Chitosan-coated Iron Oxide Nanoparticles Research Articles

Enhanced Biocompatibility by Evaluating the Cytotoxic and Genotoxic Effects of Magnetic Iron Oxide Nanoparticles and Chitosan on Hepatocellular Carcinoma Cells (HCC).

Hepatocellular carcinoma (HCC), the fifth most prevalent cancer worldwide, is influenced by a myriad of clinic-pathological factors, including viral infections and genetic abnormalities. This study delineates the synthesis, characterization, and the biological efficacy of iron oxide nanoparticles (Fe3O4) and chitosan-coated iron oxide nanoparticles (Fe3O4-CS) against HCC. Analytical methods confirmed the successful synthesis of both nanoparticles, with Fe3O4-CS demonstrating a smaller, uniform spherical morphology and distinct surface and magnetic properties attributable to its chitosan coating. The prepared materials were analyzed using various techniques, and their potential cytotoxic effects on HepG2 cancer cells line for HCC were investigated. In biological evaluations against HepG2 cells, a notable distinction in cytotoxicity was observed. Fe3O4 showed modest anticancer activity with an IC50 of 383.71 ± 23.9 µg/mL, whereas Fe3O4 exhibited a significantly enhanced cytotoxic effect, with a much lower IC50 of 39.15 ± 39.2 µg/mL. The Comet assay further evidenced Fe3O4-CS potent DNA damaging effect, showcasing its superior ability to induce apoptosis through extensive DNA fragmentation. Biochemical analyses integrated into our results reveal that Fe3O4-CS not only induces significant DNA damage but also markedly alters oxidative stress markers. Compared to control and Fe3O4-treated cells, Fe3O4-CS exposure significantly elevated levels of oxidative stress markers: superoxide dismutase (SOD) increased to 192.07 U/ml, catalase (CAT) decreased to 0.03 U/L, glutathione peroxidase (GPx) rose dramatically to 18.76 U/gT, and malondialdehyde (MDA) levels heightened to 30.33 nmol/gT. These results underscore the potential of Fe3O4-CS nanoparticles not only in inducing significant DNA damage conducive to cancer cell apoptosis but also in altering enzymatic activities and oxidative stress markers, suggesting a dual mechanism of action that may underpin their therapeutic advantage in cancer treatment. Our findings advocate for the further exploration of Fe3O4-CS nanoparticles in the development of anticancer drugs, emphasizing their capability to trigger oxidative stress and enhance antioxidant defense mechanisms.

Hybrid hydrogels support neural cell culture development under magnetic actuation at high frequency

The combination of hydrogels and magnetic nanoparticles, scarcely explored to date, offers a wide range of possibilities for innovative therapies. Herein, we have designed hybrid 3D matrices integrating natural polymers, such as collagen, chitosan (CHI) and hyaluronic acid (HA), to provide soft and flexible 3D networks mimicking the extracellular matrix of natural tissues, and iron oxide nanoparticles (IONPs) that deliver localized heat when exposed to an alternating magnetic field (AMF). First, colloidally stable nanoparticles with a hydrodynamic radius of ∼20 nm were synthesized and coated with either CHI (NPCHI) or HA (NPHA). Then, collagen hydrogels were homogeneously loaded with these coated-IONPs resulting in soft (E0 ∼ 2.6 kPa), biodegradable and magnetically responsive matrices. Polymer-coated IONPs in suspension preserved primary neural cell viability and neural differentiation even at the highest dose (0.1 mg Fe/mL), regardless of the coating, even boosting neuronal interconnectivity at lower doses. Magnetic hydrogels maintained high neural cell viability and sustained the formation of highly interconnected and differentiated neuronal networks. Interestingly, those hydrogels loaded with the highest dose of NPHA (0.25 mgFe/mg polymer) significantly impaired non-neuronal differentiation with respect to those with NPCHI. When evaluated under AMF, cell viability slightly diminished in comparison with control hydrogels magnetically stimulated, but not compared to their counterparts without stimulation. Neuronal differentiation under AMF was only affected on collagen hydrogels with the highest dose of NPHA, while non-neuronal differentiation regained control values. Taken together, NPCHI-loaded hydrogels displayed a superior performance, maybe benefited from their higher nanomechanical fluidity. Statement of significanceHydrogels and magnetic nanoparticles are undoubtedly useful biomaterials for biomedical applications. Nonetheless, the combination of both has been scarcely explored to date. In this study, we have designed hybrid 3D matrices integrating both components as promising magnetically responsive platforms for neural therapeutics. The resulting collagen scaffolds were soft (E0 ∼ 2.6 kPa) and biodegradable hydrogels with capacity to respond to external magnetic stimuli. Primary neural cells proved to grow on these substrates, preserving high viability and neuronal differentiation percentages even under the application of a high-frequency alternating magnetic field. Importantly, those hydrogels loaded with chitosan-coated iron oxide nanoparticles displayed a superior performance, likely related to their higher nanomechanical fluidity.

