The application of a topical agent to achieve tumescence has been achieved through the use of nanotechnology. Nanoparticles are packaged molecules that are comparable in size to viruses and can be synthesized to encapsulate biologically active materials, such as PDE5-I. A gel comprised of nanoparticles applied directly to the penile shaft to achieve erection has the added benefit of minimizing the side effect profiles of oral PDE5-I and directed local therapy. In the laboratory, synthesized nanoparticles are created by putting tadalafil, sialorphin and NO into a topical gel. According to the study by Han and colleagues, nanoparticles encapsulating erectogenic agents were applied to the glans and penile shaft of rats, and ICP was recorded [Han et al. 2010]. The control group consisted of nanoparticles, without the encapsulated erectogenic agent, applied to glans and penile shaft in a similar manner. Results revealed an erectile response within an average of 4.5 minutes after the administration of the topic agent comprised of NO nanoparticles, with duration of 1.42 minutes [Han et al. 2010]. Sialorphin nanoparticles achieved a visible erectile response at an average time of 4.5 minutes after application and lasted for 8 minutes. Tadalafil nanoparticles were able to achieve an erectile response at one hour only after stimulation of the cavernosal nerve [Han et al. 2010].
To date, no human trials exist, but the application of nanoparticles to provide localized therapy for ED may soon provide yet another option for patients and the nanoparticle delivery system may revolutionize the localized therapy for ED. Further studies are needed to fully develop these delivery systems with respect to dosage and toxicity.