Rhodamine B-Containing Chitosan-Based Films: Preparation, Luminescent, Antibacterial, and Antioxidant Properties.

In this study, Rhodamine B-containing chitosan-based films were prepared and characterized using their mechanical, photophysical, and antibacterial properties. The films were synthesized using the casting method and their mechanical properties, such as tensile strength and elongation at break, were found to be dependent on the chemical composition and drying process. Infrared spectroscopy and X-ray diffraction analysis were used to examine the chemical structure and degree of structural perfection of the films. The photophysical properties of the films, including absorption spectra, fluorescence detection, emission quantum yields, and lifetimes of excited states, were studied in detail. Rhodamine B-containing films exhibited higher temperature sensitivity and showed potential as fluorescent temperature sensors in the physiological range. The antibacterial activity of the films was tested against Gram-positive bacteria S. aureus and Gram-negative bacteria E. coli, with Rhodamine B-containing films demonstrating more pronounced antibacterial activity compared to blank films. The findings suggest that the elaborated chitosan-based films, particularly those containing Rhodamine B can be of interest for further research regarding their application in various fields such as clinical practice, the food industry, and agriculture due to their mechanical, photophysical, and antibacterial properties.

Chitosan and Its Derivatives: Preparation and Antibacterial Properties.

This comprehensive review illuminates the various methods of chitosan extraction, its antibacterial properties, and its multifarious applications in diverse sectors. We delve into chemical, physical, biological, hybrid, and green extraction techniques, each of which presents unique advantages and disadvantages. The choice of method is dictated by multiple variables, including the desired properties of chitosan, resource availability, cost, and environmental footprint. We explore the intricate relationship between chitosan's antibacterial activity and its properties, such as cationic density, molecular weight, water solubility, and pH. Furthermore, we spotlight the burgeoning applications of chitosan-based materials like films, nanoparticles, nonwoven materials, and hydrogels across the food, biomedical, and agricultural sectors. The review concludes by highlighting the promising future of chitosan, underpinned by technological advancements and growing sustainability consciousness. However, the critical challenges of optimizing chitosan's production for sustainability and efficiency remain to be tackled.

Benzothiazole Derivatives of Chitosan and Their Derived Nanoparticles: Synthesis and In Vitro and In Vivo Antibacterial Effects.

In this work, we focused on synthesizing and assessing novel chitosan-based antibacterial polymers and their nanoparticles by incorporating benzothiazole substituents. The growing resistance to antibiotics has necessitated the search for alternative antimicrobial compounds. This study aimed to synthesize and evaluate chitosan-based polymers and nanoparticles with benzothiazole substituents for their antibacterial properties and toxicity. The benzothiazole derivatives of chitosan and their nanoparticles were synthesized through electrochemical coupling. The in vivo antibacterial efficacy was tested on white rats with induced peritonitis using a microbial suspension containing S. aureus and E. coli. Additionally, in vitro and in vivo toxicity assessments were conducted. The chitosan-based antibacterial systems showed significant in vivo antibacterial activity, surpassing that of unmodified chitosan and commercial antibiotics. Moreover, the toxicity studies revealed low toxicity levels of the synthesized derivatives, which did not differ significantly from native chitosan. The synthesized chitosan-based polymers and nanoparticles demonstrated potent antibacterial activity and low toxicity, highlighting their potential as effective alternatives to traditional antibiotics. Further investigations in pharmacology and preclinical trials are recommended to explore their application in clinical settings.

Chitosan-Based Antibacterial Films for Biomedical and Food Applications.

Antibacterial chitosan films, versatile and eco-friendly materials, have garnered significant attention in both the food industry and medicine due to their unique properties, including biodegradability, biocompatibility, and antimicrobial activity. This review delves into the various types of chitosan films and their distinct applications. The categories of films discussed span from pure chitosan films to those enhanced with additives such as metal nanoparticles, metal oxide nanoparticles, graphene, fullerene and its derivatives, and plant extracts. Each type of film is examined in terms of its synthesis methods and unique properties, establishing a clear understanding of its potential utility. In the food industry, these films have shown promise in extending shelf life and maintaining food quality. In the medical field, they have been utilized for wound dressings, drug delivery systems, and as antibacterial coatings for medical devices. The review further suggests that the incorporation of different additives can significantly enhance the antibacterial properties of chitosan films. While the potential of antibacterial chitosan films is vast, the review underscores the need for future research focused on optimizing synthesis methods, understanding structure-property relationships, and rigorous evaluation of safety, biocompatibility, and long-term stability in real-world applications.

