Environmental and Pharmacokinetic Aspects of Zeolite/Pharmaceuticals Systems—Two Facets of Adsorption Ability

Validation of microwave acid digestion, diffusive gradients in thin-film preconcentration and inductively coupled plasma optical emission spectrometry methodology for the determination of REEs in natural zeolites

The determination of rare earth element (REE) content in different natural minerals is of high interest due to their extensive use in modern and sustainable technologies. The REEs occurring in natural zeolites are specific to each deposit. This study presents the validation and evaluation of the measurement uncertainty for the determination of REEs (Ce, Dy, Er, Eu, Gd, La, Lu, Nd, Pr, Sm, Y, and Yb) in natural zeolites using microwave-assisted acid digestion and inductively coupled plasma optical emission spectrometry (ICP-OES) after diffusive gradients in thin-film preconcentration. A mixture of HNO3 : HCl : HF of 3 : 9 : 2 (v/v/v) and microwave digestion provided suitable recoveries for the analysis of two certified reference materials, CRM BCS-CRM 375/1 and CRM OREAS 460. Good linearity over the calibration range of 0-2 μg mL-1, with correlation coefficients of 0.9995-1.0000, was obtained for each REE by ICP-OES. The limits of quantification (LOQS), calculated considering the instrumental LOQs and the sample preparation by microwave digestion, were in the range of 0.20-0.60 mg kg-1. A supplementary step of preconcentration/matrix separation based on the passive sampling by diffusive gradients in thin-films (DGT) technique improved the LOQs by about 20 times after three days of passive accumulation, allowing the measurement of the concentrations of all studied REEs in natural zeolite samples. The proposed methodology is a suitable approach for the measurement of REEs at low concentrations in natural zeolite samples by ICP-OES, and it can be extended to other geological samples. The measurement uncertainty was calculated based on the validation data. The proposed method provides reliable results for the measurement of REEs in natural zeolites and was used to measure the specific concentrations of REEs in natural zeolite samples from three Romanian quarries. The REE concentration can be used as a fingerprint for each deposit.

Algal carbohydrate polymers: Catalytic innovations for sustainable development

Algal polysaccharides, harnessed for their catalytic potential, embody a compelling narrative in sustainable chemistry. This review explores the complex domains of algal carbohydrate-based catalysis, revealing its diverse trajectory. Starting with algal polysaccharide synthesis and characterization methods as catalysts, the investigation includes sophisticated techniques like NMR spectroscopy that provide deep insights into the structural variety of these materials. Algal polysaccharides undergo various preparation and modification techniques to enhance their catalytic activity such as immobilization. Homogeneous catalysis, revealing its significance in practical applications like crafting organic compounds and facilitating chemical transformations. Recent studies showcase how algal-derived catalysts prove to be remarkably versatile, showcasing their ability to customise reactions for specific substances. Heterogeneous catalysis, it highlights the significance of immobilization techniques, playing a central role in ensuring stability and the ability to reuse catalysts. The practical applications of heterogeneous algal catalysts in converting biomass and breaking down contaminants, supported by real-life case studies, emphasize their effectiveness. In sustainable chemistry, algal polysaccharides emerge as compelling catalysts, offering a unique intersection of eco-friendliness, structural diversity, and versatile catalytic properties. Tackling challenges such as dealing with complex structural variations, ensuring the stability of the catalyst, and addressing economic considerations calls for out-of-the-box and inventive solutions. Embracing the circular economy mindset not only assures sustainable catalyst design but also promotes efficient recycling practices. The use of algal carbohydrates in catalysis stands out as a source of optimism, paving the way for a future where chemistry aligns seamlessly with nature, guiding us toward a sustainable, eco-friendly, and thriving tomorrow. This review encapsulates-structural insights, catalytic applications, challenges, and future perspectives-invoking a call for collective commitment to catalyze a sustainable scientific revolution.

Zeolite Properties, Methods of Synthesis, and Selected Applications

Zeolites, a group of minerals with unique properties, have been known for more than 250 years. However, it was the development of methods for hydrothermal synthesis of zeolites and their large-scale industrial applications (oil processing, agriculture, production of detergents and building materials, water treatment processes, etc.) that made them one of the most important materials of the 20th century, with great practical and research significance. The orderly, homogeneous crystalline and porous structure of zeolites, their susceptibility to various modifications, and their useful physicochemical properties contribute to the continuous expansion of their practical applications in both large-volume processes (ion exchange, adsorption, separation of mixture components, catalysis) and specialized ones (sensors). The following review of the knowledge available in the literature on zeolites aims to present the most important information on the properties, synthesis methods, and selected applications of this group of aluminosilicates. Special attention is given to the use of zeolites in agriculture and environmental protection.

