With the increased stress in people’s daily lives, the secretion of sweat from the human body has steadily increased. Therefore, textile industries continue to introduce various products to meet ...consumers’ demands. Thus far, people use more cotton and polyester fabrics among other textile fabrics in their daily usage or total living period. Textile products, especially those made from cellulose fibers such as cotton, can promote the growth of microorganisms due to their high surface area and moisture retention. In contrast to cellulosic materials, polyester contains no chemically functional or hydrophilic groups. Therefore, it is necessary to ensure wearers’ protection as both cotton and polyester can create unwanted odors due to the decomposition of sweat by microorganisms. The application of chitosan on textile substrates is a useful approach for textile functionalization. Chitosan has been reported as a popular finishing agent due to its intrinsic properties, such as biocompatibility, biodegradability, non-toxicity, abundance in nature, antimicrobial, and antistatic ability, etc. In this study, the solution of chitosan was applied to 100 % cotton and polyester fabrics using a common pad-dry-cure technique. The resulting fabrics were characterized by drop-test, scanning electron microscopy (SEM), and color measurement. Thus, this study presents a small overview of the finishing using chitosan-containing recipes on both cotton and polyester fabrics.
Mucoadhesive gelling systems based on chitosan and chitosan/β-glycerophosphate (β-GP) were developed in order to increase clotrimazole residence time in the vaginal cavity. Ex vivo mucoadhesiveness ...using porcine vaginal mucosa followed with mechanical, viscoelastic, and swelling properties of prepared hydrogels were evaluated. Drug-free, sterile, unmodified, and β-GP crosslinked chitosan were investigated for the in vitro cytotoxicity in CRL 2616 human vaginal mucosa cells using MTT assay, fluorescent microscopy, and flow cytometry analysis. Chitosan/β-GP hydrogels exhibited pseudoplastic and thixotropic properties. Ionic interaction between β-GP and chitosan improved mechanical properties of hydrogels in terms of hardness, cohesiveness, and compressibility. The hydrogels’ ability to interact with porcine vaginal mucosa (measured as force of detachment and work of adhesion) was comparable to those obtained with reference mucoadhesive gel Replens™. Surprisingly, greater mucoadhesive properties were noticed for chitosan/β-GP hydrogels. The cytotoxic effect of unmodified and β-GP crosslinked chitosan was hardly affected by chitosan molecular weight, exhibited mainly through inducing apoptosis, and was found to be significantly lower in the presence of chitosan/β-GP. Furthermore, the higher amount of β-GP was used to crosslink chitosan, the lower cytotoxic effect was observed.
•Magnetic carboxymethyl chitosan nanoparticles (short as Fe3O4 (PEG+CM-CTS)).•Lysozyme would adopt a more compact conformation state after immobilization.•Immobilized trypsin (short as IT).•IT could ...be used for fast and efficient BSA digestion under very facile processes.•IT exhibited 76.3% of the initial activity after re-uses for six times.
Immobilization of trypsin onto the superparamagnetic carboxymethyl chitosan (Fe3O4 (PEG+CM-CTS)) nanoparticles was studied. FTIR and fluorescence spectroscopy data demonstrated that the Fe3O4 (PEG+CM-CTS) nanoparticles were capable of preventing the trypsin unfolding. Due to the large specific surface area and excellent dispersibility, the adsorption equilibrium of trypsin onto the nanoparticles was achieved quickly within 30min. The results of kinetic parameters (Michaelis constant, Km) with regards to the free trypsin (FT) and immobilized trypsin (IT) were 23.1 and 24.1mg/mL separately, implying that IT has less affinity to the BAEE used as the substrate. However, the MALDI-TOF MS analysis indicated that, IT could be used for fast and efficient Bovine Serum Albumin (BSA) digestion under very facile processes, thanks to the easy manipulation of the magnetic nanoparticles (MNs), as well as the greatly reduced digestion time (from 12h to 15min). IT exhibited a sound stability after re-uses for six times, with 76.3% of the initial activity thereof still retained, thus making it more attractive in the application fields. These results are expected to open up a great potential use of such Fe3O4 (PEG+CM-CTS) nanoparticles as a superior nanosupport for trypsin immobilization.
