An important direction of research in increasing the effectiveness of cancer therapies is the design of effective drug distribution systems in the body. The development of the new strategies is primarily aimed at improving the stability of the drug after administration and increasing the precision of drug delivery to the destination. Due to the characteristic features of cancer cells, distributing chemotherapeutics exactly to the microenvironment of the tumor while sparing the healthy tissues is an important issue here. One of the promising solutions that would meet the above requirements is the use of Magnetotactic bacteria (MTBs) and their organelles, called magnetosomes (BMs). MTBs are commonly found in water reservoirs, and BMs that contain ferromagnetic crystals condition the magnetotaxis of these microorganisms. The presented work is a review of the current state of knowledge on the potential use of MTBs and BMs as nanocarriers in the therapy of cancer. The growing amount of literature data indicates that MTBs and BMs may be used as natural nanocarriers for chemotherapeutics, such as classic anti-cancer drugs, antibodies, vaccine DNA, and siRNA. Their use as transporters increases the stability of chemotherapeutics and allows the transfer of individual ligands or their combinations precisely to cancerous tumors, which, in turn, enables the drugs to reach molecular targets more effectively.

No abstract

Domagała J., Dziewulska K., Kirczuk L., Pilecka-Rapacz M. 2015. Sexual cycle of white bream, Blicca bjoerkna (Actinopterygii, Cypriniformes, Cyprinidae), from three sites of the lower Oder River (NW Poland) differing in temperature regimes. Acta Ichthyol. Piscat. 45 (3): 285-298.Background. One of the largest European populations of white bream, Blicca bjoerkna (Linnaeus, 1758), can be found in the estuary of the Oder River. This fi sh is not only very abundant in this area but also attains sizes that have no match in other areas of central Europe. In search for the clues behind such reproductive success we decided to study the annual development cycle of gonads of white bream from three sites in the lower Oder River, north-western Poland, differing in temperature regimes (depending on their position and the distance from the discharge outlet of the Dolna Odra Power Plant). Materials and methods. White bream individuals were obtained from the three sites as bycatch of commercial fi shing in 2009 and 2010. Three sites were sampled: (1) the Oder River above the power plant, (2) the warm-water canal with post-cooling water discharged from the power plant, and (3) Lake Dąbie, 20 km below the warm-water canal. The fi sh age was determined as 2+ through 9+. In total, 506 females and 190 males were designated for histological analyses. The analysis of the annual cycle of gonad development was performed in both sexes using histological methods. A standard paraffi n technique and Heidenhain's iron hematoxylin staining were used. Results. In the Oder River, spawning of white bream lasted from early May to late June. In Lake Dąbie, it extended until the beginning of July. The spawn was laid in 2 or 3 portions. In the warm-water canal spawning began one month earlier, in April. The bream males from the thermally unaffected Oder River were ready for reproduction approximately one month earlier than the females and maintained their reproductive potential similarly to the females. Males from the warm-water canal became sexually mature two months earlier (February) than those from the river above the power plant. Conclusion. In waters with elevated temperature, gametogenesis of white bream occurs without problems and the fi sh exhibit a typical pace of growth depending on the temperature. In the perspective of climate warming, white bream will be able to maintain its status of a common species in the natural waters of the region.

Histological studies of the blue bream (Ballerus ballerus L., 1758) (Actinopterygii, Cypriniformes, Cyprinidae) gonad maturation have not been conducted to date. The aim of this study was to analyse the annual gonad development cycle of the blue bream from the Oder River and Lake Dąbie in north-western Poland.The spawning period of the blue bream, a single-portion spawner, was short, lasted approximately two weeks and occurred in the first half of April in Lake Dąbie, and in the second half of April in the Oder River. The blue bream male gonads reached maturity stage IV before the winter and remained at this stage until early spring. The gonads contained cells at all spermatogenetic stages and the tubule lumen was filled with numerous spermatozoa. The males from Lake Dąbie finalized their spermatogenesis in April slightly faster than those from the Oder River. Some individuals had gonad filled with large amounts of spermatozoa even in May and June.

No abstract