Deep eutectic solvents induced changes in the phase transition behavior of smart polymers: a sustainable future approach.

Deep eutectic solvents (DESs) are considered "green" and "sustainable" alternatives to conventional organic solvents and ionic liquids (ILs) due to their characteristic properties and relatively low costs. DESs are considered IL analogs and have attracted consideration as benign media formulations for the synthesis of novel polymers because they satisfy the principle of sustainability. Over the past few years, the use of DESs has resulted in novel pathways for the synthesis of novel materials, biomaterials, functional materials, and ionic soft materials. Furthermore, DESs have been widely applied in the science, industrial, engineering, and technological fields. On the other hand, stimulus-responsive (smart) polymers have been widely utilized in intelligent devices owing to their virtues of good processibility, stimuli and environmental sensitivity, responsivity, and so on. With the introduction of a DES into the smart polymeric matrices, their potential characteristics, biocompatibility, and flexibility endow the corresponding DES-based polymeric materials with intriguing properties, which in turn will broaden their applications in various domains of polymer science and material chemistry. Substantial research has been done in the fabrication of DES-based polymeric materials. Numerous studies have extensively investigated the effects of DESs on biomolecules such as proteins/enzymes and nucleic acids, whereas few have addressed the impact of DESs on the aggregation and phase transition behaviors of smart polymers. This review focuses on mechanistic insights, aggregation behavior, and interactions between smart polymers and DESs. Opportunities and future research perspectives in this blossoming arena are also discussed. It is hoped that this review will pave futuristic pathways for the design and development of advanced DES-based polymeric materials and biomaterials for various applications.

Sustainable production of Saussurea costus under different levels of nitrogen, phosphorus and potassium fertilizers in cold desert region of Western Himalaya.

Introduction: Saussurea costus, an important critically endangered medicinal herb native to the Himalayan region, is commonly used in various ailments, viz. asthma, ulcer, inflammation, and stomach problems. In the international market, the dry roots and essential oil of S. costus has become an important drug. The lack of appropriate fertilizer dose recommendations is one of the limiting factors for its ex-situ conservation and large-scale cultivation, as plant nutrition is vital in determining crop growth and productivity. The study aimed to understand the comparative impact of different levels of fertilizer nutrients on growth, dry root and essential oil yield, and essential oil profile of S. costus. Methods: A field experiment was conducted in Himachal Pradesh, India's cold desert region (Lahaul valley), during 2020-21. The experiment comprised three levels of nitrogen (60, 90, and 120 kg ha-1), three levels of phosphorus (20, 40, 60 kg ha-1), and two levels of potassium (20 and 40 kg ha-1) in a factorial randomized block design. Results: The fertilizer application had an immense effect on growth attributes, root yield attributes, dry root yield, and essential oil yield over control. The treatment combination N120, P60, and K40 had the largest effect on the plant height, number of leaves per plant, leaf length and width, root length and diameter, dry matter per plant, dry root yield, and essential oil yield. However, the results were at par with the treatment comprising N90, P40, and K20. Dry root yield increased by 108.9%, and essential oil yield increased by 210.3% with fertilizer applications over unfertilized plots. The regression curve shows an increasing trend in dry root yield till N90, P40, and K20; after that, it nearly stabilized. The heat map showed that applying fertilizer significantly affected the chemical constituents of S. costus essential oil. Similarly, the plots fertilized with the highest level of NPK recorded the utmost value of available N, P, and K, as compared to unfertilized plots. Discussion: The results emphasize that for sustainable cultivation of S. costus, the application of N90, P40, and K20 combinations is the most suitable one.

Impact of ZIF-8, ArgHCl, and Ionic Liquid-Based Formulations on the Conformational and Colloidal Stability of Antibodies.

Various formulations consisting of biomaterials zirconium imidazolate framework-8 (ZIF-8), choline acetate ([Ch][Ac]), and arginine hydrochloride (argHCl) are optimized to study the stability of antibody, Immunoglobulin G (IgG). We have performed several instrumentations including UV-visible spectroscopy, dynamic light scattering (DLS), circular dichroism (far UV CD), and atomic force microscopy (AFM) in the presence of all the formulations to investigate the conformational and colloidal stability of the antibodies. Alongside, the packing efficiency of all the formulations was also explored by storing IgG at 4 °C for 3 months. We have tried to investigate the interactions between biomaterials and antibodies with the motive of designing aggregation-resistant formulations. The overall stability of IgG was improved in the presence of [Ch][Ac]; however, ZIF-8 and argHCl cause relatively more aggregation, although the structure was retained in all the formulations. The key aspect of this study is that the presence of [Ch][Ac] increases ZIF-8@IgG's thermal stability and resistance to IgG-argHCl aggregation. All over, for the first time, with different experimental approaches, the impact of each biomaterial individually and in combination is explored to study their effect on the stability of antibodies. Thus, better efficient formulations can be designed for the storage/packaging of IgG-based drugs which ultimately will have more applicability in pharmaceuticals.

Fortification of thermal and structural stability of hemoglobin using choline chloride-based deep eutectic solvents.

Of late, DESs have occupied the centre stage due to their eco-friendly and resource-efficient nature and their low toxicity. In this work, we have investigated the structural and thermal stability of hemoglobin (Hb) in two choline chloride ([Ch]Cl)-based DESs namely urea [Ch]Cl-urea (DES1) and [Ch]Cl-glycerol (Gly); (DES 2). Different biophysical techniques reveal that the presence of DESs facilitates the stability of Hb in a concentration-dependent manner and the extent of stability is more pronounced in [Ch]Cl-Gly as compared to [Ch]Cl-urea. Additionally, for a better understanding of the role of DESs in modulating the thermal and structural stability of Hb, studies have been performed on Hb in the presence of individual constituents of DESs, i.e., [Ch]Cl, urea, and Gly. Altogether, it was observed that the effect on the stability of Hb was by the presence of the DESs rather than their individual constituents. For instance, urea itself is a destabilizing co-solvent for biomolecules. However, the harmful effects of urea were surpassed when a DES is formed in the presence of [Ch]Cl. Therefore, overall, it can be concluded that both DESs can be described as potential non-harmful, green, and promising solvents for enhancing the structural and thermal stability of Hb.