Lu Fan,Xiaoxuan Zhang,Min Nie,Ye Xu,Yuetong Wang,Luoran Shang,Yongxiang Zhao,Yuanjin Zhao
Microneedle (MN) patches are promising stratagems for transdermal drug delivery owing to its minimal invasiveness and portability. Particularly, separable MN patches attract more attention for durable and long-term drug delivery. Here, a new strategy for designing controllably separable MN patches by integrating photothermal responsive phase-changing microspheres (MPs) into conical hydrogel MNs, is presented. Such MPs consist of near-infrared (NIR)-responsive black-phosphorus (BP) and phase-changing gelatin (GT), and are fabricated using a simple capillary microfluidic device. When the composite MN patch is exposed to NIR, the contained BP/GT MPs can transform light into heat, increase local temperature, turn into a liquid state, and form cavities in MNs, resulting in the convenient detachment of the backing plate and the needles by shear force. Subsequently, the embedded needles can sustainably release the drug. In addition to intelligently controlling the detachment of MNs, the BP/GT MPs can load macromolecular drugs and release them in response to NIR stimulation. Results further demonstrated that such controllably separable MN patch can effectively load and release two drugs to ameliorate disease progression for systemic lupus erythematosus treatment. These features indicate the practical values of controllably separable MN patches for versatile drug delivery and clinical applications.
Bacterial infection will attack the wound and aggravate inflammation, which is the main reason for the difficulty in wound healing. Here, we reported a dextran-based hydrogel composed of methacrylated gelatin (GelMA) and oxidized dextran (oDex), which loaded with black phosphorus (BP) nanosheets and zinc oxide nanoparticles (ZnO NPs). The hydrogel exhibited synergistic antibacterial activity of photothermal and zinc ions with an irradiation of 808 nm NIR laser. Meanwhile, trace zinc released from the hydrogel reduced polarization of macrophages towards the M2 phenotype. A larger proportion of M2 macrophages secreted anti-inflammatory factors and cytokines to reduce inflammation and facilitate neovascularization . Under the combined treatment of photothermal stimulation and immune factors, more neovascularization and shorter inflammation appeared in infected full-thickness defect wounds of mouse, which greatly accelerated wounds closure. Therefore, the combined treatment of antibacterial activity and anti-inflammatory properties of hydrogel Gel/BP/ZnO + NIR is suggested to be a hopeful approach for chronic wounds.
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