scholarly journals Antagonistic Effect of Azoxystrobin Poly (Lactic Acid) Microspheres with Controllable Particle Size on Colletotrichum higginsianum Sacc

Nanomaterials ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 857 ◽  
Author(s):  
Junwei Yao ◽  
Bo Cui ◽  
Xiang Zhao ◽  
Heng Zhi ◽  
Zhanghua Zeng ◽  
...  
Keyword(s):  
Particle Size ◽  
Lactic Acid ◽  
Drug Loading ◽  
Critical Factor ◽  
Antagonistic Activity ◽  
Antagonistic Effect ◽  
Poly Lactic Acid ◽  
Water Emulsion ◽  
Colletotrichum Higginsianum ◽  
Controllable Particle Size

Size-controlled azoxystrobin-poly (lactic acid) microspheres (MS) were prepared by an oil/water emulsion solvent evaporation approach. The hydrated mean particle sizes of the MS1, MS2, and MS3 aqueous dispersions were 130.9 nm, 353.4 nm, and 3078.0 nm, respectively. The drug loading and encapsulation efficiency of the azoxystrobin microspheres had a positive relationship with particle size. However, the release rate and percentage of cumulative release were inversely related to particle size. The smaller-sized microspheres had a greater potential to access the target mitochondria. As a result, the more severe oxidative damage of Colletotrichum higginsianum Sacc and higher antagonistic activity were induced by the smaller particle size of azoxystrobin microspheres. The 50% lethal concentrations against Colletotrichum higginsianum Sacc of MS1, MS2, and MS3 were 2.0386 μg/mL, 12.7246 μg/mL, and 21.2905 μg/mL, respectively. These findings reveal that particle size is a critical factor in increasing the bioavailability of insoluble fungicide.

scholarly journals Preparations of Poly(lactic acid) Dispersions in Water for Coating Applications

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2767
Author(s):  
Giada Belletti ◽  
Sara Buoso ◽  
Lucia Ricci ◽  
Alejandro Guillem-Ortiz ◽  
Alejandro Aragón-Gutiérrez ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Gel Permeation Chromatography ◽  
Sem Analysis ◽  
Water Phase ◽  
Poly Lactic Acid ◽  
Water Emulsion ◽  
Preparation Conditions ◽  
Ft Ir ◽  
Homogenization Methods ◽  
Oil In Water Emulsion

A green, effective methodology for the preparation of water-based dispersions of poly(lactic acid) (PLA) for coating purposes is herein presented. The procedure consists of two steps: in the first one, an oil-in-water emulsion is obtained by mixing a solution of PLA in ethyl acetate with a water phase containing surfactant and stabilizer. Different homogenization methods as well as oil/water phase ratio, surfactant and stabilizer combinations were screened. In the second step, the quantitative evaporation of the organic provides water dispersions of PLA that are stable, at least, over several weeks at room temperature or at 4 °C. Particle size was in the 200–500 nm range, depending on the preparation conditions, as confirmed by scanning electron microscope (SEM) analysis. PLA was found not to suffer significant molecular weight degradation by gel permeation chromatography (GPC) analysis. Furthermore, two selected formulations with glass transition temperature (Tg) of 51 °C and 34 °C were tested for the preparation of PLA films by drying in PTFE capsules. In both cases, continuous films that are homogeneous by Fourier-transform infrared spectroscopy (FT-IR) and SEM observation were obtained only when drying was performed above 60 °C. The formulation with lower Tg results in films which are more flexible and transparent.

scholarly journals Probiotics and Postbiotics as Substitutes of Antibiotics in Farm Animals: A Review

Animals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3431
Author(s):  
Daria Zamojska ◽  
Adriana Nowak ◽  
Ireneusz Nowak ◽  
Ewa Macierzyńska-Piotrowska
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Large Scale ◽  
Culture Media ◽  
Body Weight Gain ◽  
Antimicrobial Effect ◽  
Antagonistic Activity ◽  
Antagonistic Effect ◽  
Farm Animals ◽  
The European Union

