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Medicine is looking for solutions to help implant patients recover more smoothly. The porous implants promote osteointegration, thereby providing better stabilization. Introducing porosity into metallic implants enhances their biocompatibility and facilitates osteointegration. The introduction of porosity is also associated with a reduction in Young’s modulus, which reduces the risk of tissue outgrowth around the implant. However, the risk of chronic inflammation remains a concern, necessitating the development of coatings to mitigate adverse reactions. An interesting biomaterial for such modifications is chitosan, which has antimicrobial, antifungal, and osteointegration properties. In the present work, a porous titanium biomaterial was obtained by powder metallurgy, and electrophoretic deposition of chitosan coatings was used to modify its surface. This study investigated the influence of ethanol content in the deposition solution on the quality of chitosan coatings. The EPD process facilitates the control of coating thickness and morphology, with higher voltages resulting in thicker coatings and increased pore formation. Ethanol concentration in the solution affects coating quality, with higher concentrations leading to cracking and peeling. Optimal coating conditions (30 min/10 V) yield high-quality coatings, demonstrating excellent cell viability and negligible cytotoxicity. The GIXD and ATR-FTIR analysis confirmed the presence of deposited chitosan coatings on Ti substrates. The microstructure of the chitosan coatings was examined by scanning electron microscopy. Biological tests showed no cytotoxicity of the obtained materials, which allows for further research and the possibility of their use in medicine. In conclusion, EPD offers a viable method for producing chitosan-based coatings with controlled properties for biomedical applications, ensuring enhanced patient outcomes and implant performance. Full article

Nanocomposites made via electrospinning were constructed of polyvinyl alcohol (PVA) and chitin. Chitin was extracted from a natural source (Fomes fomentarius), which allowed for precise control of the chemical properties of the resulting material. Chitin was chosen as a filler due to its low cost and widespread availability. Increasing the degree of acetylation of the chitin increased the Young’s Modulus of the resulting fiber mats but only at relatively high levels. While composites at lower acetylation levels were stable, no increase in the Young’s Modulus was observed, presumably due to decreased intermolecular bonding among fibers. The results suggest that precise control of the degree of acetylation of chitin, more than the loading amount and dispersibility, significantly impacts composite formation. Full article

Inhaled colistin is used to treat pneumonia and respiratory infections through nebulization or dry powder inhalers. Nevertheless, the development of a metered-dose inhaler (MDI) for colistin, which could enhance patient convenience and treatment efficacy, has not yet been developed. Colistin is known for its ability to induce cellular toxicity. Gold nanoparticles (AuNPs) can potentially mitigate colistin toxicity. Therefore, this study aimed to evaluate the antimicrobial effectiveness of colistin conjugated with chitosan-capped gold nanoparticles (Col-CS-AuNPs) and their potential formulation for use with MDIs to deliver the aerosol directly to the deep lung. Fourier-transform infrared spectroscopy, nuclear magnetic resonance, and elemental analysis were used to characterize the synthesized Col-CS-AuNPs. Drug release profiles fitted with the most suitable release kinetic model were evaluated. An MDI formulation containing 100 µg of colistin per puff was prepared. The aerosol properties used to determine the MDI performance included the fine particle fraction, mass median aerodynamic diameter, and geometric standard deviation, which were evaluated using the Andersen Cascade Impactor. The delivered dose uniformity was also determined. The antimicrobial efficacy of the Col-CS-AuNP formulation in the MDI was assessed. The chitosan-capped gold nanoparticles (CS-AuNPs) and Col-CS-AuNPs had particle sizes of 44.34 ± 1.02 and 174.50 ± 4.46 nm, respectively. CS-AuNPs effectively entrapped 76.4% of colistin. Col-CS-AuNPs exhibited an initial burst release of up to 60% colistin within the first 6 h. The release mechanism was accurately described by the Korsmeyer–Peppas model, with an R² > 0.95. The aerosol properties of the Col-CS-AuNP formulation in the MDI revealed a high fine particle fraction of 61.08%, mass median aerodynamic diameter of 2.34 µm, and geometric standard deviation of 0.21, with a delivered dose uniformity within 75–125% of the labeled claim. The Col-CS-AuNP MDI formulation completely killed Escherichia coli at 5× and 10× minimum inhibitory concentrations after 6 and 12 h of incubation, respectively. The toxicity of CS-AuNP and Col-CS-AuNP MDI formulations in upper and lower respiratory tract cell lines was lower than that of free colistin. The stability of the Col-CS-AuNP MDI formulation was maintained for at least 3 months. The Col-CS-AuNP MDI formulation effectively eradicated bacteria over a 12-h period, showing promise for advancing lung infection treatments. Full article

