Purinergic ecto-enzymes in human and ovine aortic valves: indicators of bacterial nanocellulose scaffold cellularization

Purinergic signalling pathways play a vital role in the biological functions of the aortic valve (AV) through nucleotide and adenosine-dependent receptor effects. This study focused on characterizing a side-specific purinergic cascade in human non-stenotic and stenotic AVs, ovine native AVs and a novel bacterial nanocellulose (BNC) bio-prosthesis in an ovine model. Human stenotic AVs were collected during replacement surgeries, while non-stenotic AVs came from heart transplant patients. Ovine native AVs were sourced from domestic sheep, and the BNC prosthesis was implanted in the ovine aorta for six months, with hemodynamic monitoring throughout. Biochemical assessments revealed a beneficial ecto-enzyme pattern in non-stenotic and native AVs, contrasting with a detrimental pattern in stenotic valves. The BNC prosthesis demonstrated significantly lower nucleotide conversion activities than native valves and displayed increased peripheral blood mononuclear cell adhesion on its aortic surface. These findings suggest that nucleotide-converting ecto-enzymes could serve as markers for the biological activity of AV prostheses, highlighting the need for further studies to enhance the cellularization of BNC prostheses, potentially through adenosine-releasing scaffold modifications.