Development of chitosan based microencapsulated spray dried powder of tuna fish oil: oil load impact and oxidative stability / Desenvolvimento de pó microencapsulado por pulverização de óleo de atum à base de quitosana: impacto da carga de óleo e estabilidade oxidativa

Abstract The impact of fish oil concentration on the oxidative stability of microcapsules through the spray drying process using chitosan and maltodextrin as wall material was studied. Emulsions were prepared with different Tuna fish oil (TFO) content (TFO-10%, TFO20%, TF030% TF0-40%) while wall material concentration was kept constant. Microencapsulated powder resulting from emulsion prepared with high fish oil load have high moisture content, wettability, total oil and low encapsulation efficiency, hygroscopicity and bulk tapped density. Oxidative stability was evaluated periodically by placing microcapsules at room temperature. Microcapsules prepared with TFO-10% presented high oxidative stability in terms of peroxide value (2.94±0.04) and anisidine value (1.54±0.02) after 30 days of storage. It was concluded that optimal amounts of fish oil for microencapsulation are 10% and 20% using chitosan and maltodextrin that extended its shelf life during study period.

Resumo Foi estudado o impacto da concentração de óleo de peixe na estabilidade oxidativa de microcápsulas por meio do processo de secagem por atomização, utilizando quitosana e maltodextrina como material de parede. As emulsões foram preparadas com diferentes teores de óleo de atum (TFO) (TFO-10%, TFO20%, TF030% TF0-40%), enquanto a concentração de material de parede foi mantida constante. O pó microencapsulado resultante da emulsão preparada com alta carga de óleo de peixe tem alto teor de umidade, molhabilidade e óleo total e baixa eficiência de encapsulação, higroscopicidade e densidade extraída a granel. A estabilidade oxidativa foi avaliada periodicamente colocando microcápsulas à temperatura ambiente. As microcápsulas preparadas com TFO-10% apresentaram alta estabilidade oxidativa em termos de valor de peróxido (2,94 ± 0,04) e valor de anisidina (1,54 ± 0,02) após 30 dias de armazenamento. Concluiu-se que as quantidades ideais de óleo de peixe para microencapsulação são de 10% e 20% usando quitosana e maltodextrina que prolongaram sua vida útil durante o período de estudo.

A tailored slow-release film with synergistic antibacterial and antioxidant activities for ultra-persistent preservation of perishable products.

Rapid decrease in antibacterial efficacy of existing active packages is difficult to promisingly prevent microbial infection during the storage of perishable products. Here, we pioneered an advanced ZnO-doped hollow carbon-encapsulated curcumin (ZHC-Cur)-chitosan (CS) slow-release film (ZHC-Cur-CS) with "nano-barricade" structure through demand-oriented tailoring of the structure and components of zeolitic imidazolate framework-8 (ZIF-8) carrier. Such an exquisite structure realized the effective sustained release of Curcumin through the dual complexity of diffusion pathway by the disordered hierarchical pore structure and steric hindrance. Prepared ZHC-Cur-CS film exhibited boosting bactericidal and antioxidant abilities by virtue of the functional synergy between curcumin and ZnO. Thus, ZHC-Cur-CS film demonstrated excellent preservation performance by significantly prolonging the shelf life of Citrus (∼2.4 times). Furthermore, the upgraded mechanical strength, improved barrier ability, and proven safety laid the foundation for its practical application. These satisfactory properties underscore the applicability of ZHC-Cur-CS film for the efficient preservation of perishable products.

Encapsulation of carvone in chitosan nanoemulsion as edible film for preservation of slice breads against Aspergillus flavus contamination and aflatoxin B1 production.