Recently, the use of plant-origin materials has become especially important due to the aggravation of environmental problems and the shortage and high cost of synthetic materials. One of the potential candidates among natural organic compounds is polysaccharides, characterized by a number of advantages over synthetic polymers. In recent years, natural polysaccharides have been used to design composite catalysts for various organic syntheses. This review is devoted to the current state of application of polysaccharides (chitosan, starch, pectin, cellulose, and hydroxyethylcellulose) and composites based on their catalysis. The article is divided into four main sections based on the type of polysaccharide: (1) chitosan-based nanocomposites; (2) pectin-based nanocomposites; (3) cellulose (hydroxyethylcellulose)-based nanocomposites; and (4) starch-based nanocomposites. Each section describes and summarizes recent studies on the preparation and application of polysaccharide-containing composites in various chemical transformations. It is shown that by modifying polysaccharides, polymers with special properties can be obtained, thus expanding the range of biocomposites for catalytic applications. Full article

In this work results are presented on the evaluation of HAp, HApSr, HAp_CS, and HApSr_CS layers deposited on Ti substrates regarding L929 cell viability and cytotoxicity as well as antimicrobial activity against Staphylococcus aureus, in connection with their physicochemical properties. The HAp and HApSr layers generated by radio-frequency magnetron sputtering technique were further covered with chitosan by a matrix-assisted pulsed laser evaporation technique. During the plasma depositions, the Ti substrates were heated externally by a home-made oven above 100 °C. The HApSr_CS layers generated on the unpolished Ti substrates at 100 °C and 400 °C showed the highest biocompatibility properties and antimicrobial activity against Staphylococcus aureus. The morphology of the layer surfaces, revealed by scanning electron microscopy, is dependent on substrate temperature and substrate surface roughness. The optically polished surfaces of Ti substrates revealed grain-like and microchannel structure morphologies of the layers deposited at 25 °C substrate temperature and 400 °C, respectively. Chitosan has no major influence on HAp and HApSr layer surface morphologies. X-ray photoelectron spectroscopy indicated the presence of Ca 2p_3/2 peak characteristic of the HAp structure even in the case of the HApSr_CS samples generated at a 400 °C substrate temperature. Fourier transform infrared spectroscopy investigations showed shifts in the wavenumber positions of the P-O absorption bands as a function of Sr or chitosan presence in the HAp layers generated at 25, 100, and 400 °C substrate temperatures. Full article

This article explores the use of citrus residues as a source of different pectic materials for packaging film production: a water-soluble orange residue extract (WSE) (~5% pectin), semi-pure pectins extracted in citric acid (SP) (~50% pectin), and commercial pure citrus pectins (CP). First, these materials were characterized in terms of chemical composition. Then, films were produced using them pure or mixed with chitosan or glycerol through solvent-casting. Finally, antioxidant activity, functional properties (e.g., mechanical and gas barrier properties), and visual appearance of the films were assessed. WSE films showed the highest antioxidant activity but the lowest mechanical strength with the highest elongation at break (EB) (54%); incorporating chitosan increased the films’ strength (Young’s modulus 35.5 times higher). SP films showed intermediate mechanical properties, reinforced by chitosan addition (Young’s modulus 4.7 times higher); they showed an outstanding dry O₂ barrier. CP films showed a similar O₂ barrier to SP films and had the highest Young’s modulus (~29 MPa), but their brittleness required glycerol for improved pliability, and chitosan addition compromised their surface regularity. Overall, the type of pectic material determined the film’s properties, with less-refined pectins offering just as many benefits as pure commercial ones. Full article