Designing Ubiquitin-like protease 1 (Ulp1) based nano biocatalysts: A promising technology for SUMO fusion proteins

The SUMO proteases (Ulps), a group of cysteine proteases, are well known for their efficient ability to perform structure-based cleavage of SUMO tag from the protein of interest and generation of biotherapeutics with authentic N-terminus. However, the stability of Ulps has remained a challenge for the economical production of difficult-to-produce proteins in E. coli. Therefore, the present study aimed to establish the methodology for developing stable S. pombe Ulp1 preparation using different enzyme immobilization strategies. The whole-cell biocatalyst developed using the Pir1 anchor protein of Pichia cleaved the SUMO tag within 24 h of reaction incubation. The chemical immobilization using commercial epoxy and amino methacrylate beads significantly enhanced the operational reusability of SpUlp1 up to 24 cycles. Silica beads further improved the repetitive usage of the immobilized enzyme for 65 cycles. The SpUlp1 immobilization on laboratory-developed chitosan-coated iron oxide nanoparticles exhibited more than 90 % cleavage of SUMO tag from different substrates even after 100 consecutive reactions. Moreover, an effective SUMO tag removal was observed within 10 min of incubation. The operational stability of the immobilized enzyme was confirmed in a pH range of 5 to 13. The spherical nature of nanoparticles was confirmed by FESEM and TEM results. The successful chitosan coating and subsequent activation with glutaraldehyde were established via FT-IR. Furthermore, HRTEM, SAED, and XRD proved the crystalline nature of nanoparticles, while VSM confirmed the superparamagnetic behavior.

Exogenous melatonin differentially affects biomass, total carbohydrates, and essential oil production in peppermint upon simultaneous exposure to chitosan-coated Fe3O4 NPs

Melatonin and iron play important roles in the growth processes and production of secondary metabolites in medicinal plants. To evaluate the effects of melatonin and Chitosan-Coated Iron Oxide Nanoparticles (Fe-CTs NPs) on peppermint growth, essential oil content and constituents, total carbohydrates and antioxidant enzyme activities, a factorial experiment was conducted based on randomized complete block design (CRBD) with three replications (n = 3). Treatments consisted of different concentrations of melatonin (0, 100, and 200 mg L−1) and Fe-CTs NPs (0, 7.5, and 15 mg L−1). During the experiment, foliar applications of melatonin and Fe-CTs NPs were performed three times with 20 days’ interval. Treatments with melatonin, and Fe-CTs NPs had significant effects on the studied traits. The results showed that with increasing melatonin and Fe-CTs NPs concentrations, fresh and dry weights, total carbohydrates, and leaf area index were significantly (P < 0.05) increased in treated plants. The highest CAT and APX activities were observed in plants treated with melatonin at 100 mg L−1 and Fe-CTs NPs at 15 mg L−1. Eucalyptol, Menthyl acetate, Thiophene, 2-ethyl-5-(2-methylpropyl), Mint furanone, and Viridiflorol were found as the major essential oil constituents in peppermint plants under experimental treatments. Moreover, analytical results showed that the highest amount of Menthol (38.48 %) was obtained in plants exposed to Fe-CTs NPs at 7.5 mg L−1, however, the highest L-Menthone (30.53 %) was observed in plants treated with melatonin at 200 mg L−1 and Fe-CTs NPs at 15 mg L−1. The findings provide insights into the regulatory mechanisms of melatonin and Fe-CTs NPs on peppermint growth, physiology and biosynthesis of volatile compounds.

