Cell Transplantation and “Stem Cell Therapy” in the Treatment of Myopathies: Many Promises in Mice, Few Realities in Humans

Figure 8

First device designed for the percutaneous transplantation of cells by a “high density injection” protocol, shown during transplantation in a nonhuman primate. This prototype delivers very small quantities of cell suspension throughout up to 6 standard disposable needles (a), from a container incorporated to the device (b). From this container, the cell suspension circulates towards the injection needles during the up and down movements of a precision syringe (c). To deliver the cells only in a muscle region and not in the skin and hypodermis, the operator can set the adjustable foot (d) to leave the needle length necessary to go through the skin and hypodermis (estimated by ultrasound analysis). The amplitude of the needles excursion into the muscle can be set between 0 and 3.5 cm by turning a knob (e), using the indicator of injection depth as a reference (f). The operator introduces then the needles until the foot touches the skin surface (d). At that moment, the needles tips should be at the muscle surface. Pressing a pushbutton (g), the needles penetrate the muscle, and the precision syringe (c) is filled with cell suspension. Once the needles reach the depth of injection set in (f), they are automatically retracted to their original position. The cells are homogeneously delivered in the needles trajectory during this retraction. The operator withdraws the needles and restarts the sequence in another position. Two valves (h) control the appropriate direction of circulation of the cell suspension. Container, syringe, and needles are linked by a plastic support (i) that includes the flow divisor. An electromechanical system into the device’s body governs the injection sequence.