The control of the properties and biological activities of chitosan-lysozyme hybrid hydrogels to exploit their interesting biomedical applications depends largely on the chitosan acetylation pattern, ...a difficult parameter to control. Herein, we have prepared sulfated chitosan-lysozyme hydrogels as versatile platforms with fine-tuned degradability and persistent bactericidal and antioxidant properties. The use of chitosan sulfates instead of chitosan has the advantage that the rate and mechanisms of lysozyme release, as well as antibacterial and antioxidant activities, depend on the sulfation profile, a structural parameter that is easily controlled by simple chemical modifications. Thus, while 6-O-sulfated chitosan hydrogels allow the release of loaded lysozyme in a short time (60% in 24 h), due to a high rate of degradation that allows rapid antibiotic and antioxidant activities, in 3-O-sulfated systems there is a slow release of lysozyme (80% in 21 days), resulting in long-lasting antibiotic and antioxidant activities.
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Hydrogel wound dressing is a new type of biomaterial with performance that is better than traditional and biological dressings. It has been extensively researched and the application in the field of ...biomedicine is common. In this study, we developed a simple and nontoxic method for preparing a new type of composite hydrogel, which formed through the Schiff-base reaction between the aldehyde of oxidized konjac glucomannan (OKGM) and the amino of carboxymethyl chitosan sulfate (CMSS). The chemical structures of this composite hydrogel were characterized by transform infrared spectroscopy (FT-IR). The micro-morphology of hydrogels were analyzed by scanning electron microscopy (SEM). Meanwhile, the properties of composite hydrogels including gelation time, swelling ability, water evaporation rate, hemolytic potential and biological compatibility were also investigated in different means. The results gained from these studies show that this composite hydrogels have a series of properties such as short gelation time, good swelling ability, appropriate water evaporation rate, excellent hemocompatibility and well biological compatibility. Considering these excellent performance, this composite hydrogels can be used as a wound dressing to treat injured skin.
Benign electrospinning of chitosan in aqueous medium is an open challenge mainly due to its insolubility in neutral pH and inter- and intramolecular hydrogen bonding interactions. Here, we developed ...a simple and widely-used methodology to improve the chitosan electrospinnability through the sulfation of chitosan and its further mixing with poly(vinyl alcohol) for the first time. The FTIR, 1H NMR and elemental analyses showed the successful sulfation of chitosan. Furthermore, the viscosity and electrical conductivity measurements revealed the high solubility of chitosan sulfate (CS) in aqueous media. In the next step, a uniform electrospun nanofibrous mat of CS/PVA was fabricated with a fiber diameter ranging from 90 to 340 nm. The crosslinked CS/PVA (50/50) nanofibrous mat as the optimum sample showed a swelling ratio of 290 ± 4 % and a high Young's modulus of 3.75 ± 0.10 GPa. Finally, malachite green (MG) as a cationic drug model was loaded into different samples of chitosan film, CS film, and CS/PVA (50/50) nanofibrous mat and its release behavior was studied. The results of these analyses revealed that the CS/PVA (50/50) nanofibrous mat can successfully load higher contents of the MG and also release it in a sustained manner.
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•Preparation of chitosan sulfate by using an industrial recognized green and highly reactive sulfating agent gas SO3.•The synthesized chitosan sulfate had a high sulfur ...content.•Vesicles formed in the aqueous mixture of chitosan sulfate and cetyltrimethylammonium bromide.
Chitosan of high molecular weight and 85% deacetylation was used to prepare chitosan sulfate (CHS) by employing an industrial recognized green and highly reactive sulfating agent gas SO3. FT-IR and solid-state CP-MAS 13C NMR spectra confirmed that sulfate groups were successfully introduced into chitosan chains with a sulfur content of 16.50% and the substitution degree of 1.75 according to the results of elemental analysis. The aggregation behavior of the mixture of chitosan sulfate polyelectrolyte and oppositely charged surfactant cetyltrimethylammonium bromide (CTAB) was characterized by surface tension, steady-state fluorescent, turbidity, ζ potential and transmission electron microscopy. The results indicate that the CHS/CTAB mixture has pretty high surface activity and low critical aggregation concentration. The CHS/CTAB mixture successively forms spherical aggregates, precipitation, vesicles and micelle aggregates coated by CHS chains by increasing surfactant concentration due to the cooperative hydrophobic and electrostatic interactions.
