Chitosan Films Research Articles

BIOPOLÍMERO QUITOSANA NA ADSORÇÃO DE GLIFOSATO: USO NO MONITORAMENTO OU REMEDIAÇÃO AMBIENTAL

In this work, low molecular weight chitosan was used to adsorb the herbicide glyphosate in aqueous solution. Considering the possibilities of remediation and monitoring in aquatic environments, chitosan was formatted into thin discs 0.8 mm thick and 2.5 cm in diameter. The films were characterized by SEM, EDS and FTIR. In the adsorption study, a chitosan disc was able to adsorb 100% of a 5 mgL-1 glyphosate solution. Pseudo-first-order, pseudo-second-order and Elovich kinetic models were applied and it was found that chemisorption predominates in the adsorption process. Thus, chitosan films can act very well as a material for remediating water bodies contaminated by glyphosate. For monitoring studies, the possibility of using chitosan films in DGT (Diffusive Gradients in Thin Films) technique was verified and the diffusive material used was 1.5% agarose film (m/v). The diffusion coefficient of glyphosate in the agarose gel was determined 7.94 x 10-10 m2s-1.

Polyelectrolyte Complexation of Chitosan and WS2 Nanotubes

AbstractThe inclusion of tungsten disulphide nanotubes (WS2 NTs) in chitosan, plasticized with glycerol, facilitates the formation of a polyelectrolyte complex. The glycerol interrupts the intramolecular hydrogen bonding between chitosan chains allowing positively charged protonated amines of chitosan to form a complex with negatively charged oxygen ions chemisorbed to the tungsten atoms in defects. These interactions, with the unique mechanical and chemical properties of WS2 NTs, result in a chitosan film with superior properties relative to unfilled chitosan. Even at low WS2 NT loadings (≤1 wt%), the Young's modulus (E) increases by 59%, tensile strength (σ) by 40% and tensile toughness by 74%, compared to neat chitosan, without sacrificing ductility. Addition of highly dispersed WS2 NTs significantly improves the gas barrier properties of chitosan, with a 50% reduction in oxygen permeability, while the addition of both glycerol and WS2 NTs to chitosan effectively reduces the carbon dioxide permeability by 80% and the water vapor transmission rate by 90%. The intrinsic antimicrobial efficacy of chitosan against both Gram‐positive and Gram‐negative bacteria is enhanced on inclusion of WS2 NTs. Polyelectrolyte complexation of WS2 NTs and glycerol‐plasticized chitosan provides a cost‐effective, sustainable route to biodegradable films with desirable mechanical, gas barrier properties, and antimicrobial efficacy suitable for food packaging applications.

UV- shielding and antioxidant properties of chitosan film impregnated with Acacia catechu modified with calcium carbonate for food packaging

Acacia catechu contains polyphenolic compounds such as catechin and tannins, which exhibit antioxidant and antimicrobial properties that have the potential to be used in food packaging applications. In this study, chitosan-based (CH) antioxidant films were developed with the incorporation of calcium carbonate (CC) and Acacia catechu (CT). The films were fabricated by the solvent-casting method, and the effects of the different concentrations of Acacia catechu were analyzed. The physicomechanical, antioxidant, and UV shielding properties of the films were determined. The addition of Acacia catechu and calcium carbonate has significantly increased the tensile from 2.30 MPa to 4.95 MPa, respectively, for neat CH and CH/CC/CT-4 film. At the same time, there is a reduction in the elongation at break from 26.75 % in neat CH film to 12.11 % in CH/CC/CT-4 film. The CH/CC/CT-4 film has shown the highest ferric-reducing antioxidant power (FRAP) of 0.440 mg Trolox/g dried weight of the film and 2,2 diphenyl picrylhydrazyl (DPPH) radical scavenging activity of 93.05 %. The UV transmittance of CH/CC/CT-4 film was 0.46 %, the lowest compared to the rest of the fabricated films. These active properties depict that CH/CC/CT-4 film has the potential to be utilized for the packaging of light and oxygen-sensitive food products.

Characterization of intact chitosan obtained from Bradyporus sp. (Orthoptera, Insecta) and its cytotoxicity on human cell line (HEK293)

Intact chitosan film was produced from Bradyporus sp. (Orthoptera, Insecta) and characterized by Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA), X-ray diffractometer (XRD), Scanning Electron Microscopy (SEM) and elemental analysis. MTT test was performed to determine the cytotoxic effects of chitosan. Chitosan administered at optimal and overdose intervals was applied to HEK293 cells for 24, 48 and 72 hours. In the MTT cytotoxicity test, the IC 50 dose of chitosan was 1427 µM at 24 hours, 808.9 µM at 48 hours, and 611.6 µM at 72 hours. Considering all the conducted analyses and cytotoxic experiments, the obtained intact novel chitosan film from the insects could find applications for biotechnological applications.

