The preparation of maghemite (gama Fe2O3) micro and nanoparticles coated with chitosan, used as carriers for immobilized enzymes, was investigated. Fe2O3 nanoparticles were synthesized by coprecipitation of Fe2+ and Fe3+ ions in the presence of ammonium. They were coated with chitosan by the microemulsion process, suspension crosslinking technique, and covalent binding of chitosan on the Fe2O3 surface. The methods distinguished the concentration of chitosan, concentration of acetic acid solution, concentration of a crosslinking agent, temperature of synthesis, pH of the medium, and time of synthesis. Fe2O3 micro and nanoparticles coated with chitosan prepared after three preparation methods were evaluated by scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy analysis, energy dispersive spectrometry, thermogravimetric analysis, differential scanning calorimetry analysis, vibrating sample magnetometry, dynamic light scattering, laser diffraction granulometry, and Xray diffractometry. These positive attributes demonstrated that these magnetic micro and nanoparticles coated with chitosan may be used as a promising carrier for further diverse biomedical applications.
COBISS.SI-ID: 16941078
Nanoparticles of inorganic magnetic core surrounded by layers of functional coatings are potential representatives of nanostructures for immobilization of bio-substances. Magnetic nanoparticles (MNPs) are often bound in aggregates due to a strong magnetic dipole, which has a lot of advantages, such as large surface area for binding biologically active substances. Chitosan is a polysaccharide polymer that is non-toxic, hydrophilic, biocompatible and has hydroxy and amino groups in its structure. Because of these chemical and biological properties it is a desirable bio-product for immobilization of enzymes and for binding of other biologically active substances. Magnetic micro and nanoparticles were synthesized with chitosan by three different methods; microemulsion process, suspension cross-linking technique and covalent binding of chitosan. Toxic effect of the prepared magnetic particles was determined as well and was examined on five different bacterial cultures; Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Enterococcus faecalis and Klebsiella pneumoniae. At concentrations of 10-30 mg of magnetic particles per 0.5 McFarland Standard solution of E. coli and per 400 CFU of S. aureus, P. aeruginosa, E. faecalis in K. pneumonia, no inhibition on the chosen bacterial cultures was detected.
COBISS.SI-ID: 4955199
Growth factors are key inducers of fibrosis but can also mediate inflammatory responses resulting in increasing pleural effusion and acute respiratory distress syndrome. The primary aim of the study was to analyse growth factors release after performing chemical and mechanical pleurodesis in the first 48 hours at the patients with malignant pleural effusion. The secondary endpoints were to evaluate the effectiveness of the both pleurodeses, symptoms release and the quality of life of patients after the treatment.
COBISS.SI-ID: 18435094
Nanotechnology represents an area holding significant promise for health care and biotechnology for many years to come. Nanomaterials are an emerging familyof novel materials that could be designed for specific properties. Thesematerials will probably bring about significant shifts in the manner we design, develop, and use materials. With the emergence of novel fabrication and characterization technologies, new combinations of nanomaterials or nanocomposites are beginning to be synthesized and characterized. They have potential for various biomedical applications; including magnetic resonance imaging (MRI) contrast enhancement, targeted drug delivery, hyperthermia, biological separation, protein immobilization, biosensors, etc. The use of magnetic carriers for efficient transport of various biomolecules (e.g. antibody, enzyme) has increased drastically in the recent years, especially inthe field of nanomedicine, where the bioactive molecule immobilized onto thesurface of a magnetic carrier acts a potential bioactive substance or drug to be transported and effectively released in the specific location. In this direction, superparamagnetic iron oxide nanoparticles (SPIONs) with appropriate surface chemistry have been widely used experimentally for numerous applications. In past decades, many carriers have been developed and investigated extensively, but mostly the group of chemically modified inorganic nanoparticles have showed low toxicity and generally possess versatile properties suitable for cellular delivery, including wide availability, rich functionality, good biocompatibility, potential capability of targeted delivery and controlled released of carried drugs. Because surfacechemistry greatly influences magnetic nanoparticles (MNPs) fate in the biological system, including the mechanisms of their cell recognition, biodistribution and immunes response it presents a specific focus for advancing engineering strategies to minimize potential nanotoxicity. Surface functionalization, a controlled process of chemical attachment of functional groups to the surface, is now integral to magnetic nanoparticle designs. Moreover, surface chemistry is essential to target the nanoparticles to specific sites. Several groups of coating materials are generally used to modify magnetic nanoparticle surface chemistry. Additionally, one of the most attractive routes for the surface modification of nanoparticles is using an organosilane. The biocompatibility of most nanoparticles could be greatly enhanced by introducing various synthetic polymers to their surface, thus, promoting better water solubility of the magnetic carrier. Silica is also one of the most frequently functional coatings used so far, as it has inherently superior functionalization capabilities, respectively. For these reasons, overthe last decade, nanomaterials have been highlighted as promising candidates for improving traditional materials.
COBISS.SI-ID: 16159766
Interest to the nanomedicine has increased dramatically during past years. Since nanotechnology has the potential to have a revolutionary impact on cancer diagnosis and therapy, is there a major challenge to produce magnetic nanoparticles (MNPs) suitable for biomedical applications. In this review the main theoretical views on the properties, synthesis, characterization, functionalization, and bioapplication of MNPs in the current context of science are considered. This review examines some of the recent developments in MNPs technology and provides a brief background of their applications and results of in-vitro and in-vivo, animal and clinical experiments of targeted drug delivery. Finally, some of the recent biological, medical and scientific applications of MNPs are briefly reviewed, and some future trends and perspectives in these research areas will be outlined.
COBISS.SI-ID: 17988374