Photothermal responsive porous hollow microneedles as Chinese medicine versatile delivery system for wound healing

Chinese medicine is identified as a candidate for wound healing. Attempts in this field tend to develop efficient dosage forms for delivering Chinese medicine with low side effects. In this paper, we proposed novel photothermal responsive porous hollow microneedles (PRPH-MNs) as a versatile Chinese medicine delivery system for efficient antibacterial wound treatment. The PRPH-MNs are composed of porous resin shells with good mechanical property, hydrogel cores, and a photothermal graphene oxide hybrid substrate. The hollow structure provides sufficient space for loading the drug dispersed hydrogel, while the porous resin shells could not only block the direct contact between drugs and wound sites but also provide channels for facilitating the drug release from the core. In addition, benefiting from the photothermal effect of their substrate, the PRPH-MNs could be heated under near-infrared (NIR) irradiation for controllable promotion of drug release. Based on these features, we have proved that the antibacterial Chinese medicine Rhein loaded PRPH-MNs were effective in promoting wound healing due to their good antibacterial property and on-demand drug release. Thus, we believe that the proposed PRPH-MNs are valuable for delivery of different drugs for clinical applications.