Novel Highly Efficient Antibacterial Chitosan-Based Films.

In this study, we elaborated new chitosan-based films reinforced by iron(III)-containing chitosan nanoparticles Fe(III)-CS-NPs at different concentrations. We found that the optimum concentration of Fe(III)-CS-NPs for the improvement of antibacterial and mechanical properties of the films was 10% (σb = ca. 8.8 N/mm2, εb = ca. 41%, inhibition zone for S. aureus = ca. 16.8 mm and for E. coli = ca. 11.2 mm). Also, using the click-chemistry approach (thiol-ene reaction), we have synthesized a novel water-soluble cationic derivative of chitin. The addition of this derivative of chitin to the chitosan polymer matrix of the elaborated film significantly improved its mechanical (σb = ca. 11.6 N/mm2, εb = ca. 75%) and antimicrobial (inhibition zone for S. aureus = ca. 19.6 mm and for E. coli = ca. 14.2 mm) properties. The key mechanism of the antibacterial action of the obtained films is the disruption of the membranes of bacterial cells. The elaborated antibacterial films are of interest for potential biomedical and food applications.

Biologically Active Supplements Affecting Producer Microorganisms in Food Biotechnology: A Review.

Microorganisms, fermentation processes, and the resultant metabolic products are a key driving force in biotechnology and, in particular, in food biotechnology. The quantity and/or quality of final manufactured food products are directly related to the efficiency of the metabolic processes of producer microorganisms. Food BioTech companies are naturally interested in increasing the productivity of their biotechnological production lines. This could be achieved via either indirect or direct influence on the fundamental mechanisms governing biological processes occurring in microbial cells. This review considers an approach to improve the efficiency of producer microorganisms through the use of several types of substances or complexes affecting the metabolic processes of microbial producers that are of interest for food biotechnology, particularly fermented milk products. A classification of these supplements will be given, depending on their chemical nature (poly- and oligosaccharides; poly- and oligopeptides, individual amino acids; miscellaneous substances, including vitamins and other organic compounds, minerals, and multicomponent supplements), and the approved results of their application will be comprehensively surveyed.

Chitosan-Based Ciprofloxacin Extended Release Systems: Combined Synthetic and Pharmacological (In Vitro and In Vivo) Studies.

Ciprofloxacin is one of the most effective antibiotics, but it is characterized by a range of side effects. Elaboration of drug-releasing systems which allow to diminish toxicity of ciprofloxacin is a challenging task in medicinal chemistry. The current study is focused on development of new ciprofloxacin releasing systems (CRS). We found that ultrasound efficiently promotes N,N'-dicyclohexyl carbodiimide-mediated coupling between COOH and NH2 functionalities in water. This was used for conjugation of ciprofloxacin to chitosan. The obtained ciprofloxacin/chitosan conjugates are capable of forming their self-assembled nanoparticles (SANPs) in aqueous medium. The SANPs can be additionally loaded by ciprofloxacin to form new CRS. The CRS demonstrated high loading and encapsulation efficiency and they are characterized by extended release profile (20 h). The elaborated CRS were tested in vivo in rats. The in vivo antibacterial effect of the CRS exceeded that of the starting ciprofloxacin. Moreover, the in vivo acute and subacute toxicity of the nanoparticles was almost identical to that of the chitosan, which is considered as the non-toxic biopolymer.

The first selenium containing chitin and chitosan derivatives: Combined synthetic, catalytic and biological studies.

Ultrasonic approach to the synthesis of the first selenium-containing derivatives of chitin and chitosan has been developed. The synthetic procedure is simple, provides high yields, does not require harsh conditions, and uses water as the reaction medium. The elaborated chitin and chitosan derivatives and their based nanoparticles are non-toxic and possess high antibacterial and antifungal activity. Their antimicrobial activity exceeds the effect of the classic antibiotics (Ampicillin and Gentamicin) and the antifungal drug Amphotericin B. The obtained selenium-containing cationic chitin and chitosan derivatives exhibit a high transfection activity and are promising gene delivery vectors. Nanoparticles of the synthesized polymers are highly efficient catalysts for the oxidation of 1-phenylethyl alcohol to acetophenone by bromine at room temperature.

Water-soluble triazole chitin derivative and its based nanoparticles: Synthesis, characterization, catalytic and antibacterial properties.