Aspergillus flavus is a common fungus causing bread spoilage by aflatoxin B1 (AFB1) production. Essential oil components are considered as effective antifungal agent; however, volatility and oxidative-instability limited their practical applications. The aim of this study was to fabricate novel chitosan nanoemulsion film incorporating carvone (carvone-Ne) for protection of bread slices against A. flavus and AFB1 contamination in storage conditions. The nanoemulsion was characterized by SEM, DLS, XRD, and FTIR analyses accompanying with sustained delivery of carvone. The carvone-Ne displayed better inhibition of A. flavus (0.5 µL/mL) and AFB1 production (0.4 µL/mL) over unencapsulated carvone along with promising antioxidant activity (p < 0.05). Destruction of ergosterol, mitochondrial-membrane-potential, ions leakage, deformities in methylglyoxal biosynthesis, and in-silico interaction of carvone with Afl-R protein emphasized the antifungal and antiaflatoxigenic mechanisms of action. Further, in-situ preservation potentiality of Carvone-Ne in bread slices with improved gas compositions, and acceptable sensory qualities strengthen its application as innovative packaging material for food preservation.

Fe3O4-carboxyl modified AuNPs-chitosan@AgNPs as a robust surface-enhanced Raman scattering substrate for rapid analysis of tryptamine and ofloxacin in aquatic products.

Rapid and accurate quantification of trace targets in complex samples is an extremely challenging issue in fast analysis field. Herein, we developed Fe3O4-carboxyl modified AuNPs-chitosan@AgNPs composite (Fe3O4-AuNCs-Cs@AgNPs) as a robust surface-enhanced Raman scattering (SERS) substrate for rapid analysis of tryptamine (TPA) and ofloxacin (OFX). The substrate possessed abundant surficial active sites of -NH2, -OH and -COOH groups. The substrate exhibited good SERS activity for several different model molecules with enhancement factors (EFs) of 1.2 × 108 for 4-mercaptobenzoic acid. The substrate presented good stability for detection of TPA at pH 6.0 and OFX at pH 8.0, and relative standard deviations less than 5.0% for intra-batch and 6.0% for inter-batch. Also, the substrate possessed good time-stability within 50 days. The substrate integrated advantages of efficient enrichment, fast magnetic separation, and strong localized surface plasmon resonance properties of AgNPs. With versatile merits, TPA and OFX can be enriched and separated within 10 min. SERS methods for analysis of TPA and OFX were developed with detection limits of 35.5 µg/L and 15.8 µg/L, respectively. TPA and OFX were actually found in aquatic product, and recoveries during sample analysis were 89.3%-110% for TPA and 89.3%-96.8% for OFX. The analytical process completed within 30 min via enrichment-separation-detection all-in-one, exhibiting great potential for rapid analysis of toxic biogenic monoamines and antibiotic residues in food.

Unveiling the multifaceted applications of magnetically responsive chitosan capped ZnS QDs for sensing and annihilation of pharmaceutical drugs.

The persistence of active pharmaceutical ingredients in water bodies has lead to detrimental impacts on public health as well as deteriorated aquatic resources at breakneck pace. To address this, highly fluorescent chitosan capped ZnS QDs (CZS QDs) were integrated with nickel ferrite nanoparticles (NF NPs) through ultrasonic assisted method to yield a series of magnetically responsive CZS-xNF nanohybrids (x = 5, 10, 15 and 20 wt% of NF). The successful fabrication of nanohybrids were affirmed through various techniques such as Fourier transform infra-red spectroscopy (FT-IR), powder X-ray diffraction (XRD), X-ray photoelectron microscopy (XPS), high resolution transmission electron microscopy (HRTEM), vibrating sample magnetometer (VSM) and diffused reflectance spectroscopy (DRS). The dual applicability of CZS-xNF nanohybrid was witnessed for the detection of pharmaceutical waste by fluorescence sensing and their concomitant annihilation via visible light driven photodegradation reactions. The developed nanohybrid showed exceptional selectivity towards tetracycline antibiotics, with ultra-low limit of detection of 0.53 µM for tetracycline (TC) and 0.30 µM for minocycline (MC), respectively. The fluorescent sensor was also analysed for trace level detection of tetracyclines in real water samples that showed satisfactory recoveries of 90-106%, depicting practical applicability of sensor. Additionally, the excellent photocatalytic features of synthesized nanohybrid prompted their use in photodegradation of TC and MC and a superior photocatalytic performance was achieved in comparison to CZS QDs. The enhanced photocatalytic performance of CZS-xNF nanohybrid can be attributed to type-I charge transfer mechanism, which resulted in efficient charge separation and reduced photo-induced recombination rate of charge carriers. The nanohybrids were recyclable up to four cycles after being utilized in sensing and photocatalysis, thus offering a promising strategy for environmental remediation through synchronized sensing and extirpation of pharmaceutical waste.

