Chitosan-coated Fe3O4 Research Articles

Efficient Removal of Heavy Metals, Dyes, and Contaminants from Industrial Wastewater Using Chitosan-Coated Fe3O4 Nanocomposites: Biosynthesis, Characterizations, and Performance Evaluation

Efficient Removal of Heavy Metals, Dyes, and Contaminants from Industrial Wastewater Using Chitosan-Coated Fe3O4 Nanocomposites: Biosynthesis, Characterizations, and Performance Evaluation

Surface Modification Strategies for Chrysin-Loaded Iron Oxide Nanoparticles to Boost Their Anti-Tumor Efficacy in Human Colon Carcinoma Cells.

Enhancing nanoparticles' anti-cancer capabilities as drug carriers requires the careful adjustment of formulation parameters, including loading efficiency, drug/carrier ratio, and synthesis method. Small adjustments to these parameters can significantly influence the drug-loading efficiency of nanoparticles. Our study explored how chitosan and polyethylene glycol (PEG) coatings affect the structural properties, drug-loading efficiency, and anti-cancer efficacy of Fe3O4 nanoparticles (NPs). The loading efficiency of the NPs was determined using FTIR spectrometry and XRD. The quantity of chrysin incorporated into the coated NPs was examined using UV-Vis spectrometry. The effect of the NPs on cell viability and apoptosis was determined by employing the HCT 116 human colon carcinoma cell line. We showed that a two-fold increase in drug concentration did not impact the loading efficiency of Fe3O4 NPs coated with PEG. However, there was a 33 Å difference in the crystallite sizes obtained from chitosan-coated Fe3O4 NPs and drug concentrations of 1:0.5 and 1:2, resulting in decreased system stability. In conclusion, PEG coating exhibited a higher loading efficiency of Fe3O4 NPs compared to chitosan, resulting in enhanced anti-tumor effects. Furthermore, variations in the loaded amount of chrysin did not impact the crystallinity of PEG-coated NPs, emphasizing the stability and regularity of the system.

Multi-responsive Pickering emulsifiers: a comprehensive study on the emulsification-demulsification behavior of modified chitosan-coated Fe3O4 nanocomposites.

The surface characteristics of stimuli-responsive Pickering emulsifiers can be modified by external environmental triggers, making them highly versatile in various applications. In this study, we report three novel organic-inorganic composite structure emulsifiers. These emulsifiers were designed with a core of magnetic Fe3O4 particles, surrounded by a protective silica layer, and coated on the exterior with three distinct types of modified chitosan (CS). Experimental results demonstrate that these emulsifiers can stabilize emulsion systems consisting of liquid paraffin and deionized water at a concentration of 0.5 wt%. The unique properties of the modified CS coatings allowed for the controlled demulsification of two types of emulsions by adjusting the proton concentration. Additionally, these emulsifiers exhibited magnetic-responsive demulsification under the control of an external magnetic field. The findings of this study provide valuable insights into the design and construction of multi-responsive chitosan-based magnetic Pickering emulsifiers with controllable properties.

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.

An Alternating Magnetic Field-Controlled Drug Delivery System Based on 4,4′-Azobis (4-cyanovaleric Acid)-Functioned Fe3O4@Chitosan Nanoparticles

