Fabrication of chitosan-polyethylene glycol nanocomposite films containing ZIF-8 nanoparticles for application as wound dressing materials.

Biocompatible nanocomposite films based on chitosan (CS) and polyethylene glycol (PEG) polymers containing cephalexin (CFX) antibiotic drug and zeolitic imidazolate framework-8 (ZIF-8) nanoparticles (NPs) were designed and fabricated to develop wound dressing materials capable of controlled drug release. Swelling experiment was performed in three acidic, neutral, and alkaline solutions. The tensile strength test reflected that upon increasing the NPs loading within the films, the tensile strength was enhanced but the elongation at break was diminished. The release of the CFX was intensively increased within approximately 3, 8, and 10 h (burst release) in acidic, neutral, and alkaline media, respectively while after that the CFX was smoothly released over time (sustained release). The antibacterial activities of all films were examined against Gram-positive (S. aureus, B. cereus) and Gram-negative (E. coli, P. aeruginosa, and Acinetobacter) bacteria frequently found in the infected wounds. Moreover, the MTT assay revealed that all films had high cell viabilities towards the L929 fibroblast cells confirming these nanocomposites could be used as favorable wound dressing materials. Finally, the film containing 4% ZIF-8 NPs (film 5) was chosen as the best sample due to it revealed appropriate mechanical properties, swelling, drug release and cell viability among all samples examined.

Development and characterization of a novel conductive polyaniline-g-polystyrene/Fe3O4 nanocomposite for the treatment of cancer.

The goal of this study is to synthesize, characterize and investigate some physicochemical properties of conductive polyaniline-g-polystyrene/Fe3O4 (Fe3O4/PSt-g-PANi) nanocomposites. For this purpose, initially, Fe3O4 nanoparticles were synthesized by a co-precipitation method. Then, the desired nanocomposite was synthesized in two steps. First, the atom transfer radical polymerization (ATRP) of styrene was performed using an ATRP initiator attached to the surface of Fe3O4 nanoparticles, followed by functionalization of the Fe3O4-PSt with amine groups (-NH2). Second, surface oxidative graft copolymerization of aniline was accomplished using the -NH2 moieties on the Fe3O4/PSt-NH2 as the anchoring sites. The prepared materials were characterized by various instruments, including TEM, SEM, TGA, EDX, FT-IR, XRD and conductivity measurements. The results indicated that the synthesized conductive polymer/Fe3O4 nanocomposites had higher electrical conductivity and thermal resistance than those of the corresponding homopolymers.

Porous MnFe2O4@SiO2 magnetic glycopolymer: A multivalent nanostructure for efficient removal of bacteria from aqueous solution.

The focuses of this research is to prepare an efficient magnetic glycopolymer for bacteria removal from aqueous solution. To perform this idea; porous MnFe2O4@SiO2 was functionalized with glucose and or maltose as an anchors to adhere onto bacteria cell surface. Aminopropyltriethoxysilane was employed to link the saccharides on magnetic nanoparticle surface. The hybrid materials were characterized with XRD, VSM, FT-IR, FESEM, TEM, zeta potential measurement and elemental mapping. Microscopic image showed that MnFe2O4 is in cluster form composed from tiny nanoparticles. After saccharide functionalization hybrid composite generate hyper-crosslinked porous structure as a result of polysilicate formation due to hydrolysis of silica source. Escherichia coli and bacillus subtilis were selected as sample pathogens to evaluate the bacteria capturing ability of the magnetic glycopolymer. At the optimum conditions (pH = 6, time of 20 min, dosage of 15 mg) removal efficiency was more than 99% using both saccharide.

Glucose reinforced Fe3O4@cellulose mediated amino acid: Reusable magnetic glyconanoparticles with enhanced bacteria capture efficiency.

In this study glucose reinforced Fe3O4@cellulose glyconanoparticles (MGN) were prepared using epichlorohydrin and amino acid (lysine and arginine) as a linker. Bacillus capturing capability of amino acid modified Fe3O4@cellulose was compared to the glucose reinforced system. Results showed enhanced bacterial capturing of MGN relative to amino acid modified particles. Bacterial capturing efficiencies were increased to 91% and 95% in the magnetic cellulose arginine-glucose (MCAG) and magnetic cellulose lysine-glucose (MCLG), respectively, which confirmed the role of synergism on microbial efficiency. Effective parameters on bacterial capturing efficiency including; solution pH, contact time, dosage of MGN and the presence of some anions were also investigated. Moreover, presented system was employed for bacteria capturing from river water, sea water and milk samples. The results showed that these nanocomposites have good performance to be used as reusable antimicrobial magnetic materials. The results showed that these nanocomposites have good reusability after three cycles of sorption and desorption which confirmed the efficiency of the system for bacterial removing from water solutions.

Application of nanostructured drug delivery systems in immunotherapy of cancer: a review.

The cancer immunotherapy method uses the specificity of the immune system to provide a more effective than more conventional treatments, such as chemotherapy and radiotherapy. Immunotherapy has two main strategies (passive or active) to organize the immune system. Passive strategies use advantage of tumor-hyperpermeable cells, which have enhanced permeability and retention effects. Nanoparticles due to their better accumulation within tissues and cells of the immune system are well suitable for delivery of immune therapies such as vaccines or adjuvants. In this review, we explained application of nanotechnology in immunotherapy of cancer.