Magnetic solid phase extraction of aminoglycosides residue in chicken egg samples using Fe3O4-GO-Agarose-Chitosan composite.

Difficulties in identification of drug residues in food products arise due to their trace amounts in complex matrices. An eco-friendly and low-cost agarose-chitosan-magnetic graphene oxide based adsorbent was synthesized and employed for determination of aminoglycosides from chicken egg samples through HPLC. Synthesized adsorbent was characterized by SEM, FTIR, XRD, and VSM. Among two investigated aminoglycosides, streptomycin was derivatized with ninhydrin while gentamicin was detected without its derivatization. Impact of experimental variables such as adsorbent dose, extraction time, temperature, pH, and analyte concentration on extraction efficiency was investigated. Statistical analysis for determination of streptomycin and gentamicin demonstrated excellent linearity in the range of 0.2-1.6 µg kg-1, LOQ of 0.3 and 0.6 µg kg-1 for streptomycin and gentamicin, respectively and LOD of 0.1 and 0.19 µg kg-1 for streptomycin and gentamicin, respectively with RSD of 2.5% and recoveries up to 94%. Regeneration studies revealed that composite film can be used four times without considerable reduction in its extraction efficiency.

Encapsulation of Triphasia trifolia extracts by pH and thermal dual-sensitive chitosan hydrogels for controlled release.

Recent studies have developed varied delivery systems incorporating natural compounds to improve the limitations of plant extracts for clinical use while enabling their controlled release at treatment sites. For the first time, ethanolic limeberry extract (Triphasia trifolia) has been successfully encapsulated in thermo-sensitive chitosan hydrogels by a facile in situ loading. The extract-incorporated chitosan hydrogels have a pH value of nearly 7.00, gelation temperatures in the range of 37-38 °C, and exhibit an open-cell porous structure, thus allowing them to absorb and retain 756 % of their mass in water. The in vitro extract release from the hydrogels is driven by both temperature and pH, resulting in more than 70 % of the initial extract being released within the first 24 h. Although the release half-life of hydrogels at pH 7.4 is longer, their release capacity is higher than that at pH 6.5. Upon a 2 °C increase in temperature, the time to release 50 % initial extract is sharply reduced by 20-40 %. The release kinetics from the hydrogels mathematically demonstrated that diffusion is a prominent driving force over chitosan relaxation. Consequently, the developed hydrogels encapsulating the limeberry extract show their heat and pH sensitivity in controlled release for treating chronic wounds.

Trojan-horse mineralization of trigger factor to impregnate non-woven alginate fabrics for enhanced hemostatic efficacy.

Uncontrolled hemorrhage remains a leading cause of mortality after trauma. This work describes a facile mineralization strategy for enhancing hemostatic efficacy of alginate non-woven fabrics, involving the precipitation of amorphous CaCO3 induced by alginate fibers, along with Trojan-horse-like tissue factor (TF) encapsulation. The amorphous CaCO3 served as a transient carrier, capable of releasing Ca2+ and TF upon contact with blood. Coagulation test and rat tail cut and hemorrhaging liver models all revealed superior hemostatic capability of mineralized TF-in-alginate fabrics compared to bare fabrics, solely mineralized form, or commercial zeolite-modified gauze, benefiting from the combined hemostatic properties of alginate matrix and released Ca2+ and TF. Meanwhile, comprehensive biocompatibility and mechanical stability evaluations demonstrate the ternary composite's good biosafety. These results along with the extension study with chitosan- and cellulose-based dressings underline the great potential and versatility of polysaccharide-hemostat-mediated CaCO3 mineralization with TF integration for achieving rapid hemorrhage control.

