Biomineralized Nanocomposite‐Integrated Microneedle Patch for Combined Brachytherapy and Photothermal Therapy in Postoperative Melanoma Recurrence and Infectious Wound Healing

In the surgical management of malignant melanoma, incomplete tumor resection and large-area cutaneous defects are major contributors to high locoregional recurrence and uncontrolled wound infections, resulting in poor prognosis and prolonged recovery times for patients. Herein, a versatile nanocomposite microneedle patch (referred to as GM-Ag₂S/Ca³²P) is designed to simultaneously eliminate residual tumor post-surgery and promote the healing of infectious wounds. This microneedle patch effectively penetrates subcutaneous tissues, delivering therapeutic payloads to infiltrating tumor cells and bacteria. The Ag₂S/Ca³²P nanocomposites encapsulated within the microneedle patch decompose in the acidic microenvironment of tumors and bacterial biofilms, releasing radioactive ³²P and Ag₂S nanodots, which enhance tumor eradication and bacteria killing through synergistic brachytherapy and photothermal therapy (PTT). Moreover, the nanocomposite microneedle patch promotes scar-free wound healing by reducing inflammation, and promoting granulation tissue formation, collagen deposition, and angiogenesis, thanks to localized hyperthermia, radiation, and the swelling and biodegradation of the microneedle matrices. This microneedle patch-based postoperative adjuvant therapy offers a comprehensive strategy for addressing melanoma recurrence and infectious wound healing, with promising potential for clinical application in postsurgical management.