A Parkinson’s disease model composed of 3D bioprinted dopaminergic neurons within a biomimetic peptide scaffold

Abstract

Parkinson’s disease (PD) is a progressive neurological disorder that affects movement. It is associated with lost dopaminergic (DA) neurons in the substantia nigra, a process that is not yet fully understood. To understand this deleterious disorder, there is an immense need to develop efficient in vitro three-dimensional (3D) models that can recapitulate complex organs such as the brain. However, due to the complexity of neurons, selecting suitable biomaterials to accommodate them is challenging. Here, we report on the fabrication of functional DA neuronal 3D models using ultrashort self-assembling tetrapeptide scaffolds. Our peptide-based models demonstrate biocompatibility both for primary mouse embryonic DA neurons and for human DA neurons derived from human embryonic stem cells. DA neurons encapsulated in these scaffolds responded to 6-hydroxydopamine, a neurotoxin that selectively induces loss of DA neurons. Using multi-electrode arrays, we recorded spontaneous activity in DA neurons encapsulated within these 3D peptide scaffolds for more than 1 month without decrease of signal intensity. Additionally, vascularization of our 3D models in a co-culture with endothelial cells greatly promoted neurite outgrowth, leading to denser network formation. This increase of neuronal networks through vascularization was observed for both primary mouse DA and cortical neurons. Furthermore, we present a 3D bioprinted model of DA neurons inspired by the mouse brain and created with an extrusion-based 3D robotic bioprinting system that was developed during previous studies and is optimized with time-dependent pulsing by microfluidic pumps. We employed a hybrid fabrication strategy that relies on an external mold of the mouse brain construct that complements the shape and size of the desired bioprinted model to offer better support during printing. We hope that our 3D model provides a platform for studies of the pathogenesis of PD and other neurodegenerative disorders that may lead to better understanding and more efficient treatment strategies.

The Impact of Mechanical Cues on the Metabolomic and Transcriptomic Profiles of Human Dermal Fibroblasts Cultured in Ultrashort Self-Assembling Peptide 3D Scaffolds

“…The bundles are likely juxtapositions of 2, 3, or 4 protofilaments, as extensively reported in the literature indicating that short peptides protofilaments bear a diameter of 2−3 nm. 18,22,23 When observing the helical pitch of the two fibers, we noticed that FFIK fibers have longer pitches than FIIK, indicating a tighter packing of FIIK. Moreover, FFIK manifests an additional arrangement of the fibers, with a helical pitch at around 170 nm.…”

The Influence of Prenatal Exposure to Methamphetamine on the Development of Dopaminergic Neurons in the Ventral Midbrain

“…In order to recapitulate the complex brain tissue architecture, a 3D in vitro VMDN model was used in this study to assess viability, ATP release, morphogenesis, and gene expression. To this end, ultrashort self-assembling peptides proved to be promising biomaterials for the development of functional 3D neuronal models [ 25 , 26 ]. An Ac-Ile-Ile-Cha-Lys-NH 2 (IIZK) tetrameric self-assembling peptide was used in this study to establish the 3D neuronal cultures as described previously [ 47 ].…”

“…These peptides self-assemble into nanofibrous networks in physiological buffers without chemical or UV cross-linking, which make them suitable biomaterials for a myriad of tissue engineering applications. The peptide sequence selected in this study was successfully used in previous studies to develop 3D in vitro neuronal models [ 25 , 26 ].…”

3D printing of bone and cartilage with polymer materials

“…Embryonic stem cells (ESCs) can be induced to differentiate into mesenchymal stem cells and chondrocytes and are often used in cartilage tissue engineering (Hong et al, 2020). Gene expression and immunostaining analysis confirmed that this co-culture system could form the cell colonies and secrete extracellular matrix (ECM) containing glycosaminoglycan (GAG) (Abdelrahman et al, 2022). The dynamic expression of chondrocyte-specific genes was observed during the cell monolayer expansion in this co-culture system, fully confirming the chondrogenic differentiation of human embryonic stem cells (hESCs) (Edgar et al, 2020).…”