L-serine combined with carboxymethyl chitosan guides amorphous calcium phosphate to remineralize enamel.

The aim of this study is to investigate a robust and stable calcium-phosphorus system to remineralize human early enamel caries lesions with nanocomplexes of carboxymethyl chitosan/L-serine/amorphous calcium phosphate (CMC-Ser-ACP) to develop an effective method for mimicking the amelogenin (AMEL) mineralization pattern through ACP assembly. A CMC-Ser-ACP nanocomplex solution was first synthesized by a chemical precipitation method, and then 1% sodium hypochlorite (NaClO) was added to induce ACP phase formation. The morphologies of the nanocomplexes were characterized by transmission electron microscopy (TEM), and zeta potential analysis and Fourier transform infrared spectroscopy (FTIR) were performed to detect surface charge and functional group changes. The subtle changes of the demineralized enamel models induced by the remineralization effect were observed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The CMC-Ser-ACP nanocomplex solution could be preserved without any precipitation for 45 days. After the application of NaClO and through the guidance of Ser, ACP nanoparticles transformed into relatively orderly arranged hydroxyapatite (HAP) crystals, generating an aprismatic enamel-like layer closely integrated with the demineralized enamel, which resulted in enhanced mechanical properties for the treatment of early enamel caries lesions. The CMC-Ser-ACP nanocomplex solution is a remineralization system with great solution stability, and when NaClO is added, it can rapidly regenerate an aprismatic enamel-like layer in situ on the demineralized enamel surface. This novel remineralization system has stable chemical properties and can greatly increase the therapeutic effects against early enamel caries.

Toxicological, hepato-renal, endocrine disruption, oxidative stress and immunohistopathological responses of chitosan capped gold nanocomposite on Biomphalaria alexandrina snails.

The present investigation aimed to synthesize chitosan­gold nanocomposites (Ch-AuNPs) with gamma radiation, then to evaluate its toxic effect on the freshwater snails Biomphalaia alexandrina. Results showed that Ch-AuNPs is spherical shaped with average size 12 nm. It had a toxic effect against B. alexandrina snails with LC50 20.43 mg/l. Exposure of B. alexandrina snails to LC10 7.51 or LC25 13.63 mg/l of Ch-AuNPs, reduced the survival, reproductive and fecundity rates; total protein and albumin; both testosterone (T) and 17ß Estradiol (E) levels; SOD and CAT activities of exposed snails while increased the activities of transaminases (AST & ALT), uric acid, creatinine, TAC and MDA levels compared to the control group. Results were supported by histopathological and immunohistopathological alterations of the digestive and hermaphrodite glands. In conclusion B. alexandrina could be used as a model to screen the negative impact of nanomaterials. Also, Ch-AuNPs could be used as a molluscicidal agent.

Chitosan-thymol nanoparticle with pH responsiveness as a potential intelligent botanical fungicide against Botrytis cinerea.

The practical application of essential oils (EOs) as an alternative for synthetic pesticides in agricultural production is severely limited because of their instability, high volatility, and water insolubility. Nanoencapsulation of EOs is an important strategy to overcome these limitations. In view of this, this study aimed to develop chitosan-thymol nanoparticle (NCS-Thy) with pH-responsive which can be used as an intelligent botanical fungicide to control Botrytis cinerea. The NCS-Thy nanoparticle was prepared by ionic crosslinking method with the loading capacity and encapsulation efficiency of 29.87% and 41.92%, respectively. The synthesized NCS-Thy nanoparticle was further characterized by Fourier transform infrared spectroscopy analysis, transmission electron microscopy observation, and dynamic lights scattering. The results of release kinetics and antifungal activity of NCS-Thy under different pH conditions were determined. The results showed that the NCS-Thy nanoparticle had excellent pH-responsiveness and can release more thymol under acidic conditions formed by B. cinerea, thereby achieving higher antifungal effects. Therefore, compared with unencapsulated thymol, the NCS-Thy nanoparticle had higher antifungal activity against B. cinerea in vitro. In addition, both the protective and curative efficacies of detached leaf test and pot experiment were significantly higher than those of unencapsulated thymol. Among them, the protective efficacy of NCS-Thy in the pot experiment was 78.73%, which was significantly higher than that of unencapsulated thymol with 61.13%. Therefore, the pH-responsive chitosan-thymol nano-preparation had a promising prospect of application in practical management of gray mold as an intelligent botanical fungicide.

