Polycaprolactone nanofiber mats decorated with photoresponsive nanogels and silver nanoparticles: Slow release for antibacterial control

Smart nanomaterials activated by light is one of the most exciting strategies to control the release of substances in varied environments. Here we developed a smart nanomaterial composed by a photoresponsive nanogel containing silver nanoparticles (AgNps) immobilized on the surface of biodegradable and biocompatible polycaprolactone (PCL) nanofibers mats produced by electrospinning. The AgNps are released from the nanogel and dispersed inside the nanofiber mats when this system is irradiated by light at 405 nm. This light excites the plasmonic band of the AgNps, which breaks the nanogel and, as a consequence, releases the AgNps on the nanofibers. Consequently, this AgNps release mechanism controls the propagation of silver ions by the application of light. Different configurations of antibacterial nanofibers mats, including neat PCL nanofibers and PCL nanofibers modified with AgNps-Nanogels and AgNps, excited by laser light at 405 nm, were investigated regarding antibacterial properties. The best result was achieved using PCL nanofiber mats functionalized with AgNps and AgNps-Nanogels after light exposure, which generated inhibition diameters of 2.6 +/- 0.3 mm and 1.8 +/- 0.5 mm for S. aureus and E. coli, respectively. The smart nanomaterial developed here is a promising material for clinical application as wound dressing activated by light.