Chitosan/konjac glucomannan bilayer films: Physical, structural, and thermal properties

To overcome the limitations of chitosan (CS) and konjac glucomannan (KGM), the bilayer films of CS and KGM were prepared by layer-by-layer (LBL) casting method, and the effects of different mass ratios (i.e., C5: K0, C4:K1, C3:K2, C1:K1, C2:K3, C1:K4, and C0:K5) on the microstructures and physicochemical properties of bilayer films were examined to evaluate their applicability in food packaging. The results revealed that the bilayer films had uniform microstructures. When compared with pure films, the bilayer films displayed lower swelling degrees and water vapor permeability. However, the tensile tests revealed a reduction in the mechanical properties of the bilayer films, which was nonetheless superior to that of the pure KGM film. In addition, the intermolecular interactions between the CS and KGM layers were observed through FTIR and XRD analyses. Finally, TGA and DSC analyses demonstrated a decrease in the thermal stability of the bilayer films. Our cumulative results verified that CS-KGM bilayer films may be a promising material for use in food packaging and further properties of the bilayer films can be supplemented in the future through layer-by-layer modification and the addition of active ingredients.

Synergistic Effects of f-MWCNTs and Nano Titania on the Wound Healing Efficacy of Chitosan Films in Drosophila and Rat Models

Synergistic Effects of <i>f</i>-MWCNTs and Nano Titania on the Wound Healing Efficacy of Chitosan Films in Drosophila and Rat Models

Reactive oxygen species-responsive hydrophobic crosslinked chitosan films based on triple-function crosslinkers

Chitosan is widely used in reactive oxygen species (ROS)-responsive films but remains great challenges owing to its weak mechanical strength and strong hydrophilicity. Herein, we synthesized novel hydrophobic crosslinked CS films with ROS-responsive properties and excellent physicochemical properties. A novel crosslinker, 2-((10-carboxydecyl)thio)succinic acid, with long-chain alkanes, three carboxyl groups, and sulfhydryl groups was synthesized and then used to produce thioether-containing crosslinked CS membranes. The results suggested that crosslinking could significantly increase the tensile strength of the film from 15.67 MPa to 24.32 MPa. The compact structure of crosslinked chitosan film improved the hydrophobicity and degradability, reduced the thermal stability and swelling rates, exhibited excellent non- cytotoxicity. The in vitro release studies revealed that crosslinked chitosan films could displayed the highest flux about 1.40 mg/ (cm2 h) and significant NR fluorescence change over 80 %. Collectively, our results demonstrate the applicability of these films as ROS-responsive drug delivery systems.

A critical review on the fabrication of chitosan films from marine wastes

A critical review on the fabrication of chitosan films from marine wastes

Effect of Nanotubes on the Electrical and Mechanical Properties of Chitosan Films

Effect of Nanotubes on the Electrical and Mechanical Properties of Chitosan Films

Microfluidic fabrication of encapsulated probiotic microspheres using cysteine-modified chitosan with dual functions of bacterial adhesion and intestinal mucosal adhesion

Compared with previous encapsulation methods, the emerging microfluidic approach has the potential of preparing monodispersed particles with considerable advantages, such as controlled size and morphology, stable yield, and enhanced repeatability. In addition to introducing probiotics to the intestine with high-viability, designing a novel carrier matrix to improve the mucoadhesion of probiotics in the intestine is imperative. Thus, in this study, the thiol groups of cysteine were grafted to chitosan to form disulfide bonds with the cysteine residues on the bacterial surface and mucus to achieve the dual function of probiotic adhesion and mucoadhesion. Upon examination, the adhesion rate of Bifidobacterium bifidum FL-276.1 (FL-276.1) to thiolated chitosan film increased by 1.33 times compared with non-modified chitosan film. Thiolated chitosan microspheres prepared by microfluidic method assisted by a crosslinking unit with a crosslinker of genipin had a uniform size distribution, high loading efficiency (80%) to FL-276.1, and improved resistance to simulated gastrointestinal digestion with a survival rate of FL-276.1 up to 92%. Moreover, the results of mucoadhesion test of thiolated chitosan microspheres demonstrated that the amount of thiolated chitosan microspheres adhered to the HT-29 cells was 2.27 times higher than that of chitosan microspheres. The monodispersed cysteine modified chitosan microspheres with dual adhesion function prepared by microfluidic technology has the potential to enhance the viability and function of probiotics after gastrointestinal digestion and intestinal adhesion.