Efficiency of Artemisia annua L. essential oil and its chitosan/tripolyphosphate or zeolite encapsulated form in controlling Sitophilus oryzae L.

The rice weevil, Sitophilus oryzae L., is one of the most widespread and destructive stored-product pests and resistant to a wide range of chemical insecticides. In this research, Artemisia annua L. essential oil (EO) and its encapsulated form by chitosan/TPP (tripolyphosphate) and zeolite were tested against S. oryzae adults. The order of toxicity was chitosan/TPP (LC30: 30.83, LC50: 39.52, and LC90: 72.50 µL/L air) > pure EO (LC30: 35.75, LC50: 46.25, and LC90: 86.76 µL/L air) > EO loaded in the zeolite (LC30: 43.35, LC50: 55.07, and LC90: 98.80 µL/L air). These encapsulated samples were characterized by dynamic light scattering (DLS) and field emission scanning electron microscope (FE-SEM) which revealed the size and morphology of the droplets measuring 255.2 to 272 nm and 245 to 271.8 nm for EO loaded in chitosan and zeolite respectively. The encapsulation efficiency and loading percentages of A. annua EO in chitosan/TPP and zeolite were 40.16% and 6.01%, and 88% and 85%, respectively. Fumigant persistence was increased from 6 days for pure EO then, 20 and 22 days for encapsulated oil in zeolite and chitosan/TPP, respectively. Our results showed that A. annua EO contains (±)-camphor (29.29%), 1,8-cineole (12.56%), ß-caryophyllene (10.29%), α-pinene (8.68%), and artemisia ketone (8.48%) as its major composition. The activity level of glutathione S-transferase increased while general esterase and acetylcholinesterase activity were significantly inhibited in the treated group compared with the control. Antioxidant enzymes, including catalase, peroxidase, and superoxide dismutase were activated in treated adults compared to controls. The current results suggest that encapsulation of A. annua EO by chitosan/TPP and zeolite in addition to safety and environmentally friendly approach could increase its sustainability and therefore enhancing the efficiency in controlling S. oryzae in storage.

Chitosan oligosaccharide suppresses osteosarcoma malignancy by inhibiting CEMIP via the PI3K/AKT/mTOR pathway.

Osteosarcoma is a malignant bone tumor that is prone to metastasize early and primarily affects children and adolescents. Cell migration-inducing protein (CEMIP) plays a crucial role in the progression and malignancy of various tumor diseases, including osteosarcoma. Chitosan oligosaccharide (COS), an oligomer isolated from chitin, has been found to have significant anti-tumor activity in various cancers. This study investigates the effects of COS on CEMIP expression in osteosarcoma and explores the underlying mechanism. In present study, in vitro experiments were conducted to confirm the inhibitory activity of COS on human osteosarcoma cells. Our results demonstrate that COS possesses inhibitory effects against human osteosarcoma cells and significantly suppresses CEMIP expression in vitro. Next, we studied the inhibition of the expression of CEMIP by COS and then performed bioinformatics analysis to explore the potential inhibitory mechanism of COS against signaling pathways involved in regulating CEMIP expression. Bioinformatics analysis predicted a close association between the PI3K signaling pathway and CEMIP expression and that the inhibitory effect of COS on CEMIP expression may be related to PI3K signaling pathway regulation. The results of this study show that COS treatment significantly inhibits CEMIP expression and the PI3K/AKT/mTOR signaling pathway, as observed both in vitro and in vivo. This study demonstrates that COS could inhibit the expression of CEMIP, which is closely related to osteosarcoma malignancy. This inhibitory effect may be attributed to the inhibition of the PI3K/AKT/mTOR signaling pathway in vitro and in vivo.

