Biology subjects

Roth, J. G.

Publications and source records attributed to Roth, J. G..

5 recordsLinked to original sources

bioRxiv2026

Hydrogel-imposed boundary conditions guide single-lumen neuroepithelial morphogenesis

Three-dimensional (3D) stem cell-based cultures have emerged as promising in vitro model systems for studying human neurodevelopment. Current neural organoid protocols lack well-defined extracellular matrix (ECM) signaling and are limited by the formation of irregular tissue morphologies with multiple organizing centers, in contrast to the single neuroepithelial structure that emerges during embryonic development. This variability limits inter-organoid reproducibility and constrains their utility for modeling early developmental processes. To overcome these limitations, we leverage a materials-based approach to impose dynamic boundary conditions that extrinsically guide the self-organization of human induced pluripotent stem cells (iPSCs). Specifically, we develop a family of hyaluronic acid-elastin-like protein (HELP) hydrogels crosslinked with dynamic covalent bonds that recapitulate key biochemical and biophysical properties of the developing human neural ECM. Within these HELP hydrogels, iPSCs robustly self-organize from a single cell into complex neuroepithelial tissues with a single lumen. By tuning the boundary conditions imposed by the hydrogel, we identify matrix stress relaxation rate and tensional homeostasis as key regulators of single-lumen rosette formation and maintenance. With this hydrogel-enabled system, we identify phenotypic abnormalities in an early neurodevelopmental model of 22q11.2 deletion syndrome. Ultimately, our tunable engineered hydrogel supports the initiation of single-cell derived 3D neuroepithelial tissues, enables investigation into how matrix-imposed boundary conditions guide developmental morphogenesis, and establishes a reproducible platform for disease modeling.

bioengineering↗

bioRxiv2023

Gelation of Uniform Interfacial Diffusant in Embedded 3D Printing

While the human body has many different examples of perfusable structures with complex geometries, biofabrication methods to replicate this complexity are still lacking. Specifically, the fabrication of self-supporting, branched networks with multiple channel diameters is particularly challenging. Here, we present the Gelation of Uniform Interfacial Diffusant in Embedded 3D Printing (GUIDE-3DP) approach for constructing perfusable networks of interconnected channels with precise control over branching geometries and vessel sizes. To achieve user-specified channel dimensions, this technique leverages the predictable diffusion of crosslinking reaction-initiators released from sacrificial inks printed within a hydrogel precursor. We demonstrate the versatility of GUIDE-3DP to be adapted for use with diverse physiochemical crosslinking mechanisms by designing seven printable material systems. Importantly, GUIDE-3DP allows for the independent tunability of both the inner and outer diameters of the printed channels and the ability to fabricate seamless junctions at branch points. This 3D bioprinting platform is uniquely suited for fabricating lumenized structures with complex shapes characteristic of multiple hollow vessels throughout the body. As an exemplary application, we demonstrate the fabrication of vasculature-like networks lined with endothelial cells. GUIDE-3DP represents an important advance toward the fabrication of self-supporting, physiologically relevant networks with intricate and perfusable geometries.

bioengineering↗

bioRxiv2022

Biocompatible polymers for scalable production of human neural organoids

The generation of neural organoids from human pluripotent stem cells holds great promise in modeling disease and screenings drugs, but current approaches are difficult to scale due to undesired organoid fusion. Here, we develop a scalable neural organoid platform by screening biocompatible polymers that prevent fusion of organoids cultured in suspension. We show that addition of one inexpensive polysaccharide enables straightforward screening of 298 FDA-approved drugs and teratogens for growth defects using over 2,400 cortical organoids.

neuroscience↗

bioRxiv2020

Copy Number Variation at 16p11.2 Imparts Transcriptional Alterations in Neural Development in an hiPSC-derived Model of Corticogenesis

Microdeletions and microduplications of the 16p11.2 chromosomal locus are associated with syndromic neurodevelopmental disorders and reciprocal physiological conditions such as macro/microcephaly and high/low body mass index. To facilitate cellular and molecular investigations of these phenotypes, 65 clones of human induced pluripotent stem cells (hiPSCs) were generated from 13 individuals with 16p11.2 copy number variations (CNVs). Cortical neural progenitor cells derived from these hiPSCs were profiled using RNA-Seq, which identified alterations in radial glial gene expression that precede morphological abnormalities reported at later neurodevelopmental stages. Moreover, a customizable bioinformatic strategy for the detection of random integration and expression of reprogramming vectors was developed and leveraged towards identifying a subset of "footprint"-free hiPSC clones that are available by request from the Simons Foundation Autism Research Initiative. This publicly available resource of 65 human hiPSC clones can serve as a powerful medium for probing the etiology of developmental disorders associated with 16p11.2 CNVs.

neuroscience↗

bioRxiv2020

Genome-wide molecular effects of the neuropsychiatric 16p11 CNVs in an iPSC-to-iN neuronal model

Copy number variants (CNVs), either deletions or duplications, at the 16p11.2 locus in the human genome are known to increase the risk for autism spectrum disorders (ASD), schizophrenia, and for several other developmental conditions. Here, we investigate the global effects on gene expression and DNA methylation using a 16p11.2 CNV patient-derived induced pluripotent stem cell (iPSC) to induced neuron (iN) cell model system. This approach revealed genome-wide and cell-type specific alterations to both gene expression and DNA methylation patterns and also yielded specific leads on genes potentially contributing to some of the known 16p11.2 patient phenotypes. PCSK9 is identified as a possible contributing factor to the symptoms seen in carriers of the 16p11.2 CNVs. The protocadherin (PCDH) gene family is found to have altered DNA methylation patterns in the CNV patient samples. The iPSC lines used for this study are available through a repository as a resource for research into the molecular etiology of the clinical phenotypes of 16p11.2 CNVs and into that of neuropsychiatric and neurodevelopmental disorders in general.

genetics↗