Since 2006, the use of growth-promoting antibiotics has been banned throughout the European Union. To meet the expectations of livestock farmers, various studies have been carried out with the use of lactic acid bacteria. Scientists are trying to obtain the antimicrobial effect against the most common pathogens in large-scale farms. Supplementing the diet of broilers with probiotics (live, nonpathogenic microorganisms) stabilized the intestinal microbiota, which improved the results of body weight gain (BWG) and feed intake (FI). The positive effect of probiotics based on lactic acid bacteria has been shown to prevent the occurrence of diarrhea during piglet weaning. The antagonistic activity of postbiotics (inanimate bacteria, cell components, or post-fermentation by-products) from post-culture media after lactobacilli cultures has been proven on Staphylococcus aureus—the pathogen most often responsible for causing mastitis among dairy cows. The article aims to present the latest research examining the antagonistic effect of lactic acid bacteria on the most common pathogens in broilers, piglets, pigs, and cow farms.

scholarly journals Study on characteristics, properties, and morphology of poly(lactic acid)/chitosan/hydroquinine green nanoparticles

2018 ◽  
Vol 7 (5) ◽  
pp. 417-423
Author(s):  
Nguyen Thi Thu Trang ◽  
Tran Thi Mai ◽  
Nguyen Vu Giang ◽  
Tran Huu Trung ◽  
Do Van Cong ◽  
...  
Keyword(s):  
Particle Size ◽  
Lactic Acid ◽  
Particle Size Analysis ◽  
Poly Lactic Acid ◽  
Size Analysis ◽  
Linear Regression Coefficient ◽  
Scanning Calorimetry ◽  
Calibration Equation ◽  
Basic Particle ◽  
Fast Release

Abstract Poly(lactic acid)/chitosan (PLA/CS) green nanoparticles containing hydroquinine (Hq) were prepared by emulsion method. The content of Hq was 10–50 wt% compared with the weight total of PLA and CS. The characteristics of these nanoparticles were analyzed by Fourier transform infrared (FTIR), differential scanning calorimetry, field emission scanning electron microscopy (FESEM), and particle size analysis. The wavenumbers of C=O, C=N, OH, and CH3 groups in FTIR spectra of the PLA/CS/Hq (PCHq) nanoparticles shifted in comparision with neat PLA, CS, and Hq that proved the interaction between these components. The FESEM images and particle size analysis results showed that the basic particle size of PCHq nanoparticles ranged between 100 and 200 nm. The Hq released from PLA/CS nanoparticles in pH 2 and pH 7.4 solutions was determined by ultraviolet-visible method. The obtained results indicated that the linear regression coefficient of calibration equation of Hq in the above solutions approximates 1. The Hq release from the PCHq nanoparticles includes fast release for the eight first testing hours, and then, controlled slow release. The Hq released process was obeyed according to the Korsmeyer-Peppas kinetic model.

scholarly journals Atomic-level characterization and cilostazol affinity of poly(lactic acid) nanoparticles conjugated with differentially charged hydrophilic molecules

2018 ◽  
Vol 9 ◽  
pp. 1328-1338 ◽  
Author(s):  
María Francisca Matus ◽  
Martín Ludueña ◽  
Cristian Vilos ◽  
Iván Palomo ◽  
Marcelo M Mariscal
Keyword(s):  
Lactic Acid ◽  
Rational Design ◽  
Drug Loading ◽  
Surface Region ◽  
Structural Features ◽  
Modern Medicine ◽  
Poly Lactic Acid ◽  
Surface Design ◽  
Key Factor ◽  
Full Picture

Nanotherapeutics is a promising field for numerous diseases and represents the forefront of modern medicine. In the present work, full atomistic computer simulations were applied to study poly(lactic acid) (PLA) nanoparticles conjugated with polyethylene glycol (PEG). The formation of this complex system was simulated using the reactive polarizable force field (ReaxFF). A full picture of the morphology, charge and functional group distribution is given. We found that all terminal groups (carboxylic acid, methoxy and amino) are randomly distributed at the surface of the nanoparticles. The surface design of NPs requires that the charged groups must surround the surface region for an optimal functionalization/charge distribution, which is a key factor in determining physicochemical interactions with different biological molecules inside the organism. Another important point that was investigated was the encapsulation of drugs in these nanocarriers and the prediction of the polymer–drug interactions, which provided a better insight into structural features that could affect the effectiveness of drug loading. We employed blind docking to predict NP–drug affinity testing on an antiaggregant compound, cilostazol. The results suggest that the combination of molecular dynamics ReaxFF simulations and blind docking techniques can be used as an explorative tool prior to experiments, which is useful for rational design of new drug delivery systems.