Foliar application of chitosan-putrescine nanoparticles (CTS-Put NPs) alleviates cadmium toxicity in grapevine (Vitis vinifera L.) cv. Sultana: modulation of antioxidant and photosynthetic status.

BACKGROUND: Cadmium (Cd) stress displays critical damage to the plant growth and health. Uptake and accumulation of Cd in plant tissues cause detrimental effects on crop productivity and ultimately impose threats to human beings. For this reason, a quite number of attempts have been made to buffer the adverse effects or to reduce the uptake of Cd. Of those strategies, the application of functionalized nanoparticles has lately attracted increasing attention. Former reports clearly noted that putrescine (Put) displayed promising effects on alleviating different stress conditions like Cd and similarly chitosan (CTS), as well as its nano form, demonstrated parallel properties in this regard besides acting as a carrier for many loads with different applications in the agriculture industry. Herein, we, for the first time, assayed the potential effects of nano-conjugate form of Put and CTS (CTS-Put NP) on grapevine (Vitis vinifera L.) cv. Sultana suffering from Cd stress. We hypothesized that their nano conjugate combination (CTS-Put NPs) could potentially enhance Put proficiency, above all at lower doses under stress conditions via CTS as a carrier for Put. In this regard, Put (50 mg L- 1), CTS (0.5%), Put 50 mg L- 1 + CTS 0.5%" and CTS-Put NPs (0.1 and 0.5%) were applied on grapevines under Cd-stress conditions (0 and 10 mg kg- 1). The interactive effects of CTS-Put NP were investigated through a series of physiological and biochemical assays. RESULTS: The findings of present study clearly revealed that CTS-Put NPs as optimal treatments alleviated adverse effects of Cd-stress condition by enhancing chlorophyll (chl) a, b, carotenoids, Fv/Fm, Y(II), proline, total phenolic compounds, anthocyanins, antioxidant enzymatic activities and decreasing Y (NO), leaf and root Cd content, EL, MDA and H2O2. CONCLUSIONS: In conclusion, CTS-Put NPs could be applied as a stress protection treatment on plants under diverse heavy metal toxicity conditions to promote plant health, potentially highlighting new avenues for sustainable crop production in the agricultural sector under the threat of climate change.

Ti3C2Tx-rGO-chitosan-based microcatheter sensor for real-time continuous monitoring of propofol: toward improved anesthetic management.

We are aiming to develop an electrochemical microcatheter sensor for the detection and real-time continuous monitoring of propofol (PPF), which is an anesthetic drug majorly used during medical treatment. This proposed microcatheter-based sensing strategy meets the challenge of real-time periodic and continuous monitoring of propofol by using d-Ti3C2Tx-rGO-chi-modified carbon paste microcatheter sensor transducer. The sensing methodology relies on voltammetry and chronoamperometry transduction methods. The reusable microcatheter sensor was fabricated by embedding the three electrodes into a few millimeters-wide Teflon tube. The nanocomposite was characterized using advanced analytical instruments such as XRD, FE-SEM, EDX, Raman spectroscopy, and XPS. Further, electrode interfacial properties were characterized with voltammetry and electrochemical impedance spectroscopy. The electroanalytical performance of the modified microcatheter sensor was tested for the detection of PPF in phosphate buffer by using chronoamperometry with a wide linear range of 5 to 110 µM (at an applied potential of 0.3 V vs. Ag/AgCl). The sensor's practical potency was confirmed in human serum with a dynamic linear range of 10 to 130 µM. The sensor exhibited a good limit of detection values in phosphate buffer (2 µM) and natural human plasma (4 µM). The new sensor displays different dimensions of information while displaying high sensitivity, selectivity, and long-term stability. The outstanding analytical performance of the developed sensor holds considerable promise for the continuous monitoring of propofol, its effective management, and optimization of the doses in the patient's body.