Phycocyanin-conjugated chitosan-coated iron oxide nanoparticles for the separation of Escherichia coli cells

Phycocyanin-conjugated chitosan-coated iron oxide nanoparticles for the separation of Escherichia coli cells

Chitosan-coated iron oxide nanoparticles obtained by laser pyrolysis

The structural and magnetic properties of iron oxide nanoparticles (NPs) synthesized by laser pyrolysis, as well as their chitosan-stabilized aqueous suspensions were studied in regards to the ratio between O2 and Ar. During the synthesis, the flow of Fe(CO)5 precursor vapors and C2H4 sensitizer molecules was kept constant, while the ratio between O2 and Ar in the reactive mixture was increased (1:4, 1:2, 1:1, and 2:1). The formation of small particles (under 4 nm in size) was observed at lower O2 concentrations, whereas their mean crystallite size increased to ∼14 nm for those formed from the richest O2 content, which also induced the formation of particles with the highest magnetization saturation (101.4 emu/g). Maghemite and/or magnetite phases were identified as the main components in all samples, while a small amount of α iron/iron carbides presence was detected with the exception of sample obtained at 1:1 O2 to Ar ratio. The formation of these minor phases reveals the interplay between oxidative and reductive processes which depend on O2 content and C2H4 reactivity at different temperatures. After chitosan loading, all aqueous suspensions presented excellent stability (zeta potential values over 76 mV). Moreover, the samples stabilized using low polymer concentration (0.05 g/l) displayed relatively low hydrodynamic sizes (110–125 nm).

Adsorption of antimicrobial peptide onto chitosan-coated iron oxide nanoparticles fosters oxidative stress triggering bacterial cell death.

In the prevailing environmental status quo, bacterial resistance has made antibiotics and antimicrobial peptides (AMPs) ineffective, imparting a serious threat and putting a much greater financial burden on the biomedical and food industries. For this reason, the present study investigates the potential of iron oxide nanoparticles (IONPs) coated with chitosan (CS-IONP) as a platform for augmenting the antimicrobial activity of antimicrobial peptides like nisin. Hence, the nisin is allowed to be adsorbed onto chitosan-coated IONPs to formulate nisin-loaded CS-IONP nanoconjugates. The nanoconjugates were characterized by various optical techniques, such as XRD, FTIR, SEM, zeta and DLS. Remarkably, lower concentrations of N-CS-IONP nanoconjugate exhibited significant and broad-spectrum antibacterial potency compared to bare IONPs and nisin against both Gram-positive and Gram-negative bacteria. Biofilm production was also found to be drastically reduced in the presence of nanoconjugates. Further investigation established a relationship between an increase in antibacterial activity and the enhanced generation of reactive oxygen species (ROS). Oxidative stress exhibited due to enhanced ROS generation is a conclusive reason for the rupturing of bacterial membranes and leakage of cytoplasmic contents, eventually leading to the death of the bacteria. Thus, the current study emphasizes the formulation of a novel antimicrobial agent which exploits magnetic nanoparticles modulated with chitosan for enhanced remediation of resistant bacteria due to oxidative stress imparted by the nanoconjugates upon interaction with the bacteria, leading to cell death.

A new method in mitigation of drought stress by chitosan-coated iron oxide nanoparticles and growth stimulant in peppermint

