Nanoparticles of silver do not affect growth, development and DNA oxidative damage in chicken embryos

The noble and semi noble metals like silver and copper and to a less degree palladium have been known since ancient time as antimicrobial and antifungal factors (DOLLWET and SORENSON, 2001; BORKOW and GABBAY, 2005; OTERO et al., 2006). Furthermore, the anti-inflammatory, re-epitheliasation and antihaemorrhagic properties of the silver-releasing materials are also known (BHOL and SCHECHTER, 2005; MELAIYE and YOUNGS, 2005). Silver is used in medicine (WRIGHT et al., 1999; BURRELL et al., 1999; OLSON et al., 2000; WRIGHT et al., 2002; ALT et al., 2004) while copper is one of the most effective non-antibiotic growth promoters used in animal production (CHOWDHURY et al., 2004). Silver, copper, palladium or the alloys of them, disintegrated to the size of 1–100 nm (nm = 1 × 10–9 m) posses unique biological properties. Physico-chemical and in consequence biological properties of nanomaterials are determined by energetic state of the particle’s core, which manifests itself by changed interatomic distances reflecting their non-equilibrium higher energetic state (PALOSZ et al., 2003). Consequently, nanoparticles might show unique electronic, optical and catalytic properties due to the quantum effects (MANDAL et al., 2005). Furthermore, very high surface area to volume ratio allows nanoparticles to be effective in very small amount. Investigations in vitro corroborated antimicrobial and antifungal property of silver and copper nanoparticles (HOET et al., 2004; SONDI and SALOPEK-SONDI, 2004) Recently, we have demonstrated that levels of 10-20 ppm of silver, silver/copper, and silver/palladium alloys used as hydrocolloids of nanoparticles showed antimicrobial properties (LEPIANKA and SOKO , 2006). Furthermore, in in vivo experiments with young quails receiving water containing hydrocolloids of nano-silver we have demonstrated that administration of 25 ppm of nano-silver increased numbers of bacteria Lactobacillus salivarius, Lactobacillus fermentum, Leuconostoc lactis in caeca (SAWOSZ et al., 2007). Thus, hydrocolloid nano-silver might act as preprobiotic stimulating populating of LAB bacteria in the digestive tract. Use of nanoparticles of silver and probably copper and palladium or the alloys of them may to be an alternative to antibiotic based feed additives and other pharmacological agents, improving health status of poultry. However, a possible application of nanoparticles in poultry production requires detailed investigations regarding potential toxicity of nanoparticles of noble and semi noble metals (HOET et al., 2004), especially, in in vivo experiments and in relation to environmental aspects (OWEN and HANDY, 2007). In the present experiment chicken embryos, being in comparing to cells’ culture true organisms, have been used to assess potential toxicity of nanoparticles and to verify influence of nanoparticles on growth, development and health. The objective of this work was to evaluate potential toxic effects of silver and alloys of silver/copper and silver/palladium nanoparticles, administrated in ovo, at the whole body, tissue and DNA level.