A self-healing crosslinked-xanthan gum/soy protein based film containing halloysite nanotube and propolis with antibacterial and antioxidant activity for wound healing.

Traumatic multidrug-resistant bacterial infections are the most threat to wound healing. Lower extremity wounds under diabetic conditions display a significant delay during the healing process. To overcome these challenges, the utilization of protein-based nanocomposite dressings is crucial in implementing a successful regenerative medicine approach. These dressings hold significant potential as polymer scaffolds, allowing them to mimic the properties of the extracellular matrix (ECM). So, the objective of this study was to develop a nanocomposite film using dialdehyde-xanthan gum/soy protein isolate incorporated with propolis (PP) and halloysite nanotubes (HNTs) (DXG-SPI/PP/HNTs). In this protein-polysaccharide hybrid system, the self-healing capability was demonstrated through Schiff bonds, providing a favorable environment for cell encapsulation in the field of tissue engineering. To improve the properties of the DXG-SPI film, the incorporation of polyphenols found in PP, particularly flavonoids, is proposed. The synthesized films were subjected to investigations regarding degradation, degree of swelling, and mechanical characteristics. Additionally, halloysite nanotubes (HNTs) were introduced into the DXG-SPI/PP nanocomposite films as a reinforcing filler with varying concentrations of 3 %, 5 %, and 7 % by weight. The scanning electron microscope (SEM) analysis confirmed the proper embedding and dispersion of HNTs onto the DXG-SPI/PP nanocomposite films, leading to functional interfacial interactions. The structure and crystallinity of the synthesized nanocomposite films were characterized using Fourier Transform Infrared Spectrometry (FTIR) and X-ray diffraction (XRD), respectively. Moreover, the developed DXG-SPI/PP/HNTs nanocomposite films significantly improved cell growth of NIH-3T3 fibroblast cells in the presence of PP and HNTs, indicating their cytocompatibility. The antibacterial activity of the nanocomposite was evaluated against Escherichia coli (E. Coli) and Staphylococcus aureus (S. Aureus), which are commonly associated with wound infections. Overall, our findings suggest that the synthesis of DXG-SPI/PP/HNTs nanocomposite scaffolds holds great promise as a clinically relevant biomaterial and exhibits strong potential for numerous challenging biomedical applications.

Encapsulation of thymol and menthol loaded N/S co-doped carbon dots derived from a mixture of herbal extracts as theranostic agents with anticancer properties.

This research was conducted by synthesizing carbon dots MNE-CDs (mixed natural extract-carbon dots) based on mixed natural extract (ginger, garlic, turmeric) through the hydrothermal routh. Menthol and thymol were loaded as multi-therapeutic drugs with the addition of the bio-enhancer loaded on MNE-CDs with the hydrothermal method during a separate stage. These nanostructures were successfully encapsulated in chitosan by the nanospray drying method to enhance sustainability and release control. This study answered three of these issues by fabricating novel carbon dots for anticancer potential, release behavior and bioimaging at the same time. Preparation carbon dots are characterized using UV-vis, PL, FE-SEM, DLS, EDX, and FT-IR analysis. A moderate and sustained release profile of encapsulated carbon dots was noticed in comparison to the free carbon dots over 48 h of study in both simulated physicological environment (pH 7.4) and tumor tissue (pH 5.2) conditions. It was found that the release of bioactive substances from encapsulated samples was significantly attenuated. The cell viability assay showed all the samples, including free and encapsulated carbon dots, offered acceptable cytotoxicity against MCF-7 breast cancer cells. Despite this, the toxicity of free carbon dots is more than the encapsulated samples, and also the enhancement in anticancer potential was not observed for carbon dots loaded with menthol and thymol. Upon the obtained results, the synthesized fluorescence N/S co-doped carbon dots hold great anticancer potential and biological fluorescent labeling.

Enhancing the properties of electrospun polyvinyl Alcohol/Oxidized sodium alginate nanofibers with fluorescence carbon Dots: Preparation and characterization.

