Biomimetic approaches toward the control of bacterial infections

Bacterial infection form a growing health problem worldwide, requiring novel strategies to prevent and treat bacterial infections. This thesis aims to learn from the natural defense systems of the human body to fight bacterial infection. Firstly, inspired by the natural versatility of cell membranes, macrophage-membrane coated, antimicrobial nanoparticles were developed to kill bacteria, that were seeking shelter inside the same macrophages that were supposed to kill them. This class of infections is troublesome as it often causes re-occurrence of infection after traditional antibiotic treatment, since antibiotics may have difficulty entering infected macrophages. Macrophage-membrane coated, antimicrobial nanoparticles however, easily entered infected macrophages and killed infecting bacteria more effectively than a clinically-used antibiotic. Secondly, inspired by the secondary G-quadruplex structure of DNA, a hydrogel based novel biomimetic cascade reaction container material was designed producing reactive oxygen species (ROS) from endogenous glucose to control bacterial infections. Animal evaluation was successful and demonstrated reduced glucose levels around an infected wound making it extremely suitable for use in diabetic patients as an antimicrobial wound dressing. Importantly, this strategy was non-antibiotic based and induction of ROS resistance is unlikely. Nature has more to teach us than the two examples developed further in this thesis and lessons from nature are worth to consider more extensive in developing novel strategies for bacterial infection control.