Login to Access Video or Poster Abstract: MP94-06
Sources of Funding: National Natural Science Foundation of China?81370860?81670622?

Introduction

Confronted by the limitations of current biomaterials applied in bladder augmentation and urgent clinic needs of alternatives for traditional enterocystoplasty, this study compared the performance of a novel asymmetric bilayer chitosan scaffold with conventional bladder acellular matrix graft (BAMG) in the purpose to assess the feasibility of this strategy as a supplement or replacement for current bladder biomaterials.

Methods

Twenty-four 4-week-old male Sprague-Dawley rats were randomly divided into 3 groups which were subjected to augmentation cystoplasty with BAMG, bilayer chitosan scaffolds and sham operation respectively, with 8 rats in each group. At the time-points of 21 days and 70 days post-implantation, basic epidemiological data, morphological, histological (hematoxylin and eosin, Masson’s trichrome and immunofluorescence analyses) and functional evaluations were carried out to compare bladder regeneration comprehensively.

Results

Bilayer chitosan scaffold exhibited an excellent combination of mechanical strength and flexibility, with minimal fibrosis and contracture after integrated into bladder defect. All rats survived during the experimental period, recovered to normal activities and were able to void spontaneously without significant difference in body weight, except that one rat in BAMG group (70 days group) died of urinary ascites within first week post-op. It was proved that bilayer chitosan scaffold had a better performance in both histological staining and morphological analyses of cystography. While the de novo cytokeratin positive urothelia appeared more abundant in BAMG group than chitosan group when compared to control group, the regeneration of ?-smooth muscle actin (?-SMA) and SM22-? positive smooth muscle bundles, NeuN positive neural buttons, the mean number of CD31 positive vessels were more favorable in chitosan group than BAMG group, but still did not catch up with the normal level. The mean diameter of CD31 positive vessels revealed that the neo-vessels in BAMG and chitosan group were relatively immature. For both BAMG and chitosan groups, urodynamic analyses demonstrated that the bladder compliance was improved after augmentation, and the interval void cycle time, void volume and bladder capacity were elevated correspondingly, while the peak void pressure of BAMG was exceptionally high.

Conclusions

The asymmetric bilayer chitosan scaffold displayed a high potential in facilitating defect regeneration in the rat model of bladder augmentation, which still need further modifications in enhancing the regeneration of urothelia, accelerating re-innervation and promoting neo-angiogenesis.

Funding

National Natural Science Foundation of China?81370860?81670622?