Among various parameters that influence the formation of polyelectrolyte complexes and multilayers, special emphasis should be placed on ion-specific and solvent effects. In our study, we systematically examined the above-mentioned effects on poly(diallyldimethylammonium chloride) (PDADMACl)-sodium poly(4-styrenesulfonate) (NaPSS) complexation in solution and at the surface by means of dynamic light scattering, ellipsometry and atomic force microscopy measurements. As solvents, we used water and water/ethanol mixture. The obtained results confirm the importance of ion-specific and solvent effects on complexes prepared in solution, as well as on multilayers built up on a silica surface. The experiments in mixed solvent solution showed that at a higher ethanol mole fraction, the decrease in monomer titrant to titrand ratio, at which the increase in the size of complexes is observed, takes place. The difference between chloride and bromide ions was more pronounced at a higher mole fraction of ethanol and in the case of positive complex formation, suggesting that the larger amount of bromide ions could be condensed to the polycation chain. These findings are in accordance with the results we obtained for polyelectrolyte multilayers and could be helpful for designing polyelectrolyte multilayers with tuned properties needed for various applications, primarily in the field of biomedicine.

The study was carried out with the aim of establishing how the outcomes of polyelectrolyte multilayer formation can be predicted on the basis of the results of complexation studies in solution and vice versa .

The growing concern over implant‐associated infections motivates the development of novel antibacterial coatings for medical devices as an effective strategy in reducing the occurrence of IAI. Polyelectrolyte multilayers (PEMs) incorporating metal/metal oxide nanoparticles (NPs) as antimicrobial components receive special attention for their ability to coat diverse surface types and low potential to induce antimicrobial resistance. This study investigates the potential of poly(amino acid) multilayers consisting of poly‐L‐lysine and poly‐L‐glutamic acid with embedded silver (PEMAg) or copper oxide (PEMCuO) deposited on titanium surfaces for the coating of medical surfaces. The results of the quartz crystal microbalance with dissipation, scanning electron microscopy, and electron dispersive spectroscopy show that both types of NPs are successfully incorporated in the PEM and deposited over the entire coated surface. The incorporation of NPs in PEM prevents the burst release. The viability of MG‐63 cells is higher than 70% on all investigated PEMs, confirming their biocompatibility. PEMCuO shows better biofilm prevention compared to PEMAg, entirely preventing Pseudomonas aeruginosa biofilm and allowing the formation of only weak Staphylococcus aureus biofilm. The results obtained confirm the high potential of poly(amino acids) multilayers with embedded metal/metal oxide NPs as biocompatible antimicrobial coatings for medical devices.

Alginate hydrogels are promising materials for biomedical applications due to their biocompatibility and ability to mimic the extracellular matrix. However, poor mechanical stability and limited bioactivity hinder their wider clinical application. This problem can be overcome by incorporating nanoparticles (NPs) and calcium phosphates (CaPs). In this study, the simultaneous gelation and CaP mineralization of bulk alginate hydrogels in the presence of antimicrobial silver (AgNP), copper oxide (CuONP), and zinc oxide (ZnONP) was investigated. Calcium‐deficient hydroxyapatite forms at pH 7.4, and stable amorphous calcium phosphate at pH 9.0. The incorporation of NPs influences the morphology of mineral phases but not composition. Rheological testing revealed that mineralized hydrogels exhibit earlier network breakdown compared to the non‐mineralized ones, with critical strain values dependent on both pH and NP type. Ion release is pH‐dependent, with generally higher metal ion release from non‐mineralized hydrogels. Antibacterial assays demonstrate significant inhibition of S. aureus by hydrogels prepared at pH 9.0, except for hydrogels containing CuONPs. For P. aeruginosa , the differences in inhibition rates between different hydrogels were less pronounced. The obtained results indicate that CaP‐mineralized alginate hydrogels incorporating metal and metal oxide NPs exhibit tunable properties, confirming their potential for bone tissue engineering applications and infection prevention.