Fabricating chitosan/low-density polyethylene (CS-LDPE) films and its efficacy to prolong shelf life of rainbow trout fish

This study aimed to explore how fabrication methods can influence surface morphology, physical, and mechanical characteristics of chitosan and low-density polyethylene (CS-LDPE) films to fulfill requirements of sustainable food packaging. The efficacy of CS-LDPE film for improving shelf life of rainbow trout fish products was also investigated. The field emission scanning electron microscopy assessment revealed that employing the two-step fabrication approach in the presence of grafted maleic anhydride (PE-g-MA) as a compatibilizer modified the surface morphology of the films, implying a better miscibility of constituents. Adding chitosan adversely influenced the thermal, mechanical, and morphological characteristics of the CS-LDPE films, which were mitigated by reducing chitosan size and application of 10 % PE-g-MA compatibilizer. According to the experimental assessments, two-step fabricated films consisting of 15 % chitosan and 10 % grafted maleic anhydride (PE-g-MA) was the best sustainable composite displaying the closest properties compared with the conventionally utilized LDPE films. Exploring several biochemical indices, including pH, peroxide level, membrane integrity (TBARS), free fatty acids (FAAs), and total volatile basic nitrogen (TVB-N) manifested that packaging fish samples with CS-LDPE improved the shelf life. The most pronounced differences between two packaging types were observed in the sixth day of storage time. Moreover, total viable count, Pseudomonas spp. count, and Enterobacteriaceae count markers revealed that the employing CS-LDPE film declined in the microbial proliferation rate, thereby prolonging shelf life of fishes. This study underlined the significance of CS-LDPE films to fulfilling needs for sustainable food packaging, conferring competitive advantage, and prolonging the food shelf life.

Chitosan-Bidens pilosa Extract-Based Coating with Enhanced Free Radical Scavenging, Antifungal, and Water Barrier Properties: Metabolite Profiling, Film Characterization, and Raspberry Preservation

Chitosan (Ch) was functionalized with Bidens pilosa (BP) extract at 1, 3, or 5% to form Ch-1 BP, Ch-3 BP, and Ch-5 BP, respectively. Ch without plant extract was used as a control. The composite films were characterized and tested for antifungal properties in the agar disc diffusion approach and antioxidant capacity in the 2,2-diphenyl-1-picrylhydrazyl assay. Chitosan films fused with B. pilosa extract inhibited the growth of P. expansum with a 10 mm inhibition diameter compared to control films (3.33 mm). Ch-1 BP exhibited the highest (79.13%) radical scavenging activity (RSA), and control films had the lowest RSA (50.97%). Liquid chromatography-mass spectrometry analysis identified 20 metabolites, including phenolic acids (9), organic acids (8), monosaccharides (1), amino acids (1), flavonoids (1), and six unknown polyphenols. Chitosan-based composite coating (Ch-1% BP) exhibited the lowest weight loss percentage (16.74%) and decay incidence (17.3%), while the untreated fruit showed higher weight loss and decay incidence (48.33% and 83.2%, respectively). The effectiveness of chitosan-enriched coating in maintaining the postharvest quality of raspberry fruit suggests that this plant could be a postharvest agent for controlling microbial spoilage and protecting against oxidative stress, ultimately resulting in extended storage in horticultural crops.

Daily sonic toothbrush triggered biocompatible BaTiO3/chitosan multiporous coating with enhanced piezocatalysis for intraoral antibacterial activity

Pure titanium and its alloys are widely used in dental implants because of their excellent physical chemistry and biocompatibility properties, but their negligible antibacterial activity may lead to bacterial infection and implants failure. Inspired by the piezoelectricity and porous structure of living bone, a multiporous piezo-coating with barium titanate (BaTiO3, BTO) nanoparticles embedded in chitosan film is modified on acid-etched pure titanium. The surface of coating shows antibacterial effects and can be further improved under daily sonic toothbrush stimulation with an antibacterial rate of 90.41%. Interestingly, the planktonic bacteria around this coating also have low proliferation. The antibacterial mechanism may be BTO-mediated intracellular and extracellular reactive oxygen species (ROS). On the one hand, the contact potential difference (CPD) caused by the spontaneous polarization of BTO nanoparticles may destroy the intracellular electron transfer and lead to ROS burst. On the other hand, BTO could transfer mechanical energy to electrical energy under the stimulation of sonic toothbrushing (ST), then driving piezocatalytic effect to generate extracellular ROS. In addition, the piezo-coating also exhibits excellent biocompatibility to MC3T3-E1 cells, and promotes more hydroxyapatite deposition and plasma albumin adhesion. In summary, during the stimulation of daily sonic toothbrush, the bioinspired piezo-coating can effectively inhibit the formation of bacterial biofilm, which is a promising strategy to prevent dental implants infection in daily life.

