Potency Assay Development: A Keystone for Clinical Use.

Potency can be described as the quantitative measure of biological activity, that is, the ability of an Advanced Therapy Medicinal Product (ATMP) to elicit the intended effect necessary for clinical efficacy. Potency testing is part of the quality control strategy necessary for batch release and is required for market approval application of an ATMP. Thus, it is crucial to develop a reliable and accurate potency assay.

Skeletal Muscle-Derived Cell Implantation for the Treatment of Fecal Incontinence: A Randomized, Placebo-Controlled Study.

Background And Aims: Fecal incontinence (FI) improvement following injection of autologous skeletal muscle-derived cells has been previously suggested. This study aimed to test the efficacy and safety of said cells through a multicenter, placebo-controlled study, to determine an appropriate cell dose, and to delineate the target patient population that can most benefit from cell therapy.

Methods: Patients experiencing FI for at least 6 months were randomized to receive a cell-free medium or low or high dose of cells.

Myogenic progenitor cell transplantation for muscle regeneration following hindlimb ischemia and reperfusion.

Background: Muscle is severely affected by ischemia/reperfusion injury (IRI). Quiescent satellite cells differentiating into myogenic progenitor cells (MPC) possess a remarkable regenerative potential. We herein established a model of local application of MPC in murine hindlimb ischemia/reperfusion to study cell engraftment and differentiation required for muscle regeneration.

Generation of myogenic progenitor cell-derived smooth muscle cells for sphincter regeneration.

Background: Degeneration of smooth muscles in sphincters can cause debilitating diseases such as fecal incontinence. Skeletal muscle-derived cells have been effectively used in clinics for the regeneration of the skeletal muscle sphincters, such as the external anal or urinary sphincter. However, little is known about the in vitro smooth muscle differentiation potential and in vivo regenerative potential of skeletal muscle-derived cells.

Skeletal muscle-derived cell implantation for the treatment of sphincter-related faecal incontinence.

Background: In an earlier pilot study with 10 women, we investigated a new approach for therapy of faecal incontinence (FI) due to obstetric trauma, involving ultrasound-guided injection of autologous skeletal muscle-derived cells (SMDC) into the external anal sphincter (EAS), and observed significant improvement. In the current study, we tested this therapeutic approach in an extended patient group: male and female patients suffering from FI due to EAS damage and/or atrophy. Furthermore, feasibility of lower cell counts and cryo-preserved SMDC was assessed.

Development of an in vitro potency assay for human skeletal muscle derived cells.

Background: Potency is a quantitative measure of the desired biological function of an advanced therapy medicinal product (ATMP) and is a prerequisite for market approval application (MAA). To assess the potency of human skeletal muscle-derived cells (SMDCs), which are currently investigated in clinical trials for the regeneration of skeletal muscle defects, we evaluated acetylcholinesterase (AChE), which is expressed in skeletal muscle and nervous tissue of all mammals.

Methods: CD56+ SMDCs were separated from CD56- SMDCs by magnetic activated cell sorting (MACS) and both differentiated in skeletal muscle differentiation medium.

Autologous fibroblast transplantation at the vesico-ureteral junction as potential reconstructive cell replacement in an animal model.

Purpose: To evaluate the cellular survival of donor fibroblasts after transplantation at the vesico-ureteral junction (VUJ) and to analyse their potential for reconstructive cell replacement in an animal model as autologous fibroblasts have been used as soft tissue augmentation material for scared and damaged tissue.

Methods: Muscles biopsies were procured from the lower limb muscles of 4 pigs; cytoplasm of fibroblasts was labelled with nano-sized iron oxide particles. Six weeks after taking of the muscle biopsies, fibroblast transplantation was performed, 3 × 10(6) cells suspended in transplantation medium (in 1-ml syringes) were injected at the VUJ using the modified STING technique.

Can autologous myoblasts be used as a potential bulking agent?

Objective: To investigate the behaviour of donor myoblasts at the vesico-ureteric junction (VUJ) and to evaluate their potential as an autologous bulking agent, as myoblast transplantation has been shown to regenerate damaged or degenerated tissue, and it was postulated that they could be used to treat vesico-ureteric reflux.

Materials And Methods: Muscle biopsies were obtained from the lower limb muscles of 10 pigs. The quality of the cells was evaluated by electrophysiological and immunohistochemical tests.

