Surface Potential Of Nanoparticles Research Articles

Intracytoplasmic Trafficking of Nanoparticles based on Hyaluronic Acid and Chitosan for Targeted Delivery of Anticancer Drugs

Cancer diseases are characterized by high incidence and mortality worldwide. The main problem in cancer therapy is the lack of specificity of anti-cancer drugs. Therefore, the development of new methods of targeted delivery of anti-cancer drugs is an urgent task in oncology. Nanoparticles from hyaluronic acid and chitosan (HA:CS) were obtained using ionotropic gelation technology. The size of the nanoparticles was investigated using dynamic light scattering. Nanoparticles were obtained of a size of 100-400 nm. A physical association method has been developed for encapsulating nanoparticles with doxorubicin, a well-known antitumor drug, and dinitrosyl iron complex (DNIC; donor of nitric oxide). Using the method of dynamic light scattering, the surface potential of nanoparticles was measured. It was found that the resulting nanoparticles (HA-DOX:CS) were stable and had a surface potential of -45.6 meV. Using the method of confocal and FLIM microscopy, the localization of nanoparticles in cancer cells was studied. These methods have shown that nanoparticles pass through the cytoplasmic membrane and are localized inside the cells. It was also shown that nanoparticles (HA:CS-Rhod) were localized in the cytoplasm of African green monkey renal epithelial cells. It was found that the incorporation of DNIC into the composition of nanoparticles significantly increased the stability of DNIC, while prolonging the formation time and increasing the yield of nitric oxide. Thus, we have developed unique nanoparticles for the targeted delivery of antitumor drugs into cells.

New Relevant Descriptor of Linear QNAR Models for Toxicity Assessment of Silver Nanoparticles.

The use of silver nanoparticles (NPs) in medical, industrial and agricultural fields is becoming more widespread every year. This leads to an increasing number of experimental toxicological and microbiological studies of silver NPs aimed at establishing the risk–benefit ratio for their application. The following key parameters affecting the biological activity of silver dispersions are traditionally taken into consideration: mean diameter of NPs, surface potential of NPs and equilibrium concentration of Ag+. These characteristics are mainly predetermined by the chemical nature of the capping agent used for stabilization. However, the extent to which they influence the biological activity and the toxicity of silver NPs varies greatly. In this work, dispersions of silver NPs stabilized with a wide array of substances of different chemical nature were used for quantitative evaluation of whether the various measurable properties of silver NPs fit as descriptors of linear QNAR (quantitative nanostructure–activity relationship) models for silver NP toxicity evaluation with respect to a model eukaryotic microorganism—Saccharomyces cerevisiae yeast cells. It was shown that among the factors that determine silver NP toxicity, the charge of particles, their colloidal stability and the ability to generate Ag+ ions carry more importance than the descriptors related to the particle size. A significant synergistic effect between the ζ-potential and the colloidal stability of silver NPs on their toxicity was also discovered. Following this, a new descriptor has been proposed for the integral characterization of the silver dispersion colloidal stability. According to the obtained data, it can be considered applicable for building QNAR models of higher efficacy. The validity testing of the proposed model for theoretical prediction of silver NP toxicity using a wide range of living organisms has shown that this new descriptor correlates with toxicity much better compared to most traditionally used descriptors. Consequently, it seems promising in terms of being used not only in situations involving the rather narrow array of the objects tested, but also for the construction of silver NP toxicity models with respect to other living organisms.

Development of chitosan-hyaluronic acid nanoparticles and study of their physico-chemical properties for targeted delivery of anticancer drugs

Nanoparticles from chitosan and hyaluronic acid were obtained using ionotropic gelation technology. The size of the nanoparticles was investigated using electron microscopy and dynamic light scattering. Nanoparticles were obtained of an optimal size of ∼ 100 nm. A physical association method has been developed of encapsulating nanoparticles with doxorubicin, a well-known antitumor drug, and dinitrosyl iron complex (donor of nitric oxide). The surface potential of nanoparticles was determined by dynamic light scattering. It was shown that HA-DOX: CS {6: 1} nanoparticles were stable and had a potential of -45.6 meV. The localization of nanoparticles in the cancer cells has been studied by confocal and FLIM microscopy. It was found that nanoparticles with doxorubicin are located in the cell near and inside the nucleus. It was shown that the encapsulation of DNIC in the composition of nanoparticles significantly increases the stability of DNIC, prolongs the formation and increases the yield of nitric oxide. A unique nano-system has been created for the delivery of anticancer drugs into the cell.

Evaluating cell specific cytotoxicity of differentially charged silver nanoparticles

Silver nanoparticles (AgNPs) are one of the most commercially viable nanotechnological products, nevertheless; safety issues are raised regarding the use of such nanoparticles due to unintentional health and environmental impacts. In the present study, AgNPs were synthesized by chemically reducing silver nitrate alternatively with sodium borohydride, tannic acid, ascorbic acid and sodium citrate. AgNPs synthesized by reduction with tannic acid (TSNPs) and sodium borohydride (BSNPs) exhibited highest and lowest surface potential respectively. Therefore these two types of AgNPs were selected for their toxicity assessment in cellular environment. We treated skin epithelial A431, lung epithelial A549 and murine macrophages RAW264.7 cells with AgNPs over a range of doses (5–100μg/ml). Toxicity was evaluated by measuring changes in cellular morphology, ROS generation, metabolic activity and expression of various stress markers. Interestingly, TSNPs exhibited a higher negative zeta-potential and also higher toxicity. Higher toxicity of TSNPs was attested by dose-dependent increase in cellular disruption and ROS generation. BSNPs showed cytotoxic effect up to the concentration of 50μg/ml and thereafter the cytotoxic effect attenuated. TSNPs induced a dose dependent increase in the expression of stress markers pp38, TNF-α and HSP-70. Our report proposes that cytotoxicity of AgNPs changes with surface potential of nanoparticles and cells type.