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Stem cell magnetic separation-microfluidics
During 2004-2005, the first microfluidics structures using PDMS molds and a 40um thick resist were fabricated at INESC MN (see Fig.6). Particle flow through 40um high channels was monitored by integrating spin valve sensors in the flow lines.
A new project started in 2006, where a lab on chip for Stem Cell separation and differerntiation monitoring is being developed. This work aims to establish and develop a novel separation and purification method for hematopoietic stem/progenitor (HSC) cells from the whole blood and concomitantly the monitoring of HSC culture ex-vivo, by using an integrated lab-on-chip platform.
Until now a microfluidic module has been developed to separate stem cell from the more mature cells. MAbs-functionalized magnetic nanobeads (50nm) will be specifically attached to stem cells. The cells will then be separated from the others due to an effective magnetic field gradient, created by on chip current lines.
The microfluidic structure was made in PDMS using a 14mm resist mold. It consists in two channels, 40mm width each, separated by a 20mm width wall. The structure has two inlets, one is the blood inlet and the other is the buffer solution inlet. In the middle of the structure, there is a hole in the wall allowing magnetically labeled stem cells to move from one channel to the other. At the end, the first outlet will have blood, and MAbs-functionalized magnetic nanobeads, without stem cells, and the other outlet will have the separated stem cells in the buffer solution. Both processes were developed and performed at INESC-MN.
Microfluidic module for the stem cells separation showing details of the resist mold and the PDMS. The simulation of the stem cells separation due to the magnetic field created by the current lines is also showed.