Strategies to get drugs across bladder penetrating barriers for improving bladder cancer therapy

Bladder cancer is a significant public health concern and social burden due to its high recurrence risk. Intravesical drug instillation is the primary therapy for bladder cancer to prevent recurrence. However, the intravesical drug therapeutic effect is limited by bladder penetrating barriers. The inadequate intravesical treatment might cause the low drug concentration in lesions, resulting in a high recurrence/progression rate of bladder cancer. Many strategies to get drugs across bladder penetrating barriers have been developed to improve intravesical treatment, including physical and chemical methods. This review summarizes the classical and updated literature and presents insights into great therapeutic potential strategies to overcome bladder penetrating barriers for improving the intravesical treatment of bladder cancer.