Background: This study investigated the biocompatibility and antibacterial efficacy of chitosan–gelatin (CH-G) scaffolds loaded with slow-releasing antibiotic formulations used in regeneration endodontic procedures (REPs). Methods: Scaffolds were fabricated using freeze drying and loaded with varying concentrations of augmentin or modified triple antibiotic paste (mTAP). High-resolution scanning electron microscopy (SEM) was used to characterize the scaffold, while drug release was monitored via UV-Vis spectrophotometry. Immortalized human mesenchymal stem cells (hMSCs) were cultured on CH-G scaffolds alone (control), either 0.1 mg/mL or 1 mg/mL of augmentin or mTAP, and 10 mg/mL calcium hydroxide (Ca(OH)₂). Cell viability and proliferation were assessed using the Alamar Blue assay and SEM, respectively, and live/dead staining further corroborated cell viability. Antibacterial activity against Enterococcus faecalis was evaluated using the MTT assay and confocal laser scanning microscopy (CLSM). Results: Augmentin at 0.1 mg/mL appeared to promote better cell growth and attachment within the scaffolds than all other formulations, exhibiting acceptable viability. SEM revealed improved cell attachment in augmentin and mTAP groups compared to the Ca(OH)₂ group. Augmentin at 1 mg/mL and mTAP groups significantly reduced viable bacteria compared to controls. Augmentin groups and mTAP at 1 mg/mL were highly effective in eliminating E. faecalis biofilms, with mTAP potentially causing more cell death within the remaining biofilm structures. Conclusions: This study suggests that CH-G scaffolds loaded with augmentin and mTAP, particularly at a concentration of 1 mg/mL, offer promising advantages for REPs due to their biocompatibility, antibacterial efficacy, and ability to promote cell attachment. Further research may explore the long-term effects in clinical settings. Full article

This study deals with the facile synthesis of a single-pot chemical technique for chitosan–curcumin (CUR)-based hybrid nanocomposites with nanostructured graphene oxide (GO) and copper oxide (CuO) as the antibacterial and cytotoxic drugs. The physicochemical properties of synthesized hybrid nanocomposites such as CS-GO, CS-CuO, CS-CUR-GO, and CS-CUR-GO/CuO were confirmed with various advanced tools. Moreover, the in vitro drug release profile of the CS-CUR-GO/CuO nanocomposite exhibited sustained and controlled release during different time intervals. Also, the antibacterial activity of the CS-CUR-GO/CuO hybrid nanocomposite presented the maximum bactericidal effect against Staphylococcus aureus and Escherichia coli pathogens. The hybrid nanocomposites revealed improved cytotoxicity behaviour against cultured mouse fibroblast cells (L929) via cell adhesion, DNA damage, and proliferation. Thus, the chitosan-based hybrid nanocomposites offer rich surface area, biocompatibility, high oxidative stress, and bacterial cell disruption functionalities as a potential candidate for antibacterial and cytotoxicity applications. Full article

The chemical stability and ion transport properties of quaternized chitosan (QCS)-based anion exchange membranes (AEMs) were explored using Density Functional Theory (DFT) calculations and all-atom molecular dynamics (MD) simulations. DFT calculations of LUMO energies, reaction energies, and activation energies revealed an increasing stability trend among the head groups: propyl trimethyl ammonium chitosan (C) < oxy propyl trimethyl ammonium chitosan (B) < 2-hydroxy propyl trimethyl ammonium chitosan (A) at hydration levels (HLs) of 0 and 3. Subsequently, all-atom MD simulations evaluated the diffusion of hydroxide ions (${\mathrm{OH}}^{-}$) through mean square displacement (MSD) versus time curves. The diffusion coefficients of ${\mathrm{OH}}^{-}$ ions for the three types of QCS (A, B, and C) were observed to increase monotonically with HLs ranging from 3 to 15 and temperatures from 298 K to 350 K. Across different HLs and temperatures, the three QCS variants exhibited comparable diffusion coefficients, underlining their effectiveness in vehicular transport of ${\mathrm{OH}}^{-}$ ions. Full article