Optimization of process parameters for trimethoprim and sulfamethoxazole removal by magnetite-chitosan nanoparticles using Box-Behnken design.

The contamination of the aquatic environment with antibiotics is among the major and developing problems worldwide. The present study investigates the potential of adsorbent magnetite-chitosan nanoparticles (Fe3O4/CS NPs) for removing trimethoprim (TMP) and sulfamethoxazole (SMX). For this purpose, Fe3O4/CS NPs were synthesized by the co-precipitation method, and the adsorbent characteristics were investigated using XRD, SEM, TEM, pHzpc, FTIR, and VSM. The effect of independent variables (pH, sonication time, adsorbent amount, and analyte concentration) on removal performance was modeled and evaluated by Box-Behnken design (BBD). The SEM image of the Fe3O4/CS adsorbent showed that the adsorbent had a rough and irregular surface. The size of Fe3O4/CS crystals was about 70 nm. XRD analysis confirmed the purity and absence of impurities in the adsorbent. TEM image analysis showed that the adsorbent had a porous structure, and the particle size was in the range of nanometers. In VSM, the saturation magnetization of Fe3O4/CS adsorbent was 25 emu g-1 and the magnet could easily separate the adsorbent from the solution. The results revealed that the optimum condition was achieved at a concentration of 22 mg L-1, a sonication time of 15 min, an adsorbent amount of 0.13 g/100 mL, and a pH of 6. Among different solvents (i.e., ethanol, acetone, nitric acid, and acetonitrile), significant desorption of TMP and SMX was achieved using ethanol. Also, results confirmed that Fe3O4/CS NPs can be used for up to six adsorption/desorption cycles. In addition, applying the Fe3O4/CS NPs on real water samples revealed that Fe3O4/CS NPs could remove TMP and SMX in the 91.23-95.95% range with RSD (n = 3) < 4. Overall, the Fe3O4/CS NPs exhibit great potential for removing TMP and SMX antibiotics from real water samples.

Effect of Time on the Properties of Bio-Nanocomposite Films Based on Chitosan with Bio-Based Plasticizer Reinforced with Nanofiber Cellulose.

The deterioration of the performance of polysaccharide-based films over time, particularly their hydrophilicity and mechanical properties, is one of the main problems limiting their applications in the packaging industry. In the present study, we proposed to improve the performance of chitosan-based films through the use of: (1) nanocellulose as an additive to reduce their hydrophilic nature; (2) bio-based plasticizer to improve their mechanical properties; and (3) chestnut extract as an antimicrobial agent. To evaluate their stability over time, the properties of as-formed films (mechanical, hydrophilic, barrier and antibacterial) were studied immediately after preparation and after 7, 14 and 30 days. In addition, the morphological properties of the films were characterized by scanning electron microscopy, their structure by FTIR, their transparency by UV-Vis and their thermal properties by TGA. The films showed a hydrophobic character (contact angle above 100°), barrier properties to oxygen and carbon dioxide and strong antibacterial activity against Gram-negative (E. coli) and Gram-positive (S. aureus) bacteria. Moreover, the use of nanofillers did not deteriorate the elongation at breaks or the thermal properties of the films, but their addition reduced the transparency. In addition, the results showed that the greatest change in film properties occurred within the first 7 days after sample preparation, after which the properties were found to stabilize.

Creation of Chemically Tri-Layered Collagen Crosslinked Membranes and Their Comparison with Ionically Tri-Layered Chitosan Crosslinked Membranes to Study Human Skin Properties.