The objective of this study was to develop fluorescence nanofibrous polyvinyl alcohol/oxidized sodium alginate (PVA-OSA) incorporated with carbon dots (CDs) through Schiff-base interaction. The carbon dots used in this study were derived from the polyphenol-enriched extract of pomegranate peel, as established in previous work, as the reinforcing and antioxidant agent to enhance the physicochemical and biological properties of the nanofibers were used. The fabricated nanofibers were characterized using FE-SEM, FT-IR, XRD, and DSC analysis. The FE-SEM results revealed that an increase in the number of CDs in the nanofibers led to a decrease in diameter (809.6 ± 77.1 nm to 273.16 ± 41.1 nm). Furthermore, surface modification caused a significant reduction in the amount of surface roughness of the nanofibers. Incorporating CDs not only reduced the scaffold diameter but also improved its mechanical properties and promoted the growth of fibroblast cells. The ultimate tensile strength of scaffolds with and without CDs was 2.15 ± 0.02 MPa and 1.53 ± 0.74 MPa respectively. The influence of CDs amount on the properties of nanofibers showed that the swelling capacity and degradability of nanofibers can be adjusted by changing the range of CDs. Apart from the aforementioned benefits of incorporating CDs in improving nanofiber properties, their exceptional antioxidant properties can be harnessed for protecting nanofibers against oxidation and as a healing agent in wound dressings.

Preparation of Fe3O4/vine shoots derived activated carbon nanocomposite for improved removal of Cr(VI) from aqueous solutions.

In this study, Fe3O4/activated carbon nanocomposite was successfully synthesized for removal of Chromium from aqueous solutions. The Fe3O4 nanoparticles were decorated on vine shoots-derived activated carbon using co-precipitation method. The atomic absorption spectrometer was used to evaluate the removal of Chromium ions by the prepared adsorbent. The effect of various parameters such as adsorbent dose, pH, contact time, reusability, electric field, and initial Chromium concentration were examined to find the optimum conditions. According to the results, the synthesized nanocomposite showed a high ability to remove Chromium at an optimized pH of 3. At optimum conditions, a high removal efficiency of 90% and an excellent adsorption capacity of 305.30 mg/g was obtained. In addition, adsorption isotherms and adsorption kinetics were studied in this research. The results showed that the data are well fitted with the Freundlich isotherm and the adsorption process is spontaneous and follows the pseudo-second-order model.

The catalytic performance of CuFe2O4@CQD nanocomposite as a high-perform heterogeneous nanocatalyst in nitroaniline group reduction.

In this study, we fabricated an economical, non-toxic, and convenient magnetic nanocomposite of CuFe2O4 nanoparticles (NPs)/carbon quantum dots (CQDs) of citric acid via the co-precipitation method. Afterward, obtained magnetic nanocomposite was used as a nanocatalyst to reduce the ortho-nitroaniline (o-NA) and para-nitroaniline (p-NA) using a reducer agent of sodium borohydride (NaBH4). To investigate the functional groups, crystallite, structure, morphology, and nanoparticle size of the prepared nanocomposite, FT-IR, XRD, TEM, BET, and SEM were employed. The catalytic performance of the nanocatalyst was experimentally evaluated based on the ultraviolet-visible absorbance to assess the reduction of o-NA and p-NA. The acquired outcomes illustrated that the prepared heterogeneous catalyst significantly enhanced the reduction of o-NA and p-NA substrates. The analysis of the absorption showed a remarkable decrease for ortho-NA and para-NA at λmax = 415 nm in 27 s and λmax = 380 nm in 8 s, respectively. The constant rate (kapp) of ortho-NA and para-NA at the stated λmax was 8.39 × 10-2 s-1 and 5.48 × 10-1 s-1. The most highlighted result of this work was that the CuFe2O4@CQD nanocomposite fabricated from citric acid performed better than absolute CuFe2O4 NPs, since nanocomposite containing CQDs had a more significant impact than copper ferrite NPs.

Investigation of wound healing efficiency of multifunctional eudragit/soy protein isolate electrospun nanofiber incorporated with ZnO loaded halloysite nanotubes and allantoin.