Damage to the plant's photosynthetic system is known as the main symptoms of sensitivity to environmental stresses. Little is known about beneficial role of new chitosan compounds such as Kitoplus®, and chitosan-coated nanomaterials on alleviation of adveres effects of drought stress in plants. In the present study, a factorial experiment was conducted in a split-plot manner based on a randomized complete block design (RCBD) with three replications to evaluate the effects of Kitoplus® growth stimulant and Chitosan-Coated Iron Oxide Nanoparticles (Fe-CTs NPS) on peppermint growth, chlorophyll fluorescence and essential oil biosynthesis under drought stress conditions. Treatments included three levels of drought stress (irrigation at soil moisture levels of 30%, 60%, and 90%), three concentrations of Kitoplus®(control without Kitoplus®, 0.5% and 1%), and three concentrations of Fe-CTs NPs (control without Fe-CTs NPs, 5 and 10 µM). Drought stress, growth stimulation treatment with Kitoplus®, and Fe-CTs NPs had significant dual and triple effects on the studied physiological traits. According to the results, chlorophyll index and stomatal conductance were significantly lower in control plants than in those undergoing drought stress. Under 60% field capacity moisture conditions, the chlorophyll index was increased with 1% Kitoplus® treatment. The maximum fluorescence (Fm) and variable fluorescence (Fv) raised as the drought stress intensity increased. The highest Fm and Fv were observed in plants treated with 1% Kitoplus® and 10 µM Fe-CTs NPS under 30% soil moisture stress . Results also showed that the highest value of menthone (33.31%) was obtained in plants treated with Kitoplus® at 1% and Fe-CTs NPs at 10 μM under drought stress of 60% field capacity. In addition, the highest amount of menthol (26.5%) was observed in plants treated with 0.5% Kitoplus® under drought stress of 30% field capacity. The overall importance of the study lies in devising the simultaneous application of biostimulants and nanomaterials in enhancing essential oils production in the mint plant under drought stress challenges. • Peppermint Vegetative yield improved by increasing the concentration of Kitoplus® and Fe-CTs NPS. • Menthol's highest amount was observed in plants with Kitoplus® (0.5%) and Fe-CTs NPs (10 μM) interaction under 90% FC. • The highest amount of menthol was observed in plants following interaction of Kitoplus® (0.5%) and Fe-CTs NPs (10 μM) under 90% FC. • The maximum menthone obtained in plants treated with Kitoplus® (1%) and Fe-CTs NPs (10 μM) under drought stress of 60% FC. • Chlorophyll fluorescence in plants treated with Kitoplus® and Fe-CTs NPS was significantly higher than that of controls.

Magnetic chitosan nanoparticles loaded with Amphotericin B: Synthesis, properties and potentiation of antifungal activity against common human pathogenic fungal strains

Amphotericin B has long been regarded as the gold standard for treating invasive fungal infections despite its toxic potential. The main objective of this research was to develop a novel IONPs@CS-AmB formulation in a cost-effective manner in order to enhance AmB delivery performance, with lowering the drug's dose and adverse effects. The chitosan-coated iron oxide nanoparticles (IONPs@CS) were synthesized afterward, AmB-loaded IONPs@CS (IONPs@CS-AmB) prepared and characterized by AFM, FT-IR, SEM, EDX, and XRD. Biological activity of the synthesized NPs determined and the cytotoxicity of IONPs@CS-AmB evaluated using the MTT and in vitro hemolysis tests. The IONPs@CS-AmB was synthesized using the coprecipitation method with core-shell structure in size range of 27.70 to ∼70 nm. The FT-IR, XRD and EDX pattern confirmed the successful synthesis of IONPs @CS-AmB. The IONPs@CS-AmB exhibited significant antifungal activity and inhibited the metabolic activity of Candida albicans biofilms. The hemolysis and MTT assays showed that IONPs@CS-AmB is biocompatible with high cell viability when compared to plain AmB and fungizone. The IONPs@CS-AmB is more effective, less toxic and may be a suitable alternative to conventional drug delivery. IONPs@CS-AmB may be a viable candidate for use as a microbial-resistant coating on the surfaces of biomedical devices.

Photothermally responsive chitosan-coated iron oxide nanoparticles for enhanced eradication of bacterial biofilms

This work developed a pH/NIR responsive antibacterial agent (CS-FeNPs) composed of chitosan (CS) and Fe3O4 nanoparticles (FeNPs). CS triggers bacterial attraction through surface charge, while Fe acts as a photothermal agent (PTA). The CS-Fe NPs exhibited antibacterial and antibiofilm activity against both bacteria (G+/G−). However, higher activity was observed against bacteria (G−) due to electrostatic interactions. The CS-FeNPs bind with the bacterial membrane through electrostatic interactions and disturb bacterial cells. Later, in an acidic environment, CS-FeNPs bind with bacterial membrane, and NIR irradiation leads the antibacterial activity. CS-FeNPs exhibited a potential photothermal conversion efficiency (η) of 21.53 %. Thus, it converts NIR irradiation into heat to kill the bacterial pathogen. The CS-FeNPs were found to be less cytotoxic with great antibacterial efficiency on planktonic bacteria and their biofilm, which indicates that they deserve to develop potential and safe treatment strategies for the treatment of bacterial infections.

