In recent years, microneedle technology has been widely used for the transdermal delivery of substances, showing improvements in drug delivery effects with the advantages of minimally invasive, painless, and convenient operation. With the development of nano- and electrochemical technology, different types of microneedles are increasingly being used in other biomedical fields. Recent research progress shows that dissolving microneedles have achieved remarkable results in the fields of dermatological treatment, disease diagnosis and monitoring, and vaccine delivery, and they have a wide range of application prospects in various biomedical fields, showing their great potential as a form of clinical treatment. This review mainly focuses on dissolving microneedles, summarizing the latest research progress in various biomedical fields, providing inspiration for the subsequent intelligent and commercial development of dissolving microneedles, and providing better solutions for clinical treatment.

Noncompressible wounds resulting from accidents and gunshots are typically associated with excessive bleeding, slow wound healing, and bacterial infection. Shape-memory cryogel presents great potential in controlling the hemorrhaging of noncompressible wounds. In this research, a shape-memory cryogel was prepared using a Schiff base reaction between alkylated chitosan (AC) and oxidized dextran (ODex) and then incorporated with a drug-laden and silver-doped mesoporous bioactive glass (MBG). Hydrophobic alkyl chains enhanced the hemostatic and antimicrobial efficiency of the chitosan, forming blood clots in the anticoagulated condition, and expanding the application scenarios of chitosan-based hemostats. The silver-doped MBG activated the endogenous coagulation pathway by releasing Ca²⁺ and prevented infection through the release of Ag⁺. In addition, the proangiogenic desferrioxamine (DFO) in the mesopores of the MBG was released gradually to promote wound healing. We demonstrated that AC/ODex/Ag-MBG DFO(AOM) cryogels exhibited excellent blood absorption capability, facilitating rapid shape recovery. It provided a higher hemostatic capacity in normal and heparin-treated rat-liver perforation-wound models than gelatin sponges and gauze. The AOM gels simultaneously promoted infiltration, angiogenesis, and tissue integration of liver parenchymal cells. Furthermore, the composite cryogel exhibited antibacterial activity against Staphylococcus aureus and Escherichia coli. Thus, AOM gels show great promise for clinical translation in treating lethal, noncompressible bleeding and the promotion of wound healing.

Traumatic non-compressible hemorrhage and subsequent wound management remain critical challenges in military and civilian settings to this day. Cryogels have emerged as promising hemostatic materials for non-compressible hemorrhage due to their blood-triggered shape recovery. In this study, a biodegradable and mechanically resilient cryogel (CF/PD) was produced via cryopolymerization, employing methacrylated recombinant collagen as a macromolecular crosslinker alongside poly (ethylene glycol) diacrylate (PEGDA) and dopamine methacrylate (DMA). With its interpenetrating macro-porous structure and high hydrophilicity, the CF/PD rapidly absorbs blood and returns to its original shape within 1.5 s. In a rat liver defect model, CF/PD outperformed commercially available gelatin sponges, reducing hemostasis time by 74.4% and blood loss by 76.5%. Moreover, CF/PD cryogels facilitate in situ tissue regeneration by virtue of the bioactivity and degradability of recombinant collagen. This work establishes a bioactive recombinant collagen-driven cryogel platform, offering a transformative solution for managing non-compressible hemorrhage while enabling tissue regeneration.