Characteristics of the response of the microalga (Dunaliella viridis) to cerium compounds in culture

Abstract

Recently, nanobiotechnology has been developing intensively; therefore, various properties of nanoparticles, which depend on their origin, concentration, and size, are of interest. It is known that CeO2 nanoparticles cause a positive biological effect. These particles are able to penetrate through biomembranes. At the same time, there are assumptions about a high degree of biological risks when using nanomaterials, and it is obvious that the biosafety of nanomaterials is decisive in the development of new products, including for medicine. The cytotoxicity of samples of cerium salts and cerium dioxide nanoparticles of different sizes was assessed at different concentrations using D. viridis. The cytotoxicity level by morphological and functional disorders of D. viridis was investigated, as determined by the change in cell shape, accumulation of inclusions, loss of flagellum, change in nature and movement, the formation of micro- and macroaggregates by D. viridis cells and exometabolite release. The cytotoxicity coefficient was calculated as a quotient of total detected changes divided by their number. It was shown that cerium salts (cerium (IV) ammonium nitrate and cerium (III) chloride) had pronounced cytotoxicity, which exceeded cytotoxicity values of the control by 7 and 6 times, respectively. Cerium dioxide nanoparticles with a size of 6 nm at a concentration of 0.01 M showed intermediate cytotoxicity, which exceeded control values by 3.5 times, and after the effect of nanoparticles with a size of 2 nm at a concentration of 0.1 M, the cytotoxicity coefficient corresponded to control values. The addition of inactivated blood serum to the incubation mixture resulted in a decreased cytotoxic effect of cerium dioxide. The use of D. viridis as a test system will supplement the arsenal of biotesting tools for nanomaterials and the study of the mechanisms of their effect.

Nanocrystalline Cerium Dioxide Affects Erythrocyte Membrane State Under Blood Hypothermic Storage

“…After blood collection and stabilization, the studied samples were divided into the following groups: the control was the samples, supplemented with 0.018 ml of water for injections (Halychpharm, Ukraine) to 9.0 ml of blood; in the experimental group there were the specimens with added 0.018 ml of NCD solution to 9.0 ml of blood (20 mg/l fi nal concentration of NCD). The mentioned concentration of NCD has no toxic eff ect [6]. Blood samples were stored in sterile plastic tubes at 4-5°C for 5 weeks.…”

“…У отриманих осадах еритроцитів після екстракції у суміші гептану та ізопропанолу (1:1) спектрофотометрично вимірювали концентрацію первинних продуктів ПОЛ, яку розраховували за законом Бугера-Ламберта-Бера у наномолях на 1 мл еритроцитів з використанням коефіцієнта молярної екстинкції ℇо: для дієнових кон'югатів (ДК) ℇ о = 2,2 • 10 5 • М -1 • см -1 , триєнових кон'югатів (ТК) ℇ о = 4,34 • 10 см -1 . Для тетраєнових кон'югатів (ТЕТ) коефіцієнт молярної екстинкції не визначений, тому їх вміст виражали у одиницях молярної екстинкції на 1 мл еритроцитів [2,3,6].…”