Interferon production by Viral, Bacterial & Yeast system: A comparative overview in 2023.

Interferons play a critical role in the innate immune response against several infections and play a key role in the control of a variety of viral and bacterial infectious diseases such as hepatitis, covid-19, cancer, and multiple sclerosis. Therefore, natural or synthetic IFN production is important and had three common methods, including bacterial fermentation, animal cell culture, and recombinant nucleic acid technology. However, the safety, purity, and accuracy of the most preferred INF production systems have not been extensively studied. This study provides a comprehensive comparative overview of interferon production in various systems that include viral, bacterial, yeast, and mammalian. We aim to determine the most efficient, safe, and accurate interferon production system available in the year 2023. The mechanisms of artificial interferon production were reviewed in various organisms, and the types and subtypes of interferons produced by each system were compared. Our analysis provides a comprehensive overview of the similarities and differences in interferon production and highlights the potential for developing new therapeutic strategies to combat infectious diseases. This review article offers the diverse strategies used by different organisms in producing and utilizing interferons, providing a framework for future research into the evolution and function of this critical immune response pathway.

Crystallization and Rheology of Mono- and Diglycerides and Their Role in Stabilization of Emulsion Droplets in Model Topical Ointments.

The crystallization behavior of commercial mono- and diglycerides (MDG) in paraffin oil is studied to develop an in-depth understanding of the polymorphic transitions useful for the physical stability of petroleum oil-based topical emulsions. Optical microscopy and differential scanning calorimetry measurements showed the formation of plate-like and spherulite crystals at high and low temperatures, in sequence, while cooling a solution of MDG dissolved in oil. High-resolution NMR and X-ray scattering demonstrate that 1-monoglycerides (mixture of 1-glyceride monostearate and 1-glyceride monopalmitate) cocrystallize to an inverse-lamellar structure (Lα polymorph) that mainly forms plate-like crystals at a higher temperature. The Lα polymorph is seen to exist up to room temperature during the cooling process. At lower temperatures, 1,3-diglycerides (mixture of 1,3-glyceryl distearate and 1,3-glyceryl dipalmitate) crystallize into ß-polymorphs that form spherulites. The spherulites tend to assemble into elongated strands via aggregation, leading to the formation of a percolating network structure. The sizes of both types of crystals decrease with an increasing cooling rate, leading to a higher mechanical modulus due to the increased network connectivity of spherulites. In an emulsion, monoglycerides in the form of Lα polymorphs having plate-like crystal morphology show a higher affinity to the polar liquid/oil interface, thereby providing better interfacial stability compared to the spherulitic ß-polymorphs. However, diglycerides in the form of spherulites form bulk network structures which provide network stabilization to the suspended droplets. This work demonstrates that MDG, a commercially available ingredient that combines the differential functionality of monoglycerides and diglycerides, is an effective, bifunctional, emulsifying agent for petrolatum-based topical emulsions.

Pinhole mirror-based ultra-small angle light scattering setup for simultaneous measurement of scattering and transmission.

An ultra-small angle light scattering setup with the ability of simultaneous registration of scattered light by a charge-coupled device camera and the transmitted direct beam by a pin photodiode was developed. A pinhole mirror was used to reflect the scattered light; the transmitted direct beam was focused and passed through the central pinhole with a diameter of 500 µm. Time-resolved static light scattering measurement was carried out over the angular range 0.2° ≤θ≤ 8.9° with a time resolution of ∼33 ms. The measured scattering pattern in the q-range between 5 × 10-5 and 1.5 × 10-3 nm-1 enables investigating structures of few micrometers to submillimeter, where q is the scattering vector. A LabVIEW-based graphical user interface was developed, which integrates the data acquisition of the scattering pattern and the transmitted intensity. The Peltier temperature-controlled sample cells of varying thicknesses allow for a rapid temperature equilibration and minimization of multiple scattering. The spinodal decomposition for coacervation (phase separation) kinetics of an aqueous mixture of oppositely charged polyelectrolytes was demonstrated.

