Hyaluronate modified upconversion nanoparticles for near infrared light-triggered on–off tattoo systems†
Abstract
An in vivo on–off tattoo system was developed using upconversion nanoparticles conjugated with hyaluronate (HA-UCNPs). Two-photon microscopy clearly visualized the transdermal delivery of HA-UCNPs into the deep skin tissue. Upon near-infrared light irradiation, invisible HA-UCNPs in the skin were visualized showing the feasibility as a new on–off tattoo system.