Biocompatibility of α-Al₂O₃ Ceramic Substrates with Human Neural Precursor Cells

Biocompatible materials-topography could be used for the construction of scaffolds allowing the three-dimensional (3D) organization of human stem cells into functional tissue-like structures with a defined architecture.

Structural characterization of an alumina-based substrate was performed through XRD, Brunauer-Emmett-Teller (BET) analysis, scanning electron microscopy (SEM), and wettability measurements. Biocompatibility of the substrate was assessed by measuring the proliferation and differentiation of human neural precursor stem cells (NPCs).

α-Al₂O₃ is a ceramic material with crystallite size of 40 nm; its surface consists of aggregates in the range of 8-22 μm which forms a rough surface in the microscale with 1-8 μm cavities. The non-calcined material has a surface area of 5.5 m²/gr and pore size distribution of 20 nm, which is eliminated in the calcined structure. Thus, the pore network on the surface and the body of the ceramic becomes more water proof, as indicated by wettability measurements. The alumina-based substrate supported the proliferation of human NPCs and their differentiation into functional neurons.

Our work indicates the potential use of alumina for the construction of 3D engineered biosystems utilizing human neurons. Such systems may be useful for diagnostic purposes, drug testing, or biotechnological applications.