Multifunctional magnetite nanoparticles for drug delivery: preparation, characterisation, antibacterial properties and drug release kinetics

Multifunctional nanoparticles (NPs) with magnetic (M) and antibacterial properties were prepared for drug delivery purposes by a method involving co-precipitation synthesis. Partial and complete substitutions of ferrous ions (Fe2+) by copper ions (Cu2+) were carried out for the preparation of the magnetite NPs, which are designated as Cu0.5M and CuM, respectively, in this work. In addition, chitosan and ciprofloxacin were hybridized with the NPs from the previous step to achieve multifunctional properties. XRD, TEM, SEM/EDAX, VSM and FTIR were subsequently employed to characterize various properties of the prepared NPs, namely, crystallinity, nanostructure (size), particle morphology, elemental mapping, magnetic strength and chemical composition. Antibacterial properties of the NPs were tested against Bacillus cereus (Gram-positive bacteria), Escherichia coli (Gram-negative bacteria) and Candida albicans (yeast). Efficiency of the ciprofloxacin release was also studied for the drug-loaded NPs. It is demonstrated that the obtained NPs possess mixed phases with crystalline structures that are affected by the degree of Cu ion substitution (5-10nm (M), 2.5-3.5nm (Cu0.5M) and 11-16nm (CuM)). Saturation magnetization values of the NPs were recorded as 38.7, 3.5 and 1.3 emu/g, respectively. It was also found that the introduction of Cu ions in the NP samples improved the significance of their antibacterial activity, especially against Escherichia coli. Chitosan and ciprofloxacin were found to have stronger effects against Bacillus cereus and Escherichia coli and lesser effects against Candida albicans. However, the samples containing chitosan, ciprofloxacin and the higher Cu ion concentration exhibited strong influence against Candida albicans. During a study period of 30- days, the amounts of released drug from the tested NPs were 85, 26 and 20% of the originally loaded amount, respectively. Owing to the findings in this paper, the developed NPs are considered to have good potential for drug delivery applications and to study them further such as in pre-clinical studies

Magnetic nanosystems substituted with zinc for enhanced antibacterial, drug delivery and cell viability behaviours

Nanoparticles (NPs) of magnetite (M) and zinc ferrites (Zn0.5M and ZnM) with different zinc concentrations were synthesized through a co-precipitation method and coated with chitosan containing ciprofloxacin antibiotic to enhance the cells compatibility to these nanosystems. The prepared magnetic nanoparticles (MNPs), chitosan/MNPs and ciprofloxacin/chitosan/MNPs were characterized using X-ray diffraction (XRD), transmittance electron microscopy (TEM), scanning electron microscopy (SEM) accessorized with energy dispersive X-rays (EDAX), vibrating-sample magnetometer (VSM), Fourier transform infrared (FTIR) and BET surface area measurements. Antibacterial properties of the MNPs were examined against Candida albicans (yeast), Bacillus cereus (Gram-positive bacteria) and Escherichia coli (Gram-negative bacteria).The drug-loaded NPs were also studied for their efficiency of ciprofloxacin release. The average crystallite size of the fabricated NPs was 10.4 nm (Fe3O4) and 14 nm (ZnFe2O4) for samples M and Zn0.5M, respectively. The surface areas of the achieved specimens were recorded to be 145.92±2.32, 102.94±0.39 and 168.71±2.05 m²/g for M, Zn0.5M and ZnM, respectively. The saturation magnetization values were determined to be approximately 38.7, 60.6 and 2 emu/g for M, Zn0.5M and ZnM, respectively. It was revealed that the bactericidal activity towards the tested strains was highly pronounced for the nanosytems containing ciprofloxacin drug alongside with those substituted with zinc. During a period of 30 days, the total dosage of released ciprofloxacin from CipChM, CipChZnM and CipChZn0.5M was 82, 90 and 96%, respectively. Finally, cells viability and proliferation of different cell lines were found to be increased by the developed nanosystems, especially by those containing zinc and chitosan in the presence of extra MNPs. </p