The MRI assessment of intraurethrally--delivered muscle precursor cells using anionic magnetic nanoparticles.

Autografting of cultured myogenic precursor cells (MPC) is a therapeutic strategy for muscle disorders, including striated urethral sphincter insufficiency. Implantation of myofibers with their satellite cells into the urethra is a recently described method of MPC transfer aimed at generating a new sphincter in incontinent patients. In this study, we magnetically labeled muscle implants with dextran-free anionic iron oxide nanoparticles (AMNP).

Intraurethral transfer of satellite cells by myofiber implants results in the formation of innervated myotubes exerting tonic contractions.

Purpose: We investigated a new method of muscle precursor cell transfer in the urethra for the treatment of urinary incontinence, consisting of implanting myofibers with their satellite cells.

Materials And Methods: In preliminary experiments to test the regenerative capacities of satellite cells histological analysis was performed on days 7 and 30 after the implantation of myofiber cores in the urethra of 6 female pigs. In the main experiments 11 pigs underwent baseline urodynamics, followed by endoscopic destruction of the striated urethral sphincter located around the distal urethra (day 0).

The striated urethral sphincter of the pig shows morphological and functional characteristics essential for the evaluation of treatments for sphincter insufficiency.

Purpose: New treatments are currently under investigation for intrinsic sphincter insufficiency. However, animal models in which to study the resting urethral tone generated by the striated urethral sphincter are still lacking. We describe the striated urethral sphincter in the pig.

[Cell therapy for urethral sphincter incompetence by muscle precursor cell autograft].

This article reviews cell therapy for muscle diseases and describes the development of a treatment for urethral sphincter insufficiency by muscle precursor cell (MPC) autograft. These studies were conducted in several successive steps, comprising: 1) comparative study of the cellular mechanisms of regeneration of skeletal striated muscle and urethral striated sphincter and development of a method of extraction of MPC; 2) creation of an animal model of sphincter injury reproducing chronic denervation lesions and fibrosis responsible for sphincter insufficiency in human; 3) study of the biology of intrasphincteric transplantation of MPC extracted from peripheral muscle, taking into account the interactions between these cells and the peripheral nervous system.