Stem and progenitor cell compositions recovered from bone marrow or cord blood; system and method for preparation thereof
The invention includes compositions of stem and progenitor cells recovered from bone marrow or cord blood containing most of the viable CD34+ cells and substantially depleted of red blood cells resident in the original sample, without any xenobiotic additives to aid cell separation. The invention also includes a system and method for preparing the compositions. The system includes a bag set and a processing device, which utilizes an optical sensor, microcontroller, servo motor, accelerometer, load cell, and battery. The system and method utilize centrifugation to stratify the cells into layers and then separate and transfer the stem cells into a stem cell bag. The processing device's microcontroller receives input from the device's accelerometer, load cell and optical sensor to direct the metering valve in the bag set to open and close to permit the transfer of as many stems cells as possible with as few red cells as possible.
1. A method of preparing a stem cell composition from bone marrow or cord blood, comprising:
a. placing collected bone marrow or cord blood into a processing bag, wherein said processing bag is part of a bag set which also includes a red blood cell concentrate bag, a stem cell bag, and a metering valve, and further, wherein said metering valve is connected to said processing bag, said red blood cell concentrate bag, and said stem cell bag;
b. placing said bag set into a processing device, wherein said processing device includes a microcontroller, a servo motor, an optical sensor, an LED, a load cell, and an accelerometer, wherein said servo motor is operatively coupled to said metering valve when said bag set is contained in said processing device;
c. centrifuging said processing device containing said bag set at a g force and for a time sufficient to stratify the cells of said bone marrow or cord blood in said processing bag into a layer of red blood cells, a layer of WBC/stem and progenitor cells, and a layer of plasma, wherein said metering valve is closed;
d. centrifuging said processing device containing said bag set at a g force that is lower than the g force used in said stratifying step and for a time sufficient to separate most of said red blood cells from said processing bag into said red blood cell concentrate bag, wherein said metering valve is open from said processing bag to said red blood cell concentrate bag;
e. causing said metering valve to close in response to said optical sensor detecting a preset amount of light transmittance from said LED;
f. centrifuging said processing device containing said bag set at a g force and for a time sufficient to separate more of said red blood cells from said processing bag into said red blood cell concentrate bag, wherein said metering valve opens and closes multiple times in succession;
g. causing said metering valve to close in response to said optical sensor detecting a preset rate of change of light transmittance;
h. taring said stem cell bag to zero, wherein said taring is performed using data from said load cell;
i. centrifuging said processing device containing said bag set at a g force and for a time sufficient to separate the remaining red blood cells, said WBC/stem and progenitor cell layer, and some of said plasma from said processing bag into said stem cell bag, wherein said metering valve opens and closes multiple times in succession;
j. causing said metering valve to close in response to said load cell measuring a preset weight of said stem cell bag;
k. removing said bag set from said processing unit; and
l. removing said stem cell bag containing said stem cell composition from said bag set.
2. The method of claim 1 , further comprising, between steps (e) and (f), centrifuging said processing device containing said bag set at a g force and for a time sufficient to restratify the cells of said bone marrow or cord blood in said processing bag into a layer of red blood cells, a layer of WBC/stem and progenitor cells, and a layer of plasma, wherein said metering valve is closed.
3. The method of claim 1 , further comprising selecting the volume of said stem cell composition in advance.
4. The method of claim 3 , wherein said selected volume is determined by selecting the weight of said stem cell composition in said stem cell bag.
5. The method of claim 1 , wherein the volume of said collected bone marrow is about 40 mL to about 240 mL.