Enhanced Treatment of Potato Starch Wastewater Using Chitosan-Modified Biochar Film Adsorption Coupled with Ultrafiltration

Potato starch wastewater, a byproduct of potato processing, is an escalating environmental concern due to its high concentrations of COD (chemical oxygen demand), ammonia nitrogen, and total phosphorus (TP). Addressing this challenge, this research introduced a novel method combining chitosan-modified biochar film (CBC) adsorption with subsequent ultrafiltration. SEM (scanning electron microscope), FTIR (Fourier transform infrared spectral), XRD (X-ray diffractometer), and BET (specific surface area) analyses validated CBC’s enhanced surface characteristics, confirming successful chitosan (CS) film impregnation. CBC exhibited superior adsorption capacities, especially 40%wt-CBC, optimizing COD removal at 79.8%, ammonia nitrogen at 93.3%, and TP at 91.2%. Kinetic studies associated the adsorption process with a pseudo-second-order model, highlighting chemical adsorption. Additionally, the Langmuir isotherm model suggested monolayer adsorption with no inter-adsorbate interactions. The treated effluent, post adsorption, was directed through an ultrafiltration membrane, ensuring water quality suitable for reuse. This integrative treatment not only offers an effective solution for potato starch wastewater management but also underscores the potential for sustainable water resource recovery in the food processing sector.

Performance analysis and structural characterization of flaxseed gum/chitosan/cinnamaldehyde composite films

The low mechanical strength, water deficiency, and oxidative protection of organic membranes impede their use as food-grade packaging materials. Cinnamaldehyde (CIN) tends to lose its activity owing to its instability. In this study, CIN was added to flaxseed gum (FG)/chitosan (CS) films prepared in a “sandwich” structure. The influence of CIN dosage on the properties of the composite films was studied, and the film formation mechanism of the membrane was explored. The elongation at break, water vapor permeability, oxygen permeability, and light transmittance of the composite film with 1.5% CIN were lower than those of the FG/CS/FG film. Supplementation of the composite membrane with CIN generated new hydrogen bonds, electrostatic interactions, and C-O-C bonds, which converted the structure of the composite film into a sheet and increased its crystallinity without markedly affecting its thermal stability. Therefore, CIN is an extremely useful additive for improving the applicability of flaxseed gum/CS membranes as food-grade packaging films.

Biomass-derived nanoparticles reinforced chitosan films: as high barrier active packaging for extending the shelf life of highly perishable food.

The online version contains supplementary material available at 10.1007/s13197-023-05896-9.

Designing antimicrobial active packaging films based on chitosan plus fungus comb ethyl acetate extract from Indo-Malayan termite mounds

Abstract. Witasari LD, Lizar DP, Florencia OM, Ramadhan A, Fiana NAO, Supriyadi S, Pratiwi SUT, Nandika D, Karlinasari L, Arinana A, Batubara I, Santoso D, Rachmayanti Y, Firmansyah D, Sudiana IK, Hertanto DM, Rachmayanti Y, Firmansyah D. 2023. Designing antimicrobial active packaging films based on chitosan plus fungus comb ethyl acetate extract from Indo-Malayan termite mounds. Biodiversitas 24: 5947-5955. Antimicrobial active packaging systems incorporate antimicrobial compounds into polymer films, i.e., chitosan, thus suppress spoilage microorganism growth in foods. Chitosan films itself cannot prevent microbial growth, thus other antimicrobial agent must be added. Fungus comb extract from Indo-Malayan termite (Macrotermes gilvus (Hagen, 1858)) mounds is a potential active organic antimicrobial compound, which can be incorporated into chitosan films. The purpose of this study was to develop and characterize active packaging films based on chitosan plus an antimicrobial fungus comb ethyl acetate extract. Films contained 1% chitosan and fungus comb ethyl acetate extract (0.5, 1, 2, and 5% w/v). Notably, films containing 2 and 5% extracts inhibited Escherichia coli (ATCC 25922), Staphylococcus aureus (ATCC 25923), and Pseudomonas aeruginosa (ATCC 27853), but not fungi. Films plus 2% extract showed a thickness, tensile strength, and strain of 0.13 mm, 2.15 MPa, and 32.55%, respectively. Films had a moisture content of 0.26%, water solubility of 2.68%, swelling property of 2.37%, and water vapor permeability (WPV) of 3.31×10?10 g.m?1s?1.Pa?1. They displayed smooth morphology but no new functional groups. Thus, chitosan plus 2% of fungus comb ethyl acetate extract can be used in antimicrobial active packaging films for food application. It could be applied as a green alternative to prolong the shelf-life of food products.