Herein, we designed chitosan-coated Fe3O4 nanocomposites for the control release of drugs by an alternating magnetic field (AMF). The chitosan-coated Fe3O4 nanoparticles (Fe3O4@CS) were prepared by a alkaline co-precipitation method, and then, the model drug toluidine blue (TB) was covalently grafted onto the surface of the nanocomposite by a two-step amide reaction with the thermosensitive molecule 4,4'-azobis (4-cyanovaleric acid) (ACVA) as the linker group. The prepared nanocomposites were superparamagnetic and showed high magnetization saturation (about 54.0 emu g-1). In vitro hydrothermal release studies showed that most parts of the TB would be effectively enclosed within the nanocarriers at lower ambient temperatures (23 or 37 °C) due to the molecular bonding of ACVA. The results of kinetic fitting of hydrothermal release data showed that TB released from nanoparticles followed first-order kinetics (R2 > 0.99) and the Korsemeyer-Peppas model (R2 > 0.99, n < 0.5). Most importantly, a single magnetron release experiment demonstrated an approximately linear relationship between the cumulative release of the drug and the duration of action of AMF (R2 = 0.9712). Moreover, the increase in the cumulative release of the drug can be controlled by controlling the switch of the AMF generation device. Therefore, the ACVA-modified Fe3O4@CS nanocarrier designed in this study is a promising model for drug delivery that enables the control of drug release dose by AMF.

The human immune cell simulated anti-breast cancer nanorobot: the efficient, traceable, and dirigible anticancer bio-bot

BackgroundVarious types of cancer therapy strategies have been investigated and successfully applied so far. There are a few modern strategies for improving drug selectivity and biocompatibility, such as nanoparticle-based drug delivery systems. Herein, we designed the traceable enzyme-conjugated magnetic nanoparticles to target human breast cancer cells by simulating the innate immune cell’s respiratory explosion response.MethodsThe human immune cell simulated anti-breast cancer-nanorobot (hisABC-NB) was produced by conjugating the mouse-derived iNOS and human-originated MPO enzymes on the folate-linked chitosan-coated Fe3O4 nanoparticles. The synthesized nanoparticles were functionalized with folic acid as the breast cancer cell detector. Then, the hisABC-NB’s stability and structural properties were characterized by studying Zeta-potential, XRD, FTIR, VSM, FESEM, and DLS analysis. Next, the selectivity and anti-tumor activity of the hisABC-NB were comparatively analyzed on both normal (MCF-10) and cancerous (MCF-7) human breast cells by analyzing the cells’ survival, apoptotic gene expression profile (P53, BAX, BCL2), and flow cytometry data. Finally, the hisABC-NB’s traceability was detected by T2-weighted MRI imaging on the balb-c breast tumor models.ResultsThe hisABC-NB significantly reduced the MCF-7 human breast cancer cells by inducing apoptosis response and arresting the cell cycle at the G2/M phase compared with the normal cell type (MCF-10). Moreover, the hisABC-NB exhibited a proper MRI contrast at the tumor region of treated mice compared with the non-treated type, which approved their appropriate MRI-mediated traceability.ConclusionThe hisABC-NB’s traceability, dirigibility, and selective cytotoxicity were approved, which are the three main required factors for an efficient anticancer compound. Therefore, it has the potential to be used as an intelligent safe anticancer agent for human breast cancer treatment. However, several in vitro and in vivo studies are required to clarify its selectivity, stability, and safety.

Surface Chitosan-coated Fe3O4 immobilized lignin for adsorbed phosphate radicals in solution

The design of green, efficient, and conveniently recyclable biomass-based adsorbents is of great importance, but little has been reported. Therefore, magnetic Fe3O4 doped lignin-chitosan based microspheres (CS-Li@Fe3O4) was prepared by emulsion crosslinking for phosphate removal in water. The prepared CS-Li@Fe3O4 shows a spherical structure with a diameter of 5–40 µm. Benefiting from its unique morphological structure and the abundant functional groups on the surface, CS-Li@Fe3O4 exhibits excellent phosphate adsorption capacity and is applicable in environments with a pH of 2–10. More importantly, the CS-Li@Fe3O4 retains excellent adsorption capacity after 6 adsorption/desorption cycles, demonstrating remarkable recyclability and stability. The adsorption isotherm was well described by the Langmuir model, the adsorption kinetics accords with the pseudo-first order kinetic model, which indicates that the adsorption process is monolayer chemisorption. Hence, CS-Li@Fe3O4 holds promising future for water remediation owing to its green raw material and excellent phosphate capture properties.

