Advancements in the management of overactive bladder in women using nano-botulinum toxin type A: A narrative review

Intravesical injections of botulinum toxin type A (BTX-A) are effective for treating refractory overactive bladder (OAB) in women. However, the adverse effects linked to the injections, such as hematuria, pain, and infection, and need for repeated injections can lower patient compliance and make the treatment inconvenient. Hence, urologists are actively pursuing less invasive and more convenient methods for the intravesical delivery of BTX-A. Advances in nanotechnology have facilitated noninvasive intravesical drug delivery. Currently, liposomes, hydrogels, nanoparticles, and many other forms of carriers can be used to enhance bladder wall permeability. This facilitates the entry of BTX-A into the bladder wall, allowing it to exert its effects. In this review, the feasibility and efficacy of liposomes, thermosensitive hydrogels, and hyaluronic acid-phosphatidylethanolamine for the treatment of OAB in women are discussed along with recent animal experiments on the use of nanotechnology-delivered BTX-A for the treatment of OAB in female rat models. Although the clinical efficacy of nanocarrier-encapsulated BTX-A for the treatment of OAB in women has not yet matched that of direct urethral muscle injection of BTX-A, improvements in certain symptoms indicate the potential of bladder instillation of nanocarrier-encapsulated BTX-A for future clinical applications. Consequently, further research on nanomaterials is warranted to advance the development of nanocarriers for the noninvasive delivery of BTX-A in the bladder.