# Alginate Silver Nanoparticles and Their Effect on Sperm Parameters of the Domestic Rabbit
## 1 Introduction
The increase in bacterial resistance to antibiotics as a result of their widespread use in various industries is forcing the search for other substances, agents with antibacterial properties that could replace antibiotics in certain processes [25; 30]. One of the potential agents with antibacterial properties for use in the dilution and storage of animal semen are silver nanoparticles [17]. Research on obtaining composites containing silver nanoparticles suggests that the chemical synthesis method, which involves reducing silver ions using various substances such as sugars, is an effective way to obtain nanostructures. It is also possible to embed these particles in the structures of non-toxic carriers, which act as a stabilizer for the resulting structures. For instance, polysaccharide sodium alginate can be used as an ecological stabilizer [33]. Sodium alginate is commonly obtained from natural sources. The chemical structure of alginate consists of numerous subunits composed mainly of \(\beta\)-d-mannuronic and \(\alpha\)-1-galuronic acid residues. Sodium alginate has a number of valuable biological properties, including biodegradability and biocompatibility with the natural environment. Importantly, from the point of view of the conducted research, this substance easily undergoes the gelatinization process and, thus, creates plastic gels [33; 34; 35; 36]. Alginate is widely used in various industries, such as pharmaceuticals, tissue engineering, and agri-food, due to its low toxicity [37; 38; 39; 40; 41]. Interdisciplinary industrial applications of polymer composites with metal nanoparticles result in the need to assess their safety, and, therefore, the degree of their toxicity, towards organisms inhabiting the natural environment, including farm animals. Due to the fact that these animals are particularly exposed to the undesirable effects of xenobiotics entering the ecosystem, it is necessary to directly verify the new substances against cells that are particularly important for the proper growth and development of these organisms. Spermatozoa are mature male reproductive cells with half the number of chromosomes reduced; in addition, they are characterized by an almost 90% smaller size than somatic cells. Through evolution, spermatozoids have evolved a mechanism for condensing genetic material that results in sperm chromatin that is 6-20 times more packed and condensed than nuclear chromatin in somatic cells [42; 43]. The transformation and packing of chromatin are linked in the process of sperm formation, which is spermiogenesis. During this process, only about 5-15% of histone proteins, which are part of the nucleosome, remain in the sperm nucleus and undergo chemical transformations [44]. Other chromatin proteins, such as protamine 1 and 2, are also bound to the sperm's DNA; they are proteins rich in cysteine and arginine, which allow for stable association with DNA. Due to the presence of protamines, the process of protamination and transformation of DNA strand structure takes place [43; 44; 45]. As a result of the remodeling of sperm chromatin, these cells achieve a high degree of DNA condensation in the sperm head, and this allows for a reduction in cell size, as well as the development of a more hydrodynamic shape [42]. In addition, this strong degree of chromatin packing protects the genetic material from damage, which is important because repair processes are usually not observed in spermatozoa [42; 43; 44]. The processes of chromatin reorganization occurring in cells as a result of endogenous and exogenous factors can be disrupted, resulting in abnormal chromatin condensation, and, thus, the occurrence of single and double DNA strand breaks, their fragmentation, or abnormalities in the process of converting histone proteins into transition proteins and further into protamines [46; 47]. The consequences of these changes can lead to the destabilization of the genetic material of male germ cells [45; 46].