Cytocompatibility of pH-sensitive, chitosan-coated Fe3O4 nanoparticles in gynecological cells.

Nanoparticles that contact human cells without damaging basic human tissues are becoming more widely used in medicine. Efficient delivery to the intracellular target cell or compartment through the cell membrane must be achieved with minimal cytotoxicity to healthy cells. Fe3O4 nanoparticles have been widely used in biomedical research for their magnetic, non-toxic, and biocompatible properties. However, the effects of Fe3O4 nanoparticles coated with chitosan (CS) on gynecological cells are unclear. In this study, the Fe3O4 nanoparticles were coated with CS to enhance their cytocompatibility and dispersion in water. These CS-Fe3O4 nanoparticles were taken up by gynecological cells and did not affect cell viability in vitro. They have greater cytocompatibility in acidic environments than normal Fe3O4 nanoparticles and have the potential for drug delivery into gynecological cells.

Synthesis and Characterization Studies of Mesostructured Chitosan Coated Fe3O4 Nanoparticles with Folic Acid

In this present work, Fe3O4 nanoparticles were obtained by a one-part Co-precipitation method. Secondly, a simple solvothermal method was employed to synthesize Chitosan (CS) coated Fe3O4 nanoparticles. Chitosan was used as a surface modification agent. The surface of Chitosan-coated Fe3O4 nanoparticles was conjugated with Folic Acid (FA). Various properties of the resultant products were performed by characterization studies. The structure and surface morphology of as-prepared nanoparticles were characterized by X-ray diffraction (XRD) and Scanning electron microscopy (SEM). The physical parameter such as strain and the crystallite size was evaluated for all the reflection peaks of the samples by using Williamson–Hall (W-H plot) method. Determination of the chemical component was marked by Fourier transform infrared spectroscopy (FTIR) and Energy-dispersive X-ray spectroscopy (EDAX) analyses. UV- Vis experiment was carried out to record optical absorbance and the bandgap energy of the nanoparticles was determined by Tauc’s plot. Thermogravimetric analysis (TGA) was conducted to recognize the thermal stability of the magnetic nanoparticles and endothermic peaks were observed from the first derivative of the TGA curve (DTG curve).

Post-hydrolysis of cellulose oligomers by cellulase immobilized on chitosan-grafted magnetic nanoparticles: A key stage of butanol production from waste textile

The recently developed technologies for immobilization of cellulase may address the challenges in costly hydrolysis of cellulose for cellulosic butanol production. In this study, a “hybrid” hydrolysis was developed based on chemical hydrolysis of cellulose to its oligomers followed by enzymatic post-hydrolysis of the resulting “soluble oligomers” by cellulase immobilized on chitosan-coated Fe3O4 nanoparticles. This hybrid hydrolysis stage was utilized in the process of biobutanol production from a waste textile, jeans waste, leading to selective formation of glucose and high yield of butanol production by Clostridium acetobutylicum. After validating the immobilization process, the optimum immobilization parameters including enzyme concentration and time were achieved on 8 h and 15.0 mg/mL, respectively. The reusability of immobilized enzyme showed that immobilized cellulase could retain 51.5% of its initial activity after three times reuses. Dilute acid hydrolysis of regenerated cellulose at 120–180 °C for 60 min 0.5–1.0% phosphoric acid led to less than 10 g/L glucose production, and enzymatic post-hydrolysis of the oligomers resulted in up to 51.5 g/L glucose. Fermentation of the hydrolysate was accompanied by 5.3 g/L acetone-butanol-ethanol (ABE) production. The simultaneous co-saccharification and fermentation (SCSF) of soluble and insoluble oligomers of cellulose led to 17.4 g/L ABE production.