One significant aspect of the current therapeutic agents employed in wound healing involves the engineering of nano polymeric scaffolds to mimic the properties of extracellular matrix (ECM). The present work aimed to prepare and evaluate Eudragit® L100 (EU) nanofibers in combination with soy protein isolate (SPI). Allantoin (Ala) with a 2 wt% was encapsulated as a model drug renowned for its anti-inflammatory and antioxidant agents. Moreover, the synthesized ZnO-halloysite nanotubes (ZHNTs) with different concentrations of 1, 3, and 5 wt% were incorporated into the EU/SPI/Ala nanofiber as a reinforcing filler and a remarkable antibacterial agent. The scanning electron microscope (SEM) analysis showed that by increasing the weight percentage of SPI from 1 % to 2.5 %, the average diameter of nanofibers decreased from 132.3 ± 51.3 nm to 126.7 ± 47.2 nm. It was 223.5 ± 95.6 nm for nanofibers containing 5 wt% ZHNTs (the optimal sample). The evaluation of in vitro release kinetics of Ala for 24 h, showed a burst release during the first 2 h and a sustained release during the subsequent times. Moreover, the structure, crystallinity, and thermal stability of synthesized nanofibers were characterized by Fourier Transform Infrared Spectrometry (FTIR), X-ray diffraction (XRD), and Thermo gravimetric analysis (TGA), respectively. In vitro degradation and mechanical characteristics of these nanofibers were studied. Furthermore, the capability of the nanofibers for cell proliferation was revealed through the MTT test and field emission scanning electron microscopy (FESEM) images of cell attachment. The antimicrobial activity of EU/SPI/Ala/ZHNTs showed that this sample with high ZHNTs content (5 w%t) had the most remarkable antibacterial activity against S. aureus. The results revealed that EU/SPI/Ala/ZHNTs mats could be promising potential wound dressings.

The Catalytic Reduction of Nitroanilines Using Synthesized CuFe2 O4 Nanoparticles in an Aqueous Medium.

The primary objective of this research is to investigate the reduction of 4-nitroaniline (4-NA) and 2-nitroaniline (2-NA) using synthesized copper ferrite nanoparticles (NPs) via facile one-step hydrothermal method as a heterogeneous nano-catalyst. Nitroanilines were reduced in the presence and without the catalyst with a constant amount (100 mg) of reducing agent of sodium borohydride (NaBH4 ) at room temperature in water to amino compounds. To characterize the functional groups, size, structure, and morphology of as-prepared magnetic NPs, FTIR, XRD, SEM, and TEM were employed. The UV-Vis spectrum was utilized to explore the catalytic effect of CuFe2 O4 . The outcomes revealed that the synthesized CuFe2 O4 as a heterogeneous magnetic nano-catalyst catalyzed the reduction of 4-NA and 2-NA significantly faster than other candidate catalysts. The outcomes demonstrated that the catalyst catalyzed 4-nitroaniline to para-phenylenediamine (p-PDA) and 2-nitroaniline to ortho-phenylenediamine (o-PDA) with a constant rate of 7.49×10-2  s-1 and 3.19×10-2  s-1 , and conversion percentage of 96.5 and 95.6, in 40 s and 90 s, sequentially. Furthermore, the nanoparticles could be recovered by a magnetic separation method and reused for six consecutive cycles without remarkable loss of catalytic ability.

Decontamination of Fuchsin dye by carboxymethyl cellulose-graft-poly(acrylic acid-co-itaconic acid)/carbon black nanocomposite hydrogel.

In the present work, carboxymethyl cellulose (CMC) was used to develop hydrogels as adsorbents for wastewater treatment applications due to its surface functionality and modifiable characteristics. Hydrogels (Hyd) were synthesized by grafting copolymers of acrylic acid (AA) and itaconic acid (IA) onto the CMC backbone by free radical polymerization method in order to remediate Fuchsin from aqueous solution. The presence of CMC in copolymer hydrogel of AA and IA (Poly(AA-co-IA)) up to 14.29 wt% enhances equilibrium swelling and removal efficiency. Different novel nanocomposite hydrogel samples were prepared by varying weight percentages of carbon black (CB) nanoparticles in the range of 0 to 12.5 wt%. The addition of CB up to 5 wt% enhanced the swelling and removal efficiency of the Hyd. Brunauer-Emmett-Teller (BET) test gave the surface area of 0.615, and 0.890 m2/g for Hyd and Hyd/CB, respectively, indicating that incorporation of CB led to a significant increase in Hyd surface area. The Maximum removal efficiency of Fuchsin under the optimum conditions was obtained to be 83.33, 93.54, and 98.76 % for Poly(AA-co-IA), Hyd, and Hyd/CB, respectively. The kinetic study showed that the pseudo-second-order is the best-fitted model. Isotherm studies showed that equilibrium data have a good fitness with the Langmuir model with R2 of 0.978, 0.992, and 0.982 for Poly(AA-co-IA), Hyd, and Hyd/CB, respectively. The Langmuir model gave an adsorption capacity of 26.99, 31.6, and 33.75 mg/g for Poly(AA-co-IA), Hyd, and Hyd/CB, respectively. Also, the value of n and RL parameters demonstrated that the adsorption process is physical and favorable for adsorbents. The study of thermodynamic parameters illustrated that the adsorption of Fuchsin using adsorbents is a spontaneous, exothermic, and entropy-decreasing process. Regeneration study showed that CMC-based hydrogels have higher performance in ad(de)sorption cycles than Poly(AA-co-IA) and the addition of CB to the Hyd matrix enhances reusability. Overall, Hyd and Hyd/CB can be used as promising adsorbents for the remediation of Fuchsin due to high swelling and adsorption capability.

