No abstract

The biological and medical aspects of magnetochemical effects in nanotherapy of tumors remain poorly studied. The present paper investigates the influence of nonlinear magnetochemical effects of anisotropic magnetic nanodots on an animal tumor model. The magnetic properties and electron spin resonance spectra of magnetic nanodots and doxorubicin were investigated after mechano-magnetochemical synthesis. The results obtained from the analysis of nonlinear kinetics and survival in Walker-256 carcinosarcomabearing animals found a nonlinear dependence between the value of the growth factor, braking ratio, survival rate, tumor redox state, and the treatment by the magnetic nanodot combined with a nonuniform constant magnetic field. To quantify the heterogeneity in microphotographs of Walker-256 carcinosarcoma sections, we applied the entropy parameter. The control (no treatment) group showed the greatest heterogeneity. The lowest value of tumor heterogeneity among animals given treatment was found in groups with the minimum growth factor. Similarly, the lowest entropy value was found in muscle tissue taken from inoculation areas of the tumor. The evidence from this study concluded that inhomogeneous constant magnetic fields with different strength applied to heterogeneous tumor tissues induced different magnetic anisotropy in the magnetic nanodot which had a significant influence on the nonlinear kinetics, redox state, and histological pattern of the tumor.

The paper aims to compare zeta potentials, magnetic properties, electron spin resonance, photoluminescence (PL) spectra and antitumor effect of magneto-mechano-chemically synthesized magneto-sensitive nanocomplexes loaded with the anticancer drug doxorubicin (DOXO) during nanotherapy of Walker-256 carcinosarcoma carried out by a magnetic resonance system. Diamagnetic DOXO acquired the properties of a paramagnetic substance after synthesis. MNC comprising superparamagnetic nanoparticles (NP) and DOXO had different g-factors, zeta potentials, a lower saturation magnetic moment, area of the hysteresis loop, and a higher coercivity compared to similar MNC with ferromagnetic NP. The main PL peak of MNC spectrum was defined by DOXO at 598 nm. MNC composed of superparamagnetic NP and DOXO showed a lower standard deviation of the normal PL spectral distribution than MNC based on ferromagnetic NP in relation to conventional DOXO. MNC containing superparamagnetic NP responded to resonance conditions leading to a more pronounced antitumor effect compared to MNC with ferromagnetic NP in the course of magnetic nanotherapy for Walker-256 carcinosarcoma bearing animals (temperature inside the tumor did not exceed 40 °C). Therefore, these findings are associated with differences in chemotherapeutic effect between MNC due to a different surface charge and conformational changes in DOXO molecules during its magnetoelectric interaction with single-and multidomain NP.

No abstract

No abstract