To be effective in vivo, antisense oligonucleotides (AS ON) should be nuclease resistant, form stable ON/RNA duplexes and support ribonuclease H mediated heteroduplex cleavage, all with negligible non-specific effects on cell function. We report herein that AS ONs containing a 2′-deoxy-2′-fluoro-β-d-arabinonucleic acid (2′F-ANA) sugar modification not only meet these criteria, but have the added advantage of maintaining high intracellular concentrations for prolonged periods of time which appears to promote longer term gene silencing. To demonstrate this, we targeted the c-MYB protooncogene's mRNA in human leukemia cells with fully phosphorothioated 2′F-ANA–DNA chimeras (PS-2′FANA–DNA) and compared their gene silencing efficiency with AS ON containing unmodified nucleosides (PS-DNA). When delivered by nucleofection, chemically modified ON of both types effected a >90% knockdown of c-MYB mRNA and protein expression, but the PS-2′F-ANA–DNA were able to accomplish this at 20% of the dose of the PS-DNA, and in contrast to the PS-AS DNA, their silencing effect was still present after 4 days after a single administration. Therefore, our data demonstrate that PS-2′F-ANA–DNA chimeras are efficient gene silencing molecules, and suggest that they could have significant therapeutic potential.
20 December 2002 in Journal of the American Chemical Society
Pectin is a complex and versatile polysaccharide crucial for various industries. It functions as a thickener, gelling agent, emulsifier, and low-calorie food. Its anti-inflammatory and immunomodulatory properties have attracted biomedical interest, while its biodegradability and biocompatibility make it valuable for biomaterial applications. The effectiveness of these applications depends on the quality of pectin extraction procedures. While traditional extraction methods exist, green methodologies and alternative techniques have improved pectin’s physicochemical properties—a significant advantage for industrial applications. Pectin can be extracted from various sources, with its molecular structure and functional groups analyzed through different characterization techniques. Modern green extraction methods include ultrasound-assisted extraction, pulsed ultrasound-assisted extraction, pulsed electric field, moderate electric field mediated extraction, microwave-assisted extraction, subcritical water extraction, enzyme-assisted extraction, ohmic heating-assisted extraction, ultrasound-assisted microwave extraction, ultrasound-assisted ohmic heating extraction, hydrothermal processing, high-pressure processing extraction, and dielectric barrier discharge extraction. This review examines these methods’ advantages and disadvantages, along with their applications and future possibilities; it serves as a comprehensive guide for researchers exploring new pectin-rich sources and green extraction technologies for commercial applications.
There is an increasing demand for sustainable and safe packaging technologies to improve consumer satisfaction, reduce food loss during storage and transportation, and track the quality status of food throughout its distribution. This study reports the fabrication of colorimetric pH-indicative and flame-retardant nanocomposite films (NCFs) based on polyvinyl alcohol (PVA) and nanoclays for smart and safe food packaging applications. Tough, flexible, and transparent NCFs were obtained using 15% nanoclay loading (PVA-15) with superior properties, including low solubility/swelling in water and high thermal stability with flame-retardant behavior. The NCFs showed average mechanical properties that are comparable to commercial films for packaging applications. The color parameters were recorded at different pH values and the prepared NCFs showed distinctive colorimetric pH-responsive behavior during the transition from acidic to alkaline medium with high values for the calculated color difference (∆E ≈ 50). The prepared NCFs provided an effective way to detect the spoilage of the shrimp samples via monitoring the color change of the NCFs during the storage period. The current study proposes the prepared NCFs as renewable candidates for smart food packaging featuring colorimetric pH-sensing for monitoring food freshness as well as a safer alternative choice for applications that demand films with fire-retardant properties.
1 January 2018 in World Journal of Chemical Education
This paper presents practical applications of a laboratory inquiry for systematic chemistry learning of carbohydrates. In the laboratory inquiry, students are requested to perform qualitative tests for monosaccharides, disaccharides, and polysaccharides. In addition to that, students are instructed to distinguish specific sugars from non-specific ones. The chemical knowledge and concepts of organic chemistry are actively used to reinforce the previous learning. Such practical activities promote students' readiness for their future career as lab technicians. Our approach is also to link all written laboratory activities with infographics or illustrations to facilitate well understanding of all practical laboratory steps.