Safranin-O cationic dye removal from wastewater using carboxymethyl cellulose-grafted-poly(acrylic acid-co-itaconic acid) nanocomposite hydrogel.

Copolymer of acrylic acid (AA) and itaconic acid (IA) grafted onto sodium carboxymethyl cellulose hydrogel (CMC-g-poly (AA-co-IA)) was successfully synthesized as an adsorbent to remove safranin-O from wastewater. The swelling and removal efficiencies of CMC-g-poly (AA-co-IA) were enhanced by increasing IA/AA molar ratio as well as by incorporation of montmorillonite clay nano-sheets (MMT). The surface area of MMT, CMC-g-poly (AA-co-IA), and CMC-g-poly (AA-co-IA) samples was 15.632, 0.61452, and 0.66584 m2/g, respectively, indicating the effectiveness of MMT nano-sheets in improving hydrogel surface area. The maximum removal efficiency of CMC-g-poly (AA-co-IA)/MMT under optimum conditions i.e., pH of 8, initial concentration of 10 mg/L, adsorbent dose of 2 g/L, and contact time of 40 min was ascertained 99.78% using a response surface methodology-central composite design (RSM-CCD). Pseudo-second-order and Langmuir models giving the maximum monolayer adsorption capacity of 18.5185 mg/g and 19.1205 mg/g for CMC-g-poly (AA-co-IA) and CMC-g-poly (AA-co-IA)/MMT samples, respectively are the best-fitted models for kinetic and equilibrium data. Thermodynamically, safranin-O decontamination was spontaneous, exothermic, and entropy decreasing. Moreover, ad (de)sorption behavior study showed that CMC-g-poly (AA-co-IA)/MMT performance was not changed after multiple recovery steps. Therefore, CMC-g-poly (AA-co-IA)/MMT was considered as a highly potential adsorbent for safranin-O removal from wastewater.

Crystal violet dye sorption over acrylamide/graphene oxide bonded sodium alginate nanocomposite hydrogel.

The synthesis of acrylamide bonded sodium alginate (AM-SA) hydrogel and acrylamide/graphene oxide bonded sodium alginate (AM-GO-SA) nanocomposite hydrogel was successfully performed using the free radical method. The AM-SA and AM-GO-SA hydrogels were applied as composited adsorbents in crystal violet (CV) dye removal. The adsorption process experiments were performed discontinuously and the acquired data showed that the efficiency is more dependent on pH than other factors. The C-O, CO, and CC groups were detected in the produced hydrogels. The amount of surface area was computed to be 44.689 m2/g, 0.0392 m2/g, and 6.983 m2/g for GO, AM-SA, and AM-GO-SA nanocomposite hydrogel, respectively. The results showed that the experimental data follow the Redlich-Peterson isotherm model. Also, the maximum adsorption capacity of monolayer for CV dye adsorption was determined using AM-SA hydrogel and AM-GO-SA nanocomposite hydrogel 62.07 mg/g and 100.30 mg/g, respectively. In addition, the parameters RL, n, and E showed that the processes of adsorption of CV dye using both types of adsorbents are physical and desirable. Thermodynamically, the CV elimination was exothermic and spontaneous. Besides, thermodynamic results showed that the adsorption process is better proceeding at low temperatures. The experimental data followed a pseudo- second- order (PSO) kinetic model. Also, the Elovich model showed that AM-GO-SA nanocomposite hydrogel has more ability to absorb CV dye. Therefore, according to the obtained results, it can be stated that the produced hydrogels are efficient and viable composited adsorbent in removing CV dye from aqueous solution.

Removal of malachite green using carboxymethyl cellulose-g-polyacrylamide/montmorillonite nanocomposite hydrogel.