Biobased chitosan-derived self-nitrogen-doped porous carbon nanofibers containing nitrogen-doped zeolites for efficient removal of uremic toxins during hemodialysis

Highly efficient adsorbents are needed to remove uremic toxins and reduce the economic and societal burden of the current dialysis treatments in resource-limited environments. In this study, nanostructured porous carbon nanofibers with nitrogen-doped zeolites (NZ-PCNF) were prepared, by electrospinning zeolites with chitosan-poly(ethylene oxide) blends, followed by a one-step carbonization process, without further activation steps or aggressive chemical additives for N-doping. The results showed that N-zeolites were successfully integrated into an ultrafine carbon nanofiber network, with a uniform nanofiber diameter of approximately 25 nm, hierarchical porous structure (micro- and mesopores), and high specific surface area (639.29 m2/g), facilitating uremic toxin diffusion and adsorption. The self-N-doped structure in the NZ-PCNF removed more creatinine (∼1.8 times) than the porous carbon nanofibers when using the same weight of precursor materials. Cytotoxicity and hemolysis tests were performed to verify the safety of NZ-PCNF. This study provides a novel strategy for transforming chitosan-based materials into state-of-the-art porous carbon nanofiber/zeolite self-N-doped composites, affording an efficient bioderived adsorbent for the removal of uremic toxins in patients with chronic kidney disease.

Can Zeolite-Supporting Acridines Boost Their Anticancer Performance?

Acridine and its derivatives (9-chloroacridine and 9-aminoacridine) are investigated here, supported on FAU type zeolite Y, as a delivery system of anticancer agents. FTIR/Raman spectroscopy and electron microscopy revealed successful drug loading on the zeolite surface, while spectrofluorimetry was employed for drug quantification. The effects of the tested compounds on cell viability were evaluated using in vitro methylthiazol-tetrazolium (MTT) colorimetric technique against human colorectal carcinoma (cell line HCT-116) and MRC-5 fibroblasts. Zeolite structure remained unchanged during homogeneous drug impregnation with achieved drug loadings in the 18-21 mg/g range. The highest drug release, in the µM concentration range, with favourable kinetics was established for zeolite-supported 9-aminoacridine. The acridine delivery via zeolite carrier is viewed in terms of solvation energy and zeolite adsorption sites. The cytotoxic effect of supported acridines on HCT-116 cells reveals that the zeolite carrier improves toxicity, while the highest efficiency is displayed by zeolite-impregnated 9-aminoacridine. The 9-aminoacridine delivery via zeolite carrier favours healthy tissue preservation while accompanying increased toxicity toward cancer cells. Cytotoxicity results are well correlated with theoretical modelling and release study, providing promising results for applicative purposes.

Targeting Underlying Inflammation in Carcinoma Is Essential for the Resolution of Depressiveness

In modern clinical practice and research on behavioral changes in patients with oncological problems, there are several one-sided approaches to these problems. Strategies for early detection of behavioral changes are considered, but they must take into account the specifics of the localization and phase in the course and treatment of somatic oncological disease. Behavioral changes, in particular, may correlate with systemic proinflammatory changes. In the up-to-date literature, there are a lot of useful pointers on the relationship between carcinoma and inflammation and between depression and inflammation. This review is intended to provide an overview of these similar underlying inflammatory disturbances in both oncological disease and depression. The specificities of acute and chronic inflammation are considered as a basis for causal current and future therapies. Modern therapeutic oncology protocols may also cause transient behavioral changes, so assessment of the quality, quantity, and duration of behavioral symptoms is necessary to prescribe adequate therapy. Conversely, antidepressant properties could be used to ameliorate inflammation. We will attempt to provide some impetus and present some unconventional potential treatment targets related to inflammation. It is certain that only an integrative oncology approach is justifiable in modern patient treatment.

Essential Oils Encapsulated in Zeolite Structures as Delivery Systems (EODS): An Overview

Essential oils (EO) obtained from plants have proven industrial applications in the manufacturing of perfumes and cosmetics, in the production and flavoring of foods and beverages, as therapeutic agents in aromatherapy, and as the active principles or excipients of medicines and pharmaceutics due to their olfactory, physical-chemical, and biological characteristics. On behalf of the new paradigm of a more natural and sustainable lifestyle, EO are rather appealing due to their physical, chemical, and physiological actions in human beings. However, EO are unstable and susceptible to degradation or loss. To tackle this aspect, the encapsulation of EO in microporous structures as zeolites is an attractive solution, since these host materials are cheap and non-toxic to biological environments. This overview provides basic information regarding essential oils, including their recognized benefits and functional properties. Current progress regarding EO encapsulation in zeolite structures is also discussed, highlighting some representative examples of essential oil delivery systems (EODS) based on zeolites for healthcare applications or aromatherapy.