scholarly journals Evaluation of Drug-Loading Ability of Poly(Lactic Acid)/Hydroxyapatite Core–Shell Particles

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1959
Author(s):  
Seiya Suzuki ◽  
Sungho Lee ◽  
Tatsuya Miyajima ◽  
Katsuya Kato ◽  
Ayae Sugawara-Narutaki ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Lactic Acid ◽  
Drug Loading ◽  
Poly Lactic Acid ◽  
Core Shell ◽  
Vitamin K1 ◽  
Acidic Conditions ◽  
Living Organisms ◽  
Shell Particles ◽  
Hydrophobic Substance

Poly(lactic acid)/hydroxyapatite (PLA/HAp) core–shell particles are prepared using the emulsification method. These particles are safe for living organisms because they are composed of biodegradable polymers and biocompatible ceramics. These particles are approximately 50–100 nm in size, and their hydrophobic substance loading can be controlled. Hence, PLA/HAp core–shell particles are expected to be used as drug delivery carriers for hydrophobic drugs. In this work, PLA/HAp core–shell particles with a loading of vitamin K1 were prepared, and their drug-loading ability was evaluated. The particles were 40–80 nm in diameter with a PLA core and a HAp shell. The particle size increased with an increase in the vitamin K1 loading. The drug-loading capacity (LC) value of the particles, an indicator of their drug-loading ability, was approximately 250%, which is higher than the previously reported values. The amount of vitamin K1 released from the particles increased as the pH of the soaking solution decreased because the HAp shell easily dissolved under the acidic conditions. The PLA/HAp particles prepared in this work were found to be promising candidates for drug delivery carriers because of their excellent drug-loading ability and pH sensitivity.

scholarly journals First characterization of the probiotic potential of lactic acid bacteria isolated from Costa Rican pineapple silages

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12437
Author(s):  
Jannette Wen Fang Wu Wu ◽  
Mauricio Redondo-Solano ◽  
Lidieth Uribe ◽  
Rodolfo WingChing-Jones ◽  
Jessie Usaga ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Epithelial Cells ◽  
Lactic Acid Bacteria ◽  
Hela Cells ◽  
High Capacity ◽  
Antagonistic Activity ◽  
Antagonistic Effect ◽  
Probiotic Potential

Background Agro-industrial waste from tropical environments could be an important source of lactic acid bacteria (LAB) with probiotic potential. Methods Twelve LAB isolates were isolated from pineapple silages. The species identification was carried out considering 16S rRNA and pheS genes. Experiments to evaluate the probiotic potential of the isolates included survival under simulated gastrointestinal environment, in vitro antagonistic activity (against Salmonella spp. and Listeria monocytogenes), auto-aggregation assays, antibiotic susceptibility, presence of plasmids, adhesiveness to epithelial cells, and antagonistic activity against Salmonella in HeLa cells. Results Lacticaseibacillus paracasei, Lentilactobacillus parafarraginis, Limosilactobacillus fermentum, and Weissella ghanensis were identified. Survival of one of the isolates was 90% or higher after exposure to acidic conditions (pH: 2), six isolates showed at least 61% survival after exposure to bile salts. The three most promising isolates, based on survivability tests, showed a strong antagonistic effect against Salmonella. However, only L. paracasei_6714 showed a strong Listeria inhibition pattern; this isolate showed a good auto-aggregation ability, was resistant to some of the tested antibiotics but was not found to harbor plasmids; it also showed a high capacity for adhesion to epithelial cells and prevented the invasion of Salmonella in HeLa cells. After further in vivo evaluations, L. paracasei_6714 may be considered a probiotic candidate for food industry applications and may have promising performance in acidic products due to its origin.

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