Biomedical Engineering Reference
In-Depth Information
22.
Adv Biochem Eng Biotechnol
. 2010;
115:117-43. Transport advances
in disposable bioreactors for
liver tissue engineering.
Catapano G, Patzer JF 2nd,
Gerlach JC. Department of
Chemical Engineering and
Materials, University of Calabria,
Rende (CS), Italy,
catapano@
Acute liver failure (ALF) is a devastating diagnosis
with an overall survival of approximately 60%. Liver
transplantation is the therapy of choice for ALF
patients but is limited by the scarce availability of
donor organs. The prognosis of ALF patients may
improve if essential liver functions are restored
during liver failure by means of auxiliary methods,
because liver tissue has the capability to regenerate
and heal. Bioartificial liver (BAL) approaches use
liver tissue or cells to provide ALF patients with
liver-specific metabolism and synthesis products
necessary to relieve some of the symptoms and to
promote liver tissue regeneration. The most
promising BAL treatments are based on the culture
of tissue-engineered (TE) liver constructs, with
mature liver cells or cells that may differentiate into
hepatocytes to perform liver-specific functions, in
disposable continuous-flow bioreactors. In fact, adult
hepatocytes perform all essential liver functions.
Clinical evaluations of the proposed BALs show that
they are safe, but their treatment efficacy is not
clearly proved as compared to standard supportive
treatments. Ambiguous clinical results, the time loss
of cellular activity during treatment, and the
presence of a necrotic core in the cell compartment of
many bioreactors suggest that improvement of
transport of nutrients, and metabolic wastes and
products to or from the cells in the bioreactor is
critical for the development of therapeutically
effective BALs. In this chapter, advanced strategies
that have been proposed over to improve mass
transport in the bioreactors at the core of a BAL for
the treatment of ALF patients are reviewed.
23.
Appl Microbiol Biotechnol
. 2009
Jul; 83(5):809-23. Epub 2009 Jun
2. Bioprocessing of plant cell
cultures for mass production of
targeted compounds. Georgiev
MI, Weber J, Maciuk A.
Department of Microbial
Biosynthesis and
Biotechnologies, Institute of
Microbiology, Bulgarian
Academy of Sciences, Plovdiv,
Bulgaria.
milengeorgiev@gbg.bg
More than a century has passed since the first attempt
to cultivate plant cells in vitro. During this time,
plant cell cultures have become an increasingly
attractive and cost-effective alternatives to classical
approaches for the mass production of plant-derived
metabolites. Furthermore, plant cell culture is the
only economically feasible way of producing some
high-value metabolites (e.g., paclitaxel) from rare
and threatened plants. This review summarizes
recent advances in bioprocessing aspects of plant cell
cultures, from callus culture to product formation,
with particular emphasis on the development of
suitable bioreactor configurations (e.g., disposable
reactors) for plant-cell-culture-based processes; the
optimization of bioreactor culture environments as a
powerful means of improving yields; bioreactor
operational modes (fed-batch, continuous, and
perfusion); and biomonitoring approaches. Recent
trends in downstream processing are also
considered.