Molecular Mass Dependence of Interfacial Tension in Complex Coacervation.

The interfacial tension of coacervates, the liquidlike phase composed of oppositely charged polymers that coexists at equilibrium with a supernatant, forms the basis for multiple technologies. Here we present a comprehensive set of experiments and molecular dynamics simulations to probe the effect of molecular mass on interfacial tension γ, far from the critical point, and derive γ=γ_{∞}(1-h/N), where N is the degree of polymerization, γ_{∞} is the infinite molecular mass limit, and h is a constant that physically corresponds to the number of monomers of one chain within the coacervate correlation volume.

Ultra-small angle neutron scattering to study droplet formation in polyelectrolyte complex coacervates.

Associating soft matter such as surfactants, polymers, proteins, and liposomes, may form structures with dimensions not readily accessible by optical methods. Scattering methods can provide detailed information about the mechanism of associative phase separation including nucleation density, size, and shape. Ultra-small angle neutron scattering, a reciprocal space method, provides sensitivity to submicron to micron-scale structures in a non-invasive manner and described in the context of nucleation and growth of dilute droplets formed by a temperature jump into the meta-stable region of polyelectrolyte complex coacervates.

Characterization of the Ultralow Interfacial Tension in Liquid-Liquid Phase Separated Polyelectrolyte Complex Coacervates by the Deformed Drop Retraction Method.

Dilute droplets form upon changing the temperature of a phase separated polyelectrolyte complex coacervate. This provides an in situ approach to measure the interfacial tension between supernatant (dilute droplet) and dense coacervate by the deformed drop retraction (DDR) method. The aqueous coacervate, formed via a model 1:1 by charge stoichiometric polyelectrolyte blend, exhibits ultralow interfacial tension with the coexisting phase. DDR finds the interfacial tension scales as γ = γ 0(1 - C s/C s,c) µ , with µ = 1.5 ± 0.1, γ 0 = 204 ± 36 µN/m, and C s,c = 1.977 mol/L. The value of µ independently validates the classical exponent of 3/2. The scaling holds between C s/C s,c of 0.75 to 0.94, the closest measurements to date near the critical salt concentration (C s,c). The temperature dependence of the interfacial tension is consistent with observed lower critical solution phase behavior and classical scaling. A detailed account of the DDR method and validation of assumptions are demonstrated.

Lower Critical Solution Temperature in Polyelectrolyte Complex Coacervates.

A model linear oppositely charged polyelectrolyte complex exhibits phase separation upon heating consistent with lower critical solution temperature (LCST) behavior. The LCST coexistence curves narrow with increasing monovalent salt concentration (C s) that reduces the polymer concentration (C p) in the polymer-rich phase. The polymer-rich phase exhibits less hydration with increasing temperature, while an increase in C s increases the hydration extent. The apparent critical temperature, taken as the minimum in the phase diagram, occurs only for a narrow range of C s. Mean field theory suggests an increasing Bjerrum length with temperature can lead to an electrostatic-driven LCST; however, the temperature dependence of the Flory-Huggins interaction parameter and solvation effects must also be considered.

Relaxation Behavior by Time-Salt and Time-Temperature Superpositions of Polyelectrolyte Complexes from Coacervate to Precipitate.

Complexation between anionic and cationic polyelectrolytes results in solid-like precipitates or liquid-like coacervate depending on the added salt in the aqueous medium. However, the boundary between these polymer-rich phases is quite broad and the associated changes in the polymer relaxation in the complexes across the transition regime are poorly understood. In this work, the relaxation dynamics of complexes across this transition is probed over a wide timescale by measuring viscoelastic spectra and zero-shear viscosities at varying temperatures and salt concentrations for two different salt types. We find that the complexes exhibit time-temperature superposition (TTS) at all salt concentrations, while the range of overlapped-frequencies for time-temperature-salt superposition (TTSS) strongly depends on the salt concentration (Cs) and gradually shifts to higher frequencies as Cs is decreased. The sticky-Rouse model describes the relaxation behavior at all Cs. However, collective relaxation of polyelectrolyte complexes gradually approaches a rubbery regime and eventually exhibits a gel-like response as Cs is decreased and limits the validity of TTSS.

