Srikanth R Chary

US Patent:

57285810, Mar 17, 1998

Filed:

Jun 7, 1995

Appl. No.:

8/482259

Inventors:

Richard Merrill Schwartz - San Mateo CA
Sean Newton Tucker - San Francisco CA
Srikanth Ranga Chary - Fremont CA
Suzanne Chang Kuo - Cupertino CA

Assignee:

Systemix, Inc. - Palo Alto CA

International Classification:

C12N 500
C12N 502
C12M 122

US Classification:

435385

Abstract:

The present invention provides methods and bioreactors for expanding stem cells in a population of cells substantially enriched in hematopoietic stem cells and substantially free of stromal cells. The method comprising the steps of inoculating the population of cells in an expansion container in a volume of suitable medium such that the cell density is at least about 5,000 cells/1 mL and at an initial oxygen concentration of less than 8%; adding an effective amount of at least one cytokine to cause stem cell expansion; culturing the cells under suitable conditions such that the cells condition the medium; increasing the oxygen concentration to about 20%; exchanging the medium at a rate which allows expansion of the stem cells; and culturing the cells under conditions such that the stem cells are expanded. The present invention also provides a bioreactor constructed to accomodate the operational requirements for stroma-free stem cell expansion.

US Patent:

62418947, Jun 5, 2001

Filed:

Oct 10, 1997

Appl. No.:

8/948357

Inventors:

Donald David Briggs - Scotts Valley CA
Srikanth Ranga Chary - Fremont CA
Richard Merrill Schwartz - San Mateo CA

Assignee:

Systemix - Palo Alto CA

International Classification:

B01D 3506

US Classification:

210695

Abstract:

The separation device of the invention is directed to a container having an interior surface defining a channel. The container further has an inlet and an outlet. On the interior surface of the channel are pole tips which may be in a sawtooth configuration having sharp angles facing the interior of the channel that generate a high gradient magnetic field in the channel. Within the channel may be incorporated separating material. The separating material eliminates the direct contact of cells with the magnetic pole material. The separating material, as well as the sawtooth pole tips also serves the purpose of creating a field gradient across the entire container to avoid the problem of zero field gradient in the center of the container where the velocity is greatest, and where more cells flow. The separating material is designed to cause a substantially unobstructed flow of medium through the channel so that unlabeled substances are not trapped in the separating material.

US Patent:

54095247, Apr 25, 1995

Filed:

Sep 10, 1993

Appl. No.:

8/119800

Inventors:

John A. Jensvold - Benicia CA
Srikanth R. Chary - Fremont CA
Wendy S. Jacks - Indianapolis IN
Hans R. Keller - Concord CA
Theodore L. Parker - Alpharetta GA
Damoder Reddy - Walnut Creek CA

Assignee:

The Dow Chemical Company - Midland MI

International Classification:

B01D 5322

US Classification:

96 8

Abstract:

The invention is a process for obtaining membranes having improved selectivity and recovery using a combination of heat treating and UV irradiation.