Tam Çiçeklenme Döneminde Yapraktan Uygulanan Kitosan, Demir Oksit ve Kitosanla Kaplanmış Demir Oksit Nanopartiküllerinin Farklı Konsantrasyonlarının Hypericum triquetrifolium Turra.’nın İkincil Metabolitleri Üzerine Etkileri

Hypericum triquetrifolium Turra. (Hypericaceae) is one of the important medicinal plants. This herb is used in Turkish folk medicine for its antidepressant, anthelmintic and antiseptic effects. Hypericum extracts have an important commercial value in the pharmaceutical industry. Therefore, studies to increase the amount of secondary metabolites it contains are becoming widespread. Elicitors are biological and non-biological factors that can affect the synthesis of secondary metabolites in plants. In recent years, nanoelicitors have been used to increase the amount of active ingredients. In this study, to stimulate the synthesis of biologically active secondary compounds of H. triquetrifolium; chitosan, iron oxide and chitosan-coated iron oxide nanoparticles in concentrations of 0 (control), 50, 75, 100 and 150 ppm were sprayed on the leaves during full bloom. LC-MS/MS analysis showed that application of 100 and 150 ppm chitosan nanoparticles increased the amount of flavonol (hyperocyte and quercitrin) and naphthodianthrons (pseudohypericin and hypericin) in H. triquetrifolium. 50 ppm iron oxide nanoparticle hyperocyte, quercitrin and pseudohypericin; 75 and 100 ppm iron oxide nanoparticles increased the amount of hyperocyte, quercitrin and hyperforin. The 150 ppm iron oxide nanoparticle resulted in an increase in all compounds except hypericin. In this study, iron oxide nanoparticles coated with chitosan were also used as elicitors to improve the chemical and biological properties of iron oxide. In this series, iron oxide nanoparticle coated with 100 ppm chitosan was effective and increased the amounts of quercitrine, kaempferol and pseudohypericin. The concentration of 75 ppm of this group was effective on quercitrin.

Penetration and photodynamic ablation of drug-resistant biofilm by cationic Iron oxide nanoparticles.

As we step into the post-antibiotic era, the accelerated emergence of antibiotic-resistant pathogenic bacteria poses an increasingly serious threat to public health. The formation of antibiotic-resistant biofilms further challenges currently available drugs and treatment options, calling for novel strategies for effective ablation of such biofilm with minimal concern on safety and development of resistance. Herein, we report a novel type of photodynamic nanoagent, composed of chlorin e6 (Ce6)-loaded water-soluble chitosan-coated iron oxide nanoparticles (named Ce6@WCS-IONP), for drug-resistant bacteria killing and biofilm eradication. The fabricated Ce6@WCS-IONP has negligible toxicity to mammalian cells and exhibited equivalent singlet oxygen generation capacity to free Ce6; however, its association with methicillin-resistant Staphylococcus aureus (MRSA) was greatly enhanced, as evidenced by flow cytometry analysis and transmission electron microscope. In vitro studies verified that Ce6@WCS-IONP has superior photodynamic bactericidal effect against planktonic MRSA. Furthermore, with the aid of the cationic nature and small size, Ce6@WCS-IONP could effectively penetrate into MRSA biofilm, revealed by 3D fluorescence imaging. Both biomass analysis and viable bacteria counting demonstrated that Ce6@WCS-IONP showed potent biofilm ablation efficacy, averagely 7.1 log unit lower than that in free Ce6 group upon identical light irradiation. In addition, local treatment of MRSA-infected mice with Ce6@WCS-IONP plus light irradiation resulted in significant antibacterial and wound healing effect, accompanied by good biocompatibility in vivo. Collectively, photosensitizer-loaded cationic IONP with effective biofilm penetration and photodynamic eradication potential might be a promising nano platform in fighting against antibiotic-resistant microbial pathogen and biofilm.

