Cyanobacteria-inspired Microneedles: Hydroxypropyl Chitosan Enables Efficient Wrinkle Removal Within One Week

Recently, innovative breakthroughs have been made in skin anti-aging research. A research team developed cyanobacteria-inspired ROS-responsive core-shell hydrogel microneedles (AR-CSMNs) based on hydroxypropyl chitosan. The microneedles can nearly eliminate wrinkles within seven days, bringing new innovations to the field of intelligent cosmetic medicine. As the core substrate material, hydroxypropyl chitosan serves as an essential support for this advanced technology.

Skin wrinkles are mainly caused by reactive oxygen species (ROS), which trigger the degradation of collagen. Antioxidants such as ascorbic acid (AA) and retinoic acid (RA) are limited by the skin barrier during transdermal delivery. Conventional chitosan possesses biocompatibility and antibacterial properties, yet its poor water solubility restricts its application in microneedle fabrication. As an etherified derivative of chitosan, hydroxypropyl chitosan retains the inherent advantages of chitosan including hemostasis, antibacterial activity and biodegradability. Meanwhile, it exhibits greatly improved water solubility and chemical reactivity, successfully overcoming the technical limitations of raw chitosan.

The research team fabricated core-shell structured microneedles using hydroxypropyl chitosan. The outer shell composed of HPCMAH-A (a hydroxypropyl chitosan derivative) maintains the pyramidal morphology and sufficient mechanical strength for skin penetration. The inner core is crosslinked with an ROS-responsive crosslinker to realize targeted release of retinoic acid. Experimental results demonstrated that the drug release rate reached 95% in high-ROS environments. In aging SD rat models, wrinkles were visibly reduced within four days and almost completely removed within seven days.

Benefiting from hydroxypropyl chitosan, the optimized microneedles achieve biosafety and intelligent responsiveness. Its favorable biocompatibility avoids skin irritation and allergic risks, while biodegradability reduces medical waste pollution. Besides, its excellent mechanical properties ensure painless transdermal delivery. Compared with traditional creams and injections, this technology realizes targeted, efficient and safe skin treatment.

Experts stated that this innovative technology centered on hydroxypropyl chitosan provides a novel strategy for wrinkle treatment. It broadens the application scope of natural polymers in intelligent cosmetic medicine and is expected to promote the development of precise and minimally invasive anti-aging therapies.