Investigation on the Protective Effect of α-Mannan against the DNA Damage Induced by Aflatoxin B1 in Mouse Hepatocytes

Aflatoxin B1 is a contaminant of agricultural and dairy products that can be related to mutagenic and carcinogenic effects. In this report we explore the capacity of α-mannan (Man) to reduce the DNA damage induced by AFB1 in mouse hepatocytes. For this purpose we applied the comet assay to groups of animals which were first administered Man (100, 400 and 700 mg/kg, respectively) and 20 min later 1.0 mg/kg of AFB1. Liver cells were obtained at 4, 10, and 16 h after the chemical administration and examined. The results showed no protection of the damage induced by AFB1 with the low dose of the polysaccharide, but they did reveal antigenotoxic activity exerted by the two high doses. In addition, we induced a co-crystallization between both compounds, determined their fusion points and analyzed the molecules by UV spectroscopy. The obtained data suggested the formation of a supramolecular complex between AFB1 and Man

Synthesis of Bio-Compatible SPION–based Aqueous Ferrofluids and Evaluation of RadioFrequency Power Loss for Magnetic Hyperthermia

Bio-compatible magnetic fluids having high saturation magnetization find immense applications in various biomedical fields. Aqueous ferrofluids of superparamagnetic iron oxide nanoparticles with narrow size distribution, high shelf life and good stability is realized by controlled chemical co-precipitation process. The crystal structure is verified by X-ray diffraction technique. Particle sizes are evaluated by employing Transmission electron microscopy. Room temperature and low-temperature magnetic measurements were carried out with Superconducting Quantum Interference Device. The fluid exhibits good magnetic response even at very high dilution (6.28 mg/cc). This is an advantage for biomedical applications, since only a small amount of iron is to be metabolised by body organs. Magnetic field induced transmission measurements carried out at photon energy of diode laser (670 nm) exhibited excellent linear dichroism. Based on the structural and magnetic measurements, the power loss for the magnetic nanoparticles under study is evaluated over a range of radiofrequencies

Fizikalni mehanizmi i metode u tumorskim terapijama i prijenosu lijekova do tumora

In addition to several well-known drug delivery strategies developed to facilitate effective chemotherapy with anticancer agents, some new approaches have been recently established, based on specific effects arising from the applications of ultrasound, magnetic and electric fields on drug delivery systems. This paper gives an overview of newly developed methods of drug delivery to tumors and of the related anticancer therapies based on the combined use of different physical methods and specific drug carriers. The conventional strategies and new approaches have been put into perspective to revisit the existing and to propose new directions to overcome the threatening problem of cancer diseases.Osim dobro poznatih metoda prijenosa lijekova u kemoterapijskom pristupu liječenja tumora, nedavno su otkriveni novi načini prijenosa koji se zasnivaju na specifičnim mehanizmima uzrokovanim upotrebom ultrazvuka, magnetskih i električnih polja. Članak sadrži prikaz fizikalnih mehanizama na kojima se temelje ove nove metode, kao i pregled novootkrivenih prijenosnika lijekova (Pluronske micele, magnetoliposomi, magnetski fluidi), novih terapija tumora (magnetska hipertermija, elektrokemoterapija) i najnovijih istraživanja temeljenih na fizikalnom pristupu ovoj problematici

Magnetic cationic liposomal nanocarriers for the efficient drug delivery of a curcumin-based vanadium complex with anticancer potential

In this work novel magnetic cationic liposomal nanoformulations were synthesized for the encapsulation of a crystallographically defined ternary V(IV)-curcumin-bipyridine (VCur) complex with proven bioactivity, as potential anticancer agents. The liposomal vesicles were produced via the thin film hydration method employing N-[1-(2,3-dioleoyloxy)propyl]-N,N,N-trimethylammonium (DOTAP) and egg phosphatidylcholine lipids and were magnetized through the addition of citric acid surface-modified monodispersed magnetite colloidal magnetic nanoparticles. The obtained nanoformulations were evaluated for their structural and textural properties and shown to have exceptional stability and enhanced solubility in physiological media, demonstrated by the entrapment efficiency and loading capacity results and the in vitro release studies of their cargo. Furthermore, the generated liposomal formulations preserved the superparamagnetic behavior of the employed magnetic core maintaining the physicochemical and morphological requirements for targeted drug delivery applications. The novel nanomaterials were further biologically evaluated for their DNA interaction potential and were found to act as intercalators. The findings suggest that the positively charged magnetic liposomal nanoformulations can generate increased concentration of their cargo at the DNA site, offering a further dimension in the importance of cationic liposomes as nanocarriers of hydrophobic anticancer metal ion complexes for the development of new multifunctional pharmaceutical nanomaterials with enhanced bioavailability and targeted antitumor activity

