Persistence and survival of autologous muscle derived cells versus bovine collagen as potential treatment of stress urinary incontinence

Purpose: We explored the use of autologous muscle derived cells as a method of treating stress urinary incontinence. We determined whether urethral mu scle derived cell injection is feasible and compared it with bovine collage n injection. Materials and Methods: Muscle derived cells isolated from female Sprague-Da wley rats were first transduced with retrovirus carrying the transgene for beta -galactosidase. We injected approximately 1 to 1.5 x 10(6) cells into the bladder wall and proximal urethra of 6 autologous animals. Tissue was h arvested after 3 and 30 days, sectioned, stained for fast myosin heavy chai n and assayed for beta -galactosidase. To compare muscle derived cell and b ovine collagen injections 100 mul, of commercially available bovine collage n were also injected in Sprague-Dawley female rats. Tissue was harvested in 3 animals each after 3 and 30 days, sectioned and stained for trichrome. S ubsequently, 3 adult SCID mice were used to compare the level of transgene expression at each time point after injecting 1.5 x 10(6) cells per injecti on, which were transduced with adenovirus carrying the transgene for beta - galactosidase. Results: A large number of cells expressing beta -galactosidase were observ ed in the bladder and urethral wall 3 and 30 days after autologous cell inj ection in Sprague-Dawley rats. The persistence of primary muscle derived ce lls at 3 days was similar to that of collagen. However, at 30 days there wa s significant cell persistence while only a minimal amount of injected bovi ne collagen was detectable. Approximately 88% of the beta -galactosidase ex pression at day 3 remained at day 30 in SCID mice. Conclusions: We present 2 new findings important for the emerging field of urological tissue engineering, including the feasibility of injecting autol ogous skeletal muscle derived cells into the lower urinary tract and the gr eater persistence of such injected cells versus injected bovine collagen. T herefore, autologous muscle derived cell injection may be an attractive alt ernative treatment option for stress urinary incontinence.