Aggregation and stability of anisotropic charged clay colloids in aqueous medium in the presence of salt.

Na-montmorillonite nanoclay is a colloid of layered mineral silicate. When dispersed in water, this mineral swells on absorption of water and exfoliates into platelets with electric double layers on their surfaces. Even at low particle concentration, the aqueous dispersion can exhibit a spontaneous ergodicity breaking phase transition from a free flowing liquid to nonequilibrium, kinetically arrested and disordered states such as gels and glasses. In an earlier publication [Applied Clay Science, 2015, 114, 8592], we showed that the stability of clay gels can be enhanced by adding a salt later to the clay dispersion prepared in deionized water, rather than by adding the clay mineral to a previously mixed salt solution. Here, we directly track the collapsing interface of sedimenting clay gels using an optical method and show that adding salt after dispersing the clay mineral does indeed result in more stable gels even in very dilute dispersions. These weak gels are seen to exhibit a transient collapse after a finite delay time, a phenomenon observed previously in depletion gels. The velocity of the collapse oscillates with the age of the sample. However, the average velocity of collapse increases with sample age up to a peak value before decreasing at higher ages. With increasing salt concentration, the delay time for transient collapse decreases, while the peak value of the collapsing velocity increases. Using ultrasound attenuation spectroscopy, rheometry and cryogenic scanning electron microscopy, we confirm that morphological changes of the gel network assembly, facilitated by thermal fluctuations, lead to the observed collapse phenomenon. Since clay minerals are used extensively in polymer nanocomposites, as rheological modifiers, stabilizers and gas absorbents, we believe that the results reported in this work are extremely useful for several practical applications and also for understanding geophysical phenomena such as the formation and stability of quicksand and river deltas.

Effect of electrolytes on the microstructure and yielding of aqueous dispersions of colloidal clay.

Na-montmorillonite is a natural clay mineral and is available in abundance in nature. The aqueous dispersions of charged and anisotropic platelets of this mineral exhibit non-ergodic kinetically arrested states ranging from soft glassy phases dominated by interparticle repulsions to colloidal gels stabilized by salt induced attractive interactions. When the salt concentration in the dispersing medium is varied systematically, viscoelasticity and yield stress of the dispersion show non-monotonic behavior at a critical salt concentration, thus signifying a morphological change in the dispersion microstructures. We directly visualize the microscopic structures of these kinetically arrested phases using cryogenic scanning electron microscopy. We observe the existence of honeycomb-like network morphologies for a wide range of salt concentrations. The transition of the gel morphology, dominated by overlapping coin (OC) and house of cards (HoC) associations of clay particles at low salt concentrations to a new network structure dominated by face-face coagulation of platelets, is observed across the critical salt concentration. We further assess the stability of these gels under gravity using electroacoustics. This study, performed for concentrated clay dispersions for a wide concentration range of externally added salt, is useful in our understanding of many geophysical phenomena that involve the salt induced aggregation of natural clay minerals.

Use of ultrasound attenuation spectroscopy to determine the size distribution of clay tactoids in aqueous suspensions.

The dispersion processes of aqueous samples of clay are studied using ultrasound attenuation spectroscopy. The attenuation spectra that are acquired in the frequency range 10-100 MHz are used to determine the particle size distributions (PSDs) for different concentrations and ages of the clay suspensions. Our analysis, using equivalent spherical diameter (ESD) for circular discs under Stokes drag in samples of concentrations greater than 1.5% w/v, shows that a substantial fraction of the aggregates in suspension are actually tactoids that are composed of more than one platelet. This is in contrast to the general belief that clay disperses into individual platelets in the concentration range where their suspensions exhibit glassy behavior. We conclude that the incomplete fragmentation of the clay tactoids arises from the rapid enhancement of the intertactoid Coulombic repulsion.