A review of recent developments on micro/nanostructured pharmaceutical systems for intravesical therapy of the bladder cancer

Bladder cancer (BC) is the most common tumor type of genitourinary tract, which affects more men than women. The conventional treatment is through chemotherapy or immunotherapy, but the radiotherapy and surgery may be necessary in cases of invasive cancer. The search for less invasive, safe and effective therapies has attracted researchers to the development of new drug delivery systems to carry drugs to be administered by catheter into the bladder. The research on intravesical systems for the BC treatment continues at a rapid pace and a variety of micro or nanostructured systems have been used. Micro/nanoparticles, liposomes, micelles, carbon nanotubes, hydrogels and nanogels can contribute to reduce the number of intravesical administrations due to the extended drug release as well as to reduce the adverse effects and to increase the patient adherence to the treatment. Thus, this article reviews relevant studies regarding these systems, which have shown promising perspectives for the treatment of BC. It is hoped that in a near future they can prove to be safe and efficient to benefit patients with BC.