Immobilization of lipase on β-cyclodextrin grafted and aminopropyl-functionalized chitosan/Fe3O4 magnetic nanocomposites: An innovative approach to fruity flavor esters esterification

The lipase from Bacillus licheniformis NCU CS-5 was immobilized onto β-cyclodextrin (CD) grafted and aminopropyl-functionalized chitosan-coated Fe3O4 magnetic nanocomposites (Fe3O4-CTS-APTES-GA-β-CD). Fourier transform infrared spectroscopy, thermogravimetry analysis, X-ray diffraction, scanning electron microscopy and transmission electron microscopy showed that not only the functionalized magnetic nanoparticles were synthesized but also the immobilized lipase was successfully produced. The immobilized lipase exhibited higher optimal pH value (10.5) and temperature (60℃) than the free lipase. The pH and thermal stabilities of the immobilized lipase were improved significantly compared to the free lipase. The immobilized lipase remained more than 80% of the relative activity at temperature of 60 ℃ and pH 12.0. The immobilized lipase also remained over 80% of its relative activity after 28 days of storage and 15 cycles of application. The application of the immobilized lipase in esterification of isoamyl acetate and pentyl valerate showed that maximum esterification efficiency was achieved in n-hexane having 68.0% and 89.2% respectively. Therefore, these results indicated that the Fe3O4-CTS-APTES-GA-β-CD nanoparticles are novel carriers for immobilizing enzyme, and the immobilized lipase can be used as an innovative green approach to the synthesis of fruity flavor esters in food industry.

Comparative Study of Specific Loss Power and Transverse Relaxivity of Spinel Ferrite Nanoensembles Coated With Chitosan and Polyethylene Glycol

We synthesized spinel ferrite nanoensembles (MnFe2O4, CoFe2O4, and Fe3O4) using the chemical co-precipitation method and characterized their physical, chemical, and magnetic properties by X-ray diffraction (XRD), transmission electron microscopy (TEM), physical properties measurement system (PPMS), Mössbauer spectroscopy, Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS) and Raman spectroscopy. Their relaxation properties and potential for hyperthermia therapy were determined using nuclear magnetic resonance (NMR) and cell viability assay, respectively. XRD and TEM data confirmed that the particle core sizes were 6–9 nm before coating while their sizes increased to 10–14 nm and 14–20 nm after coating with chitosan and polyethylene glycol (PEG), respectively. Mössbauer spectroscopy showed superparamagnetic behavior for MnFe2O4 nanoparticles and ferrimagnetic behavior for the CoFe2O4 and Fe3O4 nanoparticles. A detailed studies of MH loops of all three ferrites before and after coating showed surface functionalization by a large reduction of coercivity and anisotropy. The successful coating was further confirmed by the peak shifts in the FTIR spectra of the particles whereas Raman spectra of coated ferrites also displayed the characteristic absorption patterns and suppression of the ferrite peaks suggesting successful coating. The induced heating profile of the nanoparticles in stable suspension was tested with a radio frequency magnetic field of 76 mT and a frequency of 400 kHz. High mortality (&amp;gt;98%) of 9 L gliosarcoma cancer cells by hyperthermia suggested that these nanoparticles could be used for cancer therapy. Transverse relaxivities (r2) determined by NMR for chitosan-coated MnFe2O4, CoFe2O4, and Fe3O4 nanoparticles were 297 (±22), 353 (±26), and 345 (±13), mM−1S−1, while for PEG-coated nanoparticles are 165 (±22), 146 (±14), and 159 (±07) mM−1S−1, respectively. Overall these spinel ferrite nanoensembles show great promise for cancer theranostics research applications.

Effect of Aminated Chitosan-Coated Fe3O4 Nanoparticles with Applicational Potential in Nanomedicine on DPPG, DSPC, and POPC Langmuir Monolayers as Cell Membrane Models.

