Recently, antimicrobial peptides (AMPs), also called host defence peptides (HDPs), are attracting great interest, as they are a highly viable alternative in the search of new approaches to the resistance presented by bacteria against antibiotics in infectious diseases. However, due to their nature, they present a series of disadvantages such as low bioavailability, easy degradability by proteases, or low solubility, among others, which limits their use as antimicrobial agents. For all these reasons, the use of vehicles for the delivery of AMPs, such as polymers, nanoparticles, micelles, carbon nanotubes, dendrimers, and other types of systems, allows the use of AMPs as a real alternative to treatment with antibiotics.

Novel amine- and ammonium-terminated carbosilane dendrimers of type G_n-[Si{CH₂O-(C₆H₄)-3-NMe₂}]_x or G_n-[Si{CH₂O-(C₆H₄)-3-NMe₃ ⁺I⁻}]_x have been synthesized and characterized up to second generation by phenolysis of (chloromethyl)silyl-terminated dendrimers with 3-dimethylamine phenol and subsequent quaternization with methyl iodide. Quaternized carbosilane dendrimers are stable in protic solvents and can be solubilised in water after the addition of less than 1% of dimethyl sulfoxide. A study of the antimicrobial activity of these cationic dendrimers of first and second generation against both Gram-positive and Gram-negative bacteria is also described. The results obtained demonstrate that the new ammonium-terminated carbosilane dendrimers can be considered as multivalent biocides.