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Small interfering RNAs (siRNAs) acting via RNA interference mechanisms are able to recognize a homologous mRNA sequence in the cell and induce its degradation. The main problems in the development of siRNA-based drugs for therapeutic use are the low efficiency of siRNA delivery to target cells and the degradation of siRNAs by nucleases in biological fluids. Various approaches have been proposed to solve the problem of siRNA delivery (e.g., viruses, cationic lipids, polymers, nanoparticles), but all have limitations for therapeutic use. One of the most promising approaches to solve the problem of siRNA delivery to target cells is bioconjugation; i.e., the covalent connection of siRNAs with biogenic molecules (lipophilic molecules, antibodies, aptamers, ligands, peptides, or polymers). Bioconjugates are \"ideal nanoparticles\" since they do not need a positive charge to form complexes, are less toxic, and are less effectively recognized by components of the immune system because of their small size. This review is focused on strategies and principles for constructing siRNA bioconjugates for use.

Oleanolic acid, a naturally occurring triterpenoid compound, has garnered significant attention in the scientific community due to its diverse pharmacological properties. Continuing our previous work on the synthesis of oleanolic acid dimers (OADs), a simple, economical, and safe acetylation reaction was performed. The newly obtained derivatives (AcOADs, 3a–3n) were purified using two methods. The structures of all acetylated dimers (3a–3n) were determined based on spectral methods (IR, NMR). For all AcOADs (3a–3n), the relationship between the structure and the expected directions of pharmacological activity was determined using a computational method (QSAR computational analysis). All dimers were also tested for their cytotoxic activity on the SKBR-3, SKOV-3, PC-3, and U-87 cancer cell lines. HDF cell line was applied to evaluate the Selectivity Index of the tested compounds. All cytotoxic tests were performed with the application of the MTT assay. Finally, all dimers of oleanolic acid were subjected to DPPH and CUPRAC tests to evaluate their antioxidant activity. The obtained results indicate a very high level of cytotoxic activity (IC50 for most AcOADs below 5.00 µM) and a fairly high level of antioxidant activity (Trolox equivalent in some cases above 0.04 mg/mL).

Proteins serve as crucial functional components in food processing, with their unique physicochemical properties directly influencing the texture and stability of food products. Proteins exhibit a range of functional properties, including emulsification, foaming, gelation, and hydration. These properties arise from the structural differences in protein molecules. To equip proteins with enhanced and diversified biological functions, researchers have developed a variety of protein modification techniques. Recent breakthroughs in artificial intelligence technologies have opened new opportunities for research on protein chemical modifications. Novel algorithms based on advanced techniques, such as deep learning, image recognition, and natural language processing, have been developed for intelligent prediction of protein modification sites. The application of these AI technologies provides innovative research tools and methodological support for rational design and targeted engineering of protein functions. This review delves into the applications of chemical modification methods aimed at improving protein solubility, emulsifying capabilities, gelation capacity, antioxidant activity, antimicrobial properties, and nutritional value. These modifications alter the structural and functional attributes of proteins, significantly enhancing their performance within food systems and expanding their application prospects in such domains as medicine and biomaterials.

The introduction of biobased carbon sources in intumescent flame retardant formulations is extensively explored, particularly for biopolymers such as poly(lactic acid) (PLA). In this work, the flame retardant efficiency of alginate, a favorable renewable charring agent candidate, is enhanced by chemical modification with a phosphorus‐ and silicon‐containing compound and subsequent coagulation in the presence of Ca 2+ ions. The simultaneous presence of P and Si atoms in the reactive compound is shown to be an effective way to avoid thermal stability issues related to the biobased carbohydrate. The newly synthesized PSilAlg additive boosts the flame‐retardant effectiveness of ammonium‐polyphosphate (APP) at low loadings. Adding 5 wt% PSilAlg to 15 wt% APP containing PLA composite increases the limiting oxygen index from 26.0 to 34.0 vol% and decreases the total heat emission during combustion by 46%, accompanied by significantly (by 66%) reduced smoke production. The outstanding flame retardant performance of PSilAlg is attributed to the high amount and thermally stable carbonaceous fire‐protecting layer that forms as a result of the enhanced charring, catalyzed by the high oxidation state P, and the strengthening mechanism of inorganic silicates and calcium salts.

Izuzetna fizikalno-kemijska svojstva nanoceluloze omogućavaju njezinu primjenu u biomedicini, farmaceutskoj industriji, proizvodnji papira i konstrukcijskih materijala te u proizvodnji materijala posebnih svojstava. Danas se istražuju novi postupci proizvodnje nanoceluloze korištenjem novih tehnologija, a s ciljem smanjenja utroška energije i proizvodnje nanoceluloze naprednih svojstava. Vrsta i zastupljenost funkcionalnih grupa na površini nanoceluloze određuju njezina svojstva i potencijalnu primjenu. U ovome radu biti će opisane kemijske metode modifikacije nanoceluloze kao i utjecaj pojedine metode na fizikalno-kemijska svojstva nanoceluloze. The exceptional physical and chemical properties of nanocellulose enable the production of specific materials and applications in the fields of medicine, pharmaceuticals, paper and construction materials. New methods of producing nanocellulose are being explored today with new technologies to reduce energy consumption and obtain advanced properties of nanocellulose. The nature and presence of functional groups on the surface of nanocellulose determine its properties and potential applications. This article describes the chemical methods used to modify nanocellulose and their influence on the physicochemical properties of nanocellulose.