Packaging plays a crucial role in protecting food by providing excellent mechanical properties as well as effectively blocking water vapor, oxygen, oil, and other contaminants. The low degradation of widely used petroleum-based plastics leads to environmental pollution and poses health risks. This has drawn interest in renewable biopolymers as sustainable alternatives. The seafood industry generates significant waste that is rich in bioactive substances like chitin, chitosan, gelatins, and alginate, which can replace synthetic polymers in food packaging. Although biopolymers offer biodegradability, biocompatibility, and non-toxicity, their films often lack mechanical and barrier properties compared with synthetic polymer films. This comprehensive review discusses the chemical structure, characteristics, and extraction methods of biopolymers derived from seafood waste and their usage in the packaging area as reinforcement or base materials to guide researchers toward successful plastics replacement and commercialization. Our review highlights recent advancements in improving the thermal durability, mechanical strength, and barrier properties of seafood waste-derived packaging, explores the mechanisms behind these improvements, and briefly mentions the antimicrobial activities and mechanisms gained from these biopolymers. In addition, the remaining challenges and future directions for using seafood waste-derived biopolymers for packaging are discussed. This review aims to guide ongoing efforts to develop seafood waste-derived biopolymer films that can ultimately replace traditional plastic packaging. Full article

Chitosan-based films show great potential in terms of application in food preservation and are also promising carriers of biologically active ingredients. This paper presents the potential use of chitosan-based films with the addition of essential oil components, e.g., carvacrol, eugenol, and isoeugenol, intended for food packaging. The characteristics of the obtained films were determined, including antibacterial, mechanical, barrier, and structural parameters. In addition, the antibacterial and antioxidant effects of the essential oil components were assessed. Eugenol (44.41%) and isoeugenol (43.56%) showed high antiradical activities, similar to the activity of Trolox (44.33%), which is used as a standard antioxidant. In turn, carvacrol was characterized by the strongest effect against the examined strains of bacteria, both Gram-positive and Gram-negative. The chitosan film with carvacrol showed the most valuable antibacterial and mechanical properties (tensile strength and elongation at break). The antibacterial activities of the chitosan–carvacrol films were higher than that of the carvacrol solution. The inhibition zones of the chitosan–carvacrol films were in the range 29–41 mm (except for Enterococcus faecalis, with an inhibition zone of 15 mm) compared to the inhibition zones of the carvacrol solution (28 mm). The results showed that chitosan is an effective carrier of fragrance compounds, mainly carvacrol. However, all the tested chitosan-based films with the addition of fragrance compounds showed appropriate parameters (biological, mechanical, and barrier), which makes them an ecological alternative to plastics intended for food packaging. Full article

Nanoclays are a class of nanomaterials extensively used to prepare polymer nanocomposites. In this study, four types of common nanoclays were selected to prepare chitosan–polyvinyl alcohol (CP) nanocomposite films. Montmorillonite cloisite Na⁺ (MMT), organically modified montmorillonite (OMMT), and bentonite (BNT), as layered aluminosilicates, and halloysite nanotubes (HNT), as a tubular nanoclay, were blended with CP films at concentrations of 1.5, 3 and 4.5%. The nanocomposite films were characterized by FTIR, XRD, SEM/EDX, AFM, tensile strength, and antibacterial tests. SEM/EDX results showed a more uniform distribution of the OMMT and HNT nanoclays in the polymer matrix. AFM images showed a rougher surface for nanocomposite films compared to CP film. Increasing the nanoclay concentration in the films from 1.5 to 4.5% resulted in higher tensile strength for HNT and MMT while the trend was reversed for OMMT and BNT. Among the samples, nanocomposite films composed of OMMT and BNT showed the highest tensile strength at the lowest concentrations (CP-OMMT1.5 99 ± 3.7 MPa, CP-B1.5 81 ± 1.5 MPa). The nanocomposite films prepared from OMMT showed the highest antibacterial activity against E. coli and S. aureus with an inhibition zone of 15 and 19 mm, respectively. The results of this study showed that BNT and OMMT are promising nanoclays for enhancing the mechanical properties and antibacterial activity of hydrophilic polymers. The results of this research can provide new insights into selecting suitable nanoclays for different applications. Full article

