The graft copolymerization of N-vinyl-2-pyrrolidone onto carboxymethyl cellulose and its application for controlled release of water-soluble levofloxacin

Functionalization of almond gum through covalent and non-covalent interactions for biomedical applications

The versatile properties of carbohydrate polymers make them a relevant, promising precursor to design innovative materials for use in biomedical applications. Recent research mainly focuses on the development of the polysaccharide based functional materials. Hydrogel derived materials are a source of great motivation for the development of drug delivery (DD) carriers with inherent therapeutic potential. Herein, almond gum-based hydrogels were synthesized for the delivery of the anticancer drug methotrexate after impregnation to improve the DD profile. Hydrogels were characterized by FESEM, EDS, AFM, 13C NMR, FTIR, TGA, DSC, XRD, mechanical strength & biomedical assay. The optimized network hydrogel exhibited a mesh size of 19.764 mm and a cross-linking density of 5.002 × 10-5 mol/cm3 of the hydrogels. Morphological features revealed irregular, uneven internal morphology of hydrogels in FE-SEM. The inclusion of sulphated and amide polymers in hydrogels was found in elemental composition (C = 60.72 %, O = 29.79 %, N = 6.63 % and S = 2.86 %) of hydrogels inferred from EDS. Spectroscopic characterization by FT-IR and 13C NMR confirmed the inclusion of PVP and PVSA through grafting reaction. The crosslinked product formed was found thermally stable and amorphous in nature through TGA and XRD analysis. The sustained release was found through supramolecular interactions and release complied a non-Fickian mechanism for drug diffusion (n = 0.73) and the release profile was best described by the Hixson-Crowell kinetic model in colonic pH. The hydrogels were mucoadhesive in nature and required 144 ± 10.54 mN force for the separation of hydrogels from the mucosal surface during the adhesion test. Hydrogel illustrated antioxidant activity (32.68 ± 0.83 μg GAE) during their radical scavenging test by FC reagent assay. Drug encapsulated hydrogels demonstrated antimicrobial efficacy against microbes. The results of physico-chemical and biomedical properties of hydrogels suggested their suitability for biomedical uses.

Challenges associated with cellulose composite material: Facet engineering and prospective

Cellulose is the most abundant polysaccharide on earth. It has a large number of desirable properties. Its low toxicity makes it more useful for a variety of applications. Nowadays, its composites are used in most engineering fields. Composite consists of a polymer matrix and use as a reinforcing material. By reducing the cost of traditional fibers, it has an increasing demand for environment-friendly purposes. The use of these types of composites is inherent in moisture absorption with hindered natural fibers. This determines the reduction of polymer composite material. By appropriate chemical surface treatment of cellulose composite materials, the effect could be diminished. The most modern and advanced techniques and methods for the preparation of cellulose and polymer composites are discussed here. Cellulosic composites show a reinforcing effect on the polymer matrix as pointed out by mechanical characterization. Researchers tried their hard work to study different ways of converting various agricultural by-products into useful eco-friendly polymer composites for sustainable production. Cellulose plays building blocks, that are critical for polymer products and their engineering applications. The most common method used to prepare composites is in-situ polymerization. This help to increase the yields of cellulosic composites with a significant enhancement in thermal stability and mechanical properties. Recently, cellulose composites used as enhancing the incorporation of inorganic materials in multi-functional properties. Furthermore, we have summarized in this review the potential applications of cellulose composites in different fields like packaging, aerogels, hydrogels, and fibers.

Preparation and Photochromic Performance of Homogeneous Phase Nitrocellulose Membrane Grafting Spirooxazine Moieties

The synthesis of 1,3,3-trimethyl-9′-acryloxyspiro[indoline-2,3′(3H)naphtho[2,1-b][l,4]-oxazine] (AISO) was carried out by catalytic esterification of 1,3,3-trimethyl-9′-hydroxyspiro-[indoline-2,3′(3H)naphtho[2,1-b][l,4]oxazine] (SO–OH) and acrylic acid in the presence of 1,3-dicyclohexylcarbodiimide (DCC) and N-dimethylaminopyridine (DMAP). Then, the synthesis of the target copolymer (NC-g-AISO) was was carried out by benzoyl peroxide (BPO)-induced graft copolymerization of the AISO monomer onto nitrocellulose (NC) in a homogeneous methyl isobutyl ketone medium. The structure of NC-g-AISO was characterized by Fourier transform infrared (IR) spectroscopy, 13C Nuclear Magnetic Resonance (NMR) spectra and thermogravimetric (TG) analysis. The photochromic properties of NC-g-AISO were investigated by examining UV–Vis spectra in ethyl acetate solution and solid membrane. Compared with the AISO monomer in ethyl acetate solution, the thermal color decay stability of the colored form of NC-g-AISO in ethyl acetate solution and in solid membrane improved significantly. The thermal color decay reaction rate constants in ethyl acetate solution and membrane at 25 °C were 1.77 × 10–2 and 1.36 × 10–3 s–1, respectively, fitted using the first-order reaction equation. After ten photochromic cycles, the relative absorption intensity of the colored form of NC-g-AISO decreased by 0.85%, indicating that the NC-g-AISO membrane has good reversible photochromic behavior.