Nanozyme-Activated PLLA Microspheres for Effective Tissue Detection, Treatment, and Restoration

Due to the complex pathological characteristics and poor healing properties of tissue injury, current methods are unable to integrate diagnosis, treatment, and repair effectively. To address this challenge, the team is the first to combine PLLA microspheres with self-powered technology, designing and fabricating self-powered enzyme-linked PLLA microspheres, which are composed of an anode and cathode dual-array. These microspheres load glycerol oxidase (Pd@Pt NPs) and horseradish peroxidase (AuAg-Fe MOF), with the latter exhibiting a hydrogen peroxide enzyme activity (K_Cat/K_m) of 1.75 × 10¹⁰ M^-1s^-1, which is 1900 times higher than that of HRP. The enzyme cascade within the PLLA microspheres effectively detects and inhibits bacterial infection in injured tissue, enabling quantitative bacterial detection as low as 4 CFU/mL and achieving over 95% antibacterial efficiency. It also suppresses inflammatory infection and generates a stable microcurrent, with biological currents as high as 4.0 µA, promoting rapid tissue healing and repair. Consequently, tissue wounds treated with enzyme-linked PLLA microspheres demonstrate preventive, rapid, and efficient healing, attributed to the synergistic effects of bacterial detection, antibacterial action, inflammation inhibition, tissue regeneration, and bioelectric stimulation. In summary, self-powered enzyme-linked PLLA microspheres offer an effective method for rapid detection, treatment, and repair of tissue injuries.