The generation of organoids and tissues with programmable cellular complexity, architecture and function would benefit from the simultaneous differentiation of human induced pluripotent stem cells (hiPSCs) into divergent cell types. Yet differentiation protocols for the overexpression of specific transcription factors typically produce a single cell type. Here we show that patterned organoids and bioprinted tissues with controlled composition and organization can be generated by simultaneously co-differentiating hiPSCs into distinct cell types via the forced overexpression of transcription factors, independently of culture-media composition. Specifically, we used such orthogonally induced differentiation to generate endothelial cells and neurons from hiPSCs in a one-pot system containing either neural or endothelial stem-cell-specifying media, and to produce vascularized and patterned cortical organoids within days by aggregating inducible-transcription-factor and wild-type hiPSCs into randomly pooled or multicore-shell embryoid bodies. Moreover, by leveraging multimaterial bioprinting of hiPSC inks without extracellular matrix, we generated patterned neural tissues with layered regions composed of neural stem cells, endothelium and neurons. Orthogonally induced differentiation of stem cells may facilitate the fabrication of engineered tissues for biomedical applications. Patterned organoids and bioprinted tissues can be generated by simultaneously co-differentiating pluripotent stem cells into distinct cell types via the forced overexpression of transcription factors, independently of culture-media composition.

The ability to engineer complex multicellular systems has enormous potential to inform our understanding of biological processes and disease and alter the drug development process. Engineering living systems to emulate natural processes or to incorporate new functions relies on a detailed understanding of the biochemical, mechanical, and other cues between cells and between cells and their environment that result in the coordinated action of multicellular systems. On April 3-6, 2022, experts in the field met at the Keystone symposium "Engineering Multicellular Living Systems" to discuss recent advances in understanding how cells cooperate within a multicellular system, as well as recent efforts to engineer systems like organ-on-a-chip models, biological robots, and organoids. Given the similarities and common themes, this meeting was held in conjunction with the symposium "Organoids as Tools for Fundamental Discovery and Translation".

By integrating ongoing bioethical collaboration, neuroscientists can create a positive effect on their research and the knowledge it produces. To this end, we offer our experiences with an interdisciplinary model for the ethical advancement of a promising area of neuroscience — human neural organoid research.

The ability to replicate the 3D myocardial architecture found in human hearts is a grand challenge. Here, the fabrication of aligned cardiac tissues via bioprinting anisotropic organ building blocks (aOBBs) composed of human induced pluripotent stem cell derived cardiomyocytes (hiPSC-CMs) is reported. A bioink composed of contractile cardiac aOBBs is first generated and aligned cardiac tissue sheets with linear, spiral, and chevron features are printed. Next, aligned cardiac macrofilaments are printed, whose contractile force and conduction velocity increase over time and exceed the performance of spheroid-based cardiac tissues. Finally, the ability to spatially control the magnitude and direction of contractile force by printing cardiac sheets with different aOBB alignment is highlighted. This research opens new avenues to generating functional cardiac tissue with high cell density and complex cellular alignment.

The programmable assembly of innervated LCE actuators (iLCEs) with prescribed contractile actuation, self-sensing, and closed loop control via core-shell 3D printing is reported. This extrusion-based direct ink writing method enables coaxial filamentary features composed of pure LM core surrounded by an LCE shell, whose director is aligned along the print path. Specifically, the thermal response of the iLCE fiber-type actuators is programmed, measured, and modeled during Joule heating, including quantifying the concomitant changes in fiber length and resistance that arise during simultaneous heating and self-sensing. Due to their reversible, high-energy actuation and their resistive feedback, it is also demonstrated that iLCEs can be regulated with closed loop control even when perturbed with large bias loads. Finally, iLCE architectures capable of programmed, self-sensing 3D shape change with closed loop control are fabricated.

Simultaneous differentiation of human induced pluripotent stem cells (hiPSCs) into divergent cell types offers a pathway to achieving tailorable cellular complexity, patterned architecture, and function in engineered human organoids and tissues. Recent transcription factor (TF) overexpression protocols typically produce only one cell type of interest rather than the multitude of cell types and structural organization found in native human tissues. Here, we report an orthogonal differentiation platform for genomically programming stem cells, organoids and bioprinted tissues with controlled composition and organization. To demonstrate this platform, we orthogonally differentiated endothelial cells and neurons from hiPSCs in a one-pot system containing neural stem cell-specifying media. By aggregating inducible-TF and wildtype hiPSCs into pooled and multicore-shell embryoid bodies, we produced vascularized and patterned cortical organoids within days. Using multimaterial 3D bioprinting, we patterned 3D neural tissues from densely cellular, matrix-free stem cell inks that were orthogonally differentiated on demand into distinct layered regions composed of neural stem cells, endothelium, and neurons, respectively. Given the high proliferative capacity and patient-specificity of hiPSCs, our platform provides a facile route for programming cells and multicellular tissues for drug screening and therapeutic applications.

We demonstrate a new method for realizing modified Luneburg lens antennas with nearly continuously graded permittivity profiles in three-dimensions. The method used a quasi-conformal transformation optics (QCTO) approach to modify the geometry and permittivity of a spherical Luneburg lens to have a flat surface for convenient integration of antenna feeds. The modified lens was then fabricated using Fused Deposition Modeling (FDM) printing with an effective media approach that employs space-filling curves. The method was validated by designing and fabricating a modified Luneburg lens antenna designed to operate in the Ka-band. The antenna performance of the sample was measured experimentally and shown to compare well to predicted results using full wave simulations. The device was able to achieve a reasonably high degree of beam steering (ie, -55 degrees to +55 degrees) over the entire Ka-band. We believe this new approach provides a cost-effective and scalable means of realizing practical passive beam steering lenses that operate over a broad range of frequencies.

We demonstrate a new method for realizing Luneburg lens antennas with nearly continuously graded permittivity profiles in three dimensions. The method combines fused filament fabrication, a nearly ubiquitous additive manufacturing technique, with an effective media approach that employs space-filling curves. We experimentally validate our design methodology by fabricating and characterizing two Luneburg lenses designed to operate at separate frequency bands (26-40 GHz and 70-110 GHz) with antenna gains of 20 and 24 dBi, respectively. The results demonstrate good agreement with rigorous electromagnetic simulations. We also demonstrate the ability to passively beam steer over a wideband of operation (26-40 GHz and 70-110 GHz) with less than 0.5% power loss due to dielectric material losses within the Luneburg lens.

Additive manufacturing (AM) systems are capable of creating complex geometries that are difficult to fabricate using conventional manufacturing methods. While AM techniques are becoming increasingly advanced and accessible to broad set of users, the bottleneck for many electromagnetic applications is the lack of suitable materials. In this presentation we will describe a new magnetodielectric ink developed specifically for microdispensing based AM. Using this new material a miniaturized slotted patch antenna was designed and fabricated using a microdispensing AM platform. Computational and experimental results will be presented.