Choi H, et al. ACS Nano 2020.
The intravesical therapeutic delivery has been extensively investigated for various bladder diseases such as bladder cancer, overactive bladder, urinary incontinence, and interstitial cystitis. However, conventional drug carriers have a low therapeutic delivery efficiency because of the passive diffusion of drug molecules in bladder and the rapid clearance by the periodic urination. Here, we report biocompatible and bioavailable enzyme-powered polymer nanomotors which can deeply penetrate into a
mucosa layer of bladder wall and remain for a long-term period in the bladder. The successful fabrication of nanomotors was confirmed by high resolution - transmission electron microscopy (HR-TEM), energy-dispersive X-ray (EDX) mapping, zeta-particle analysis, Fourier transform - infrared (FT-IR) spectroscopy, and urease activity and nanomotor trajectory analyses. After injection into the bladder, urease immobilized nanomotors became active moving around in the bladder by converting urea into carbon dioxide and ammonia. The nanomotors resulted in the facilitated penetration to the mucosa layer of bladder wall and the prolonged retention in the bladder even after repeated urination. The enhanced penetration and retention of the nanomotors as a drug delivery carrier in the bladder would be successfully harnessed for treating a variety of bladder diseases.