Secondary amine pendent β-peptide polymers realizing antimicrobial surfaces to prevent bacterial infection of implants

•The antibacterial surfaces are prepared using host defense peptide-mimicking β-peptide polymers bearing either primary, secondary or tertiary amine groups.•The surface modified with cationic-amphiphilic copolymer P3 containing secondary amino groups is found to have high antibacterial activity and low cytotoxicity.•Potent antibacterial activity against drug-resistant bacteria in vitro and in vivo of β-peptide polymer-modified surfaces makes it a favorable candidate for medical implants.