In this work, we treated chitin with 2-(azidomethyl)oxirane and successfully involved the resultant azido chitin derivatives in the ultrasound-assisted Cu(I)-catalyzed azido-alkyne click (CuAAC) reaction with propargylic ester of N,N,N-trimethyl glycine. Thus, we obtained novel water-soluble triazole chitin derivatives. The triazole chitin derivatives and their nanoparticles are characterized by a high in vitro antibacterial activity, which is the same or even higher than that of commercial antibiotics ampicillin and gentamicin. The obtained derivatives are non-toxic. Moreover, the obtained water-soluble polymers are highly efficient green catalysts for the aldol reaction in green solvent water. The catalysts can be easily extracted from the reaction mixture by its precipitation with green solvent ethanol followed by centrifugation and they can be reused at least 10 times.

New water-soluble chitin derivative with high antibacterial properties for potential application in active food coatings.

The synthesis of new chitin derivatives through ultrasound-assisted treatment of the chitin with 1-azido-3-chloropropan-2-ol under Green Chemistry conditions is described. This is the first example of ultrasound-assisted polymer analogues transformation of chitin unaccompanied by noticeable backbone degradation or deacetylation. The obtained water-soluble azido chitin derivatives are characterized by high antibacterial activity, which is comparable with that of commercial antibiotics ampicillin and gentamicin. At the same time, they were demonstrated almost identical in vitro toxicity as unmodified chitin and chitosan. The antibacterial activity of the obtained polymers is mainly provided by azido moiety in their macromolecules. The conjugation of azido moiety to chitin backbone strongly diminishes the toxicity of the azido pharmacophore, but preserves its antibacterial properties. The most potent chitin derivative was used for the film coating of Ricotta cheese samples. This food coating proved to be efficient for the prolongation of shelf life of Ricotta cheese.

Novel biopolymer-based nanocomposite food coatings that exhibit active and smart properties due to a single type of nanoparticles.

We used nanoparticles which possess simultaneously active (antimicrobial, UV-protective and antioxidant) and smart (temperature sensing) properties. The nanoparticles (2Rh = 450 nm, PDI = 0.118 ± 0.014, ζ-potential = 21 mV and Tg = 8 ± 1 °C) are based on polyethylene glycol (PEG)/methyl cellulose (MC) core with anthocyanidin and sodium acetate, and chitosan/gallotannin-based shell. The core of nanoparticles acts as a temperature indicator, changing its color from colorless into deep purple at 8 °C, while the shell provides antimicrobial (due to chitosan), UV-protective and antioxidant (due to gallotannin) effects. We incorporated these nanoparticles into the chitosan matrix. The coatings demonstrated improved mechanical and barrier properties compared with the pure chitosan coating. The elaborated coatings pronouncedly improve the shelf-life of Ricotta cheese. Moreover, they serve as thermo indicators, which warn about cheese storage at an unacceptable temperature. Thus, we developed new coatings in which all properties are enabled by a single type of nanoparticles.

Ultrasound and click chemistry lead to a new chitin chelator. Its Pd(II) complex is a recyclable catalyst for the Sonogashira reaction in water.

For the first time the possibility of chitin use as an accessible and easily-modifiable support for an efficient Pd(II) catalyst has been demonstrated. The modification of chitin avoiding a noticeable chain scission or deacetylation, is achieved by sonochemical alkylation with 1-azido-3-chloropropan-2-ol followed by a convenient azido-alkyne click reaction. The obtained polymer represents an extremely rare case of the chitin derivative soluble both in water and organic solvents. The treatment of that derivative with imino-isonitrile Pd(II) complex solution yielded a chitin-supported Pd(II) complex. The latter could be obtained as a powder or as uniform nanoparticles in different size ranges. The nanoparticles with a hydrodynamic diameter of 30 nm were shown to be the most efficient form of catalyst for the copper- and phosphine-free Sonogashira cross-coupling in water.

New water-soluble derivatives of chitin and their based nanoparticles: Antibacterial and catalytic activity.

A facile route towards new chitin derivatives with both catalytical and biological activities is proposed in the course of methodology development aimed at the design of polyfunctional materials on the basis of renewable and accessible natural polysaccharides. Ultrasound-promoted and Cu(I)-catalyzed azido-alkyne click cycloaddition of the propargylic ester of nicotinic acid and its N-methylated analogue to the azido chitin derivative allowed us to obtain previously unknown non-toxic water-soluble derivatives of chitin. The obtained polymers and their based nanoparticles demonstrated a high antibacterial activity in vitro, which is comparable or even superior to that of commercial antibiotics ampicillin and gentamicin. New derivatives of chitin were also shown to be highly efficient and reusable (at least for 10 times) green catalysts for the aldol reaction in water. The catalysts can be easily separated from the reaction mixture by their precipitation with ethanol. The results obtained highlight prospects of further studies on chitin's application in the rational design of novel functional materials with valuable properties.