CRISPR-Cas9 is quickly revolutionizing the way we approach gene therapy. CRISPR-Cas9 is a complexed, two-component system using a short guide RNA (gRNA) sequence to direct the Cas9 endonuclease to the target site. Modifying the gRNA independent of the Cas9 protein confers ease and flexibility to improve the CRISPR-Cas9 system as a genome-editing tool. gRNAs have been engineered to improve the CRISPR system's overall stability, specificity, safety, and versatility. gRNAs have been modified to increase their stability to guard against nuclease degradation, thereby enhancing their efficiency. Additionally, guide specificity has been improved by limiting off-target editing. Synthetic gRNA has been shown to ameliorate inflammatory signaling caused by the CRISPR system, thereby limiting immunogenicity and toxicity in edited mammalian cells. Furthermore, through conjugation with exogenous donor DNA, engineered gRNAs have been shown to improve homology-directed repair (HDR) efficiency by ensuring donor proximity to the edited site. Lastly, synthetic gRNAs attached to fluorescent labels have been developed to enable highly specific nuclear staining and imaging, enabling mechanistic studies of chromosomal dynamics and genomic mapping. Continued work on chemical modification and optimization of synthetic gRNAs will undoubtedly lead to clinical and therapeutic benefits and, ultimately, routinely performed CRISPR-based therapies.

Central dogma is the most fundamental hypothesis in the field of molecular biology and explains the genetic information flow from DNA to protein. Beyond residue‐by‐residue transmission of sequential information, chemical modifications of DNA, RNA, and protein are also relayed in the course of gene expression. Here, this work presents recent evidence supporting bidirectional interplay between chromatin modifications and RNA modifications. Furthermore, several RNA modifications likely affect chemical modifications of proteins. The relay of chemical modifications occurs co‐transcriptionally or co‐translationally, ensuring crosstalk among chemical modifications at the DNA, RNA, and protein levels. Overall, this work proposes a hypothetical framework that represents transmission of chemical modification information among chromatin, RNA, and proteins.

The cellular ribosome shows a naturally evolved strong preference for the synthesis of proteins with standard amino acids. An in-depth understanding of the translation process enables scientists to go beyond this natural limitation and engineer translating systems capable of synthesizing proteins with artificially designed and synthesized non-standard amino acids (nsAA) featuring more bulky sidechains. The sidechains can be functional groups, with chosen biophysical or chemical activities, that enable the direct application of these proteins. Alternatively, the sidechains can be designed to contain highly reactive groups: enabling the ready formation of conjugates via a covalent bond between the sidechain and other chemicals or biomolecules. This co-translational incorporation of nsAAs into proteins allows for a vast number of possible applications. In this paper, we first systematically summarized the advances in the engineering of the translation system. Subsequently, we reviewed the extensive applications of these nsAA-containing proteins (after chemical modification) by discussing representative reports on how they can be utilized for different purposes. Finally, we discussed the direction of further studies which could be undertaken to improve the current technology utilized in incorporating nsAAs in order to use them to their full potential and improve accessibility across disciplines.

Aluminum nitride (AlN) possesses an exceptional combination of high thermal conductivity and an ultra-wide band gap, rendering it highly attractive for electronic packaging and semiconductor substrate applications. In this study, surface chemical modification of AlN powders was performed employing low-molecular-weight organic acids, successfully yielding hydrolysis-resistant AlN powders. The underlying mechanisms responsible for the improved anti-hydrolysis performance imparted by both single organic acids and the composite acid were systematically investigated using X-ray diffraction (XRD), scanning electron microscope (SEM), and transmission electron microscope (TEM), characterization techniques. The results reveal that Oxalic acid within the concentration range of 0.25 M to 1.50 M partially inhibits the hydrolysis of aluminum nitride (AlN); however, hydrolysis products such as aluminum hydroxide are still formed. In the case of citric acid, a higher concentration leads to a stronger anti-hydrolysis effect on the modified AlN. No significant hydrolysis products were detected when the AlN sample was treated in a 1 M aqueous citric acid solution at 80 °C. The effectiveness of the organic acids in enhancing the hydrolysis resistance of AlN follows the order: composite acid (citric acid + oxalic acid) > citric acid > oxalic acid. Under the action of the composite acid, the AlN diffraction peaks exhibit the highest intensity. Furthermore, TEM observations reveal the formation of an amorphous protective layer on the surface, which contributes to the improved hydrolysis resistance. Analytical results confirmed that the surface modification process, mediated by citric acid, oxalic acid, or the composite acid, involved an esterification-like reaction between the surface hydroxyl groups on AlN and the chemical modifiers. This reaction led to the formation of a continuous protective coordination layer encapsulating the AlN particles, which serves as an effective diffusion barrier against water molecules, thereby significantly inhibiting the hydrolysis reaction.

Common non-wheel-thrown Roman pottery from the southern Aquitania and north-eastern of Tarraconensis provinces (CNT-AQTA) of the Early and Later Roman Empire (1st to 5th centuries AD) has been studied. Petrological, mineralogical, and chemical analyses were conducted to contrast with the archaeological study of the pottery. The chemical composition of many pottery samples displays different patterns of burial chemical modification, limiting their use for provenance and diffusion studies. Particular emphasis has been paid to the petrographic features of the fabrics, as they do not change during burial, reflecting the nature of the raw material and making it possible to identify the provenance areas of the raw materials. Around the Bay of Biscay, the same pottery tradition continued in the neighbouring provinces during Roman times. Petrographic studies make it possible to determine the distribution of pottery and the changes in trade networks during the Roman period across the area of the Bay of Biscay being studied.