In 2009, a new European regulation came into force that forbade the use of animals in the cosmetics industry. As a result, new alternatives were sought, taking into account the new ethical considerations. The main objective of this article is to continue a line of research that aims to build a physical model of skin from a biomaterial scaffold composed of collagen, chitosan or a combination to investigate whether they offer similar behavior to human skin. Collagen, the major component in the dermis, was crosslinked with glutaraldehyde (GTA) to develop three formulations for studying some properties of the skin through rheological tests like swelling index, elasticity or water loss. In addition, this article makes a comparison with the results obtained in the previous article where the membranes were made of chitosan and tripolyphosphate (TPP). The results obtained highlight that the tri-layered membranes scaffold better than the mono-layered ones to increase the elastic modulus (G') and the permeability. Furthermore, they offer a protective effect against water loss compared to mono-layered membranes. As regards chitosan membranes, these have a higher G' modulus than collagen membranes when the degree of deacetylation (DDA) is 85%. However, collagen membranes are more elastic when the DDA of chitosan is 76%, and their linear viscoelastic limit (LVL) doubles that of chitosan membranes, both for the degree of acetylation of 76 and 85%.

Novel Double Hybrid-Type Bone Cements Based on Calcium Phosphates, Chitosan and Citrus Pectin.

In this work, the influence of the liquid phase composition on the physicochemical properties of double hybrid-type bone substitutes was investigated. The solid phase of obtained biomicroconcretes was composed of highly reactive α-tricalcium phosphate powder (α-TCP) and hybrid hydroxyapatite/chitosan granules (HA/CTS). Various combinations of disodium phosphate (Na2HPO4) solution and citrus pectin gel were used as liquid phases. The novelty of this study is the development of double-hybrid materials with a dual setting system. The double hybrid phenomenon is due to the interactions between polycationic polymer (chitosan in hybrid granules) and polyanionic polymer (citrus pectin). The chemical and phase composition (FTIR, XRD), setting times (Gillmore needles), injectability, mechanical strength, microstructure (SEM) and chemical stability in vitro were studied. The setting times of obtained materials ranged from 4.5 to 30.5 min for initial and from 7.5 to 55.5 min for final setting times. The compressive strength varied from 5.75 to 13.24 MPa. By incorporating citrus pectin into the liquid phase of the materials, not only did it enhance their physicochemical properties, but it also resulted in the development of fully injectable materials featuring a dual setting system. It has been shown that the properties of materials can be controlled by using the appropriate ratio of citrus pectin in the liquid phase.

Sustainable Biomass Lignin-Based Hydrogels: A Review on Properties, Formulation, and Biomedical Applications.

Different techniques have been developed to overcome the recalcitrant nature of lignocellulosic biomass and extract lignin biopolymer. Lignin has gained considerable interest owing to its attractive properties. These properties may be more beneficial when including lignin in the preparation of highly desired value-added products, including hydrogels. Lignin biopolymer, as one of the three major components of lignocellulosic biomaterials, has attracted significant interest in the biomedical field due to its biocompatibility, biodegradability, and antioxidant and antimicrobial activities. Its valorization by developing new hydrogels has increased in recent years. Furthermore, lignin-based hydrogels have shown great potential for various biomedical applications, and their copolymerization with other polymers and biopolymers further expands their possibilities. In this regard, lignin-based hydrogels can be synthesized by a variety of methods, including but not limited to interpenetrating polymer networks and polymerization, crosslinking copolymerization, crosslinking grafted lignin and monomers, atom transfer radical polymerization, and reversible addition-fragmentation transfer polymerization. As an example, the crosslinking mechanism of lignin-chitosan-poly(vinyl alcohol) (PVA) hydrogel involves active groups of lignin such as hydroxyl, carboxyl, and sulfonic groups that can form hydrogen bonds (with groups in the chemical structures of chitosan and/or PVA) and ionic bonds (with groups in the chemical structures of chitosan and/or PVA). The aim of this review paper is to provide a comprehensive overview of lignin-based hydrogels and their applications, focusing on the preparation and properties of lignin-based hydrogels and the biomedical applications of these hydrogels. In addition, we explore their potential in wound healing, drug delivery systems, and 3D bioprinting, showcasing the unique properties of lignin-based hydrogels that enable their successful utilization in these areas. Finally, we discuss future trends in the field and draw conclusions based on the findings presented.