NIR-II-responsive conductive silk fibroin microneedle patches for postoperative melanoma ablation, infected-wound healing, and real-time monitoring

Postoperative management of melanoma remains a significant clinical challenge due to the concurrent risks of residual tumor recurrence, bacterial infection, impaired healing, and the lack of real-time monitoring. Here, we presented an all-in-one theranostic microneedle patches (MNs) engineered from a natural biomaterial framework. The patch is fabricated via photo-crosslinking of methacrylated silk fibroin (SFMA) and acrylated β-cyclodextrin (Ac-CD), which incorporates lignosulfonate-doped poly-N-phenylglycine (LS@PNPG) nanocomposites as multifunctional photothermal and conductive components, alongside β-cyclodextrin-encapsulated curcumin (Cur) for hydrophobic drug delivery. The optimized MNs exhibited robust mechanical strength (1.73 N per needle), ensuring reliable skin penetration. The LS@PNPG component exhibited a high NIR-II photothermal conversion efficiency (30.65 % at 1064 nm), enabling effective photothermal heating (>58 °C in vitro; ∼50 °C in vivo) that triggered on-demand Cur release. This synergistic photothermal-chemotherapy achieved 98.9 % tumor eradication in vivo. Concurrently, the patch demonstrated potent antioxidant (87.2 % DPPH scavenging) and antibacterial activities (>98 % elimination of <i>E. coli</i> and <i>S. aureus</i>), which, together with silk fibroin's intrinsic pro-healing properties, significantly accelerated the repair of infected full-thickness wounds. The percolating conductive network further enabled real-time monitoring of wound temperature, pH, mechanical deformation, and electrophysiological signals. This comprehensively engineered MNs platform seamlessly integrates on-demand combination therapy with intelligent multiparameter sensing, offering a minimally invasive strategy for advanced postoperative melanoma care.