Researchers out of the University of Hong Kong (HKUMed) have designed a new microneedle patch that offers a non-antibiotic approach for the treatment of infected acne.

The design is engineered with ultrasound-responsive zinc-based metal-organic framework (MOF) antibacterial nanoparticles  nd promises pain-free delivery to treat bacterial infection on skin tissue and facilitate skin repair at the same time. The novel microneedle is around 50 microns in diameter. 

The findings appear in Science Advances.

The first-line treatment for infected pimple is antibiotics administered either oral or topical. However, the therapeutic effect of topical antibiotic treatment is concerning, particularly when the drugs pass through the skin tissue. Also, the treatment becomes less effective, when bacteria are drug resistant or when they migrate to subcutaneous tissue. Especially, P. acnes bacteria can secrete extracellular polysaccharides to form biofilm that blocks out the attacks initiated by antibacterial agents or immune cells.

Enter the HKUMed team’s new microneedle patch.

This patch  facilitates the transdermal delivery of ultrasound-responsive antibacterial nanoparticles to treat the infection induced by P. acnes . In the current design, ultrasound-responsive antibacterial nanomaterials are introduced to the microneedle patch that responds to bacterial infection quickly and efficiently.

The use of drugs is avoided. The modified nanoparticles comprised of ZnTCPP and ZnO are able to produce a substantial amount of reactive oxygen species (ROS) subject to ultrasound stimulation that can effectively oxidize the key cellular macromolecules of bacteria. The results demonstrate that the killing of P. acnes bacteria mediated by ROS can reach to 99.73% after 15 minutes of ultrasound stimulation. Also, the levels of inflammatory markers, including tumour necrosis factor-a (TNF-α), interleukins (ILs), and matrix metalloproteinases (MMPs) are significantly reduced. Furthermore, the zinc ions released can elevate the DNA replication-related genes, thereby augmenting more fibroblasts towards superior skin repair.

“‘The new microneedle patch enabling ROS generation upon ultrasound stimulation, regarding as a non-antibiotic and transdermal approach, can not only effectively address the infection induced by P. acnes bacteria, but also facilitates the skin repair due to zinc ion release,” says Professor Kelvin Yeung from the Department of Orthopaedics and Traumatology, School of Clinical Medicine, LKS Faculty of Medicine, HKUMed in a news release. “Due to the specific killing mechanism of ROS, we believe that this design is also able to address the other skin infections induced by fungi, parasites, or viruses, such as tinea pedis.”

PHOTO CAPTION: Treatment of acne through efficient ultrasound-triggered antibacterial nanoparticles embedded microneedle patch.

PHOTO CREDIT: The University of Hong Kong