Controlled Release of Silver Nanoparticles Contained in Photoresponsive Nanogels.

Smart nanomaterials can selectively respond to a stimulus and consequently be activated in specific conditions, as a result of their interaction with electromagnetic radiation, biomolecules, or pH change. These nanomaterials are produced through distinct routes and can be used in artificial skin, drug delivery, and other biomedical applications. Here, we report on the fabrication of an antibacterial nanogel formed by aniline- and chitosan-containing silver nanoparticles (AgNp's), with an average size of 78 ± 19 nm. The AgNp nanogel release was triggered by light at 405 nm. Specifically, the electronic energy vibration resulting from the interaction of the irradiation with the AgNp surface plasmon breaks the hydrogen bonds of the nanogels and releases AgNp's. To understand the perturbation of AgNp-nanogels against bacteria, membrane model studies were performed using the main components of the cell membrane of Escherichia coli ( E. coli ), 1,2-dipalmitoyl- sn -glycero-3-phospho-(1'-rac-glycerol) (DPPG) and 1,2-dimyristoyl- sn -glycero-3-phosphoethanolamine (DMPE). DPPG has more influence on the incorporation of the nanoparticles on the cell membrane due to the electrostatic interaction between the nanoparticle surface and lipid charged groups. The results indicate new possibilities for designing smart antibacterial photoresponsive nanogels with enhanced optical and antibacterial properties to increase E. coli death.