•Carboxymethyl chitosan sulfate granted with collagen peptides were prepared, transglutaminase as a cross-linking agent.•The polymer has antioxidant, reductive, anticoagulant properties.•The polymer ...promotes cell growth, proliferation, differentiation.•CMCS-COP would appear to be a promising candidate for wound dressing application.
Free radicals are closely related to the occurrence and development of aging, cancer and inflammation. In this paper, the microbial transglutaminase (MTGase) was used as a catalyst to graft the collagen peptide (COP) molecules on the amino group of carboxymethyl chitosan sulfate (CMCS) to improve the antioxidant effects. FT-IR and NMR spectroscopy were used to confirm the successful grafting of COP to CMCS. Degree of substitution (DS) of CMCS-COP could be controlled by adjusting the reaction conditions. With the increase of concentration, the ability of each sample on scavenging capacity and reducibility tends to increase obviously. The results of anticoagulant experiments showed that the ability of CMCS and CMCS-COP with three different degrees of substitution on activated partial thrombin time (APTT) and prothrombin time (PT) values were all increased to compare with the control group. No relevant cytotoxicity against NIH-3T3 mouse fibroblasts was found for the copolymers. These results suggested that CMCS-COP would appear to be a promising candidate for wound dressing application.
This study aimed to investigate the effects of selenide chitosan sulfate (Se-CTS-S) on glutathione (GSH) system in hepatocytes and chickens. Chitosan, sodium selenite (Na2SeO3), selenide chitosan, ...chitosan sulfate (CTS-S), and Se-CTS-S were added to the culture medium and the basal diets; glutathione peroxidase (GSH-Px) activity, GSH content, total antioxidant capacity (T-AOC), and mRNA levels of cellular GPx (GPx-1) and phospholipid hydroperoxide GPx (GPx-4) in vivo and in vitro were determined. The results showed that Se-CTS-S increased (P < 0.05) GPx-1 and GPx-4 mRNA levels in hepatocytes and livers, and GSH-Px activity, GSH content, and T-AOC in the medium, hepatocytes, plasma, and livers compared with the control and chitosan treatments. Compared with CTS-S, Se-CTS-S treatments increased (P < 0.05) GPx-1 and GPx-4 mRNA levels in hepatocytes and livers, and GSH-Px activity, GSH content, and T-AOC capacity in the medium, hepatocytes, and livers. Compared with Na2SeO3 and CTS-Se, Se-CTS-S increased (P < 0.05) GPx-1 mRNA levels in hepatocytes and livers, GPx-4 mRNA levels in hepatocytes and livers, GSH-Px activity in the medium, hepatocytes, and livers, GSH contents in plasma and livers, and T-AOC in the medium, plasma, and livers. Thus, Se-CTS-S showed better biological activity that mainly benefited from the synergistic effects of Se and sulfate on GSH system.
•A variety of chitosan sulfate with different degree of sulfation was prepared.•Chitosan sulfate exhibited strong interaction with protein growth factors.•The effect of chitosan sulfate on neural ...stem cell depends on its chemical structure.
Despite the relevant biological functions of heparan sulfate (HS) glycosaminoglycans, their limited availability and the chemical heterogeneity from natural sources hamper their use for biomedical applications. Chitosan sulfates (ChS) exhibit structural similarity to HSs and may mimic their biological functions. We prepared a variety of ChS with different degree of sulfation to evaluate their ability to mimic HS in protein binding and to promote neural cell division and differentiation. The structure of the products was characterized using various spectroscopic and analytical methods. The study of their interaction with different growth factors showed that ChS bound to the proteins similarly or even better than heparin. In cell cultures, a transition effect on cell number was observed as a function of ChS concentration. Differences in promoting the expression of the differentiation markers were also found depending on the degree of sulfation and modification in the chitosan.
