SAXS Reveals the Stabilization Effects of Modified Sugars on Model Proteins

Many proteins are usually not stable under different stresses, such as temperature and pH variations, mechanical stresses, high concentrations, and high saline contents, and their transport is always difficult, because they need to be maintained in a cold regime, which is costly and very challenging to achieve in remote areas of the world. For this reason, it is extremely important to find stabilizing agents that are able to preserve and protect proteins against denaturation. In the present work, we investigate, by extensively using synchrotron small-angle X-ray scattering experiments, the stabilization effect of five different sugar-derived compounds developed at ExtremoChem on two model proteins: myoglobin and insulin. The data analysis, based on a novel method that combines structural and thermodynamic features, has provided details about the physical-chemical processes that regulate the stability of these proteins in the presence of stabilizing compounds. The results clearly show that some modified sugars exert a greater stabilizing effect than others, being able to maintain the active forms of proteins at temperatures higher than those in which proteins, in the absence of stabilizers, reach denatured states.

Silica Nanoparticles from Coir Pith Synthesized by Acidic Sol-Gel Method Improve Germination Economics

Lignin is a natural biopolymer. A vibrant and rapid process in the synthesis of silica nanoparticles by consuming the lignin as a soft template was carefully studied. The extracted biopolymer from coir pith was employed as capping and stabilizing agents to fabricate the silica nanoparticles (nSi). The synthesized silica nanoparticles (nSi) were characterized by ultraviolet–visible (UV–Vis) spectrophotometry, X-ray diffraction analysis (XRD), Scanning Electron Microscope (SEM), Energy-Dispersive X-ray Analysis (EDAX), Dynamic Light Scattering (DLS) and Fourier-Transform Infrared Spectroscopy (FTIR). All the results obtained jointly and independently verified the formation of silica nanoparticles. In addition, EDAX analysis confirmed the high purity of the nSi composed only of Si and O, with no other impurities. XRD spectroscopy showed the characteristic diffraction peaks for nSi and confirmed the formation of an amorphous nature. The average size of nSi obtained is 18 nm. The surface charge and stability of nSi were analyzed by using the dynamic light scattering (DLS) and thus revealed that the nSi samples have a negative charge (−20.3 mV). In addition, the seed germination and the shoot and root formation on Vigna unguiculata were investigated by using the nSi. The results revealed that the application of nSi enhanced the germination in V. unguiculata. However, further research studies must be performed in order to determine the toxic effect of biogenic nSi before mass production and use of agricultural applications.

High-yield synthesis of CsPbBr3 nanoparticles: Diphenylphosphine as a reducing agent and its effect in Pb-seeding nucleation and growth

Based on the reported nucleation mechanisms for CsPbX3 and II-VI/IV-VI quantum dots, CsPbBr3 nanoparticles with a high reaction-yield, up to 393% mass-increment, were synthesized by the hot-injection method. The introduction of diphenylphosphine (DPP) as a reducing agent improved nanoparticle nucleation and growth, giving out evidence for Pb-seeding in CsPbBr3 nanoparticles formation. Additionally, a clear influence of the DPP in a CsPbBr3-Cs4PbBr6 incomplete phase transformation was observed, marked by the appearance of several PbBr2 nanoparticles, indicating the need for an improved ratio between the stabilizing agents and the precursors, due to the increased number of nucleation sites produced by the DPP. The resulting CsPbBr3 nanoparticles showed high quality, as they displayed 70%-90% photoluminescence quantum yield (PLQY), narrow size distribution with an average nanoparticle size of ~10 nm and the characteristic cubic morphology reported in previous works. This increment in CsPbBr3 nanoparticles’ reaction yield will contribute to making them a more attractive option for different optoelectronic applications.

Lattice defects induced by microtubule-stabilizing agents exert a long-range effect on microtubule growth by promoting catastrophes

Microtubules are dynamic cytoskeletal polymers that spontaneously switch between phases of growth and shrinkage. The probability of transitioning from growth to shrinkage, termed catastrophe, increases with microtubule age, but the underlying mechanisms are poorly understood. Here, we set out to test whether microtubule lattice defects formed during polymerization can affect growth at the plus end. To generate microtubules with lattice defects, we used microtubule-stabilizing agents that promote formation of polymers with different protofilament numbers. By employing different agents during nucleation of stable microtubule seeds and the subsequent polymerization phase, we could reproducibly induce switches in protofilament number and induce stable lattice defects. Such drug-induced defects led to frequent catastrophes, which were not observed when microtubules were grown in the same conditions but without a protofilament number mismatch. Microtubule severing at the site of the defect was sufficient to suppress catastrophes. We conclude that structural defects within the microtubule lattice can exert effects that can propagate over long distances and affect the dynamic state of the microtubule end.

