[In vitro generation of a human bladder wall substitute by tissue engineering]

Certain urological congenital conditions, such as bladder exstrophy and acquired conditions such as trauma and tumors may require the use of different tissues like small bowel, sigmoid colon or stomach for bladder reconstruction. However, these tissues are often associated to important complications. The aim of this study is to develop a novel substitute of the human bladder wall by tissue engineering.

We first generated primary cell cultures of epithelial and stromal bladder mucosa cells from small tissue biopsies of human bladder by using enzymatic methods based on trypsin-EDTA and collagenase I. Then, a three-dimensional substitute of the bladder mucosa was generated using fibrin-agarose biomaterials. The analysis of the tissue substitutes was carried out at day 14th of development by histological examination of samples stained with hematoxylin-eosin.

The use of enzymatic digestion methods allowed us to efficiently generate primary cell cultures of the human bladder epithelial and stromal cells. The proliferation rate was higher in stromal cells as compared to epithelial cells. Once the bladder mucosa substitutes were generated, a good biocompatibility of the stromal and epithelial cells into the biomaterial was found. The histological structure of the bladder wall substitutes was analogue to that of the native human bladder mucosa.

The bladder mucosa substitute generated by tissue engineering showed structural and histological similarities with the native human bladder tissues and open the door to the future therapeutic use of these bioengineered tissues.