New bioactive materials based on synthetic montmorillonite (Mt) of different chemical compositions (Na_2x(Al_2(1-x),Mg_2x)Si₄O₁₀(OH)₂·nH₂O, where x = 1, 0.75, 0.5 and 0.1) modified by silver/lysozyme nanoparticles (Ag/Lys) have been synthesized. Antimicrobial and hemolytic activities, as well as sorption ability of composite materials towards the simulated toxic agent of medium molecular weight (methylene blue) in environments, similar to those found in human body (рН 1.8 and 6.9) has been studied. It was found that Ag/Lys-Mt materials are active against Gram-negative and Gram-positive bacteria (Escherichia coli ATCC 25922, Staphylococcus aureus SG-511), while maintaining a low hemolytic effect. The hemolytic activities of synthetic Mt with specified characteristics are presented for the first time. The study of synthetic Mt of different chemical compositions made it possible to establish the main regularities of the effect of Mt composition on the interaction with Ag/Lys nanoparticles. An increase in the aluminium oxide content in Mt leads to an increase in the negative zeta potential of the surface, an increase in the hemolytic activity (toxicity) of the samples, a decrease in silver content at the Mt surface, and consequently, to a decrease in antimicrobial activity with respect to aluminium-free samples. At the same time, the adsorption capacity of samples of all the compositions remains sufficiently high. This makes it possible to talk about the possibility of using them as antiseptic substances for external application, as well as new enterosorbents with antibiotic properties.