Co-encapsulating CoFe2O4 and MTX for hyperthermia

Magnetic manotheranostics can be a fascinating charm to diagnose a tumour with MRI, and treatment through hyperthermia. This study aims to synthesise and characterise magnetically responsive polymer colloids (MRPCs). Healthy tissue damage done by chemotherapy session could be minimised by MRPCs. For the colloidal formulation of MRPCs, the oil in water emulsion technique was employed with the aid of sonication and stirring. The organic phase of emulsion contained methotrexate (MTX) drug, Eudragit E100 and CoFe2O4 (synthesised by co-precipitation) in ethanol, and the aqueous phase contained tween 80 in deionised water. The emulsion was optimised by studying/adjusting two different parameters, i.e. the concentration of constituents and sonication cycles. Multiple formulations were produced at sonication amplitude of 60% at 20 kHz, followed by centrifugation and lyophilisation. Characterisation of MRPCs was done for morphology, size measurement (23-25 nm), surface charge (∼15.12), coercivity (∼1549.6 G), magnetisation (2.6 emu) and retentivity (1.34 emu). Drug release in simulating physiological environment (pH = 7.4), was observed for up to 48 h, and, to determine the best release kinetic mechanism results were compared with kinetic models. Magnetic hyperthermia studies showed that MRPCs achieved an acceptable temperature of 42°C, for hyperthermia treatments in cancer patients.

Antibacterial magnetic nanoparticles for therapeutics: a review

Along with the extensive range of exotic nanoparticle (NPs) applications, investigation of magnetic NPs (MNPs) in vitro has ushered modern antibacterial studies into an increasingly attractive research area. A great number of microorganisms exist in the size scales from nanometre to micrometre regions. The enormous potential of engineered MNPs in therapeutic procedures against various drug-resistant bacteria has declined the menace of fatal bacterial infections. Many biocompatible MNPs have been introduced that possess remarkable impacts on various bacterial strains. Conventional synthesis methods such as co-precipitation or hydrothermal techniques have been widely adopted in the production of MNPs. The MNPs for antibacterial applications are mainly required to be superparamagnetic, recyclable and biocompatible. To implement novel strategies in developing new generation antimicrobial magnetic nanomaterials, it is essential to obtain a comprehensive preview of recent achievements in synthesis, proposed antibacterial mechanisms and characterisation techniques of these nanomaterials. This review highlights notable aspects of antibacterial activity in engineered MNPs and nanocomposites including their particle properties (size, shape and saturation magnetisation), antibacterial mechanisms, synthesis methods, testing methods, surface modifications and minimum inhibitory concentrations.

Fabrication and characterisation of super-paramagnetic responsive PLGA-gelatine-magnetite scaffolds with the unidirectional porous structure: a physicochemical, mechanical, and in vitro evaluation

Architecture and composition of Scaffolds are influential factors in the regeneration of defects. Herein, synthesised iron oxide (magnetite) nanoparticles (MNPs) by co-precipitation technique were evenly distributed in polylactic-co-glycolic acid (PLGA)-gelatine Scaffolds. Hybrid structures were fabricated by freeze-casting method to the creation of a matrix with tunable pores. The synthesised MNPs were characterised by transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction spectroscopy, and vibrating sample magnetometer analysis. Scanning electron microscopy micrographs of porous Scaffolds confirmed the formation of unidirectional microstructure, so that pore size measurement indicated the orientation of pores in the direction of solvent solidification. The addition of MNPs to the PLGA-gelatine Scaffolds had no particular effect on the morphology of the pores, but reduced slightly pore size distribution. The MNPs contained constructs demonstrated increased mechanical strength, but a reduced absorption capacity and biodegradation ratio. Stability of the MNPs and lack of iron release was the point of strength in this investigation and were determined by atomic absorption spectroscopy. The evolution of rat bone marrow mesenchymal stem cells performance on the hybrid structure under a static magnetic field indicated the potential of super-paramagnetic constructs for further pre-clinical and clinical studies in the field of neural regeneration.