Ultrasound assisted chitosan coated iron oxide nanoparticles: Influence of ultrasonic irradiation on the crystallinity, stability, toxicity and magnetization of the functionalized nanoparticles

Due to unique reaction conditions of the acoustic cavitation process, ultrasound-assisted synthesis of nanoparticles has attracted increased research attention. In this study, we demonstrate the effect of ultrasonic irradiation on the crystallinity, stability, biocompatibility, and magnetic properties of chitosan-coated superparamagnetic iron oxide nanoparticles (CS-SPIONs). CS solution and colloidal suspension of SPIONs were mixed and sonicated using an ultrasonic probe of 1.3 cm tip size horn, frequency (20 kHz), and power (750 W). Different samples were sonicated for 1.5, 5, and 10 min with corresponding acoustic powers of 67, 40 and 36 W, and the samples were denoted S1.5, S5, and S10, respectively. The samples were characterized using X-ray diffractometer (XRD), Energy dispersive X-ray (EDX), Transmission electronic microscope (TEM), Fourier transform infrared spectroscopy (FTIR), Zeta sizer, and vibrating sample magnetometer (VSM). Cell cytotoxicity and cell uptake were investigated with human embryonic kidney 293 (HEK-293) cells through MTT assay and Prussian blue staining, respectively. The sharp peaks of the XRD pattern were disappearing with an increase in the sonication period but a decrease in acoustic power. EDX analysis also demonstrates that atomic and weight percentages of the various elements in the samples were decreasing with an increase in the sonication period. However, the Zeta potential (ζ) values increase with an increase in the sonication period.The saturation magnetization (Ms) of the S1.5 before and after the coating is 62.95 and 86.93 emu/g, respectively. Cell cytotoxicity and uptake of the S1.5 show that above 70% of cells were viable at the highest concentration and the longest incubation duration. Importantly, the CS-SPIONs synthesized by the sonochemical method are non-toxic and biocompatible.

Polymeric biocompatible iron oxide nanoparticles labeled with peptides for imaging in ovarian cancer.

Compared with other nanomaterials, surface-modified iron oxide nanoparticles (IONPs) have gained attraction for cancer therapy applications due to its low toxicity, and long retention time. An innocuous targeting strategy was developed by generation of fluorescein isothiocyanate (FITC)-labeled peptide (growth factor domain (GFD) and somatomedin B domain (SMB)) functionalized, chitosan-coated IONPs (IONPs/C). It can be used to target urokinase plasminogen activator receptor (uPAR), which is a surface biomarker, in ovarian cancer. Binding affinity between uPAR and peptides (GFD and SMB) were revealed by in-silico docking studies. The biophysical characterizations of IONPs, IONPs/C, and IONPs/C/GFD-FITC or SMB-FITC nanoprobes were assessed via Vibrating Sample Magnetometer (VSM), Transmission Electron Microscopy (TEM), Dynamic Light Scattering (DLS), and Fourier Transform Infrared Spectroscopy (FT-IR). Prussian Blue staining, fluorescence spectroscopy, and fluorescence imaging were performed to confirm the targeting of nanoprobes with the surface receptor uPAR. The combination of IONPs/C/GFD+SMB showed efficient targeting of uPAR in the tumor microenvironment, and thus can be implemented as a molecular magnetic nanoprobe for cancer cell imaging and targeting.

Beyond processing waste: Extraction of oil from Atlantic salmon (Salmo salar) by-products using immobilized Alcalase on chitosan-coated magnetic nanoparticles

Atlantic salmon (Salmon salar) aquaculture has been fully developed on a large scale worldwide. Currently in the Atlantic salmon processing industry, 40–50% of the fish body ends up as by-products, which contain a variety of nutrients and are mainly processed into functional ingredients for premium pet food and animal feed. With the global increase of interest in nutritional diets and supplements, more research has been performed for the valorization of salmon by-products into value-added food products for human consumption. In the present study, an immobilized protease was used for hydrolysis of Atlantic salmon by-products to extract salmon oil. Alcalase was immobilized on chitosan-coated iron (II, III) oxide nanoparticles via glutaraldehyde crosslinking. The immobilized Alcalase was characterized using Fourier transform infrared spectroscopy and transmission electron microscope. The optimum pH and temperature range for the immobilized Alcalase were determined as 8 and 55–65 °C, respectively. The salmon oil extraction process using the immobilized Alcalase was optimized through a factorial design, and the highest oil yield of 20.55% (88.30% recovery) was obtained from 1 h of hydrolysis at 65 °C. The oil recovery using the immobilized Alcalase was comparable to the use of free Alcalase. The low levels of oxidation and hydrolysis indicated the high quality of the extracted oil, which is promising to be processed into high-value products such as nutraceuticals and pharmaceuticals. The immobilized Alcalase was collected using a magnet and reused at least three batches without a significant decrease in oil yield, indicating its potential for effective and consecutive oil extraction from salmon by-products. The present study would promote the production of value chain products from unutilized Atlantic salmon resources and achieve sustainable development of the blue economy.

