Designing the Biocompatibility of Biohybrids - Tissue Engineering: Cell-Surface Interactions for Tissue Culture - page 292

tubular epithelial cells growing on semi-permeable hollow fibres were developed
[ 35 , 36 ], mostly as an external device for hemopurification. Inevitably, these are
mostly technical driven developments and most innovations occur with respect to
the engineering of the membrane compartment [ 37 ]. While kidney biohybrid
devices are already in clinical use, the development of an effective liver assistance
technology remains challenging [ 38 ].
4.2.3 Pancreas Biohybrids
Worldwide, diabetes is one of the most widespread diseases, causing enormous
costs burdening social health systems and affecting the quality of life of the
affected people. It is not astonishing that the therapeutic treatment of diabetes is in
the focus not only of pharmaceutical companies but also in basic science,
especially because the aetiology of diabetes is well known. Although the reasons
and consequences of diabetes may be complex and manifold, the main focus of
biohybrid research lies on engineering cells which form the islets of Langerhans.
Great success has been achieved with the transplantation of islets of Langerhans
from donors; however, this method is limited by the availability of donor tissue
and problems of transplant rejection, since current immunosuppressive regimes
do not prevent graft rejection [ 39 ]. Therefore current research is focussing on
producing islet cells from different stem cell sources and to develop an encapsu-
lated cell therapy in the shape of a bioartificial pancreas, protecting the grafted
cells from the host immune system [ 40 ].
4.2.4 Cardiovascular Biohybrids
In the cardiovascular system, regenerative medicine concentrates on the cure of
cardiomyocyte loss using stem cells of different origins [ 41 , 42 ], permanent or
biodegradable stents [ 43 ] with or without drug-eluting capacities to prevent e.g.
restenosis [ 44 ] and tissue engineered vessels [ 45 ]. Here, synthetic non-degradable
polymers, partly with functionalized surfaces, are used as well as degradable
polymeric scaffolds and biopolymers. In combination with bioactive molecules,
these scaffolds are able to promote and guide vascular regeneration processes [ 46 ]
which lead to cellular colonization and finally to the replacement of the artificial
graft by autologous cells and extracellular matrix.
4.2.5 Musculoskeletal Biohybrids
The structural component is of main interest in musculoskeletal biohybrids, since
these biohybrid systems are mechanically challenged implants with or without
functionalized surfaces in orthopaedic and dental applications. These functional-
ized surfaces may contain elements of the extracellular matrix, ceramics, ions or