The possibility of creating a self-expanding stent, consisting of a combination of the saline and the basic form of chitosan have been discussed. The 2 % chitosan solution in 4 % citric acid have ...been prepared. The spinning solution have been coated onto an inert substrate in a volume of 0.2-0.25 ml/cm2. Chitosan film (saline form) have been obtained by evaporation of the solvent at room temperature under static conditions. Chitosan film thickness have been measured with a micrometer. Samples of chitosan stents have been formed by winding a chitosan film on the plastic tube. The optimal concentration of NaOH and the dwell time for transfer of chitosan in the form of a saline form to basic form have been defined. The stents photos with a hundredfold magnification and AFM-images of the samples surface have been obtained. The estimate of the stent elongation at break (e) (31-46 %) have been evaluated and have been found that the data on this indicator stents are higher than those obtained from the films form with acetic acid (17 %). These results open up the possibility to create biocompatible biliary stents with their subsequent modification of the active drug substance, which gives hope for improvement of treatment results in patients with obstruction of extrahepatic bile ducts.
This article presents the results of the development process for the preparation of micro and nano-sized polymer-colloid com-plexes (РСС) on the basis of water-soluble natural polymer chitosan (СTZ) ...and the sodium salt of chitosan succinylamid (SСTZ) with silver halide sols in aqueous media. Results of research of СTZ, sodium salt of SСTZ solutions and PСС of CTZ and SСTZ with colloidal parti-cles of silver iodide influence on structurally-functional properties of erythrocytes’ membranes on model of acidic hemolisis are presented in the article. Their influence on the nature of erythrocytes distribution by degree of their stability and on kinetic parameters (the beginning, intensity and completion of process of their destruction) under the influence of the damaging agent (HCl) is shown. The comparative analysis of results convinces that СTZ, SСTZ solutions and disperse systems on the basis of PСС of СTZ and SСTZ with colloidal particles of the silver iodide are capable of modulating variously matrix properties of erythrocytes of blood.
The kinetics of the adsorption at the air-water interface and the processes of the structure formation inside the adsorption layers of hydrophobically modified systems alkylated chitosans and sodium ...dodecyl sulfate (SDS)-chitosan (Ch) complexes have been studied by the tensiometric method based on the axisymmetric rising-bubble-shape analysis as a function of the bulk concentration of polymers and the ageing time of their adsorption layers. The kinetics of the adsorption of chitosan, alkylated chitosans (ChC^sub 3^, ChC^sub 8^, and ChC^sub 12^), and surfactant-polyelectrolyte (PE) complexes formed by the chitosan and the polysoaps with oppositely charged anionic surfactant SDS is characterized by an induction time (the so-called lag time), τ^sub lag^, corresponding to the diffusion stage of the formation of adsorption layers. During this time, the decrease in the surface tension (or the increase in the surface pressure π) does not exceed several millinewtons per meter that corresponds to the "gaseous" state of adsorption layers. The postlag stage of the formation of the adsorption layer is characterized by the remarkable rate of increase in the surface pressure π that corresponds to the conformational rearrangement of PEs inside the adsorption layer by increasing the number of hydrophobic groups (adsorbing centres) in contact with the non-polar phase at the interface. It has been found that during the lag time, the adsorption of alkylated chitosans (cationic polysoaps) increases with increasing alkyl chain length, whereas during the postlag time, the adsorption of the ChC^sub 3^ is maximal with regard to other polysoaps. It has been confirmed that at equal content of alkyl groups in the system, the surface activity of the SDS-Ch complexes is much higher with regard to that of the polysoaps. The viscoelasticity of adsorption layers of individual PEs and their complexes continuously increases with the ageing time, giving evidence for the interaction between the polymers inside the adsorption layers. It has been found that the rate of increase in the dilational storage module E' of the adsorption layers of SDS-Ch complexes is much higher than for the polysoaps that correlates with the higher surface activity of the former with regard to the latter. For the mentioned systems, the module E' is much higher than the loss module E'' that confirms the solid-like properties of their adsorption layers. On the other hand, the adsorption layers of the chitosan are liquid-like, while E'<<E''.PUBLICATION ABSTRACT
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