Chitosan derivatives and their based nanoparticles: ultrasonic approach to the synthesis, antimicrobial and transfection properties.

In the present work, we demonstrate that alkylation of chitosan by alkyl halides, aza-Michael reaction with chitosan, and AdN-E reaction of chitosan with aldehydes can be efficiently mediated by ultrasound. An optimization of ultrasonic irradiation parameters allowed us to (i) accelerate the rate of the reactions dramatically, (ii) achieve high selectivity, and (iii) preserve integrity of the polysaccharide backbone avoiding its depolymerization. We evaluated antibacterial/antifungal and transfection activity of 8 different derivatives of chitosan and their based nanoparticles in vitro. Moreover, we studied antibacterial activity of the most efficient polymer and their based nanoparticles in vivo. The tested polymer proved to be superior to reference commercial antibiotics ampicillin and gentamicin.

Novel heterocyclic chitosan derivatives and their derived nanoparticles: Catalytic and antibacterial properties.

The metal-assisted nitrone-nitrile cycloaddition reaction is apply to empower chitosan chemistry. The ultrasonic irradiation has proven to efficiently accelerate the cycloaddition affording new heterocyclic (1,2,4-oxadiazoline) chitosan derivatives and avoiding ultrasonic degradation of the chitosan macromolecules. By varying the nitrone nature, both water- and toluene-soluble chitosan derivatives were successfully synthesized. Relying on the ionic gelation approach nanoparticles of heterocyclic chitosan derivatives were prepared. Water-soluble chitosan derivative demonstrated a high antibacterial activity coupled with low toxicity. The toxicity of the synthesized heterocyclic chitosan derivatives and their based nanoparticles are comparable with those of the starting chitosan, while their antibacterial activity is superior. Toluene-soluble derivatives are shown to be efficient homogeneous catalysts towards monoglyceride synthesis via the epoxide ring opening. They efficiently catalyze selective conversion of fatty acids and glycidol into corresponding monoglycerides allowing one to simplify significantly the procedure for separating the reaction product from the catalyst for its recovery and reusage.

Ultrasound-assisted catalyst-free thiol-yne click reaction in chitosan chemistry: Antibacterial and transfection activity of novel cationic chitosan derivatives and their based nanoparticles.

In this work, we demonstrate that the thiol-yne click reaction could be efficiently mediated by ultrasonic irradiation and implement the ultrasound-assisted thiol-yne click reaction to chitosan chemistry as a polymer-analogous transformation. We optimize power and frequency of ultrasound to preserve selectivity of the click reaction and avoid ultrasonic degradation of the chitosan polymer chain. Thus, we obtain a new water-soluble betaine. Using ionic gelation of the obtained betaine derivatives of chitosan, we prepare nanoparticles with a unimodal size distribution. Furthermore, we present results of antibacterial and transfection activity tests for the chitosan derivatives and their based nanoparticles. The derivative with a medium molecular weight and a high degree of substitution demonstrated the best antibacterial effect. It derived nanoparticles with a size of ca. 100 nm and ζ-potential of ca. +69 mV revealed even higher antibacterial activity, slightly superior to commercial antibiotics ampicillin and gentamicin. On the contrary, the obtained polymers possess a much more pronounced transfection activity as compared with their based nanoparticles and species with a low degree of substitution acts as the most efficient transfecting agent. Moreover, the obtained betaine chitosan derivatives as well as their derived nanoparticles are non-toxic.

Novel non-toxic high efficient antibacterial azido chitosan derivatives with potential application in food coatings.

In this work, we developed a simple method for the preparation of N-(3-azido-2-hydroxypropyl)chitosan. We compared the antibacterial activity of N-(3-azido-2-hydroxypropyl)chitosans and previously synthesized N-(2-azidoethyl)chitosans. N-(3-azido-2-hydroxypropyl)chitosans possess higher antibacterial effect which is comparable with that of ampicillin and gentamicin. The effect is due to azido pharmacophore -CH2-CH(OH)-CH2-N3 (for N-(3-azido-2-hydroxypropyl)chitosan) or -CH2-CH2-N3 (for N-(2-azidoethyl)chitosan) introduced in chitosan chain, since the corresponding organic azides NH2-CH2-CH2-N3 and NH2-CH2-CH2-N3 are characterized by high antibacterial activity. However, high antibacterial organic azides NH2-CH2-CH2-N3 and NH2-CH2-CH2-N3 are characterized by high toxicity. Their conjugation to the chitosan chain saves their antibacterial effect, but strongly diminishes their toxicity, and the toxicity of the resulting derivatives is comparable with that of the starting chitosan. These findings are of interest to food science, since novel effective food coatings can be developed on basis of prepared derivatives.

