Bio-printing is derived from the human cortical neural architecture of induced pluripotent stem cells

Contributor: Wang Sen, Wang Ling

Bio-printing USES biocompatible and rheologically appropriate biomaterials and synthetic materials, and adds cell-based bio-inks to construct micro-scale resolution 3D structures in a controlled manner.The multicellular nature of neural tissue is a challenge for bio-printing preparation, and the differentiation of multiple cell types using induced pluripotent stem cells (iPSCs) provides an effective solution.Federico Salaris et al., from the Centre for Life nanoscience at the Italian Polytechnic Institute, reported the use of ipscs-derived cortical neurons and glial progenitor cells for bio-printed neural structures.The results show that the extrud-based printing process does not impair the viability of cells in the short and long term.The bio-printed cells can further differentiate and appropriately express neurons and astrocytes.Functional analysis of 3D bio-printed nerve cells showed early neural network activity behavior.The work paves the way for bio-printing nerve cells from pluripotent stem cells to produce a more complex and reliable human nervous system.

The bio-ink used in this study was sodium alginate/stromal gel, and induced differentiated pluripotent stem cells were cultured in a petri dish to obtain cortical neurons and glial precursor cells as seed cells.The spiral inner channel with biological ink is placed in the ice bath to keep the matrix glue from solidifying. During printing, sodium alginate and calcium chloride in the outer channel are cross-linked to form the printing structure.After printing, the whole tissue was incubated in a cell incubator, leading to gelation of matrix gel components, and then treated in sodium alginate lyase solution to remove sodium alginate.

The cell activity, cell differentiation and electrophysiological function of the printed neural tissue architecture were characterized.Figure 1(E) analyzed the cell viability of DPP at different times after printing (DPP1(78±3.8%),DPP7(71±3.5%) and DPP50(68±8%).The results showed that neither the printing process nor the composition of bio-ink caused any damage to nerve cells in the short and long term.Figure 2 (A) shows the cell difference between 2D culture with bio-ink drop culture and print culture, and Figure (B) shows the rT-PCR analysis of neural cell markers, neural progenitors (PAX6,FOXG1,TBR2), cortical neurons (TBR1), and astrocytes (GFAP).The patch clamp recording results shown in Figure 3 showed the electrophysiological characteristics of typical neuronal progenitor cells, and the calcium ion imaging results showed early immature network activity, indicating that printing had no significant effect on tissue function.

References:

SALARIS F, COLOSI C, BRIGHI C, et al. 3D Bioprinted Human Neural Constructs Derived from Induced Pluripotent Stem Cells.[J]. Journal of Clinical Medicine, 2019, 8(10). DOI:10.3390/ JCM8101595.

Contributor: Wang Sen, Wang Ling

Supplier: State Key Laboratory of Mechanical Manufacturing System Engineering