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Biomedical subjects

Yujin Ahn

Publications and source records attributed to Yujin Ahn.

2 recordsLinked to original sources

Microblasting Wound Dressings Mechanically Disrupt Polymicrobial Biofilms to Enhance Healing in Treatment-Resistant Wounds.

Treatment-resistant wounds driven by polymicrobial biofilms are a major clinical challenge, affecting millions globally and leading to chronic inflammation, persistent pain, and poor healing outcomes. These wounds are characterized by mature biofilms reinforced by dense extracellular polymeric substances, which confer strong tolerance to conventional treatments. Despite emerging technologies, such as nanoparticles, bacteriophages, and engineered enzymes, effective clearance of established biofilms remains challenging. Here, we develop a microblasting wound dressing (µBLAST) that delivers spatially confined mechano-chemical disruption at the tissue-biofilm interface to remove viscoelastic biofilm matrices and promote tissue regeneration. The µBLAST is assembled by embedding MnO2-doped diatom biosilica beneath an H2O2-releasing cellulose mesh, enabling localized catalytic microbubble generation within biofilm matrices. Confined expansion and rupture of oxygen bubbles produce localized mechanical stress sufficient to dislodge mature, antibiotic-resistant polymicrobial biofilms, while sustained H2O2 release prolongs particle activity. In a murine wound model infected with mature P. aeruginosa and methicillin-resistant S. aureus biofilms, µBLAST treatment significantly reduces biofilm burden, accelerates re-epithelialization, promotes hair regrowth, and mitigates inflammation. Moreover, µBLAST enhances antibiotic efficacy, suppressing biofilm regrowth even at ten-fold reduced drug doses. These findings highlight confined mechano-chemical biofilm disruption as a therapeutic strategy for treating mature, antibiotic-resistant biofilm infections and promoting tissue regeneration.

Biofilms

Neuronal innervation regulates the secretion of neurotrophic myokines and exosomes from skeletal muscle.

Myokines and exosomes, originating from skeletal muscle, are shown to play a significant role in maintaining brain homeostasis. While exercise has been reported to promote muscle secretion, little is known about the effects of neuronal innervation and activity on the yield and molecular composition of biologically active molecules from muscle. As neuromuscular diseases and disabilities associated with denervation impact muscle metabolism, we hypothesize that neuronal innervation and firing may play a pivotal role in regulating secretion activities of skeletal muscles. We examined this hypothesis using an engineered neuromuscular tissue model consisting of skeletal muscles innervated by motor neurons. The innervated muscles displayed elevated expression of mRNAs encoding neurotrophic myokines, such as interleukin-6, brain-derived neurotrophic factor, and FDNC5, as well as the mRNA of peroxisome-proliferator-activated receptor γ coactivator 1α, a key regulator of muscle metabolism. Upon glutamate stimulation, the innervated muscles secreted higher levels of irisin and exosomes containing more diverse neurotrophic microRNAs than neuron-free muscles. Consequently, biological factors secreted by innervated muscles enhanced branching, axonal transport, and, ultimately, spontaneous network activities of primary hippocampal neurons in vitro. Overall, these results reveal the importance of neuronal innervation in modulating muscle-derived factors that promote neuronal function and suggest that the engineered neuromuscular tissue model holds significant promise as a platform for producing neurotrophic molecules.

Exosomes