COMPOSITION AND BIOMECHANICAL PROPERTIES OF THE BLADDER ACELLULAR MATRIX GRAFT - COMPARATIVE-ANALYSIS IN RAT, PIG AND HUMAN

Objective To compare the composition and mechanical properties of the newly developed bladder acellular matrix graft (BAMG) with the normal urinary bladder in rat, pig and human. Materials and methods Rat, pig and human urinary bladders were harvested and divided into control and experimental groups. For the latter, BAMGs were prepared, and light a nd transmission electron microscopic studies performed. Strips from th e normal bladders and the BAMGs (10 in each group) were tested under t ension, and the ultimate tensile strength, maximum strain, and elastic modulus were determined from stress/strain curves. Results Both types I and III collagen, as well as elastic fibres, were observed as major components of the matrix scaffold. There were more collagen type I fi bres in the rat than in the pig and human BAMGs, whereas the pig, and particularly the human, both showed higher levels of type III collagen and elastic fibres. These different matrix scaffold patterns were con firmed by electron microscopy. Results from biomechanical testing show ed no significant differences for strength, strain or elastic modulus between BAMG and control bladder strips, except in the rat where the m aximum strain values were significantly lower.Conclusion There are var iations in the acellular matrix structure with similar biomechanical p roperties between the BAMG and the normal urinary bladder in three dif ferent species. These results may underscore the potential of the BAMG . Furthermore, this in vitro model provides a suitable method to study the mechanical properties of the urinary bladder and may serve as a d iagnostic tool for various investigations.