An adsorption process of magnetite nanoparticles functionalized with aminated chitosan (Fe3O4-AChit) showing application potential in nanomedicine into cell membrane models was studied. The cell membrane models were formed using a Langmuir technique from three selected phospholipids with different polar head-groups as well as length and carbon saturation of alkyl chains. The research presented in this work reveals the existence of membrane model composition-dependent regulation of phospholipid-nanoparticle interactions. The influence of the positively charged Fe3O4-AChit nanoparticles on a Langmuir film stability, phase state, and textures is much greater in the case of these formed by negatively charged 1,2-dipalmitoyl-sn-glycero-3-phospho-rac-(1-glycerol) (DPPG) than those created by zwitterionic 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC) and 2-oleoyl-1-palmitoyl-sn-glycero-3-phosphocholine (POPC). The adsorption kinetics recorded during penetration experiments show that this effect is caused by the strongest adsorption of the investigated nanoparticles into the DPPG monolayer driven very likely by the electrostatic attraction. The differences in the adsorption strength of the Fe3O4-AChit nanoparticles into the Langmuir films formed by the phosphatidylcholines were also observed. The nanoparticles adsorbed more easily into more loosely packed POPC monolayer.

Effects of shell-thickness on the powder morphology, magnetic behavior and stability of the chitosan-coated Fe3O4 nanoparticles

Chitosan-coated Fe3O4 nanoparticles were prepared by coprecipitation followed by reaction with chitosan and different volumes of glutaraldehyde. Coating was modified by varying the volume of glutaraldehyde and reaction time. XRD pattern shows maxima compatible Fe3O4 structure. FTIR spectroscopía confirms the presence of chitosan, more evident in samples with higher chitosan content, as denoted by TGA. TEM images of samples with low glutaraldehyde content reveal particles coated with a homogeneous chitosan shell. Meanwhile, those prepared with high glutaraldehyde volume show nanoparticles dispersed in an organic matrix. Samples present almost superparamagnetic behavior with magnetization saturation values that are reduced as the content of organic matter increases. Regarding the stability of these samples in solution, the presence of a homogeneous coating improves the initial suspension, although it does not prevent its subsequent aggregation over time. However, this aggregation process is reduced for sample synthesized with 1mL of glutaraldehyde after 6h of reaction.

Rapid tumor inhibition via magnetic hyperthermia regulated by caspase 3 with time-dependent clearance of iron oxide nanoparticles.

Among conventional cancer therapies, radio-frequency magnetic hyperthermia (MHT) has widely been investigated for use with magnetic nanoparticles (MNPs). However, the majority of in vivo biodistribution studies have tested very low MNP dosages (equivalent to magnetic resonance imaging (MRI) applications) to check for clearance rate; which is far below the clinical dose of MHT. Due to this poor validation in preclinical scenarios, quite a few MNPs already in clinical use were later discontinued, on grounds of unexpected clinical outcomes in terms of inflammation, and prolonged clearance in vivo. By exploiting an economical method of synthesis, we have developed chitosan-coated Fe3O4 nanoparticles with high heating efficiency performance. Their anti-tumor response was evaluated in an ectopic tumor model of C6 glioblastoma by MHT. The intratumoral injection of MNPs on days 1 and 7 resulted in rapid tumor inhibition rate of 69.4% within 8 days, with complete inhibition within 32 days, and no recurrence recorded over a 5-month follow-up. Notably, the MNP-mediated MHT therapy achieved the highest degree of therapeutic efficacy required for complete tumor ablation by combining controlled temperature range (<44 °C), reduced MNP dosage; much lower than in most reported studies, and AMF parameters (time of exposure and frequency) within the clinical safety limit. Periodic body weight measurements confirmed negligible adverse side effects in rats. The anti-tumor activity was validated by severe apoptosis (TUNEL, cleaved Caspase-3), reduced proliferation (Ki 67) and disrupted vasculature (CD 31) in the Fe3O4-MHT-treated group. Real-time gene expression of pro-inflammatory cytokines (IL-6, TNF-α, IL-1α, IL-1β) confirmed the intratumoral activation of IL-6, suggesting the role of immunomodulation in triggering the adaptive immune response for faster tumor regression in the treated group. In addition, the biodistribution and clearance rate of MNPs monitored using ICP-OES confirmed their time-dependent biodegradation via excretion (urine, feces), phagocytosis (liver) and circulatory system (blood), with negligible deposition in other major organs (kidney, heart, lungs). Although we could not show complete clearance of our MNPs within the time frame tested, future studies should focus on combining MHT with immunotherapy, and target tumors at a much-reduced iron dose, consequently improving in vivo clearance rate, and hence overcoming the limitations of MHT in clinical therapy.

