SPAchips: Microparticles Used for the Selective In Vitro Labelling of Microglia

Both basic and preclinical research, as well as the development of new therapies, require tools that allow for the selective labelling of specific cell types and the targeted delivery of drugs. The developed tools must then be validated in biological systems. In view of the lack of effective therapies for many neurodevelopmental disorders, including neonatal brain injuries, we decided to use the newly described, innovative SPAchips^® (a4cell, Pozuelo de Alarcón, Spain) tool and test it in labelling neonatal rat neural cells. In our studies, rat primary cultures of neurons and glial cells (astrocytes, oligodendrocytes, and microglia) were incubated with different concentrations of SPAchips^®. At selected time points, uptake of the tested microchips by particular cell types was assessed using lineage-specific antibodies and visualized using a confocal microscope. Additionally, the potential cytotoxicity of added microparticles was verified, as was the possibility of microglia activation. The study indicates that the tested microdevices selectively label neonatal rat microglia and can be a useful tool for visualizing this cell type, as well as a non-toxic tool for developing innovative strategies based on the functionalization of microparticles aimed at modulating neuroinflammatory processes.