Development of a conductive biocomposite combining graphene and amniotic membrane for replacement of the neuronal network of tissue-engineered urinary bladder

J Adamowicz,M Gniadek,D Balcerczyk,I Pasternak,M Buhl,D Grzanka,M Pokrywczynska,W Strupinski,T Kloskowski,S V Van Breda,M Gagat,T Drewa

doi:10.1038/s41598-020-62197-3

Abstract

Tissue engineering allows to combine biomaterials and seeded cells to experimentally replace urinary bladder wall. The normal bladder wall however, includes branched neuronal network propagating signals which regulate urine storage and voiding. In this study we introduced a novel biocomposite built from amniotic membrane (Am) and graphene which created interface between cells and external stimuli replacing neuronal network. Graphene layers were transferred without modifying Am surface. Applied method allowed to preserve the unique bioactive characteristic of Am. Tissue engineered constructs composed from biocomposite seeded with smooth muscle cells (SMC) derived from porcine detrusor and porcine urothelial cells (UC) were used to evaluate properties of developed biomaterial. The presence of graphene layer significantly increased electrical conductivity of biocomposite. UCs and SMCs showed an organized growth pattern on graphene covered surfaces. Electrical filed stimulation (EFS) applied in vitro led additionally to increased SMCs growth and linear arrangement. 3D printed chamber equipped with 3D printed graphene based electrodes was fabricated to deliver EFS and record pressure changes caused by contracting SMCs seeded biocomposite. Observed contractile response indicated on effective SMCs stimulation mediated by graphene layer which constituted efficient cell to biomaterial interface.

Highlights

Tissue engineering allows to combine biomaterials and seeded cells to experimentally replace urinary bladder wall
The major problem hampering advances in the field of urinary bladder tissue engineering is the simplification of the targeted neobladder structure in conducted research
The graphene layer was stably placed on the amniotic membrane (Am) surface and didn’t tend to dislocate or to break during manual manipulation with the biocomposite

Summary

Introduction

Tissue engineering allows to combine biomaterials and seeded cells to experimentally replace urinary bladder wall. Regenerative medicine has developed over the last decades’ an interdisciplinary approach to urinary bladder regeneration that utilizes tissue engineering technology Following this concept, a leading scenario aims to create a neobladder by combining different biomaterials with autologous urothelial and detrusor cells. The alternative solution is to completely replace a native neural network with biocompatible current conductive material that might be linked to an external unit generating electrical stimulation[6] Before such a biocybernetics organ replacing unit may be created, there is a need to develop a biomaterial scaffold providing the interface between external stimuli and host tissue. Triggered, discharge of the dispersing action potential is the direct signal contracting the smooth muscle layer[7] On account of this two-stage mechanism, the chemical mediated stimulation could be replaced by direct electrical stimulation in the tissue-engineered bladder

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Conclusion