Biodegradable urethral stents seeded with autologous urethral epithelial cells in the treatment of post-traumatic urethral stricture: a feasibility study in a rabbit model.
OBJECTIVE
To evaluate the adhesion and growth of rabbit urethral epithelial cells (UECs) on a biodegradable unbraided mesh urethral stent, and to assess the feasibility and effect of the cell-seeded urethral stent for treating post-traumatic urethral stricture (PTUS) in a rabbit model.


METHODS
Rabbit UECs were collected by biopsy from adult rabbit urethra and seeded onto the outer layer of a mesh biodegradable urethral stent. The growth of UECs in cell-scaffolds was assessed by scanning electron microscopy, immunohistochemical and fluorescence staining. In all, 32 male New Zealand rabbits were used, with either PTUS or uninjured, as a control group. Cell-seeded stents were implanted into the rabbits strictured urethra. The histological and immunohistochemical findings were assessed after death at 1, 2, 8, 12 and 24 weeks, respectively. The reconstruction and function were evaluated by urethroscopy and retrograde urethrography.


RESULTS
The cultured UECs adhered to the stent and grew well. Immunohistochemistry showed that the cells were stained positively for cytokeratin. At 4 weeks, vs 2 weeks, the thickness of the papillary projections of the epithelium decreased and inflammatory cell infiltration diminished. At 24 weeks the injured urethra was completely covered by integrated regeneration of three to five layers of urothelium. There was no evidence of voiding difficulty, stricture recurrence or other complications.


CONCLUSIONS
The unbraided mesh biodegradable urethral stent with autologous UECs seemed to be feasible for treating PTUS in the rabbit urethra, and provides a hopeful avenue for clinical application allowing reconstruction of PTUS.
Fu
Wei-Jun
WJ
Department of Urology, Chinese People's Liberation Army General Hospital, Military Postgraduate Medical College, Beijing, People's Republic of China. fuweijun@hotmail.com
Zhang
Xu
X
Zhang
Bing-Hong
BH
Zhang
Peng
P
Hong
Bao-Fa
BF
Gao
Jiang-Ping
JP
Meng
Bo
B
Kun
Hu
H
Cui
Fu-Zhai
FZ
D000818:Animals; D001672:Biocompatible Materials / Q000627:therapeutic use*; D004847:Epithelial Cells / Q000637:transplantation*; D005240:Feasibility Studies; D008297:Male; D011817:Rabbits; D015607:Stents; D016896:Treatment Outcome; D014525:Urethral Stricture / Q000628:therapy*
D001672:Biocompatible Materials