Evaluation of antibacterial property of hydroxyapatite and zirconium oxide-modificated magnetic nanoparticles against Staphylococcus aureus and Escherichia coli

In the first section of this research, superparamagnetic nanoparticles (NPs) (Fe3O4) modified with hydroxyapatite (HAP) and zirconium oxide (ZrO2) and thereby Fe3O4/HAP and Fe3O4/ZrO2 NPs were synthesised through co-precipitation method. Then Fe3O4/HAP and Fe3O4/ZrO2 NPs characterised with various techniques such as X-ray photoelectron spectroscopy, X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis, Brunauer-Emmett-Teller, Fourier transform infrared, and vibrating sample magnetometer. Observed results confirmed the successful synthesis of desired NPs. In the second section, the antibacterial activity of synthesised magnetic NPs (MNPs) was investigated. This investigation performed with multiple microbial cultivations on the two bacteria; Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). Obtained results proved that although both MNPs have good antibacterial properties, however, Fe3O4/HAP NP has greater antibacterial performance than the other. Based on minimum inhibitory concentration and minimum bactericidal concentration evaluations, S. aureus bacteria are more sensitive to both NPs. These nanocomposites combine the advantages of MNP and antibacterial effects, with distinctive merits including easy preparation, high inactivation capacity, and easy isolation from sample solutions by the application of an external magnetic field.

HSA loaded with CoFe2 O4 /MNPs as a high‐efficiency carrier for epirubicin anticancer drug delivery

Drug delivery is one of the most important challenges in the domain of health. Non‐toxic and biocompatible carriers are provided by human serum albumin nano‐capsule (HSA/NC) for drug delivery applications. In this study, HSA, with high loadings of drug‐modified cobalt ferrite (CoFe2 O4) magnetic nanoparticle (CoFe2 O4 /MNPs) was fabricated for epirubicin anticancer drug delivery. In the initial step, CoFe2 O4 /MNPs was synthesised via co‐precipitation technique and characterised by X‐ray powder diffraction, vibrating sample magnetometry, energy dispersive X‐ray analysis, scanning electron microscopy and map analysis. Furthermore, CoFe2 O4 /MNPs and epirubicin were loaded into HSA/NC and utilised as a novel system against breast cancer cell line (MCF‐7). IC50 for free epirubicin, unloaded CoFe2 O4 /MNPs/HSA/NC, CoFe2 O4 /MNPs and epirubicin‐loaded CoFe2 O4 /MNPs/HSA/NC were 7.7, 2400, 840 and 430 μg/ml, respectively. The results obtained revealed high cytotoxicity effect of epirubicin‐loaded CoFe2 O4 /MNPs on breast cancer cell line.

Enhanced fermentative production of Cephalosporin C by magnetite nanoparticles in culture of Acremonium chrysogenum

Magnetite (Fe3 O4) nanoparticles (MNPs) have many applications in bioprocesses. This study investigated bioprocess production of Cephalosporin C (CPC) by Acremonium chrysogenum . The effect of MNPs was tested for enhancing the fermentation process. MNPs were synthetised by a straightforward method of co‐precipitation. Various concentrations of MNP (0, 0.0025, 0.005, 0.01, 0.02 and 0.04 g/l) were added to fermentation media of the strain. During fermentation, evaluations were taken for titer of CPC, biomass, pH value and morphology of the strain. Comparison was made between CPC produced in the control medium and that in the nanoparticle enriched media from several consecutive batches; it was determined that MNP addition had a positive effect on the bioprocess and enhanced titer production. The titer of CPC in MNP‐containing medium (0.04 g/l) increased by 60% compared with MNP‐free medium. These results show that MNPs present good potential for improving bioprocesses and enhancing productivity of CPC fermentation by A. chrysogenum .