scholarly journals Bacteriophage Encapsulation in pH-Responsive Core-Shell Capsules as an Animal Feed Additive

Viruses ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1131
Author(s):  
Kerry Richards ◽  
Danish J. Malik

Increasing antibiotic resistance in bacteria that cause zoonotic infections is a major problem for farmers rearing animals for food as well as for consumers who eat the contaminated meat resulting in food-borne infections. Bacteriophages incorporated in animal feed may help reduce carriage and infections in animals including chickens and pigs. There are, however, unmet challenges in protecting phages from processing stresses e.g., during animal feed pelleting operations and during transit of phages through the acidic gastric environment. Core-shell capsules were produced using a concentric nozzle and commercially available encapsulation equipment to fabricate capsules with phages formulated in an oil-in-water microemulsion in the core. pH-responsive capsules released the encapsulated phage cargo within 10–30 min triggered by changes in local environmental pH typically found in the lower gastrointestinal (GI) tract of animals. Acid stability of phages exposed to pH values as low as pH 1 was demonstrated. Encapsulated phages were able to withstand exposure to 95 °C wet heat thermal stress for up to 120 s, conditions typically encountered during feed pellet extrusion processing. Free phages were inactivated within 15 s under these conditions. The present study demonstrates that encapsulation of bacteriophages in core-shell pH-responsive capsules with water-in-oil emulsified phages in the core significantly improves phage viability upon exposure to processing and environmental stresses that require consideration during production of animal feed and application in animals for biocontrol. The results from this study should help guide future development of phage formulations suitable for use in animal feed for animal biocontrol applications.

2016 ◽  
Vol 4 (2) ◽  
pp. 272-280 ◽  
Author(s):  
Dalong Li ◽  
Xin Huang ◽  
Yadong Wu ◽  
Jiwei Li ◽  
Weilu Cheng ◽  
...  

A well-defined core–shell nano-carrier (PAA–MHAPNs) was successfully synthesized based on a graft-onto method by using mesoporous hydroxyapatite nanoparticles (MHAPNs) as the core and polyacrylic acid (PAA) as the shell.


2020 ◽  
Vol 65 (10) ◽  
pp. 904
Author(s):  
V. O. Zamorskyi ◽  
Ya. M. Lytvynenko ◽  
A. M. Pogorily ◽  
A. I. Tovstolytkin ◽  
S. O. Solopan ◽  
...  

Magnetic properties of the sets of Fe3O4(core)/CoFe2O4(shell) composite nanoparticles with a core diameter of about 6.3 nm and various shell thicknesses (0, 1.0, and 2.5 nm), as well as the mixtures of Fe3O4 and CoFe2O4 nanoparticles taken in the ratios corresponding to the core/shell material contents in the former case, have been studied. The results of magnetic research showed that the coating of magnetic nanoparticles with a shell gives rise to the appearance of two simultaneous effects: the modification of the core/shell interface parameters and the parameter change in both the nanoparticle’s core and shell themselves. As a result, the core/shell particles acquire new characteristics that are inherent neither to Fe3O4 nor to CoFe2O4. The obtained results open the way to the optimization and adaptation of the parameters of the core/shell spinel-ferrite-based nanoparticles for their application in various technological and biomedical domains.


Author(s):  
M.T. SABITOV ◽  
A.R. FARKHUTDINOVA ◽  
M.G. MALIKOVA ◽  
N.G. FENCHENKO ◽  
N.I. KHAIRULLINA ◽  
...  

