Biogenic Synthesis and antibiofilm efficacy of iron nanoparticles via computer simulation

The search for new drugs can be accelerated by in silico methods, i.e., fully computational methods known for their speed and low cost, allowing the analysis of a large amount of data, e.g., thousands of possible antimicrobials, in a few weeks. Molecular docking and first-principles calculations are great allies in this quest. They enable the assessment of protein-ligand interactions and can predict interactions between NPs and macromolecules to provide more information about the interactions and dynamics of NPs in biological systems. In this context, this work aims to use in silico methods to detect the formation of biogenic metallic nanoparticles from functional microalgal biomolecules of the genus Chlorella, which have chelation of metal ions as a fundamental property, and to verify the possible antibacterial biofilm efficacy using computational tools such as molecular docking. In a first analysis, it was found that the iron salt FeSO4 was the most suitable to bind the microalgal enzyme and produce its phytochelatin protein. Following this result, an analysis of the electronic structure of the phytochelatin complex with the iron salt was carried out, proving its structural modification at the nanometric level, after which an analysis of its therapeutic effect on antibiofilm activity was performed. S. aureus, a bacterium known for its multiresistant to antibiotics, these results demonstrate, through alternative in silico methods, the physiological role of phytochelatin from microalgae in the detoxification and bioremediation of metallic contaminants

Bacterial nanocellulose and long-chain fatty acids interaction: an in silico study

Chronic wounds are a big challenge in contemporary society, as they lead to a decrease in life-quality, amputations and even death. Infections and biofilm formation might occur with chronic wounds, due to the higher susceptibility to antibiotic multi-resistant bacteria. In this situation, novel wound dressing biomaterials are needed for treatment. Thus, the aim of this research was to evaluate a possible BNC interaction with tucumã oil/butter-derived fatty acids, as this system could be a promising biomaterial for wound treating. The interaction between  cellobiose (BNC basic unit) and four fatty acids was evaluated by ab initio simulations and density functional theory (DFT), through SIESTA code. Molecular docking was also used to investigate the effect of a possible releasing of the studied fatty acids to the quorum-sensing proteins of Pseudomonas aeruginosa (gram-negative bacterium) and Staphylococcus aureus (gram-positive bacterium). According to ab initio simulations, the interaction between cellobiose and fatty acids derived from tucumã oil/butter was suggested due to physical adsorption (energy around 0.17-1.33 eV) of the lipidic structures into cellobiose. A great binding affinity (∆G ranging from 4.2-8.2 kcal.mol-1) was observed for both protonated and deprotonated fatty acids against P. aeruginosa (LasI, LasA and Rhlr) and S. aureus (ArgA and ArgC) quorum-sensing proteins, indicating that these bioactive compounds might act as potential antimicrobial and/or antibiofilm agents in the proposed system. Hence, from a theoretical viewpoint, the proposed system could be a promising raw biomaterial in the production of chronic wound dressings

Safety profile, antimicrobial and antibiofilm activities of a nanostructured lipid carrier containing oil and butter from Astrocaryum vulgare: in vitro studies

Ethnopharmacological relevance: Tucumã (Astrocaryum vulgare)is a fruit native to the Amazon region. Extracts from the peel and pulp are thought of as promising treatments for bacterial infections. The primary constituents of Tucumã oil and butter possess unsaturated carbon chains that are susceptible to oxidation by light or heat. The oils have high volatility and low aqueous solubility that limits their use without a vehicle. Nanotechnology refers to techniques to solve these problems. Nanostructured lipid carriers (NLC), for example, protect fixed oils degradation by heat or light, as well as from oxidation and evaporation, ensuring greater stability and function, thereby prolonging the useful life of the final product. Study objectives: The objective of this study was to evaluate the hemolytic, cytotoxic, antimicrobial and antibiofilm properties of an NLC containing Tucumã butter and oil soasto improve the solubility and photosensitivity of the compounds, generating better pharmacological efficacy. Materials and methods: The NLC was assessed for stability for 60 days. The cytotoxicity of nanoparticles in peripheral blood mononucleated cells was determined in culture using assays for cell viability, DNA damage, oxidative metabolism and damage to human erythrocytes. Antimicrobial activity was determined using the broth microdilution technique and antibiofilm activity according to standardized protocols. Results: The Tucumã NLC remained stable throughout the evaluated period, with pH between 5.22–5.35, monodisperse distribution (PDI<0.3) and average particle size of 170.7 ± 3nm. Cytotoxicity studies revealed that the NLC is safe and modulates inflammatory processes, demonstrated by increased cell viability and nitric oxide levels. There was low hemolytic activity of the NLC against human erythrocytes almost concentrations tested. Conclusion: Taken together, the data suggest that NLC containing Tucumã oil and butter showed antimicrobial and antibiofilm activity against organisms that cause morbidity and mortality in humans. They may be alternative solutions to public health problems related to bacterial infections

