Novel injectable urethral bulking agents for the treatment of urinary incontinence

Collagen type Ⅰ-loaded methacrylamide hyaluronic acid hydrogel microneedles alleviate stress urinary incontinence in mice: A novel treatment and prevention strategy

Stress urinary incontinence (SUI), a chronic disease with widespread effects and an overall prevalence of up to 46% in adult women, is associated with a heavy disease burden. The clinical treatment for mild to moderate SUI is conservative, such as electrical stimulation and Kegel exercises, but the therapeutic effect is unsatisfactory, so it is imperative to seek new treatment modalities. Hydrogel microneedles (MNs) have been widely used in transdermal drug delivery because of their minimally invasive and highly biocompatible characteristics. Therefore, for the first time, we combined collagen type I with MN technology for the treatment and prevention of mild to moderate SUI.

A historical perspective and evolution of the treatment of male urinary incontinence

AIMS

To describe the historical changes from antiquity until present in the presentation and treatment of male urinary incontinence.

METHODS

A literature review of PubMed articles in English pertaining to male incontinence was performed.

RESULTS

Male urinary incontinence was first mentioned in Egyptian manuscripts in 1500 B.C. In 1564, Ambroise Pare designed portable urinals for incontinent males. Wilhem Hildanus created the first condom catheter with pig bladder in the 1600s and was also credited with fashioning the first penile clamp. Lorenz Heister introduced a perineal bulbar urethral compression belt in 1747 which would provide the blueprint for air-inflated bulbar urethral compression devices such as the one designed by S.A. Vincent in 1960. Robert Gersuny performed the first periurethral paraffin injection bulking therapy in the late 19th century. In 1929, Frederic Foley introduced the modern catheter, and also credited with conception of the first artificial sphincter. From 1970 to 1973, Joseph Kaufman surgically created bulbar compression for post-prostatectomy incontinence, but not before designing the first male sling with John Berry in 1958. In 1973, F. Brantley Scott introduced the first multi-component artificial inflatable sphincter. Improvements upon periurethral bulking therapy occurred rapidly in the late 20th century with Teflon, collagen, autologous adipose, tissue and cross-linked silicone gels. Since 2007, stem cell injection therapy has emerged as a new therapeutic option for incontinence; however, results are mixed and remains experimental.

CONCLUSION

Treatment for male urinary incontinence has evolved from noninvasive devices to various surgical procedures. Artificial sphincters remain the gold-standard therapy for male urinary incontinence.

Local moderate magnetically induced hyperthermia using an implant formed in situ in a mouse tumor model

PURPOSE

We investigate a new heat delivery technique for the local treatment of solid tumors. The technique involves injecting a formulation that solidifies to form an implant in situ. This implant entraps superparamagnetic iron oxide nanoparticles (SPIONs) embedded in silica microbeads for magnetically induced moderate hyperthermia. Particle entrapment prevents phagocytosis and distant migration of SPIONs. The implant can be repeatedly heated by magnetic induction.

METHODS

We evaluated heating and treatment efficacies by means of thermometry and survival studies in nude mice carrying subcutaneous human colocarcinomas. At day 1, we injected the formulation into the tumor. At day 2, a single 20-min hyperthermia treatment was delivered by 141-kHz magnetic induction using field strengths of 9 to 12 mT under thermometry.

RESULTS

SPIONs embedded in silica microbeads were effectively confined within the implant at the injection site. Heat-induced necro-apoptosis was assessed by histology on day 3. On average, 12 mT resulted in tumor temperature of 47.8 degrees C, and over 70% tumor necrosis that correlated to the heat dose (AUC = 282 degrees C.min). In contrast, a 9-mT field strength induced tumoral temperature of 40 degrees C (AUC = 131 degrees C.min) without morphologically identifiable necrosis. Survival after treatment with 10.5 or 12 mT fields was significantly improved compared to non-implanted and implanted controls. Median survival times were 27 and 37 days versus 12 and 21 days respectively.

CONCLUSION

Five of eleven mice (45%) of the 12 mT group survived one year without any tumor recurrence, holding promise for tumor therapy using magnetically induced moderate hyperthermia through injectable implants.