In this study, carboxymethyl cellulose based graft poly(acrylamide) hydrogel (CMC-g-P(AAm)) and its nanocomposite with montmorillonite (CMC-g-P(AAm)/MMT) were produced by the free radical method and it was used to malachite green (MG) dye removal from aqueous solution. The properties and characterization of the adsorbents were investigated using FTIR, SEM, TGA, and XRD analyzes, and the results showed that MMT nanoparticles were successfully distributed in the hydrogel system. MMT nanoparticles were loaded into the hydrogel system with different weight percentages and the maximum adsorption efficiency of MG dye was determined at 10 wt% MMT. Also, the effect of temperature, contact time, initial concentration of MG dye and initial pH on the adsorption efficiency of MG dye was studied in a batch. Equilibrium behavior investigation of the adsorption process showed that the equilibrium data determined are in good agreement with the Langmuir isotherm model and the monolayer surfaces play an effective role in the adsorption process. The maximum monolayer adsorption capacity (qmax) determined using the Langmuir isotherm model for CMC-g-P(AAm) and CMC-g-P(AAm)/MMT were determined to be 158.1 mg/g and 172.4 mg/g, respectively. Also, the kinetic study showed that the pseudo-second- order kinetic model is more capable of describing the kinetic behavior of the process than other models. Also, the α parameter values for the MG dye adsorption process using CMC-g-P(AAm) and CMC-g-P(AAm)/MMT were determined to be 0.6337 mg/g·min and 31.04 mg/g·min, respectively. This indicates that the produced composite has a high adsorption value. Gibbs free energy (ΔG°) was negative for the adsorption processes in the range of 25-50 °C, indicating that the process was spontaneous. In addition, the enthalpy parameter (ΔH°) was determined for the adsorption process using CMC-g-P(AAm) and CMC-g-P(AAm)/MMT nanocomposite hydrogels at 39.859 KJ/mol and 74.736 KJ/mol, respectively. Positive ΔH° indicates that the process is endothermic in the range of 25-50 °C using both adsorbents. Also, the concentrations effect of Na+ and K+ ions on adsorption efficiency was investigated and it was concluded that the efficiency of the adsorption process decreased with the increase of ions concentration. Adsorption efficiency decrease can be due to the occupation of active sites and repulsive electrostatic interactions at the adsorbent surface with the MG dye molecule.

Microwave-assisted and one-step synthesis of PEG passivated fluorescent carbon dots from gelatin as an efficient nanocarrier for methotrexate delivery.

A green and simple process for preparing the polyethylene glycol passivated fluorescent carbon dots (CDs-PEG) have been studied by a microwave pyrolysis method, using gelatin and PEG as starting materials. This method is very effective for development of carbon-based quantum dots from gelatin with high quantum yield (QY). The synthesized CDs-PEG were found to emit blue photoluminescence (PL) with a maximum QY of 34%. At the following research, we investigated the effect of the presence of PEG on PL intensity, and the result showed that CDs-PEG becomes stronger PL properties than pure CDs from gelatin. The synthesized CDs-PEG were characterized by FTIR, TEM, UV-vis, PL, zeta potential and XRD analyses. The anticancer performance of developed CDs-PEG was evaluated by in vitro tests such as MTT assay and fluorescence microscopy analyses. The examination of CDs-PEG as an anti-cancer drug nanocarrier for methotrexate (MTX) illustrated a better antitumor efficacy than free MTX due to its enhanced nuclear delivery in vitro, which resulting in highly effective tumour growth inhibition and improving targeted cancer therapy in clinical medicine.

Incorporating Cu-based metal-organic framework/drug nanohybrids into gelatin microsphere for ibuprofen oral delivery.

In compression with the intravenous administration, oral delivery most commonly used due to the non-invasive nature and the fact that avoids patient pain and discomfort. By consideration this aim, ibuprofen as a model drug was loaded into two-dimensional tunnels and empty face-centered cubic cubes of Cu-MOF porous through immersing of Cu-MOF in the drug solution. Cu-Based metal-organic framework/ibuprofen nanohybrid (Cu-MOF/IBU) protected with pH-sensitive biopolymeric gelatin microsphere. From the obtained results, it seems that the prepared gelatin microsphere could be a proposed capsule for the drug in the gastrointestinal tract conditions. The gelatin encapsulated Cu-MOF/IBU microsphere (Cu-MOF/IBU@GM) were characterized using FT-IR, XRD, UV-Vis and SEM analysis. For demonstrating the efficiency of the novel microsphere as a controlled drug delivery system, in-vitro the drug delivery tests were carried out in simulating the gastrointestinal tract conditions. pH point of zero charges (pHpzc) was measured for determination of surficial charge of the carrier. The drug release tests showed that the Cu-MOF/IBU@GM has a better protection against stomach pH and enhanced the stability of drug dosing for a longer time with controlled releases in the gastrointestinal tract conditions. The MTT test demonstrated that the Cu-MOF/IBU@GM has low toxicity against Caco-2 cells. According to the obtained results, the prepared Cu-MOF/IBU@GM could potentially be used as an oral drug delivery system.

