Surfactant‐Free One‐Step Synthesis of Dual‐Functional Polyurea Microcapsules: Contact Infection Control and Drug Delivery

Abstract Surface functionalized polyurea microcapsules (MCQ) are synthesized in one step. Dimethyl‐dodecyl‐(5‐hydroxy‐pentyl)‐ammonium bromide (DAB), a hydroxyl‐end‐capped quaternary ammonium salt, is synthesized and adopted as a new surfmer for the synthesis of MCQ. It is confirmed by fluorescein adsorption that DAB is covalently bonded to MCQ. The so‐formed MCQ possess dual‐functionality: contact infection control and sustained drug delivery. Agar diffusion antimicrobial tests confirm successful inhibition of multi‐drug‐resistant E. coli by MCQ alone instead of by leaching of free quaternary ammonium salts. Furthermore, few E. coli colonies survive on an agar plate coated with 3–4 layers of MCQ. Dissolution tests show a typical first‐order release profile of courmarin‐1, a model dye, from MCQ.