Effect of surface functionalization on the heating efficiency of magnetite nanoclusters for hyperthermia application

Here we report the effect of surface functionalization on Fe3O4 assembled nanoclusters with biopolymers, like chitosan and dextran using the solvo-thermal route. XRD analyses confirmed the formation of cubic spinel structure with crystallite sizes ranging from 11 to 14 nm. HRTEM analyses revealed the formation of spherical nanoclusters. Magnetic measurements demonstrate the typical ferromagnetic behavior with saturation magnetization (Ms) up to 71.048, 69.829 and 68.228 Am2Kg−1 for Fe3O4 (FO), chitosan coated Fe3O4 (CFO) and dextran coated Fe3O4 (DFO) respectively at room temperature. Negligible coercivity (Hc) and remenance (Mr) at room temperature implies nearly superparamagnetic behavior. Field cooled (FC) and Zero field cooled (ZFC) measurements of magnetization at an applied field of 100 Oe resulting in the blocking temperature above room temperature for all the samples. Induction heating ability of the samples under alternating magnetic field were studied by means of specific absorption rate measurements (SAR). It is shown that the surface functionalization significantly enhanced the SAR value up to 40% i.e., from 144.08 W/g for FO to 233.28 W/g for DFO at 1 mg/ml concentration. The study also concluded that the dipolar interactions are solely responsible for self-heating behavior of the nanoparticles. It was observed that by changing the sample concentration and different coatings, the final temperature can be tuned to the intended therapeutic (hyperthermia) temperature range (40–44 °C). The in vitro cytocompatibility test resulted in cell viability of more than 90%, which proved that the prepared nanomaterials are promising for the hyperthermia applications.

Antimicrobial and Photocatalytic Degradation Activities of Chitosan-coated Magnetite Nanocomposite

In this work, iron oxide nanoparticles (Fe3O4 NPs) were modified by chitosan (CS). Fe3O4 NPs were synthesized by co-precipitation method and their antimicrobial potential and photo-catalytic degradation of Chloramine T (CT) were investigated. The free Fe3O4 NPs and chitosan-coated Fe3O4 NPs (CS-Fe3O4 NPs) were characterized by XRD, FTIR, SEM, and HRTEM. Fe3O4 NPs have spherical shape and their diameter varied from 18.0 nm to 25.0 nm with average particle size at 21.0 nm. Antimicrobial activity was tested towards some pathogenic bacteria and Candida cells as zone of inhibition (ZOI) and minimum inhibitory concentration (MIC). UV-assisted photocatalytic degradation of CT was investigated. Various parameters affecting the photocatalytic efficiency such as (pH on CT removal, CT initial concentration, and adsorbent dose) were studied. Antimicrobial results showed that CS-Fe3O4 NPs possesses a maximum potential against Escherichia coli, Bacillus subtilis and Candida albicans, by 18.0, 17.0, 14.2 mm ZOI, respectively. Results obtained from the photocatalytic activity indicated that CS-Fe3O4 NPs (2.0 gm/l) possessed a promising removal potential, achieving 86.0% removal of CT in the neutral solution (pH = 7.0). The synthesized CS-Fe3O4 NPs are effective for the removal of CT and potent disinfectant agent for pathogenic microbes with possible application in the wastewater treatment.