The Polar Lipid Fraction E from Sulfolobus acidocaldarius Can Be Used as Liposomal Drug Stabilizing Agents to Reduce the Leakage of the Antivascular Drug Combretastatin A4 Disodium Phosphate from Tetraether/Diester Hybrid Archaeosomes

Liposomes have many advantages as therapeutic capsules over free drugs such as small molecule drugs and nucleic acids. Cholesterol is commonly used as a membrane stabilizing agent in liposomal drugs (e.g., mRNA-lipid nanoparticle COVID-19 vaccines). However, due to the vulnerability of cholesterol to oxidation and the etiological role of cholesterol in many disorders, it is desirable to find an alternative means to stabilize liposomal membranes for drug delivery. In this study, we demonstrated that the polar lipid fraction E (PLFE), which contains exclusively bipolar tetraether macrocyclic lipids, isolated from the thermoacidophilic archaeon S. acidocaldarius can greatly stabilize the liposomal formulation of the anti-vascular drug, combretastatin A4 disodium phosphate (CA4P). Stability was assessed by determining the leakage rate constant k of entrapped CA4P fluorometrically. We found that, at 37 °C, PLFE decreases the k value monotonically from 1.54 × 10−2 s−1 for 100% 1-palmitoyl-2-oleoyl-glycero-3-phosphocholine (POPC) liposomes to 3.4 × 10−5 s−1 for 100% PLFE archaeosomes, a change of k by two orders of magnitude. The changes in k of CA4P leakage are correlated well with the changes in liposomal CA4P’s cytotoxicity against MCF-7 breast cancer cells. We further showed that the reduction in spontaneous leakage of entrapped CA4P by PLFE can be attributed to the increased membrane surface charge and the increased membrane order and packing tightness in liposomes, as reflected by the zeta potential (−6.83 to −41.1 mV from 0 to 100 mol% PLFE) and diphenylhexatriene (DPH) fluorescence polarization (0.13 to 0.4 from 0 to 100 mol% PLFE) measurements. Moreover, we showed that PLFE slows down CA4P leakage more than cholesterol in POPC liposomes. These results together suggest that PLFE lipids can serve as an effective stabilizing agent for liposomal drugs and could potentially be useful for the optimization of liposomal CA4P for cancer treatment.

Algal Alginate in Biotechnology: Biosynthesis and Applications

Algae are recognized as the main producer of commercial alginate. Alginate produced using algae is located in the walls and intracellular regions of their cells. Its properties vary depending on the species, growing and harvesting seasons, and extraction methods. Alginate has attracted the attention of several industries, thanks to its unique properties such as its biodegradability, biocompatibility, renewability and lack of toxicity features. For example, it is considered a good encapsulation agent due to the transparent nature of the alginate matrices. Also, this biopolymer is recognized as a functional food in the food industry. It can be tolerated easily in human body and has the ability to reduce the risk of chronic diseases. Besides, it is used as an abrasive agent, antioxidant, and thickening and stabilizing agents in cosmetic and pharmaceutic industries. Generally, it is used in emulsion systems and wound dressing patches. Furthermore, this polysaccharide has the potential to be used in green nanotechnologies as a drug delivery vehicle via cell microencapsulation. Moreover, it is suitable to adopt as a coagulant due to its wide range of flocculation dose and high shear stability. In this chapter, the mentioned usage areas of algal alginate are explained in more detail.

SYNTHESIS AND CHARACTERIZATION OF COPPER OXIDE NANOPARTICLES USING AQUEOUS EXTRACT OF IRANIAN VIOLACEAE FLOWER

In this work, we have synthesized copper oxide nanoparticles using Iranian violaceae flower extract and explored its biological activity. Green synthesis has emerged as a reliable, sustainable and ecofriendly protocol for synthesizing a wide range of nanomaterials and hybrid materials. In this paper, we report the synthesis of Copper oxide nanoparticles by a simple biological route using the extract of Iranian violaceae flower and CuSO4, 5 H2O was used to synthesis the copper oxide Nanoparticles. The synthesized copper oxide nanoparticles were characterized using UV–visible spectroscopy, FTIR spectroscopy, FESEM, EDAX, and XRD techniques. UV –Visible analysis shows a characteristic peak around 266 nm for copper oxide nanoparticles and which is characteristic copper oxide nanoparticles. FTIR spectroscopy was used to characterize various capping and reducing agents present in the plant extract responsible for nanoparticle formation. The surface morphology was characterized using FESEM. The EDAX and XRD pattern suggested that prepared copper oxide nanoparticles were highly pure. The average particle size was calculated as 78.5 nm and α-copper oxide for all diffraction peaks (JCPDS card No. 41-1449) using the XRD technique. Our finding also support the synthesis of CuO NPs from Iranian violaceae flower sources due to relative abundance of plants for the production of reducing and stabilizing agents required for CuO NPs synthesis, potential efficiency of plant biomolecules in enhancing the toxicity effect of CuO NPs against microbes, prevention of environmental pollution due of nontoxic chemicals and degradation effectiveness of CuO NPs synthesized from plant sources. Furthermore, this study provides useful information on the rapid synthesis of CuO NPs with desired properties from plant extracts. Copper oxide NPs can have a good candidate for different applications.

