As another commenter mentioned, it would be better to use the actual title of the paper "Feasibility of an implantable bioreactor for renal cell therapy using s

As another commenter mentioned, it would be better to use the actual title of the paper "Feasibility of an implantable bioreactor for renal cell therapy using silicon nanopore membranes" - because arguably this is not an "artificial kidney", but a device containing natural kidney cells (a bioreactor containing renal cells) with an added silicon nanopore membrane designed to prevent the immune system from killing the foreign kidney cells. That's why they're using the term "bioartificial kidney".