bio-artificial liver (extracorporeal temporary liver support devices) alan golde jr. bme181 march 18...
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Bio-Artificial Liver(Extracorporeal temporary liver support devices)
Alan Golde Jr.
BME181
March 18th 2013
The Liver• Largest internal organ
• From 1.2-1.6kg (3.2-3.7lb)
• Hepatic cells (hepatocytes) responsible for liver functions
• Make up 80% of the liver
• Liver is responsible for up to 500 separate functions
• Removing/excreting body wastes and hormones as well as drugs and other foreign substances
• Synthesizing plasma proteins, including those necessary for blood clotting
• Helping the body fight infection• Producing bile to aid in digestion• Storing certain vitamins, minerals, and sugars
• Regenerative• Restoration of function not original form
Complications• Most common causes of liver failure
• hepatitis A,B,C,D,E• Alcohol damage • Fatty liver • Cirrhosis • Cancer and drug damage
TreatmentsLiver Transplant
• Pros• Most effective treatment for acute liver failure• High survival rates
• Cons• Scarcity of donors• Reduced clotting factors• Immunosuppressant's increase risk for infection• Rejection
Bio-artificial Liver• Pros
• Keep the patient alive until transplant is available• Aid in the livers regeneration
• Cons• Are only a temporary fix
Current Work in BAL’s• Molecular Absorbent Recycling System (MARS®)
• Teraklin, uses human albumin
• Extracorporeal Liver Assist Device (ELAD®)• Vitagen, uses immortalized human hepatocytes
• HepatAssist 2000 system• Circe Biomedical, uses porcine hepatocytes
• Bioartificial Liver Support System (BLSS®)• Excorp Medical, Inc., uses primary porcine hepatocytes
• LIVERX2000 system• Algenix, Inc., uses porcine hepatocytes
• Modular Extracorporeal Liver System (MELS®)• Charite Virchow Clinic-Berlin, uses human hepatocytes
Bio Engines Implantable Device
•Designed to take place of a liver or a portion of the liver•Polymer grid-like mesh used as artificial vasculature resembling that of an actual liver•Patterned silicon wafers serve as molds for polymer sheets•Currently being tested on pigs •Clotting issues
Challenges• Bio-artificial livers should be able to provide at least 10% of liver functioning
• This requires approximately 1010 hepatocytes
• Very difficult acquiring this many hepatocyte cells• Controversy over the use of porcine cells due to possible transmission of
infections• Hepatocytes and plasma have very different physio-chemical properties
• Hepatocytes do not perform well when in contact with plasma • Have a very high oxygen uptake rate
• Hepatocyte cells undergo a lot of stress inside of bio-artificial liver• Any stress above 5 dyn/cm2 renders cells useless
• Limited volume of the bioreactor• maximum blood/plasma that can be safely drawn out of liver failure patient is one liter• Difficult to achieve 10% of liver functioning within 1 liter
• Makes Bio-artificial liver designing very difficult
Future• Research in:
• Cell sources• Bioreactor design• Filtering techniques • Packaging for implantable devices
Sources• http://biomed.brown.edu/Courses/BI108/BI108_2002_Groups/liver/we
bpage/intro.html
• Palakkan, A. A., Hay, D. C., PR, A. K., TV, K. and Ross, J. A. (2013), Liver tissue engineering and cell sources: issues and challenges. Liver International. doi: 10.1111/liv.12134
• http://www.xconomy.com/boston/2007/09/20/bioengine-one-step-closer-to-artificial-liver-device/
• http://nyp.org/news/hospital/artificial-liver-lives.html• http://artificial-liver.blogspot.com/2009/11/biological-extracorporeal-
liver-assist.html