Ultrasound-assisted catalyst-free phenol-yne reaction for the synthesis of new water-soluble chitosan derivatives and their nanoparticles with enhanced antibacterial properties.

This work describes ultrasound-assisted phenol-yne addition of p-hydroxybenzaldehyde and propargylic ester of betaine hydrochloride giving only 2-((3-(4-formylphenoxy)allyl)oxy)-N,N,N-trimethyl-2-oxoethan-1-aminium chloride as a product at 100kHz 300W in water. The ultrasonic assisted phenol-yne addition was enhanced to chitosan chemistry. Phenolic chitosan derivatives were obtained by treatment of chitosan with o-, m- or p-hydroxybenzaldehyde followed by reduction of the formed CN bound by NaBH4. The phenolic chitosan derivatives (phenolic component) were involved in ultrasound-mediated reaction with propargylic ester of betaine hydrochloride (yne component). The reaction led to betaine chitosan derivatives in different degree of substitution as o-, m- and p-isomers. The phenolic and betaine derivatives were tested as antibacterial agents against E. coli in comparison with reference antibiotic Tetracycline. Betaine derivatives showed high antibacterial activity. The most effective polymer was p-isomer of high substituted betaine derivative and its activity was more than 2 times higher than the activity of Tetracycline. The nanoparticles based on this polymer were obtained by ionic gelation method. They had 2Rh 126nm, ξ-potential 20mV and were more effective than the corresponding chitosan derivative.

Ultrasound-assisted Cu(I)-catalyzed azide-alkyne click cycloaddition as polymer-analogous transformation in chitosan chemistry. High antibacterial and transfection activity of novel triazol betaine chitosan derivatives and their nanoparticles.

In this work, we involved ultrasound-assisted click CuAAC in chitosan chemistry. Ultrasound-mediated CuAAC between propargylic ester of betaine and azido chitosan derivative proceeds fast in water under aerobic conditions and gives rise novel water-soluble triazole betaine chitosan derivatives. Using ionic gelation technique, we prepared and characterized nanoparticles from the synthesized chitosan derivatives. We studied antibacterial and transfection activity of the novel chitosan derivatives and their nanoparticles. The nanoparticles with size ca. 100 nm and ζ-potential ca. +65 mV proved to possess outstanding antibacterial activity, which is much more than that of the triazole betaine derivatives in their native form, and it is equal to the activity of ampicillin and gentamicin. Opposite, triazole betaine chitosan derivatives in their native form are characterized by remarkable transfection activity as compared with their nanoparticles. The most active triazole betaine chitosan derivatives are derivatives of moderate molecular weight with moderate degree of substitution. Their transfection activity is extremely high for chitosan species and it is comparable (values of the same order) with activity of Lipofectin - commercially available gene delivery vector.

Natural polysaccharide-based smart (temperature sensing) and active (antibacterial, antioxidant and photoprotective) nanoparticles with potential application in biocompatible food coatings.

Smart and active nanoparticles are of increasing interest in food films and coatings application. In the current study, we purpose novel nanoparticles NPs-4(1:5) and NPs-4(1:5.5), which possess simultaneously both smart (temperature sensitive) and active (antibacterial, light absorbing and antioxidant) properties. The obtained nanoparticles are based on PEG/MC core with anthocyanidin and sodium acetate, and chitosan/gallotannin-based shell. The nanoparticles have hydrodynamic diameter ca. 450 nm and are positively charged (ζ-potential is 21 mV for NPs-4(1:5) and +23 mV for NPs-4(1:5.5). NPs-4(1:5) and NPs-4(1:5.5) are thermochromic and turn from colorless to purple at ca. 20 °C 0 °C respectively. The nanoparticles possess antibacterial activity much more than the starting chitosan (MIC, µg/mL, E. coli: 1.35 (NPs-4(1:5)), 1.18 (NPs-4(1:5.5)) and 10.12 (chitosan); S. aureus: 1.14 (NPs-4(1:5)), 1.10 (NPs-4(1:5.5)) and 6.20 (chitosan)). The nanoparticles efficiently absorb ultraviolet light, have high antioxidant effect (0.051 trolox equivalents), are non-toxic and fully composed of substances approved for use in the food industry.