# Development of UROGRAFT: A Bladder Acellular Matrix-Based Composite for Advanced Cystoplasty, Highlighting the Role of Graft Shape and Composition

## TL;DR

Researchers developed UROGRAFT, a new bladder graft material that could replace gastrointestinal segments in bladder augmentation surgeries.

## Contribution

The novel UROGRAFT composite combines bladder acellular matrix with collagen and cellulose, optimized for biocompatibility and graft shape.

## Key findings

- A Triton X-100 and SDS decellularization protocol effectively removed cells while preserving ECM structure.
- Cross-linking with collagen and cellulose improved scaffold properties and reduced porosity.
- Preclinical trials in pigs showed UROGRAFT is biocompatible, safe, and supports cell growth for potential tissue engineering.

## Abstract

Urinary bladder augmentation with gastrointestinal segments,
despite
many complications, remains a gold standard treatment of low-capacity,
poorly compliant, or refractory overactive urinary bladder. In this
study, we developed the UROGRAFT, a new bladder acellular matrix–collagen–cellulose
(BAM–CC) composite for urinary bladder augmentation. The study
presents the step-by-step development process of UROGRAFT, including
the selection of an optimal decellularization protocol and cross-linking
method to ensure optimal biomaterial properties. Histological and
biochemical analyses demonstrated that the combined protocol of Triton
X-100 and sodium dodecyl sulfate (SDS) was the most effective, completely
removing cellular components while preserving the extracellular matrix
(ECM). DNA quantification confirmed a significant reduction in residual
genetic material, ensuring a low immunogenic profile. Scanning electron
microscopy (SEM) confirmed high porosity and well-preserved collagen
fibers. To reduce porosity and permeability, BAM was cross-linked
with collagen type I and dialdehyde carboxymethyl cellulose, optimizing
scaffold performance. Biocompatibility tests confirmed the absence
of toxicity, tissue reactions, acute systemic toxicity, and mutagenic
effects. Based on computational modeling, verified by implantation
trials, a unique three-armed graft shape resembling lily petals was
developed. A preclinical study in porcine models demonstrated that
UROGRAFT is highly biocompatible, well-tolerated, and safe for urinary
bladder augmentation. Composite BAM–CC scaffolds provide an
appropriate environment for adipose derived mesenchymal stromal cells
(AD-MSCs) growth; therefore, the UROGRAFT can be used in the future
as an acellular graft (biomedical device) or a cell-seeded tissue-engineered
product (combined ATMP-biomedical device). UROGRAFT developed in this
study is a promising new product with the potential to be used in
augmentation cystoplasty, offering a safe and effective alternative
to gastrointestinal segments.