Thursday, 4 October 2018

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Putting 3D Biofabrication to the Use of Tissue Model Fabrication
Y. Shrike Zhang, Associate Bioengineer, Division of Engineering in Medicine, Harvard-MIT Division of Health Sciences and Technology, United States of America

The talk will discuss our recent efforts on developing a series of bioprinting strategies including sacrificial bioprinting, microfluidic bioprinting, and multi-material bioprinting, along with various cytocompatible bioink formulations, for the fabrication of biomimetic 3D tissue models. These platform technologies, when combined with bioreactors and bioanalysis, will likely provide new opportunities in constructing functional organoids with a potential of achieving precision therapy by overcoming certain limitations associated with conventional models based on planar cell cultures and animals.

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Michael GelinskyKeynote Presentation

Title to be Confirmed.
Michael Gelinsky, Professor and Head, Center for Translational Bone, Joint and Soft Tissue Research, Faculty of Medicine, Technische Universität Dresden, Germany

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Shaochen ChenKeynote Presentation

Continuous Projection 3D Bioprinting For Functional Scaffolds and Tissue Models
Shaochen Chen, Professor and Vice Chair of NanoEngineering, Co-Director of Biomaterials and Tissue Engineering Center, University of California-San Diego, United States of America

In this talk, I will present our laboratory’s recent research efforts in rapid continuous projection 3D bioprinting to create 3D scaffolds using a variety of biomaterials. These 3D biomaterials are functionalized with precise control of micro-architecture, mechanical (e.g. stiffness and Poisson’s ratio), chemical, and biological properties. Design, fabrication, and experimental results will be discussed. Such functional biomaterials allow us to investigate cell-microenvironment interactions at nano- and micro-scales in response to integrated physical and chemical stimuli. From these fundamental studies we can create both in vitro and in vivo microphysiological systems such as a human liver tissue for tissue regeneration, disease modeling, and drug discovery.

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3D Printing Functional Materials & Devices
Michael McAlpine, Benjamin Mayhugh Associate Professor of Mechanical Engineering, University of Minnesota, United States of America

The ability to three-dimensionally interweave biological and functional materials could enable the creation of devices possessing unique and compelling geometries, properties, and functionalities. Indeed, interfacing active devices with biology in 3D could impact a variety of fields, including regenerative bioelectronics, smart prosthetics, biomedical devices, and human-machine interfaces. Biology, from the molecular scale of DNA and proteins, to the macroscopic scale of tissues and organs, is three-dimensional, often soft and stretchable, and temperature sensitive. This renders most biological platforms incompatible with the fabrication and materials processing methods that have been developed and optimized for functional electronics, which are typically planar, rigid and brittle. A number of strategies have been developed to overcome these dichotomies. Our approach is to use extrusion-based multi-material 3D printing, which is an additive manufacturing technology that offers freeform, autonomous fabrication. This approach addresses the dichotomies presented above by (1) using 3D printing and imaging for personalized, multifunctional device architectures; (2) employing ‘nano-inks’ as an enabling route for introducing diverse material functionality; and (3) 3D printing a range of functional inks to enable the interweaving of a diverse palette of materials, from biological to electronic. 3D printing is a multiscale platform, allowing for the incorporation of functional nanoscale inks, the printing of microscale features, and ultimately the creation of macroscale devices. This blending of 3D printing, functional materials, and ‘living’ platforms may enable next-generation 3D printed devices, from a one-pot printer.

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Dong-Woo ChoKeynote Presentation

Title to be Confirmed.
Dong-Woo Cho, Professor, Pohang University of Science and Technology (POSTECH), Korea South

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Developing Bioink Formulations that Promote Multicellular Tumor Organoid Growth
Joseph Kinsella, Assistant Professor of Bioengineering, McGill University, Canada

The cellular, biochemical, and biophysical heterogeneity of native tissue microenvironments are not recapitulated by growing immortalized cell lines using conventional 2D cell culture. These challenges can be overcome using bioprinting techniques to build heterogeneous 3D tissue models whereby, different types of cells are embedded. Alginate and gelatin are two of the most common biomaterials employed in bioprinting due to their biocompatibility, biomimicry, and mechanical properties. By combining the two polymers we demonstrate a bioprintable composite hydrogel with likenesses to the microscopic architecture of native tissue stroma. The printability of the composite hydrogels are evaluated mechanically to acquire the optimal extrusion bioprinting timescale post-gelation. Breast cancer cells and fibroblasts embedded into the hydrogels can be printed to form a 3D model mimicking the in vivo tumor microenvironment. The bioprinted heterogeneous model achieves high viability for long-duration cell culture (>30 days) and promotes the self-assembly of the breast cancer cells into multicellular tumor spheroids (MCTSs). We observed migration of the cancer associated fibroblast cells (CAFs) with the MCTSs in this model. Using bioprinted cell culture platforms as co-culture systems we are able to develop a unique tool to study the dependence of tumorigenesis on the stroma composition. The materials developed are a continuous effort towards a physiologically relevant “universal” bioink that can be tuned to have specific initial mechanical and biochemical properties for different tissue architectures.

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Image-Guided, Laser-Based Fabrication of Hydrogel-Embedded Microfluidic Networks
John Hundley Slater, Assistant Professor of Biomedical Engineering, University of Delaware, United States of America

We demonstrate fabrication of three-dimensional, biomimetic microfluidic networks embedded in hydrogels by combining laser-induced hydrogel degradation with image-guided laser control. Generation of simple arteriole-like networks, high-density, microvascular networks that recapitulate the architecture of in vivo vasculature, and multiple independent networks that fill the same hydrogel volume but never connect is demonstrated. Recapitulating in vivo-like fluid flow and transport using biomimetic microfluidic networks may prove advantageous in fabricating advanced in vitro tissue models.

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3D Stereolitography Bioprinting of Cell-Laden Hydrogel Microarrays and LEGO-like Modular Bioceramics for Tissue Engineering
Luiz Bertassoni, Assistant Professor, Oregon Health & Sciences University, United States of America

Fabrication of three-dimensional tissues with controlled microarchitectures has been shown to enhance tissue functionality. 3D printing can be used to precisely position cells and cell-laden materials to generate controlled tissue architectures. Therefore, it represents an exciting alternative for organ fabrication. Our group has been interested in developing innovative printing-based technologies to improve our ability to regenerate tissues with improved function, as well as to engineer hydrogel based microfluidic devices. In this seminar, we will present SLA/DLP-based 3D printing methods to fabricate high-throughput screening platforms to probe mechanotransduction and geometry-controlled mechanisms of stem cell differentiation. Further, we will discuss recent methods our lab has developed to engineer hard tissues using stereolitography printing of high-density bioceramics that can be stacked with multiple 3D geometries and improved regenerative capacity.