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BSP-20
(P)
SYNERGISTIC EFFECTS OF COMBINING UNDIFFERENTIATED ADULT STEM CELLS
AND DIFFERENTIATED CELLS FOR THE ENGINEERING OF FUNC-TIONAL BLADDER
SMOOTH MUSCLE TISSUE.
Souzan SALEMI
1
, Daniel KELLER
1
, Markus ROTTMAR
1
, Maya HORST
2
, Rita GOBET
3
, Tullio SULSER
1
and Daniel EBERLI
1
1) University Hospital Zürich, Urology, Zürich, SWITZERLAND - 2) Children's Hospital Zurich, Division of Pediatric
Urology, Pediatric Surgery, Zürich, SWITZERLAND - 3) Children's Hospital Zurich, Children's Hospital Zurich, Pediatric
Surgery, Zürich, SWITZERLAND
PURPOSE
Engineered tissues for bladder augmentation or substitution would allow circumventing the side effects of using bowel
tissue for reconstruction. Tissue engineering using a combination of cells may provide novel approach for functional
reconstruction. Adipose derived stem cells (ADSC) might be a key instrument to bioengineer contractile bladder tissue
when differentiated to smooth muscle cells (SMC). However, it is uncertain whether these cells maintain their cell faith
long term in vivo. It is our aim to evaluate different combinations of cells to improve the bladder tissue formation, by
improving the microenvironment and cell-to-cell interactions.
MATERIAL AND METHODS
We have characterised rat ADSCs and optimally differentiated them to SMC (3 weeks) prior to subcutaneous injection
into nude mice. Cells were injected in different combinations (ADSC, ADSC + differentiated ADSC, SMC, differentiated
ADSC + SMC). The tissue formation was followed by MRI and PKH labelling. The formed tissue was analysed for
contractile proteins measuring gene and protein expression by using RT-qPCR, Western Blot and immunohistochemistry.
RESULTS
In all experimental conditions, the PKH positive cells could be detected after 4 weeks, indicating the presence and
survival of engineered tissues in vivo. MRI was able to visualize the engineered SM tissue over the study period.
Collagen without cells showed no signal and was absorbed quickly. The tissue size differed between the experimental
conditions with tissues grown from cells with 3 week ex vivo differentiation showing the largest constructs with good
correlation in histology. Differentiated ADSC showed positive upregulation of smooth muscle makers (Calponin,
Smoothelin, MYH 11 and αSMA) similar to bladder derived SMC.
CONCLUSIONS
The presented research offers key information on survival and functionality of bioengineered smooth muscle tissue
grown using differentiated ADSC in combination with differentiated cells. This approach could help to engineering
contractile bladder tissue for future clinical application.