Recent advances in intravesical drug/gene delivery

Abstract

Targeting of drugs administered systemically relies on the higher affinity of ligands for specific receptors to obtain selectivity in drug response. However, achieving the same goal inside the bladder is much easier with an intelligent pharmaceutical approach that restricts drug effects by exploiting the pelvic anatomical architecture of the human body. This regional therapy involves placement of drugs directly into the bladder through a urethral catheter. It is obvious that drug administration by this route holds advantage in chemotherapy of superficial bladder cancer, and it has now become the most widely used treatment modality for this ailment. In recent years, the intravesical route has also been exploited either as an adjunct to an oral regimen or as a second-line treatment for neurogenic bladder. (Lamm, D. L.; Griffith, J. G. Semin. Urol. 1992, 10, 39-44. Igawa, Y.; Satoh, T.; Mizusawa, H.; Seki, S.; Kato, H.; Ishizuka, O.; Nishizawa, O. BJU Int. 2003, 91, 637-641.) Instillation of DNA via this route using different vectors has been able to restrict the transgene expression in organs other than bladder. The present review article will discuss the shortcomings of the current options available for intravesical drug delivery (IDD) and lay a perspective for future developments in this field.

Fig.1

Illustration of bladder permeability barrier established by uroplakin covered umbrella cells of bladder epithelium (urothelium) and GAG layer that prevents adhesion.

Fig 2

Schematic illustration of liposome and sites of drug entrapment.

Fig. 3

Schematic Diagram to Illustrate Advanced Delivery Options for Intravesical Drug & Gene Delivery.