Laccase immobilized on chitosan-coated Fe3O4 nanoparticles as reusable biocatalyst for degradation of chlorophenol

The enzyme immobilization technology could enhance the overall stability and recover-ability of enzyme, which will promote the enzyme’s further application in more fields. Compared to most complex and cumbersome process of enzyme immobilization, we present a simple, mild and effective strategy to immobilize laccase on magnetic carrier and further applied in degradation chlorophenol. The Fe3O4@CS (Fe3O4@Chitosan) composite nanoparticles as enzyme carrier were prepared by self-assembly method. Laccase was successfully immobilized on Fe3O4@CS composite nanoparticles through covalent bonding and effectively remove chlorophenol from water. The specific activity of IM-laccase (immobilized laccase) reaches 112.4 U and the activity recovery is 51.8%. The storage stability, operational stability, pH stability and thermostability were all improved compare free laccase. The 2,4-DCP (2,4-Dichloro-Phenol) and 4-CP (Chloro-Phenol) were degraded by IM-laccase to test the degradation efficiency and the results showed that the degradation rate to 2,4-DCP and 4-CP reached 91.4% and 75.5% after 12 h. In test of reusability, IM-laccase showed excellent performance that the degradation rate retained 75.8% and 57.4% after 10 cycles of degradation.

Experimental Study on Targeting Brain Tumor with Ultrasound Nanoparticles Across Blood Brain Barrier

Glioma is a malignant tumor that originates in the brain and accounts for more than half of all brain tumors. The disease is associated with a high fatality rate. Satisfactory treatment cannot be achieved through conventional craniotomy. We use carboxymethyl chitosan-coated Fe3 O4 composite nanoparticles (CMCS-Fe3 O4 NPs) as a drug delivery platform, and installed transferrin (TRF) with a targeting function on the platform. The anticancer drug methotrexate (MTX) is loaded onto the composite nanomaterial to complete a new delivery system for nano-drug targeted treatment of glioma. The composite nanoparticle is not toxic to cells in vitro, but after loading with it is loaded with MTX, it significantly inhibits proliferation of C6 cells. In vivo experiments show that CMCS-Fe3 O4NPs-TRF-MTX has a marked therapeutic effect on glioma in mouse models. The nano complex quickly penetrates the blood-brain barrier and enters brain tissues. An aggregation effect is not obvious. MRI monitoring for up to 4.0 h shows that CMCS-Fe3 O4 NPs-TRF-MTX slowly releases drug molecules over an extended period, thus increasing the duration of drug activity.

Parametric modelling of Pb(II) adsorption onto chitosan-coated Fe3O4 particles through RSM and DE hybrid evolutionary optimization framework

In this study, response surface methodology (RSM) was discussed as an efficient method for the optimization of Pb(II) adsorption onto Fe3O4 nanoparticles and chitosan-coated Fe3O4 particles. To retain the non-linearity of isotherm/kinetic models and inherent characteristics of mechanism involved in adsorption process, the model parameters in these models are estimated using differential evolution (DE) based hybrid optimization. The lack of fit for first-order response-surface model and two-way interactions model were insignificant, but a higher lack-of-fit was observed in the second-order model and reduced second-order model. The results of these computations (F-value: 29.3 on 6 and 37 DF; p-value: 1.226e−12; R2: 0.8261, and LOF: 0.99) showed that the RSO model fit well with Pb (II) removal by Ch-Fe. Based on the RSM model, the optimal conditions were found to be 10.95, 5.5 mg/L, 66.59 min, and 0.1 g/L for pH, Ch-Fe dosage, initial Pb (II) concentration and residence time, respectively, resulting in maximum (93.6%) removal efficiency. Based on the findings, the model predictions from the DE based optimized parameters provided optimal parameter sets which better represent the adsorption rate models and infer the inherent mechanisms of the adsorption process.