Device and method for performing a biological modification of a fluid

A device for performing a biological modification of a fluid of a subject, comprising:

• (a) a chamber having an inlet for intake of the fluid from the subject and an outlet for outflow of the fluid to the subject;
• (b) a collection of liver portions for performing the biological modification of the fluid, each individual liver portion of said collection including cells and having dimensions, such that cells positioned deepest within said individual liver portion are at least about 100 micrometers and not more than about 225 micrometers away from a nearest surface of said individual liver portion, said collection of liver portions being located within said chamber and said collection of liver portions being in contact with at least a portion of the fluid flowing through said chamber, wherein said collection of liver portions is cryo-preserved before being located within said chamber and further wherein viability of said collection of liver portions is maintained for at least 21 days upon operation of the device;
• (c) a first tube having first and second ends, said first end for coupling to the subject for receiving the fluid from the subject, said second end for coupling to said inlet;
• and
• (d) a second tube having first and second ends, said first end for coupling to said outlet and said second end for coupling to the subject to return the fluid to the subject after the biological modification.