A novel chitosan (CS) functionalized optical fiber sensor with a bullet-shaped hollow cavity was proposed in this work for the trace concentration of Pb²⁺ ion detection in the water environment. The sensor is an optical fiber Mach–Zehnder interferometer (MZI), which consists of a sequentially spliced bullet-shaped hollow-core fiber (HCF), thin-core fiber, and another piece of spliced bullet-shaped HCF. The hollow-core fiber is caused to collapse by adjusting the amount of discharge to form a tapered hollow cavity with asymmetric end faces. The bullet-like hollow cavities act as beam expanders and couplers for optical fiber sensors, which were symmetrically spliced at both ends of a section of thin core fiber. The simulation and experiments show that the bullet-like hollow-core tapered cavity excites more cladding modes and is more sensitive to variation in the external environment than the planar and spherical cavities. The ion-imprinted chitosan (IIP-CS) film was fabricated with Pb²⁺ ion as a template and uniformly coated on the surface for specific recognition of Pb²⁺. Experimental verification confirms that the developed sensor can achieve high-sensitivity Pb²⁺ ion detection, with a sensitivity of up to −12.68 pm/ppm and a minimum Pb²⁺ ion detection concentration of 5.44 ppb Meanwhile, the sensor shows excellent selectivity, repeatability, and stability in the ion detection process, which has huge potential in the direction of heavy metal ion detection in the future. Full article

The main conservation problem of p-PVC artworks is phthalate-based plasticizer migration. Phthalate migration from the bulk to the surface of the materials leads to the formation of a glossy and oily film on the outer layers, ultimately reducing the flexibility of the material. This study aimed to develop a removable coating for the preservation of contemporary artworks and design objects made of plasticized polyvinyl chloride (p-PVC). Several coatings incorporating chitosan, collagen, and cellulose ethers were assessed as potential barriers to inhibiting plasticizer migration. Analytical techniques including optical microscopy (OM), ultraviolet/visible/near-infrared spectroscopy (UV/Vis/NIR), Fourier transform infrared spectroscopy with attenuated total reflection (FTIR-ATR), and scanning electron microscopy (SEM) were utilized to evaluate the optical and chemical stability of selected coating formulations applied to laboratory p-PVC sheet specimens. Subsequently, formulations were tested on a real tangible example of a design object, ©Barbie doll, characterized by the prevalent issue of plasticizer migration. Furthermore, the results obtained with the tested formulations were evaluated by a group of conservators using a tailored survey. Finally, a suitable coating formulation capable of safeguarding plastic substrates was suggested. Full article

Bio-aerogels have emerged as promising materials for energy storage, providing a sustainable alternative to conventional aerogels. This review addresses their syntheses, properties, and characterization challenges for use in energy storage devices such as rechargeable batteries, supercapacitors, and fuel cells. Derived from renewable sources (such as cellulose, lignin, and chitosan), bio-based aerogels exhibit mesoporosity, high specific surface area, biocompatibility, and biodegradability, making them advantageous for environmental sustainability. Bio-based aerogels serve as electrodes and separators in energy storage systems, offering desirable properties such as high specific surface area, porosity, and good electrical conductivity, enhancing the energy density, power density, and cycle life of devices. Recent advancements highlight their potential as anode materials for lithium-ion batteries, replacing non-renewable carbon materials. Studies have shown excellent cycling stability and rate performance for bio-aerogels in supercapacitors and fuel cells. The yield properties of these materials, primarily porosity and transport phenomena, demand advanced characterization methods, and their synthesis and processing methods significantly influence their production, e.g., sol–gel and advanced drying. Bio-aerogels represent a sustainable solution for advancing energy storage technologies, despite challenges such as scalability, standardization, and cost-effectiveness. Future research aims to improve synthesis methods and explore novel applications. Bio-aerogels, in general, provide a healthier path to technological progress. Full article