Myoblast and fibroblast therapy for post-prostatectomy urinary incontinence: 1-year followup of 63 patients.

Purpose: We assessed the efficacy and safety of the application of autologous fibroblasts and myoblasts for treatment in post-prostatectomy urinary incontinence after a minimal followup of 1 year.

Materials And Methods: Sixty-three patients with stress urinary incontinence after radical prostatectomy were treated with transurethral ultrasound guided injections of autologous fibroblasts and myoblasts obtained from skeletal muscle biopsies. All subjects were evaluated preoperatively and 12 months postoperatively in terms of incontinence and Quality of Life Instrument scores, urodynamic parameters, and morphology and function of the urethra and rhabdosphincter.

Autologous myoblasts and fibroblasts for female stress incontinence: a 1-year follow-up in 123 patients.

Objective: To assess the efficacy and safety of the application of autologous myoblasts and fibroblasts for treating female stress urinary incontinence (SUI) after a follow-up of >/=1 year.

Patients And Methods: In all, 123 women with SUI (aged 36-84 years) were treated with transurethral ultrasonography-guided injections with autologous myoblasts and fibroblasts obtained from skeletal muscle biopsies. The fibroblasts were suspended in a small amount of collagen as carrier material and injected into the urethral submucosa, while the myoblasts were implanted into the rhabdosphincter.

Adult stem cell therapy of female stress urinary incontinence.

Objectives: To investigate the efficacy of transurethral ultrasound (TUUS)-guided injections of autologous myoblasts and fibroblasts in women with incontinence.

Methods: Between January and June 2005, 20 female patients suffering from stress urinary incontinence (SUI) were included. Skeletal muscle biopsies were taken from the left arm to obtain cultures from autologous fibroblasts and myoblasts.

Autologous myoblasts and fibroblasts versus collagen for treatment of stress urinary incontinence in women: a randomised controlled trial.

Background: Preclinical studies have suggested that transurethral injections of autologous myoblasts can aid in regeneration of the rhabdosphincter, and fibroblasts in reconstruction of the urethral submucosa. We aimed to compare the effectiveness and tolerability of ultrasonography-guided injections of autologous cells with those of endoscopic injections of collagen for stress incontinence.

Methods: Between 2002 and 2004, we recruited 63 eligible women with urinary stress incontinence.

Functional and histological changes after myoblast injections in the porcine rhabdosphincter.

Objective: Transurethral ultrasound-guided injection of autologous myoblasts has recently been shown to cure urinary stress incontinence. In the present study, the dose-dependent changes in maximal urethral closure pressures after application of myoblasts were investigated in a porcine animal model.

Methods: Myoblast cultures were grown from a porcine muscle biopsy.

Structural determinants of L-type channel activation in segment IIS6 revealed by a retinal disorder.

The mechanism of channel opening for voltage-gated calcium channels is poorly understood. The importance of a conserved isoleucine residue in the pore-lining segment IIS6 has recently been highlighted by functional analyses of a mutation (I745T) in the Ca(V)1.4 channel causing severe visual impairment (Hemara-Wahanui, A.

A CACNA1F mutation identified in an X-linked retinal disorder shifts the voltage dependence of Cav1.4 channel activation.

Light stimuli produce graded hyperpolarizations of the photoreceptor plasma membrane and an associated decrease in a voltagegated calcium channel conductance that mediates release of glutamate neurotransmitter. The Ca(v)1.4 channel is thought to be involved in this process.

Intramyocardial microdepot injection increases the efficacy of skeletal myoblast transplantation.

Objective: Recent progress in the field of cellular cardiomyoplasty has opened new prospects for the treatment of ischemic heart disease and currently moves from bench to bedside. The aim of the present study was to develop a novel cell delivery technique, reducing target tissue damage and improving cell dispersion and engraftment.

Methods: In 30 male Fischer F344 rats an infarction of the left ventricle was generated by ligation of the left anterior descendent artery.

Membrane properties of single muscle cells of the rhabdosphincter of the male urethra.

Background: The electrophysiological properties of myoblast cultures established from the human and porcine rhabdosphincter (RS) and porcine lower limb muscle (LLSKM) were studied to elucidate their potential for tissue engineering applications in the lower urinary tract.

Methods: Muscle biopsies were collected from the prostatic part of the RS, the RS of male pigs, and the porcine LLSKM. Ion channels were studied by means of the patch-clamp technique.