Immobilization of neural cells in three-dimensional matrices for biosensorapplications

To overcome logistical difficulties with current designs of cell- or tissue -based biosensors which have individual cells or tissue slices immobilized on membranes or microelectrode arrays, we have proposed a system that uses three-dimensional cultures of neural cells immobilized in hydrogel matrices . In this design, immobilized cells would be maintained in a reservoir and then transferred to a detector platform when needed for analysis. The devel opment of such a system relies upon a renewable supply of cells and the abi lity to culture cells for long periods of time in three-dimensions while ma intaining their physiological function. To investigate the ability to cultu re neural cells in 3D matrices, embryonic rat cortical neurons and astrocyt es were immobilized by matrix entrapment in a novel sugar poly(acrylate) hy drogel and collagen gels. The sugar poly(acrylate) hydrogel does not appear to support neural cell growth as a result of a lack of cell adherence, sma ll pore size and, possibly, harshness of synthesis conditions. In contrast, collagen gels support the growth of cortical neurons, astrocytes, as well as neural progenitor cells. Evidence is also presented from immunocytochemi stry and patch-clamp measurements which shows that neural progenitor cells proliferate in culture and can be induced to differentiate into neural cell types. Thus, they potentially represent a renewable cell source. (C) 2000 Elsevier Science S.A. All rights reserved.