Abstract
Neurodegenerative disorders, such as Alzheimer's and Parkinson's diseases, are fundamentally characterized
by neuronal damage and cell death. Development of adult and pluripotent stem cells for cellular therapies or
therapeutic screening platforms may enable and accelerate novel treatment options for neuronal diseases.
However, ensuring the precise differentiation of stem cells into functional neurons within 3D culture environments
presents a significant challenge. To overcome this hurdle, this project aims to create novel bioprinting
methodologies for the production of human stem cell-based organoids by developing novel functionally-
optimized bioinks and optimized hydrogel formulations for pharmacological screens. Aim 1 focuses on
developing a customized bioink, which includes water, biopolymers, ions, and cells, to optimize biochemical
activity and mechanobiological responses. This endeavor aims to create a brain-like matrix under 100 μL using
a multi-material approach involving proteins, polysaccharides, and functionalized nanoparticles. The goal is to
reproducibly produce 3D constructs that reduce the variabilities introduced from under-defined commercial
sources. For this research, the bioink formulation incorporates gelatin, collagen, crosslinking enzymes,
photoinitiators, silica nanoparticles, neuron-inducing chemicals, and human stem cells. This formulation aims to
foster the emergence of functional neurons 2-4 weeks after the 3D bioprinting process. Aim 2 focuses on the
high-throughput (HT) assessment of neurotoxic chemicals' effects on the differentiation process of 3D hydrogel-
encapsulated neural stem cells. Utilizing commercial hydrogels for initial tests, this research will explore chemical
differentiation processes and evaluate the influence of neurotoxic chemicals on neuronal differentiation.
Characterization efforts will involve high-throughput imaging analysis methods plus flow cytometry that will allow
drawing correlations among bioink components and differentiation potentials. By comparing the outcomes with
those obtained using custom bioink formulations (from Aim 1) vs. commercial products such as Matrigel and
Geltrex, this project aims to identify a new bioink formulation that has the potential to revolutionize how we
consider and conduct tissue engineering research, including high-throughput molecular screening work. This
would accelerate progress toward the development of screening platforms and new therapies for
neurodegenerative disorders.
