Pages 347–358 Preliminary study of a genetically engineered spinal cord implant on urinary bladder after experimental spinal cord injury in rats

Abstract—The objective of this study was to determine the effect of neurotrophin-secreting Schwann cell implants on the urinary bladder after spinal cord contusion. One hour after severe spinal cord contusion at the T8 to T11 level, carbon fila-ments containing nonsecreting Schwann cells, brain-derived neurotrophic factor (BDNF)-secreting Schwann cells, neu-rotrophin-3 (NT-3)-secreting Schwann cells, or Schwann cells secreting both BDNF and NT-3 were implanted into the spinal cord. Untreated spinal cord injured (SCI) rats and noncontused rats (C) were also studied. Two months after spinal cord injury, cystometry was performed and the bladders were studied using light microscopy. SCI rats had significantly increased bladder mass, thickness, and smooth muscle mass compared to C rats. Bladder capacity of SCI rats and rats with spinal cord implants were both significantly greater than that of C rats. This prelim-inary study suggests that neurotrophin-secreting Schwann cell implants may lead to improved bladder structure after spinal cord injury. Key words: bladder, capacity, compliance, nerve regenera-tion, rat, spinal cord injury, structure