All Drug Glassy Microneedle Patches for Instantaneous Transdermal Delivery

Dissolving microneedles (DMNs) are emerging transdermal delivery platforms but rely on water-soluble polymers as carriers that inherently limit drug-loading capacity and slow release due to dissolution/diffusion barriers. Formulating drugs directly into robust DMNs is further challenged by crystallization tendencies. Here, a supramolecular engineering strategy enabling carrier-free antibiotic glass microneedles (GMNs) is presented, leveraging synergistic drug-sulfate-water interactions that suppress crystallization and form mechanically stable amorphous networks. Using tobramycin sulfate, monolithic GMNs are achieved with 100%-drug payload, exceptional strength (Young's modulus 5.1 GPa), and instant transdermal delivery (threefold faster than polymer DMNs). Eliminating polymeric carriers accelerates drug diffusion by 2.6-fold, enabling deep tissue penetration for efficient biofilm eradication. In vivo evaluation demonstrates that the antibiotic GMNs effectively promote the healing of biofilm-infected skin wounds in mice and exhibit potent therapeutic efficacy against subcutaneous abscesses. This strategy extends broadly to aminoglycoside antibiotics. By replacing the polymer matrix with supramolecular-engineered amorphous networks, a next-generation DMN platform is pioneered that bridges critical gaps in drug-loading efficiency, dissolution kinetics, and clinical translation for urgent therapeutic applications.