A possible theranostic approach of chitosan-coated iron oxide nanoparticles against human colorectal carcinoma (HCT-116) cell line.

Iron oxides have become increasingly popular for their use as a diagnostic and therapeutic tool in oncology. This study aimed to improve pharmacological valuable of Fe3O4, which may be use to diagnosis colorectal cancers (CRC). Here, we have developed chitosan (CS) coated Fe3O4 through a cost-effective procedure. First, we determined the characterization of OA-C-Fe3O4 by FTIR, UV–Vis spectra, and TEM. Then, we evaluated the photodynamic therapeutic (PDT) activity of OA-C-Fe3O4 in human colorectal carcinoma cell lines (HCT 116). Current results revealed that the light-induced enhanced reactive oxygen species (ROS) activity of the nanoparticles (NPs) and caused cell death via the activity of caspase 9/3. The in vitro magnetic resonance imaging (MRI) experiments in (HCT 116) and human embryonic kidney cells (HEK 293) illustrated that nanohybrid is an effective MRI contrasting agents for the diagnosis of colorectal cancer.

Antimicrobial Evaluation for Novel Solution of Iron Oxide Nanoparticles Functionalized with Glycine and Coated by Chitosan as Root Canal Final Irrigation

Background: This study aims to evaluate the antibacterial activity of chitosan-coated iron oxide nanoparticles (Chi-IONP) by agar direct diffusion method and determine the minimum inhibitory concentration and minimum bactericidal concentration (MIC/MBC) of this nano-solution against E.faecalis, S.mutans and Candida albicans the three oral microorganisms commonly isolated from endodontic infections. Methods: The nanoparticles solution was prepared by functionalizing the 8nm iron oxide nanoparticles with glycine and coating them by chitosan dissolved in 0.25% v/v acetic acid. E.faecalis, S.mutans and candida albicans were isolated and identified with Vitek 2 system. Agar diffusion method was used to test three groups of materials, NaOCl 5.25% serve as positive control, 0.25% Acetic acid as negative control and Chi-IONP as experimental material. Broth microdilution method used to determine the MIC/MBC of the experimental material. Statistical analysis used: Statistical analysis was conducted by independent variables t-test performed by using IBM-SPSS program version 22. Result: The used microbial isolates were confirmed with Vitek 2 system with excellent confidence level of diagnosis. Chi-IONP showed antifungal activity higher than NaOCl 5.25%, and comparable effect to NaOCl 5.25% against E.faecalis and S.mutans. The negative group showed no effect on the tested microorganisms. The MIC/MBC were determined as following 125/250 µg/ml for E.faecalis, 250/ 500 µg/ml for S.mutans and the MIC/MFC was 62.5/ 125 µg/ml for C.albicans. Conclusion: Chi-IONP was a powerful antimicrobial agent against the tested microorganisms, and this test results shows antifungal activity of Chi-IONP higher than NaOCl 5.25% and comparable antibacterial effect to NaOCl 5.25%.

Noninvasive Tracking of mPEG-poly(Ala) Hydrogel-Embedded MIN6 Cells after Subcutaneous Transplantation in Mice.

