hepatitis. The only way to sustain an acute or chronic liver failure is a liver
transplant. Liver transplant faces same problems as other organ transplants, such
as organ shortage or suitable donor availability. Therefore, in this case too, there is a
need of development of artificial liver that may help in rejuvenating the life of a
patient with acute or chronic liver failure.
Nowadays, with the advancements in membrane science, the development of an
artificial liver is made possible. The previously used blood purification techniques,
like hemofiltration, hemodialysis, hemoperfusion, and plasmapheresis, are seldom
used alone. Initially, cellophane and polyacrylonitrile membranes, with high rejection of lower molecular weight toxins, were used to detoxify the body. However,
recently with the advancements and developments in the field of membrane science,
various advanced processes and devices are into use, namely, molecular adsorbent
recirculation system (MARS), single-pass albumin dialysis (SPAD), and the Prometheus system [1, 27]. These advanced systems employ novel materials made up of
charcoal and polymers for the detoxification process. Hollow fiber membranes with
high flux are the choice for said processes and devices. For example, polysulfone
hollow fiber membranes with molecular weight cutoff of 50 kDa are used in MARS
and SPAD along with albumin dialysis. However, the Prometheus system employs a
250 kDa molecular weight cutoff albumin permeable polysulfone membrane. These
systems and processes show effective and efficient results over a short period of
time. Therefore, these membrane-based systems play an important role and provide a
patient time to arrange an organ or suitable donor in case of an acute or chronic liver
failure. Nevertheless, these systems are not able to carry out other functions of the
liver; therefore, there is a need to develop bioartificial liver.
Recently, the bioartificial liver system based on the hepatoma cells (primary
hepatocytes) attached over the surface of a flat or hollow fiber membrane is developed. This system is termed as bioartificial liver support (BALS) system. Polyether
ether ketone, polyethersulfone, and polytetrafluoroethylene are some of the commonly used membrane materials for culturing the hepatoma cells. The membranes
are fundamental part of the BALS system. Hydrophilic and hydrophobic membranes
are employed for better mass and gas transport, respectively, in the system to
successfully carry out the function of a liver. However, there is still scope for further
improvement and development to make the artificial liver truly a natural liver.
Similarly, membrane-based systems are used to develop other important organs,
namely, lungs and pancreas as reported by Purkait and Singh [1].
5.2 Drug Delivery
The effective and efficient treatment of a disease depends upon the proficient
delivery of the required drug dose. The conventional methods use oral or intravenous
administration. This method offers drug delivery only at a particular time. This
results in high drug usage, and the patient has to take the drug regularly over a
20
R. Singh et al.
transplant. Liver transplant faces same problems as other organ transplants, such
as organ shortage or suitable donor availability. Therefore, in this case too, there is a
need of development of artificial liver that may help in rejuvenating the life of a
patient with acute or chronic liver failure.
Nowadays, with the advancements in membrane science, the development of an
artificial liver is made possible. The previously used blood purification techniques,
like hemofiltration, hemodialysis, hemoperfusion, and plasmapheresis, are seldom
used alone. Initially, cellophane and polyacrylonitrile membranes, with high rejection of lower molecular weight toxins, were used to detoxify the body. However,
recently with the advancements and developments in the field of membrane science,
various advanced processes and devices are into use, namely, molecular adsorbent
recirculation system (MARS), single-pass albumin dialysis (SPAD), and the Prometheus system [1, 27]. These advanced systems employ novel materials made up of
charcoal and polymers for the detoxification process. Hollow fiber membranes with
high flux are the choice for said processes and devices. For example, polysulfone
hollow fiber membranes with molecular weight cutoff of 50 kDa are used in MARS
and SPAD along with albumin dialysis. However, the Prometheus system employs a
250 kDa molecular weight cutoff albumin permeable polysulfone membrane. These
systems and processes show effective and efficient results over a short period of
time. Therefore, these membrane-based systems play an important role and provide a
patient time to arrange an organ or suitable donor in case of an acute or chronic liver
failure. Nevertheless, these systems are not able to carry out other functions of the
liver; therefore, there is a need to develop bioartificial liver.
Recently, the bioartificial liver system based on the hepatoma cells (primary
hepatocytes) attached over the surface of a flat or hollow fiber membrane is developed. This system is termed as bioartificial liver support (BALS) system. Polyether
ether ketone, polyethersulfone, and polytetrafluoroethylene are some of the commonly used membrane materials for culturing the hepatoma cells. The membranes
are fundamental part of the BALS system. Hydrophilic and hydrophobic membranes
are employed for better mass and gas transport, respectively, in the system to
successfully carry out the function of a liver. However, there is still scope for further
improvement and development to make the artificial liver truly a natural liver.
Similarly, membrane-based systems are used to develop other important organs,
namely, lungs and pancreas as reported by Purkait and Singh [1].
5.2 Drug Delivery
The effective and efficient treatment of a disease depends upon the proficient
delivery of the required drug dose. The conventional methods use oral or intravenous
administration. This method offers drug delivery only at a particular time. This
results in high drug usage, and the patient has to take the drug regularly over a
20
R. Singh et al.