Chitosan, magnetite, silicon dioxide, and graphene oxide nanocomposites: Synthesis, characterization, efficiency as cisplatin drug delivery, and DFT calculations.

Drug delivery systems with controlled release have been considered important tools for the treatment of various diseases. The efficacy of the drug can be enhanced by increasing its solubility, stability, bioavailability, and specific site delivery. Herein, we investigated cisplatin (cisP) loading efficacy and release potentiality on chitosan (CS) functionalized with magnetite (M), silicon dioxide (S), and graphene oxide (GO) nanoparticles. Different nanocomposites [chitosan-coated magnetite, silicon dioxide, and graphene oxide (CS/M/S/GO); chitosan-coated magnetite and silicon dioxide (CS/M/S); chitosan-coated silicon dioxide (CS/S); and chitosan-coated magnetite (CS/M)] were prepared. The prepared nanocomposites were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), scanning electron microscopy, transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDS). DFT calculations were employed to explore the interaction mechanism of cisP with a selected chitosan-functionalized nanocomposite in the gas phase and water media. The UV-Vis spectroscopy was used to study cisP loading and release from the prepared nanocomposites. The results showed that the highest loading efficacy was achieved by CS/M and CS/M/S/GO nanocomposites (87% and 84% respectively). While the releasing potentiality for CS/M composite was the highest compared with the other ones (91%).

Abdel-Bary AS ，Tolan DA ，Nassar MY ，Taketsugu T ，El-Nahas AM ... -  《-》

Highly efficient multifunctional graphene/chitosan/magnetite nanocomposites for photocatalytic degradation of important dye molecules.

Multifunctional chitosan/magnetite (CS/Fe3O4) and graphene/chitosan/magnetite (Gr/CS/Fe3O4) nanocomposites (NCs) were synthesized using a simple hydrothermal method. The NCs were subsequently evaluated as magnetic photocatalysts towards the photodegradation of dye molecules that are detrimental to the environment. In the present study, sphere shaped Fe3O4 nanoparticles (NPs) were found to uniformly decorate CS and Gr surfaces. The synthesized Fe3O4 NPs, CS/Fe3O4 and Gr/CS/Fe3O4 NCs were characterized by powder X-ray diffraction, Fourier-transform infrared and Raman spectroscopy, thermogravimetric analysis, UV-visible diffuse reflectance and photoluminescence spectroscopy, and field emission scanning electron microscopy coupled with energy dispersive X-ray spectroscopy. The Gr/CS/Fe3O4 NCs showed 100% photocatalytic efficiency against rhodamine B (40 min), bromothymol blue (60 min), methylene blue (80 min) and methyl orange (100 min) compared to Fe3O4 NPs (100 min for Rh-B, 120 min for BTB, 160 min for MB and 180 min for MO) and CS/Fe3O4 NCs (90 min for Rh-B, 100 min for BTB, 140 min for MB and 150 min for MO). The photocatalytic irradiation efficiency of Fe3O4 NPs, CS/Fe3O4 and Gr/CS/Fe3O4 NCs, evaluated against visible light, was found to be significantly higher for Rh-B (100% within 40 min) compared to the other tested dyes.

Maruthupandy M ，Muneeswaran T ，Anand M ，Quero F ... -  《-》

Design and Characterization of Chitosan-Graphene Oxide Nanocomposites for the Delivery of Proanthocyanidins.

