce nanocellulose. The samples at the end were processed by (FTIR), (DSC) and morphological visualization, by (SEM). The results showed potential yields of 29 to 41% cellulose 29 to 41% cellulose and its subsequent process allowed the formation of nanocellulose with a length between 86-173 nm, thus proving that this waste can have a sustainable management and become a recyclable product.

In this review, we explore the bidimensional materials based on phthalocyanine molecules. The phthalocyanine molecule is used as a brick for the construction of new bidimensional materials. In particular, the phthalocyanine molecules can be placed at each vertex or sharing edges to form tessellations. The tessellations available are constrained to the four-fold type of the phthalocyanine molecules and can be a mix of several polygons to increase the number of possibilities. Computationally, the popular tessellations used are the Archimedean tiling, but many others expect to be discovered and well-studied. Different tessellations will provide new symmetric systems to explore. Each new symmetry pattern will modify the physical and chemical properties of the new bi-dimensional material. These new materials present many exciting applications as capture and storage of greenhouse gases and molecular electronic devices. In the present review, we summarized some of these tessellations and the many applications that they can have.

This paper reports the results of a computational nanochemistry study of the chemical reactivities and bioactivity properties of two antimicrobial peptides using a CDFT-based computational peptidology (CDFT-CP) methodology, which is derived from the combination of the chemical reactivity descriptors derived from conceptual density functional theory (CDFT) and some cheminformatics tools useful in the design of therapeutic drugs. This is complemented by an examination of the bioactivity and pharmacokinetics indices of the peptides in relation to the ADMET (absorption, distribution, metabolism, excretion, and toxicity) features. These findings provide further evidence of the superiority of the MN12SX density functional in fulfilling the Janak and ionization energy theorems using an earlier proposed KID methodology for validation. This has proven to be beneficial in accurately predicting CDFT indices, which is of help in the understanding of the chemical reactivity. The computational pharmacokinetics study revealed the potential ability of both cyclopeptides as therapeutic drugs through the interaction with different target receptors. The ADMET indices confirmed this assertion through the absence of toxicity and good absorption and distribution properties.

Polymethylmethacrylate (PMMA) is a well known material in dental prostheses and implants. It has been proven to have a desirable property for dental applications, because of its good aesthetics, biocompatibility, decreased water absorption, transparent and light-weight, and highly durable, among others. The major problem is the microbial adhesion to PMMA when it is in the oral cavity. Despite all these beneficial properties, it is still considered to have certain disadvantages that or drawbacks which could be substantially improved with the addition of different nanoparticles (NPs). In this systematic review, we studied extensively the use of various types of metal NPs (silver – Ag, and copper – Cu) as well as magnesium phosphate – MgP, and compared its effects with the PMMA alone. The research articles showed either a positive or an improved antimicrobial effects compared to conventional PMMA by experimental and non-clinical studies.