High-performance asymmetric supercapacitor based on hierarchical nanocomposites of polyaniline nanoarrays on graphene oxide and its derived N-doped carbon nanoarrays grown on graphene sheets.

Activated carbon (AC), as a material for asymmetric supercapacitor (ASC), is the most widely used as negative electrode. However, AC has some electrode kinetic problems which are corresponded to inner-pore ion transport that restrict the maximum specific energy and power that can be attained in an energy storage system. Therefore, it is an important topic for researchers to extend the carbonaceous material with qualified structure for negative electrode supercapacitor. In this work, novel promoted ASC have been fabricated using nanoarrays of polyaniline grown on graphene oxide sheets (PANI-GO) as positive electrode and also, carbonized nitrogen-doped carbon nanoarrays grown on the surface of graphene (CPANI-G) as negative electrode. The porous structure of the as-synthesized CPANI-G can enlarge the specific surface area and progress ion transport into the interior of the electrode materials. From the other point of view, nitrogen doping can impressively improve the wettability of the carbon surface in the electrolyte and upgrade the specific capacitance by a pseudocapacitive effect. Because of the high specific capacitance and distinguished rate performance of PANI-GO and CPANI-G and moreover, the synergistic effects of the two electrodes with the optimum potential window, the ASC display excellent electrochemical performances. In comparison with the symmetric cell based on PANI-GO (40 Wh kg-1), the fabricated PANI-GO//CPANI-G ASC exhibits a remarkably enhanced maximum energy density of 52 Wh kg-1. Furthermore, ASC electrode exhibits excellent cycling durability, with 90.3% specific capacitance preserving even after 5000 cycles. These admirable results show great possibilities in developing energy storage devices with high energy and power densities for practical applications.

Synthesis of Hedgehoglike F-TiO2(B)/CNT Nanocomposites for Sonophotocatalytic and Photocatalytic Degradation of Malachite Green (MG) under Visible Light: Kinetic Study.

The present study describes the preparation of hedgehoglike F-doped titanium dioxide bronze (F-TiO2(B)) and its nanocomposites containing single-walled and multiwalled carbon nanotubes (SWCNTs, MWCNTs) by using combined ball milling-hydrothermal processes. Then, sonophotocatalytic and photocatalytic degradation of malachite green (MG) dye from aqueous solution using prepared materials was performed. The results show that F-TiO2(B)/SWCNT displays a good sonophotocatalytic and photocatalytic performance among other products under visible light. In addition, they indicated that the efficiency of malachite green degradation is more than 95% and 91% for sonophotocatalytic and photocatalytic methods, respectively. Also, they demonstrate that the photocatalytic efficiency of catalysts increases in the presence of ultrasound and the sonophotocatalysis process followed a second-order kinetics. The catalysts have been characterized by transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FTIR), UV-vis diffuse reflectance spectroscopy, and energy-dispersive X-ray spectroscopy (EDX). The analyzed data confirmed the presence of CNTs and fluorine (F) as dopant in all nanocomposites. The presented hybrid method reduced the band gap from 3.02 eV for F-TiO2(B) to 2.7 eV for F-TiO2(B)/SWCNT nanocomposite.

A novel dual-responsive core-crosslinked magnetic-gold nanogel for triggered drug release.