Preparation and Characterization of Green Fe3 O4 Nanoparticle Using the Aqueous Plant Extract of Gundelia tournefortii L.

In this work, the magnetite nanoparticles (Fe3O4-NPs) synthesized using a simple, fast, and environmentally acceptable green approach. Gundelia Tournefortii Extract, an aqueous plant extract, was used for the first time in green synthesis to prepare nanoparticles as reducing, capping, and stabilizing agents. Such biomolecules as flavonoids, alkaloids, and antioxidants are found in the aqueous leaf extract, and their presence has been determined to have an important role in the synthesis of Fe3O4-NPs. The techniques used in this analysis include Fourier Transform Infrared, Scanning Electron Microscopy, Energy-Dispersive X-ray spectroscopy, X-ray Diffraction, Transmission Electron Microscopy, and Vibrating Sample Magnetometer. The Vibrating Sample Magnetometer demonstrated that the samples were superparamagnetic, with a magnetization value of 48.6 emu/g. The prepared nanoparticle was applied to remove Chrystal Violet (CV), Malachite Green(MG), and Safranin (S) dyes from prepared aqueous solutions with the adsorption capacity of 13.9, 15.6, and 14.4 mg/g respectively.

Biocompatible FePO4 Nanoparticles: Drug Delivery, RNA Stabilization, and Functional Activity

FePO4 NPs are of special interest in food fortification and biomedical imaging because of their biocompatibility, high bioavailability, magnetic property, and superior sensory performance that do not cause adverse organoleptic effects. These characteristics are desirable in drug delivery as well. Here, we explored the FePO4 nanoparticles as a delivery vehicle for the anticancer drug, doxorubicin, with an optimum drug loading of 26.81% ± 1.0%. This loading further enforces the formation of Fe3+ doxorubicin complex resulting in the formation of FePO4-DOX nanoparticles. FePO4-DOX nanoparticles showed a good size homogeneity and concentration-dependent biocompatibility, with over 70% biocompatibility up to 80 µg/mL concentration. Importantly, cytotoxicity analysis showed that Fe3+ complexation with DOX in FePO4-DOX NPs enhanced the cytotoxicity by around 10 times than free DOX and improved the selectivity toward cancer cells. Furthermore, FePO4 NPs temperature-stabilize RNA and support mRNA translation activity showing promises for RNA stabilizing agents. The results show the biocompatibility of iron-based inorganic nanoparticles, their drug and RNA loading, stabilization, and delivery activity with potential ramifications for food fortification and drug/RNA delivery.

Metal Sulfide Semiconductor Nanomaterials and Polymer Microgels for Biomedical Applications

The development of nanomaterials with therapeutic and/or diagnostic properties has been an active area of research in biomedical sciences over the past decade. Nanomaterials have been identified as significant medical tools with potential therapeutic and diagnostic capabilities that are practically impossible to accomplish using larger molecules or bulk materials. Fabrication of nanomaterials is the most effective platform to engineer therapeutic agents and delivery systems for the treatment of cancer. This is mostly due to the high selectivity of nanomaterials for cancerous cells, which is attributable to the porous morphology of tumour cells which allows nanomaterials to accumulate more in tumour cells more than in normal cells. Nanomaterials can be used as potential drug delivery systems since they exist in similar scale as proteins. The unique properties of nanomaterials have drawn a lot of interest from researchers in search of new chemotherapeutic treatment for cancer. Metal sulfide nanomaterials have emerged as the most used frameworks in the past decade, but they tend to aggregate because of their high surface energy which triggers the thermodynamically favoured interaction. Stabilizing agents such as polymer and microgels have been utilized to inhibit the particles from any aggregations. In this review, we explore the development of metal sulfide polymer/microgel nanocomposites as therapeutic agents against cancerous cells.