Liposome-nanoparticle hybrids for multimodal diagnostic and therapeutic applications

Liposomes have a decade-long clinical presence as nanoscale delivery systems of encapsulated anthracycline molecules. However, their use as delivery systems of nanoparticles is still in the preclinical development stages. Liposome-nanoparticle hybrid constructs present great opportunities in terms of nanoscale delivery system engineering for combinatory therapeutic-imaging modalities. Moreover, many novel materials are being developed in nanotechnology laboratories that often require methodologies to enhance their compatibility with the biological milieu in vitro and in vivo. Liposomes are structurally suitable to make nanoparticles biocompatible and offer a clinically proven, versatile platform for the further enhancement of pharmacological efficacy. Small iron oxide nanoparticles, quantum dots, liposomes, silica and polystyrene nanoparticles have been incorporated into liposomes for a variety of different applications. In this review, all such liposome-nanoparticle hybrid systems are described, both in terms of their structural characteristics and the potential they offer as diagnostic and therapeutic multimodality agents

Importance of Basset History Force for the Description of Magnetically Driven Motion of Magnetic Particles in Air

Lungs are used as an attractive possibility for administration of different therapeutic substances for a long time. An innovative method of such administration widely studied nowadays is the application of aerosolized magnetic particles as the carriers to the lungs in the external non-homogeneous magnetic field. For these reasons we have studied dynamics of such a system on a level of particle trajectory in air in the presence of magnetic force as a driving force exerted on micrometric magnetic particle. On two typical examples of magnetically driven systems—motion of magnetic particle in a gradient magnetic field and cyclotron-like motion of a charged particle in homogeneous magnetic field in microscale, where the external accelerating forces are very large and the relevant time scale is of the order from fraction of milliseconds to seconds, we have examined the importance of these forces. As has been shown, for particles with high initial acceleration, not only the commonly used Stokes force but also the Basset history force should be used for correct description of the motion

Study of Zn6Al6Ag Alloy Application in Ultrasonic Soldering of Al2O3–(Al/Al2O3) Joints

The aim of this research is to characterize the soldering alloy Zn6Al6Ag, and to study the ultrasonic soldering of an Al2O3/metal–ceramic composite (Al/Al2O3). Zn6Al6Ag solder presents a quasi-eutectic structure with a melting point around 425 °C. The solder microstructure consists of a (Zn) + (Al) matrix, reinforced with a silver AgZn3 phase. A bond with the metal–ceramic composite was formed due to the dissolution of Al in the liquid Zn solder. The Al2O3 particles were put into motion, and a new composite was formed on the boundary. The Zn6Al6Ag solder also wetted the surface of the Al2O3 ceramic. A decisive effect on bond formation was caused by zinc and aluminum, whose oxides were combined with the oxides of ceramic material during in-air soldering. An adhesive bond was formed. The average joint shear strength of Al2O3/metal–ceramic composite (Al/Al2O3) was found to be 23 MPa

Magnetoliposome Mediated Local Electromagnetic Tumor Hyperthermia

Magnetoliposomes prepared by enwrapping 8 nm sized superparamagnetic magnetite grains with phospholipid bilayer were evaluated as possible new material for local electromagnetic hyperthermia both in vitro and in vivo after their injection into implanted BP-6 tumor in rats. As has been found the center of tumor is heated in 10 minutes from 35°C to 44.1°C using magnetic field with induction 1.5 mT and frequency 3.5 MHz