A facial approach was reported to prepare a novel dual-responsive core-crosslinked nanogel and investigated for the triggered methotrexate (MTX) release. Nanogels with core-shell architecture were synthesized by decoration of Au/Fe3O4 core/shell NPs using poly(ethylene glycol)-b-poly((N,N-dimethylamino)ethyl methacrylate-co-2-hydroxyethyl methacrylate)-maleic acid (PEG-b-P(DMAEMA-co-HEMA)-MA) for crosslinking and autoreduction processes. The second block containing amino groups and maleate groups as the inner shell was used for the reduction of HAuCl4 (auric cation) in the presence of Fe3O4 NPs and as a crosslinker agent, respectively. Furthermore, to improve the long-term dispersibility of the nanogels, poly(ethylene glycol) was preferred as outer shell even under high ionic strength. After that, NIPAAm was polymerized from the vinyl double bonds for fabricating the thermo and pH-responsive core-crosslinked nanogels. MTX (an anti-cancer agent) was successfully loaded (the loading capacity of 37%) into the nanogels by both ionic interaction and entrapment in polymeric network in the inner shell. The triggered MTX release ability of the synthesized nanocarriers was proved through the comparison of in-vitro drug release at simulated physiological condition and tumor tissue environment. MTT assay showed that MTX-loaded nanocarriers revealed high antitumor activity in MCF7 cell line after incubation following 24 and 48h. It was concluded that the developed nanogels have many promising qualities as an efficient carrier for the targeted MTX delivery to cancer tissues.

Nano graphene oxide: a novel carrier for oral delivery of flavonoids.

The interesting physical and chemical properties of graphene oxide (GO) have led to much excitement among biomedical scientists in recent years. It is known that many potent, often aromatic medicines are water insoluble, and this has hindered their administration to treat diseases. Nano GO was synthesized and investigated for its biological application as a carrier for quercetin, a focused bioactive flavonoid widely used as a health supplement and a drug candidate. Different techniques were used to fully evaluate the synthesis, cytotoxicity, and quercetin loading capacity of nano GO. AFM and TEM results confirmed the preparation of planar nanoparticles without aggregation which was verified by reported size results (30 nm) obtained with a particle size analyzer. FTIR and DSC results proved the drug-carrier interaction. In vitro cytotoxicity assays showed that nano GO had no cytotoxicity on A549 cells in different amounts after incubation for 72 h, confirming its suitability as a drug carrier. Our results showed that nano GO can be proposed as a new carrier due to its small size, large specific surface area, low cost, and useful non-covalent interactions with aromatic low-soluble flavonoids such as quercetin. Moreover, it may find widespread applications in biomedicine.

Polyglycerol-grafted superparamagnetic iron oxide nanoparticles: highly efficient MRI contrast agent for liver and kidney imaging and potential scaffold for cellular and molecular imaging.

Polyglycerol as a water-soluble and biocompatible hyperbranched polymer was covalently grafted on the surface of superparamagnetic iron oxide nanoparticles. With this aim, superparamagnetic magnetite nanoparticles were prepared by coprecipitation in aqueous media, then the surface of nanoparticles was modified to introduce the reactive groups on the surface of nanoparticles. After that, polyglycerol was grafted on the surface of nanoparticles by ring-opening anionic polymerization of glycidol using n-bulyllithium as initiator. The magnetometry, relaxometry and phantom MRI experiments of this highly stable ferrofluid showed its high potential as a negative MRI contrast agent. Calculated r(1) and r(2) relaxivities at different magnetic fields were higher than the values reported for commercially available iron oxide contrast agents. The in vivo MRI studies showed that, after intravenous injection into mice, the particles produced a strong negative contrast in liver and kidneys, which persisted for 80 min (in liver) to 110 min (in kidneys). The negative contrast of the liver and kidneys weakened over the time, suggesting that polyglycerol coating renders the nanoparticles stealth and possibly optimal for renal excretion.

Magnetoliposomes as multimodal contrast agents for molecular imaging and cancer nanotheragnostics.

In the emerging field of molecular and cellular imaging, flexible strategies to synthesize multimodal contrast agents with targeting ligands are required. Liposomes have the ability to combine with a large variety of nanomaterials, including superparamagnetic iron oxide nanoparticles, to form magnetoliposomes (MLs). MLs can be used as highly efficient MRI contrast agents. Owing to their high flexibility, MLs can be associated with other imaging modality probes to be used as multimodal contrast agents. By using a thermosensitive lipid bilayer in the ML structure, these biocompatible systems offer many possibilities for targeting and delivering therapeutic agents for 'theragnostics', a coincident therapy and diagnosis strategy. This article deals with the fast-growing field of MLs as biomedical diagnostic tools. Different kinds of MLs, their preparation methods, as well as their surface modification with different imaging probes, are discussed. ML applications as multimodal contrast agents and in theragnostics are reviewed. Some important issues for the biomedical uses of magnetic liposomes, such as toxicity, are summarized.