Neural stem cells from human cord blood on bioengineered surfaces--novel approach to multiparameter bio-tests

Stem cell technology combined with emerging surface nano/micro-technologies provides a new tool for better understanding of the mechanisms involved in cell fate decisions and compound-induced adverse reactions. This article provides state-of-the-art on the development of modern multiparameter bio-tests based on interactions between neural stem cells derived from human cord blood and bioengineered surfaces. Cell growth platforms with controlled content, geometry and spatial distribution of bioactive and stem cell attractive areas were fabricated either by micro-contact printing or piezoelectric spotting of polycationic biomolecules or extracellular matrix proteins (ECM) on cell-repellent surfaces. HUCB-NSCs were shown to adhere, differentiate and respond to neurotoxic MeHgCl on functional domains in a manner dependent on protein type and concentration, cell density and serum conditions. While receptor-mediated interactions with ECM proteins under absence of serum promote neuronal differentiation, non-specific adhesion to polycationic molecules maintain cells attached to the surface in non-differentiated stage. Functional domains were further engineered to create "smart" microenvironment by immobilizing to the surface signaling molecules together with ECM proteins. Stimulation of selected intracellular pathways by molecules of Wnt, Shh, CNTF or Notch type resulted in differentiation of HUCB-NSC to either neuronal or astroglial lineage. Sensor techniques applied to HUCB-NSC included measurements of electrical activity using multielectrode array chips. Spontaneous electrical field potentials of HUCB-NSCs were dependent upon developmental stage of tested cells. Bioengineered surfaces, on protein microarrays and micro-electrode array chips provide a novel approach to the multiparameter bio-tests by adding an important information on the sensitivity of certain molecular pathways and functional cellular responses to selected neurotoxins.