Although
antibacterial peptides with excellent properties emerge
endlessly, the antibacterial peptides with alternating structures
have not attracted much attention. In this work, three amino acid
alternating copolymers (Orn-Ser, Orn-Gly, and Orn-Val) with similar
molecular weights but different hydrophilicity were constructed for
the study of antibacterial properties through the solid-phase peptide
synthesis (SPPS) method. We found that these three amino acid alternating
copolymers showed excellent biocompatibility and broad spectrum antibacterial
activity. Nevertheless, they showed slightly different properties
due to differences in hydrophilicity and cationic density, for instance,
better biocompatibility of Orn-Ser, stronger antibacterial property
of Orn-Gly, and a higher selectivity index of Orn-Val. In a rat periodontitis
model, Orn-Gly and Orn-Val exhibited remarkable anti-infective performance
and significant therapeutic effects. This work is expected to play
an important role in the treatment of periodontitis and the rational
design of antimicrobial peptides for different applications.