A scalable and tunable thermoreversible polymer for 3D human pluripotent stem cell biomanufacturing.

Human pluripotent stem cells (hPSCs) are an exciting and promising source to enable cell replacement therapies for a variety of unmet medical needs. Though hPSCs can be successfully derived into numerous physiologically relevant cell types, effective translation to the clinic is limited by challenges in scalable production of high-quality cells, cellular immaturity following the differentiation process, and the use of animal-derived components in culture. To address these limitations, we have developed a fully defined, reproducible, and tunable thermoreversible polymer for high-quality, scalable 3D cell production.

High-Throughput Discovery of Targeted, Minimally Complex Peptide Surfaces for Human Pluripotent Stem Cell Culture.

Human pluripotent stem cells harbor an unlimited capacity to generate therapeutically relevant cells for applications in regenerative medicine. However, to utilize these cells in the clinic, scalable culture systems that activate defined receptors and signaling pathways to sustain stem cell self-renewal are required; and synthetic materials offer considerable promise to meet these needs. development of materials that target novel pathways has been stymied by a limited understanding of critical receptor interactions maintaining pluripotency.

Advanced Materials to Enhance Central Nervous System Tissue Modeling and Cell Therapy.

The progressively deeper understanding of mechanisms underlying stem cell fate decisions has enabled parallel advances in basic biology-such as the generation of organoid models that can further one's basic understanding of human development and disease-and in clinical translation-including stem cell based therapies to treat human disease. Both of these applications rely on tight control of the stem cell microenvironment to properly modulate cell fate, and materials that can be engineered to interface with cells in a controlled and tunable manner have therefore emerged as valuable tools for guiding stem cell growth and differentiation. With a focus on the central nervous system (CNS), a broad range of material solutions that have been engineered to overcome various hurdles in constructing advanced organoid models and developing effective stem cell therapeutics is reviewed.

High-throughput 3D screening for differentiation of hPSC-derived cell therapy candidates.

The emergence of several cell therapy candidates in the clinic is an encouraging sign for human diseases/disorders that currently have no effective treatment; however, scalable production of these cell therapies has become a bottleneck. To overcome this barrier, three-dimensional (3D) cell culture strategies have been considered for enhanced cell production. Here, we demonstrate a high-throughput 3D culture platform used to systematically screen 1200 culture conditions with varying doses, durations, dynamics, and combinations of signaling cues to derive oligodendrocyte progenitor cells and midbrain dopaminergic neurons from human pluripotent stem cells (hPSCs).

Gene Editing to Generate Versatile Human Pluripotent Stem Cell Reporter Lines for Analysis of Differentiation and Lineage Tracing.

Transcription factors (TFs) are potent proteins that control gene expression and can thereby drive cell fate decisions. Fluorescent reporters have been broadly knocked into endogenous TF loci to investigate the biological roles of these factors; however, the sensitivity of such analyses in human pluripotent stem cells (hPSCs) is often compromised by low TF expression levels and/or reporter silencing. Complementarily, we report an inducible and quantitative reporter platform based on the Cre-LoxP recombination system that enables robust, quantifiable, and continuous monitoring of live hPSCs and their progeny to investigate the roles of TFs during human development and disease.

Engineering bioorthogonal protein-polymer hybrid hydrogel as a functional protein immobilization platform.

We demonstrate the synthesis of protein-polymer hybrid hydrogel that can be used as a platform for immobilizing functional proteins. Orthogonal chemistry was employed for cross-linking the hybrid network and conjugating proteins to the gel backbone, allowing for the convenient, one-pot formation of a functionalized hydrogel. The resulting hydrogel had tunable mechanical properties, was stable in solution, and biocompatible.

High-throughput combinatorial screening reveals interactions between signaling molecules that regulate adult neural stem cell fate.

Advancing our knowledge of how neural stem cell (NSC) behavior in the adult hippocampus is regulated has implications for elucidating basic mechanisms of learning and memory as well as for neurodegenerative disease therapy. To date, numerous biochemical cues from the endogenous hippocampal NSC niche have been identified as modulators of NSC quiescence, proliferation, and differentiation; however, the complex repertoire of signaling factors within stem cell niches raises the question of how cues act in combination with one another to influence NSC physiology. To help overcome experimental bottlenecks in studying this question, we adapted a high-throughput microculture system, with over 500 distinct microenvironments, to conduct a systematic combinatorial screen of key signaling cues and collect high-content phenotype data on endpoint NSC populations.

Dendritic amphiphiles strongly affect the biophysical properties of DPPC bilayer membranes.

Molecular dynamics (MD) simulations were used to gain insight on the molecular interactions in a model biological membrane comprised of a bilayer with DPPC (dipalmitoylphosphotidylcholine) and antimicrobial dendritic amphiphile molecules [RCONHC(CH(2)CH(2)COOH)(3), where R is the saturated hydrocarbon tail (R = n-C(n)H(2n+1)), to be abbreviated as 3CAmn]. This study analyzes different biophysical properties of the equilibrated mixed bilayers, at 300 and 325 K, to determine how the presence of the 3CAmn, in varying concentrations and tail lengths, affects the lipid bilayer. Lipid tail order parameter data, bilayer thickness trends, and qualitative lipid tail tilt observations suggest that a molar ratio of 0.