Sugar kelp Saccharina latissima extract as an innovative ingredient for chitosan films: Case study as cheese slice separators

Chitosan films enriched with aqueous extract of Sugar kelp Saccharina latissima (SLE) were developed and characterized by measuring the equilibrium moisture, moisture content, water vapor permeability, mechanical properties, antioxidant properties, optical properties, surface morphology and thermostability. The developed films were tested as separators with antioxidant properties for sliced Havarti cheese. The addition of SLE showed a decrease in mechanical properties such as tensile strength from 48.99 to 36.16 MPa and Young's Modulus from 929.49 to 743.71 MPa compared with pure chitosan films. The resulting chitosan-SLE films showed a high free-radical scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS+). Moreover, the presence of SLE in the chitosan matrix significantly improved the UV-barrier of the samples. When the chitosan-SLE films were employed as separators for cheese, a significant reduction of 52.8% in cheese lipid oxidation was observed after 45 days of refrigerated storage compared to the control group using chitosan films. Hence, an environmentally sustainable alternative to synthetic and non-biodegradable slice separators has been successfully developed using chitosan, a by-product of the fishing industry, fortified with an extract from sugar kelp, a commonly found brown algae.

PH-responsive color indicator films based on chitosan and purple yam extract for in-situ monitoring food freshness

The development and utilization of abundant biomass resources is a promising solution to the problems of fossil resource scarcity and the difficulty in the biodegradation of waste faced by traditional food packaging films. Novel biomass-based films are not only biodegradable but can also be endowed with a variety of functional characteristics, including smart pH indicating film that can show color changes according to pH changes during food storage to achieve real-time visual detection of the degree of food spoilage, which is intuitive, sensitive, and convenient compared to traditional food packaging films. In this work, an environmentally friendly smart pH indicating film was prepared by incorporating natural polymer chitosan (CS) with anthocyanin-rich purple yam extract (PYE). The effect of different additions (1.5, 3, 4.5, 6 wt%) of PYE on the mechanical properties, water vapor barrier properties, antioxidant, antibacterial and pH sensitivity properties of chitosan films were investigated. The results showed that the films supplemented with 4.5% and 6% PYE demonstrated higher antioxidant capacity and antibacterial properties, while showing a more pronounced color change in different pH buffers. The results of FT-IR, scanning electron microscopy and X-ray diffraction analysis indicated the presence of hydrogen bonding between CS and PYE molecules. The application of films for in-situ monitoring the freshness of food (e.g., shrimp) was also studied, and films with PYE additions between 3% and 6% all showed visible color changes. Consequently, CS-PYE films are of great potential as smart and active packaging materials for keeping and monitoring the freshness of foods.

Multifunctional packaging film with sustained release behavior triggered by pH microenvironment for efficient preservation of pork

To tackle microbial contamination and spoilage during pork storage, transportation, and sales, a novel packaging film with exogenously driven controlled release behavior was designed through the demand-directed preparation of the emulsion of shellac-encapsulated cinnamaldehyde nano-capsules (SNCs) and the ingenious integration of chitosan (CS) film matrix. Among them, the SNCs were synthesized using the solvent exchange method, allowing controlled release of cinnamaldehyde (CA) in response to volatile alkaline substances present in the meat. The electrostatic interaction between SNCs and CS molecules improved the thermal stability, water resistance, tensile strength, and viscosity of the film-forming solution, while the CA in SNCs enhanced UV resistance and antimicrobial properties of the film. Notably, the CS film with SNC-100 loaded (CSNCs-100 film) achieved 99% inhibition against both E. coli and S. aureus, regulated environmental moisture, and prolonged the freshness duration of pork by an impressive six days.