ABSTRACT
[This corrects the article DOI: 10.1039/D3RA03808D.].
ABSTRACT
Chitosan is produced by deacetylating the abundant natural chitin polymer. It has been employed in a variety of applications due to its unique solubility as well as its chemical and biological properties. In addition to being biodegradable and biocompatible, it also possesses a lot of reactive amino side groups that allow for chemical modification and the creation of a wide range of useful derivatives. The physical and chemical characteristics of chitosan, as well as how it is used in the food, environmental, and medical industries, have all been covered in a number of academic publications. Chitosan offers a wide range of possibilities in environmentally friendly textile processes because of its superior absorption and biological characteristics. Chitosan has the ability to give textile fibers and fabrics antibacterial, antiviral, anti-odor, and other biological functions. One of the most well-known and frequently used methods to create nanofibers is electrospinning. This technique is adaptable and effective for creating continuous nanofibers. In the field of biomaterials, new materials include nanofibers made of chitosan. Numerous medications, including antibiotics, chemotherapeutic agents, proteins, and analgesics for inflammatory pain, have been successfully loaded onto electro-spun nanofibers, according to recent investigations. Chitosan nanofibers have several exceptional qualities that make them ideal for use in important pharmaceutical applications, such as tissue engineering, drug delivery systems, wound dressing, and enzyme immobilization. The preparation of chitosan nanofibers, followed by a discussion of the biocompatibility and degradation of chitosan nanofibers, followed by a description of how to load the drug into the nanofibers, are the first issues highlighted by this review of chitosan nanofibers in drug delivery applications. The main uses of chitosan nanofibers in drug delivery systems will be discussed last.
ABSTRACT
A highly selective and ultra-sensitive electrochemical sensing probe was proposed by combining sulfated-carboxymethyl cellulose (CMC-S) and a functionalized-multiwalled carbon nanotube (f-MWNT) nano-composite with high conductivity and durability. The CMC-S/MWNT nanocomposite was impregnated on a glassy carbon electrode (GCE) to construct the non-enzymatic and mediator-free electrochemical sensing probe for trace detection of As(iii) ions. The fabricated CMC-S/MWNT nanocomposite was characterized by FTIR, SEM, TEM, and XPS. Under the optimized experimental conditions, the sensor exhibited the lowest detection limit of 0.024 nM, a high sensitivity (69.93 µA nM-1 cm-2) with a good linear relationship in the range of 0.2-90 nM As(iii) concentration. The sensor demonstrated strong repeatability, with the current response continuing at 84.52% after 28 days of use, in addition to good selectivity for the determination of As(iii). Additionally, with recovery ranging from 97.2% to 107.2%, the sensor demonstrated comparable sensing capability in tap water, sewage water, and mixed fruit juice. The electrochemical sensor for detecting trace levels of As(iii) in actual samples is anticipated to be produced by this effort and is expected to possess great selectivity, good stability, and sensitivity.
ABSTRACT
The primary goal of this study is to prepare chitosan nanoparticles (CSNPs) by the ionic gelation method via the treatment of chitosan (0.2 wt.%) with tripolyphosphate (0.2 wt.%) ultrasonically for 45 min. FT-IR spectroscopy and TEM images were used to characterize and validate CSNP production. Cellulosic materials with different concentrations of CSNPs have better antibacterial and colouring characteristics. The treated cellulosic fabrics were analyzed by FT-IR spectroscopy, SEM, and thermogravimetric analysis. Colourimetric data measurements expressed in K/S values were used to evaluate the impact of CSNPs on the dyeing affinity of cellulosic materials. In addition, antibacterial activity against bacteria and fungi was tested on the treated cellulosic fabrics. According to the K/S values, cellulosic textiles treated with CSNPs (0.3 wt.%) had a better affinity for acid dyeing. These textiles also offer better antibacterial properties and are more resistant to washing, light, and rubbing. A cytotoxicity study found that CSNPs give cellulosic materials antibacterial and acid dyeing properties, which is good for the environment.
ABSTRACT
The chemical reactivity of 3-[(E)-3-(dimethylamino)-2-propenoyl]-4-hydroxy-1-methy-2(1H)-quinolinone (1) towards some phosphorus reagents was studied. The enaminone 1 was cyclized into pyranoquinolinylphosphonate 2 via treatment with diethyl phosphite in basic medium. However, its reaction with triethoxy phosphonoacetate gave the substituted oxopyranylphosphonate 3. Using the same reaction conditions, both thioxopyridinylphosphonate 4 and oxopyranylphosphonate 5 were produced via a reaction of enaminone 1 with both diethyl 2-amino-2-thioxoethylphosphonate and diethyl vinylphosphonate, respectively, in low yields. In addition, the two novel oxopyridinylphosphonates 6 and 7 were obtained by treatment of enaminone 1 with a diethyl cyanomethylphosphonate reagent. Two oaxathiaphosphininyl derivatives, 8 and 9, were obtained by treatment of the enaminone 1 with O, O-diethyl dithiophosphoric acid under different reaction conditions. Diazaphosphininyl 11 and oxazaphosphininyl 12 derivatives were obtained in excellent yields using a P-phenylphosphonic diamide reagent under different reaction conditions. The treatment of the enaminone 1 with phosphorus pentasulfide produced the non-phosphorylated product thioxothiopyranoquinolinone 13. Finally, the enaminone was turned into oxathiaphosphininyl 14 using Lawesson's reagent. The possible reaction mechanisms of the formation of these products were discussed. The structures of newly isolated products were established by elemental analysis and spectral tools. The compounds were evaluated for their antioxidant activities.