Изучена целесообразность использования в рационах телят черно-пестрой породы комплексной минерально-витаминной кормовой добавки (КМВКД). Установлено пониженное содержание в кормах таких элементов, как кальций, фосфор, магний, сера, марганец, медь, цинк и кобальт. Соотношение питательных и минеральных веществ, степень их доступности для усвоения организмом не обеспечивают их потребность. Использование КМВКД способствовало улучшению всех гематологических показателей. Все испытываемые рецепты, имеющие в своем составе разные варианты макро-, микроэлементов и витаминов положительно влияют на обменные про- цессы в организме животных. У молодняка опытной группы, получавшей подкормку по рецепту 1, количество эритроцитов в сравнении с животными контрольной группы увеличилось на 6,6, гемоглобина на 6,93 соответственно, по рецепту 2 11,05 и 11,39 по рецепту 3 16,75 и 15,27, то есть соотношение макро- и микроэлементов, имеющихся в составе КМВКД и взаимодействие между собой меди, железа и кобальта сыграли особую роль на концентрацию форменных элементов. У молодняка, получавшего подкормку по рецепту 1 количество общего белка в сравнении с животными контрольной группы увеличилось на 1,99, кальция на 16,02, каротина на 10,92 соответственно, по рецепту 2 4,91, 25,96 и 19,12 по рецепту 3 на 3,58, 27,07 и 20,21. Значительное повышение содержания белка, кальция, фосфора и каротина по сравнению с животными контрольной группы объясняется тем, что недостаток их в рационах восполнялся за счет используемой подкормки, в результате их содержание увеличилось в сыворотке, но не выходило за пределы нормативных данных и соответствовало физиологическим нормам.Practicability of using a complex mineral and vitamin feed additive (CMVFA) in the ration of black-and-white calf breed was studied. Decreased content of such elements as calcium, phosphorus, magnesium, sulfur, manganese, copper, zinc, and cobalt was registered. The correlation of nutritive and mineral substances, and the level of their availability for digestion did not provide for their need. CMVFA use facilitated the increase of all hematologic parameters. Tested recipes which had different content of sapropel and zeolite, as well as various types of macronutrients, microelements, and vitamins, positively influenced the digestive processes in animal bodies. Young stock from the test group that was receiving food additives according to recipe No. 1 showed 6.6 increase in the quantity of red blood cells compared to control group animals, and 6.93 increase in hemoglobin quantity the ones who were fed according to recipe No. 2 demonstrated the increase by 11.05 and 11.39 recipe No. 3 showed 16.75 and 15.27 increase, which means that the ratio of macronutrients and microelements present in CMVFA and the mutual interaction of copper, iron, and cobalt played a special role in the concentration of formed elements due to the fact that they are integral elements of blood. Total protein of young stock that was receiving food additives according to recipe No. 1 was 1.99 higher than in test group animals calcium 16.02 higher carotene 10.92 as for recipe No. 2 the values were increased by 4.91, 25.96, and 19.12 recipe No. 3 3.58, 27.07, and 20.21. Substantial increase in the content of protein, calcium, phosphorus, and carotene compared to control group animals can be explained by the fact that their insufficiency in animal feed was replenished due to the use of feed additives, and as a result their content increased in the serum but did not go beyond the norm and corresponded to physiological norms.


Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 72
Author(s):  
Christian Zambrzycki ◽  
Runbang Shao ◽  
Archismita Misra ◽  
Carsten Streb ◽  
Ulrich Herr ◽  
...  

Core-shell materials are promising functional materials for fundamental research and industrial application, as their properties can be adapted for specific applications. In particular, particles featuring iron or iron oxide as core material are relevant since they combine magnetic and catalytic properties. The addition of an SiO2 shell around the core particles introduces additional design aspects, such as a pore structure and surface functionalization. Herein, we describe the synthesis and application of iron-based core-shell nanoparticles for two different fields of research that is heterogeneous catalysis and water purification. The iron-based core shell materials were characterized by transmission electron microscopy, as well as N2-physisorption, X-ray diffraction, and vibrating-sample magnetometer measurements in order to correlate their properties with the performance in the target applications. Investigations of these materials in CO2 hydrogenation and water purification show their versatility and applicability in different fields of research and application, after suitable individual functionalization of the core-shell precursor. For design and application of magnetically separable particles, the SiO2 shell is surface-functionalized with an ionic liquid in order to bind water pollutants selectively. The core requires no functionalization, as it provides suitable magnetic properties in the as-made state. For catalytic application in synthesis gas reactions, the SiO2-stabilized core nanoparticles are reductively functionalized to provide the catalytically active metallic iron sites. Therefore, Fe@SiO2 core-shell nanostructures are shown to provide platform materials for various fields of application, after a specific functionalization.


Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 359
Author(s):  
Francesco Ruffino

Bimetallic nanoparticles show novel electronic, optical, catalytic or photocatalytic properties different from those of monometallic nanoparticles and arising from the combination of the properties related to the presence of two individual metals but also from the synergy between the two metals. In this regard, bimetallic nanoparticles find applications in several technological areas ranging from energy production and storage to sensing. Often, these applications are based on optical properties of the bimetallic nanoparticles, for example, in plasmonic solar cells or in surface-enhanced Raman spectroscopy-based sensors. Hence, in these applications, the specific interaction between the bimetallic nanoparticles and the electromagnetic radiation plays the dominant role: properties as localized surface plasmon resonances and light-scattering efficiency are determined by the structure and shape of the bimetallic nanoparticles. In particular, for example, concerning core-shell bimetallic nanoparticles, the optical properties are strongly affected by the core/shell sizes ratio. On the basis of these considerations, in the present work, the Mie theory is used to analyze the light-scattering properties of bimetallic core–shell spherical nanoparticles (Au/Ag, AuPd, AuPt, CuAg, PdPt). By changing the core and shell sizes, calculations of the intensity of scattered light from these nanoparticles are reported in polar diagrams, and a comparison between the resulting scattering efficiencies is carried out so as to set a general framework useful to design light-scattering-based devices for desired applications.


2021 ◽  
Vol 258 ◽  
pp. 117719
Author(s):  
Hessam Jafari ◽  
Gholam Reza Mahdavinia ◽  
Bagher Kazemi ◽  
Hermann Ehrlich ◽  
Yvonne Joseph ◽  
...  

Author(s):  
Yi Guan ◽  
Nan Li ◽  
Jiao He ◽  
Yongliang Li ◽  
Lei Zhang ◽  
...  

Herein, we report a post-assembly strategy by growing the bimetallic Co/Zn zeolitic imidazolate frameworks (BIMZIF) on the surface of the customized Mo metal-organic frameworks (MOFs) (Mo-MOF) to prepare the core-shell...


Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 502
Author(s):  
Karel Šindelka ◽  
Zuzana Limpouchová ◽  
Karel Procházka

Using coarse-grained dissipative particle dynamics (DPD) with explicit electrostatics, we performed (i) an extensive series of simulations of the electrostatic co-assembly of asymmetric oppositely charged copolymers composed of one (either positively or negatively charged) polyelectrolyte (PE) block A and one water-soluble block B and (ii) studied the solubilization of positively charged porphyrin derivatives (P+) in the interpolyelectrolyte complex (IPEC) cores of co-assembled nanoparticles. We studied the stoichiometric mixtures of 137 A10+B25 and 137 A10−B25 chains with moderately hydrophobic A blocks (DPD interaction parameter aAS=35) and hydrophilic B blocks (aBS=25) with 10 to 120 P+ added (aPS=39). The P+ interactions with other components were set to match literature information on their limited solubility and aggregation behavior. The study shows that the moderately soluble P+ molecules easily solubilize in IPEC cores, where they partly replace PE+ and electrostatically crosslink PE− blocks. As the large P+ rings are apt to aggregate, P+ molecules aggregate in IPEC cores. The aggregation, which starts at very low loadings, is promoted by increasing the number of P+ in the mixture. The positively charged copolymers repelled from the central part of IPEC core partially concentrate at the core-shell interface and partially escape into bulk solvent depending on the amount of P+ in the mixture and on their association number, AS. If AS is lower than the ensemble average ⟨AS⟩n, the copolymer chains released from IPEC preferentially concentrate at the core-shell interface, thus increasing AS, which approaches ⟨AS⟩n. If AS>⟨AS⟩n, they escape into the bulk solvent.


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