In the last years, the utilization of phytomedicines has increased given their good therapeutic activity and fewer side effects compared to allopathic medicines. However, concerns associated with the biocompatibility and toxicity of natural compounds, limit the phytochemical therapeutic action, opening the opportunity to develop new systems that will be able to effectively deliver these substances. This study has developed a nanocomposite of chitosan (CS) functionalized with graphene oxide (GO) for the delivery of proanthocyanidins (PAs), obtained from a grape seed extract (Ext.). The GO-CS nanocomposite was covalently bonded and was characterized by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), atomic force microscopy (AFM) and by dynamic light scattering (DLS). The loading and release of Ext. from the GO-CS nanocomposite were performed in simulated physiological, and the cytotoxicity of the raw materials (GO and Ext.) and nanocomposites (GO-CS and GO-CS-Ext.) was determined using a human kidney cell line (HEK 293). The chemical characterization indicated that the covalent union was successfully achieved between the GO and CS, with 44 wt. % CS in the nanocomposite. The GO-CS nanocomposite was thermostable and presented an average diameter of 480 nm (by DLS). The Ext. loading capacity was approximately 20 wt. %, and under simulated physiological conditions, 28.4 wt.% Ext. (g) was released per g of the nanocomposite. GO-CS-Ext. was noncytotoxic, presenting a 97% survival rate compared with 11% for the raw extract and 48% for the GO-CS nanocomposite at a concentration of 500 µg mL-1 after 24 hrs. Due to π-π stacking and hydrophilic interactions, GO-CS was reasonably efficient in binding Ext., with high loading capacity and Ext. release from the nanocomposite. The GO-CS nanocomposite also increased the biocompatibility of PAs-rich Ext., representing a new platform for the sustained release of phytodrugs.

Figueroa T ，Aguayo C ，Fernández K 《International Journal of Nanomedicine》

Synthesis of magnetite/graphene oxide/chitosan composite and its application for protein adsorption.

In this study, a facile and novel strategy was developed to fabricate magnetite/graphene oxide/chitosan (Fe3O4/GO/CS) composite, and the composite was used as a magnetic adsorbent for the enrichment of protein, and followed by matrix-assisted laser desorption ionization mass spectrometry (MALDI-TOF MS) analysis. The phase composition, chemical structure and morphology of the composite were characterized by X-ray diffraction (XRD), Fourier transform infrared spectrometer (FTIR), transmission electron microscopy (TEM), scanning electronic microscope (SEM) and vibrating sample magnetometer (VSM). Protein cytochrome c was chosen as model target to evaluate the adsorptive property of Fe3O4/GO/CS. After enrichment procedure and magnetic separation, protein bounded with the material was analyzed by MALDI-TOF MS without desorption. The results indicated that Fe3O4/GO/CS composite exhibited a good adsorptive capacity for protein, and Fe3O4/GO/CS composite had a promising potential in magnetic separation research.

Ye N ，Xie Y ，Shi P ，Gao T ，Ma J ... -  《-》

Synthesis and characterization of carboxymethyl chitosan/Fe(3)O(4) and MnFe(2)O(4) nanocomposites hydrogels for loading and release of curcumin.

This paper presents the preparation of hydrogel with magnetic properties derived from carboxymethyl chitosan for controlled drug release performance. The magnetic Fe3O4 and MnFe2O4 nanoparticles with crosslinked Carboxymethyl Chitosan hydrogel were prepared by using epichlorohydrin as the cross-linker. The structure characterization performed by FT-IR. The XRD analysis was applied for evaluation of crystalline phase of MnFe2O4 and Fe3O4 in the hydrogels. The crystallite size of Fe3O4/CMCS and MnFe2O4/CMCS was calculated to be 30.12, and 44.51 nm, respectively. The presence of MnFe2O4 and Fe3O4 in the hydrogels can reason a rough surface morphology which that confirmed by SEM images. The Max. Saturation magnetization value as obtained from hysteresis loop is 105 and 75 Am2/kg for Fe3O4/CMCS and MnFe2O4/CMCS hydrogel, respectively. The Fe3O4 and MnFe2O4 on Carboxymethyl Chitosan hydrogels indicated a pH-sensitive for swelling behavior process. The equal amount of Fe3O4 and MnFe2O4 on hydrogels have high swelling at pH 6.4. The swelling capacity decreased from 214 to 172% and 144-114% at pH 6.4 with attendance of high amount of MnFe2O4 and Fe3O4 on hydrogels compared to other samples, respectively. Drug loading and release performances were investigated by curcumin as a model drug. The maximum curcumin release was obtained 25.1-51.52% at pH = 6.4. The drug releases system demonstrates the high ratio of Fe3O4 and MnFe2O4 containing Carboxymethyl Chitosan sample has a great efficiency in curcumin release. The effect of applied magnetic field on drug release for Fe3O4/CMCS was highest compared to MnFe2O4/CMCS. The results demonstrated that the Fe3O4 and MnFe2O4 nanocomposites hydrogel can be applied for novel drug delivery systems.

Naderi Z ，Azizian J 《-》