Thermoresponsive hydrogels based on ionic cellulose/chitosan are widely used various fields, such as smart windows and tissue engineering, while the effect of carbohydrate backbones of ...cellulose/chitosan on the thermal response and mechanical properties of hydrogels has received less attention so far. Herein, poly(2(dimethylamino)ethyl methacrylate) (PDMAEMA)-grafted cellulose sulfate (P-CS) and PDMAEMA-grafted chitosan sulfate (P-CHS) as research models are successfully synthesized through multi-step reactions. The P-CS and P-CHS polymers are further applied in crosslinked polyacrylamide networks, resulting in the P-CS and P-CHS hydrogels. Compared to P-CS hydrogels, P-CHS hydrogels could obviously block the transmission of visible light when the temperature is changed from 25 to 42 °C. In contrast to P-CHS hydrogels, the P-CS hydrogels change easily from soft and weak state to stiff and strong state according to their mechanical behaviors. These results indicate that different carbohydrate backbones of cellulose and chitosan should have caused distinct aggregation behaviors of corresponding P-CS and P-CHS hydrogels, which are accompanied by different light transmittance and mechanical properties.
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Thermoresponsive hydrogels using PDMAEMA-grafted ionic cellulose sulfate (P-CS) and chitosan sulfate (P-CHS) are successfully prepared. Distinct carbohydrate backbone displayed different effects on the thermoresponsive and mechanical properties of hydrogels.
•An anticoagulant polysaccharide has been employed to prepare gold nanoparticles.•The nanoparticle suspensions exhibit excellent anticoagulant action in aPPT and PT testing.•The adsorption of the ...nanoparticles on surfaces is monitored by QCM-D.•All the surfaces coated with show strong antimicrobial activity toward E. coli.•The modified surfaces feature anticoagulant action as demonstrated by QCM-D.
Simultaneous antibacterial and anticoagulant surfaces have been prepared by immobilization of engineered gold nanoparticles onto different kinds of surfaces. The gold nanoparticle core is surrounded by a hemocompatible, anticoagulant polysaccharide, 6-O chitosan sulfate, which serves as reduction and stabilizing agent for the generation of gold nanoparticles in a microwave mediated reaction. The particle suspension shows anticoagulant activity, which is investigated by aPTT and PT testing on citrated blood samples of three patients suffering from congenital or acquired bleeding disorders. The amount of nanoparticles deposited on the surfaces is quantified by a quartz crystal microbalance with dissipation unit. All gold containing surfaces exhibit excellent antimicrobial properties against the chosen model organism, Escherichia coli MG 1655 R1-16. Moreover, blood plasma coagulation times of the surfaces are increased after deposition of the engineered nanoparticles as demonstrated by QCM-D.
Enzyme immobilization on various carriers represents an effective approach to improve their stability, reusability, and even change their catalytic properties. Here, we show the mechanism of ...interaction of cysteine protease bromelain with the water-soluble derivatives of chitosan-carboxymethylchitosan,
-(2-hydroxypropyl)-3-trimethylammonium chitosan, chitosan sulfate, and chitosan acetate-during immobilization and characterize the structural features and catalytic properties of obtained complexes. Chitosan sulfate and carboxymethylchitosan form the highest number of hydrogen bonds with bromelain in comparison with chitosan acetate and
-(2-hydroxypropyl)-3-trimethylammonium chitosan, leading to a higher yield of protein immobilization on chitosan sulfate and carboxymethylchitosan (up to 58 and 65%, respectively). In addition, all derivatives of chitosan studied in this work form hydrogen bonds with His158 located in the active site of bromelain (except
-(2-hydroxypropyl)-3-trimethylammonium chitosan), apparently explaining a significant decrease in the activity of biocatalysts. The
-(2-hydroxypropyl)-3-trimethylammonium chitosan displays only physical interactions with His158, thus possibly modulating the structure of the bromelain active site and leading to the hyperactivation of the enzyme, up to 208% of the total activity and 158% of the specific activity. The FTIR analysis revealed that interaction between
-(2-hydroxypropyl)-3-trimethylammonium chitosan and bromelain did not significantly change the enzyme structure. Perhaps this is due to the slowing down of aggregation and the autolysis processes during the complex formation of bromelain with a carrier, with a minimal modification of enzyme structure and its active site orientation.
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