Method for proliferation of cells within a bioreactor using a disposable pumphead and filter assembly
A method for promoting biological activity uses a filter system to increase cell production of a fed batch bioreactor. The filter system cycles bioreactor fluid through a hollow fiber tangential flow filter which separates metabolic wastes (as well as proteins) from cells produced in bioreactor and returned to fed batch bioreactor, improving cell production in the fed batch bioreactor. The filter system includes a disposable pump and filter, and a reusable control system. The pump is a low shear gamma stable pump gently cycling bioreactor fluid through the filter with minimal damage to the cells produced in the bioreactor. The pumphead and hollow fiber tangential flow filter are disposable. The pump motor is part of the control system and is reusable. The pumphead and filter are provided as an assembled and pre-sterilized unit allowing simple and quick attachment to the fed batch bioreactor, and simple and quick disposal.
1. A method of assembling a system for tangential flow perfusion filtering, the system comprising
(a) a bioreactor vessel containing bioreactor fluid, the bioreactor fluid comprising cells residing in the bioreactor vessel, the cells including cells produced in the bioreactor vessel and additional material residing in the bioreactor vessel including at least one of waste material, expressed proteins, and viruses of interest,
(b) a first bioreactor fluid flow tubing in fluid communication with the bioreactor vessel,
(c) bioreactor return tubing in fluid communication with the bioreactor vessel,
(d) a disposable pumphead and tangential flow filter unit wherein the pumphead and tangential flow filter unit are assembled and pre-sterilized, configured for attachment to the bioreactor vessel and comprising in serial order of flow:
a first aseptic connector sealed by a first cap;
a second bioreactor fluid flow tubing connected to the first aseptic connector;
the disposable pumphead connected to the second bioreactor fluid flow tubing;
a third bioreactor fluid flow tubing connected to the disposable pumphead;
the tangential flow filter unit connected to the third bioreactor fluid flow tubing;
permeate tubing connected to a permeate port of the tangential flow filter unit;
a retentate return tubing connected to a retentate port of the tangential flow filter unit; and
a second disposable aseptic connector connected to the retentate return tubing and sealed by a second cap, and
(e) a reusable control system including a reusable pump motor configured for cooperation with the disposable pumphead;
the method of assembling the system consisting of:
attaching the assembled, pre-sterilized pumphead and tangential flow filter unit to the bioreactor vessel, wherein the assembled, pre-sterilized pumphead and tangential flow filter unit includes said first aseptic connector and said second aseptic connector, by:
removing the first cap from the first aseptic connector;
aseptically connecting the first bioreactor fluid flow tubing to the first aseptic connector;
removing the second cap from the second aseptic connector;
aseptically connecting the bioreactor return tubing to the second aseptic connector;
engaging the disposable pumphead with the reusable pump motor;
the disposable pumphead circulating the bioreactor fluid through the tangential flow filter; thereby separating the bioreactor fluid into a retentate flow comprising the cells that is returned from the tangential flow filter unit through the retentate return tubing to the bioreactor vessel and a permeate flow comprising the additional material that is removed from the tangential flow filter unit through the permeate tubing; and
optionally, connecting a permeate pump to the permeate tubing to draw the permeate flow from the tangential flow filter unit.
2. The method of claim 1 , wherein the tangential flow filter unit includes pore membranes greater than 0.1 micron which remove the additional material.
3. The method of claim 2 , wherein tangential flow filter unit is a Modified Polyether Sulfone (mPES) membrane hollow fiber tangential flow filter.
4. The method of claim 1 , wherein the disposable pumphead is a low shear disposable pumphead.
5. The method of claim 4 , wherein the disposable pumphead is a low shear, gamma stable, disposable pumphead.
6. The method of claim 5 , wherein the disposable pumphead is a levitating pumphead.
7. The method of claim 1 , wherein the second fluid flow tubing, third fluid flow tubing and retentate return tubing are flexible tubings allowing easy assembly of the system.