Effects of nanocapsules containing all-trans-retinoic acid under hemolytic and coagulation activity

The chemotherapeutic all-trans retinoic acid (ATRA) used in the treatment of Acute Promyelocytic Leukemia has adverse effects on its oral administration, with which we incorporated a system of drugs, the nanocapsules, in order to have a possible improvement in solubility, photosensitivity, lower toxicity, generating pharmacological efficacy. The objective was to evaluate and compare the hemolytic and coagulation activity of the free drug (AL), nanoencapsulated (NA) and the white nanocapsules (NB) by analyzing the results of hemolysis, Prothrombin Time (PT) and Activated Partial Thromboplastin Time (APTT). We developed a prospective study of treatments at different concentrations of 0.25; 0.5; 1.0; 1.5; 2.0; 2.5 μg/mL. For the first test, all concentrations showed hemolytic activity, but when compared to NA with ATRA it is observed that these carriers induced lower hemolytic toxicity. In the PT test the nanoparticles at the two lowest concentrations remained in the physiological range (12 - 15 seconds). For the APTT test the three lowest concentrations remained within the control (25 - 35 seconds). Thus, we believe there is a promising benefit of using these nanoparticles developed and no doubt further studies will be performed to confirm the responses obtained here

Analysis of antimicrobial, antibiofilm, and healing activity of lipid nanocarriers based on Tucuman butter (Astrocaryum vulgare), fixed oils from microalgae chlorella Homosphaera and from UVA seed Vitis vinifera

Therapeutic alternatives of natural origin have been arousing the interest of large research centers that are looking for new bioactive molecules to treat numerous diseases in the context of public health. Among them, infectious diseases, which present antimicrobial resistance, deserve attention. The present study aimed to evaluate the antimicrobial activity of lipid nanocarriers (CLN), as well as the healing activity, arising from the association of tucumã butter with grape seed oil and another one containing microalgae oil. Two formulations were prepared using the high-speed homogenization technique, which was evaluated for antimicrobial action for 10 strains of great clinical importance, including a multiresistant and healing activity. The formulation with Chlorella homosphaera oil showed growth inhibition for the 10 strains tested, in addition to antibiofilm activity for 8 strains, bactericidal action for 3 of 3 isolates, and satisfactory healing action in 48 hours

Effects of nanocapsules containing all-trans-retinoic acid under hemolytic and coagulation activity

The chemotherapeutic all-trans retinoic acid (ATRA) used in the treatment of Acute Promyelocytic Leukemia has adverse effects on its oral administration, with which we incorporated a system of drugs, the nanocapsules, in order to have a possible improvement in solubility, photosensitivity, lower toxicity, generating pharmacological efficacy. The objective was to evaluate and compare the hemolytic and coagulation activity of the free drug (AL), nanoencapsulated (NA) and the white nanocapsules (NB) by analyzing the results of hemolysis, Prothrombin Time (PT) and Activated Partial Thromboplastin Time (APTT). We developed a prospective study of treatments at different concentrations of 0.25; 0.5; 1.0; 1.5; 2.0; 2.5 μg/mL. For the first test, all concentrations showed hemolytic activity, but when compared to NA with ATRA it is observed that these carriers induced lower hemolytic toxicity. In the PT test the nanoparticles at the two lowest concentrations remained in the physiological range (12 - 15 seconds). For the APTT test the three lowest concentrations remained within the control (25 - 35 seconds). Thus, we believe there is a promising benefit of using these nanoparticles developed and no doubt further studies will be performed to confirm the responses obtained here

Growing knowledge: an overview of Seed Plant diversity in Brazil

Abstract An updated inventory of Brazilian seed plants is presented and offers important insights into the country's biodiversity. This work started in 2010, with the publication of the Plants and Fungi Catalogue, and has been updated since by more than 430 specialists working online. Brazil is home to 32,086 native Angiosperms and 23 native Gymnosperms, showing an increase of 3% in its species richness in relation to 2010. The Amazon Rainforest is the richest Brazilian biome for Gymnosperms, while the Atlantic Rainforest is the richest one for Angiosperms. There was a considerable increment in the number of species and endemism rates for biomes, except for the Amazon that showed a decrease of 2.5% of recorded endemics. However, well over half of Brazillian seed plant species (57.4%) is endemic to this territory. The proportion of life-forms varies among different biomes: trees are more expressive in the Amazon and Atlantic Rainforest biomes while herbs predominate in the Pampa, and lianas are more expressive in the Amazon, Atlantic Rainforest, and Pantanal. This compilation serves not only to quantify Brazilian biodiversity, but also to highlight areas where there information is lacking and to provide a framework for the challenge faced in conserving Brazil's unique and diverse flora