Recently, we demonstrated the feasibility of subcutaneous transplantation of MIN6 cells embedded in a scaffold with poly(ethylene glycol) methyl ether (mPEG)-poly(Ala) hydrogels. In this study, we further tracked these grafts using magnetic resonance (MR) and bioluminescence imaging. After being incubated overnight with chitosan-coated superparamagnetic iron oxide (CSPIO) nanoparticles and then mixed with mPEG-poly(Ala) hydrogels, MIN6 cells appeared as dark spots on MR scans. For in vivo experiments, we transfected MIN6 cells with luciferase and/or incubated them overnight with CSPIO overnight; 5 × 106 MIN6 cells embedded in mPEG-poly(Ala) hydrogels were transplanted into the subcutaneous space of each nude mouse. The graft of CSPIO-labeled MIN6 cells was visualized as a distinct hypointense area on MR images located at the implantation site before day 21. However, this area became hyperintense on MR scans for up to 64 days. In addition, positive bioluminescence images were also observed for up to 64 days after transplantation. The histology of removed grafts showed positive insulin and iron staining. These results indicate mPEG-poly(Ala) is a suitable scaffold for β-cell encapsulation and transplantation. Moreover, MR and bioluminescence imaging are useful noninvasive tools for detecting and monitoring mPEG-poly(Ala) hydrogel-embedded MIN6 cells at a subcutaneous site.

Antimicrobial, antibiofilm and cytotoxic effects of a colloidal nanocarrier composed by chitosan-coated iron oxide nanoparticles loaded with chlorhexidine

ObjectivesThis study evaluated the antimicrobial and antibiofilm effects of a colloidal nanocarrier for chlorhexidine (CHX) on Candida glabrata and Enterococcus faecalis, as well as tested its cytotoxic effect on murine fibroblasts. MethodsIron oxide nanoparticles (IONPs) were coated with chitosan (CS) and loaded with CHX at 31.2, 78 and 156 μg/mL. Antimicrobial effects were assessed by determining the minimum inhibitory concentration (MIC), using the broth microdilution method, and fractional inhibitory concentration index (FICI). Preformed biofilms (48 h) were treated with different concentrations of the nanocarrier (24 h) and quantified by colony-forming units (CFUs), total biomass and metabolic activity. For cytotoxicity, the viability of L929 cells was evaluated by MTT assay after 24 and 48 h of exposure to the nanocarrier. Data were submitted to ANOVA and Fisher LSD or Tukey post-hoc tests (α = 0.05). ResultsMIC and FICI results showed an indifferent interaction among the components of the nanocarrier for all strains evaluated. CHX alone and nanocarrier containing 156 μg/mL CHX did not differ from each other in reducing the number of CFUs. However, the nanocarrier containing 156 μg/mL CHX promoted the highest reductions in total biofilm biomass and metabolism, surpassing the effect of CHX alone. After 24 and 48 h of exposure, the nanocarrier reduced CHX toxicity to the L929 cell at low concentrations. ConclusionThese findings suggest that the CHX nanocarrier has potential to be used in the control of oral diseases associated with C. glabrata and E. faecalis. Clinical relevanceCHX has improved the antibiofilm effect and reduced the cytotoxicity (at low concentrations) when conjugated to CS-coated IONPs. This new colloidal formulation has potential as an alternative antimicrobial agent to pure CHX for the control of biofilm-related oral diseases, such as oral candidiasis and endodontic infections.

Postharvest disease inhibition in fruit by synthesis and characterization of chitosan iron oxide nanoparticles

Abstract Economic and ecofriendly surface modification of nanoparticles is a consistent challenge for agricultural purposes. Application of surface modified greatly reduces the risks of postharvest diseases and weight loss during storage. For this purpose, chitosan coated iron oxide nanoparticles (CH–Fe2O3 NPs) found to be useful due to the presence of basal metallic core and organic functional groups on the surface. The present study is based on one step synthesis of CH–Fe2O3 NPs to control emerging diseases and weight loss on postharvest peach fruit. Moreover, we characterized these synthesized NPs through Ultraviolet visible (UV–Vis) spectroscopy, X-ray diffraction pattern (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM). Characterization results showed synthesized NPs with 218 absorption band, rhombohedral crystalline nature, presence of various organic functional groups, spherical rod shape structure ranging from 20 to 30 nm. We isolated and identified a new fungal species (Rhizopus stolonifer), which causes the postharvest soft rot disease in peach fruit leading to fruit damage and weight loss. We found that 1% CH–Fe2O3 NPs showed significant difference as compared to 0.50% synthetic fungicide by effectively inhibiting microbial growth on fruit surface and reduced weight loss. We concluded that surface engineered NPs can be promising fungicide to control emerging diseases and controlling food loss.