Development of the micro-patterned 3D neuronal-hydrogel model using soft-lithography for study a 3D neural network on a microelectrode array.

In vitro patterned neuronal models have been studied as one of the strategies to investigate the relationship between structural connectivity and functional activity of neural network. Despite the importance of three-dimensional (3D) cell models, most of these studies have been performed on two-dimensional models. In this study, we present a technique to construct the micro-pattern to 3D neuronal-hydrogel model using a micromolding in capillaries (MIMIC) technique on microelectrode array (MEA).

Inertial Microfluidics-Based Separation of Microalgae Using a Contraction-Expansion Array Microchannel.

Microalgae separation technology is essential for both executing laboratory-based fundamental studies and ensuring the quality of the final algal products. However, the conventional microalgae separation technology of micropipetting requires highly skilled operators and several months of repeated separation to obtain a microalgal single strain. This study therefore aimed at utilizing microfluidic cell sorting technology for the simple and effective separation of microalgae.

Controlled 3D co-culture of beta cells and endothelial cells in a micropatterned collagen sheet for reproducible construction of an improved pancreatic pseudo-tissue.

The co-culture of beta cells and endothelial cells in constructing a pancreatic pseudo-tissue can provide a functional advancement for diabetic-related drug testing and biological studies or transplantation. In order to mimic the pancreatic tissue more similar to , it is necessary to control the microenvironment, including cell-cell and cell-extracellular matrix interactions. In this study, we report a geometrically controlled three-dimensional (3D) pancreatic model where MIN6 and MS1 cells are co-cultured within a micropatterned collagen sheet.

Hand-Maneuverable Collagen Sheet with Micropatterns for 3D Modular Tissue Engineering.

Modular tissue engineering creates a three-dimensional (3D) macroscale tissue construct from modular microscale units for complex 3D tissue reconstruction. In particular, a hydrogel sheet that is one of the module types allows easy and controllable assembly of 3D microenvironments as compared to other module types such as a microcapsule and a microfiber. However, it is difficult to manipulate a hydrogel sheet made of extracellular matrix (ECM) proteins.

Demonstration of Interposed Modular Hydrogel Sheet for Multicellular Analysis in a Microfluidic Assembly Platform.

Hydrogel sheets have emerged as a promising biomaterial scaffold for the encapsulation and transfer of multicellular structures. Although the improvement of the chemical interactions and the design of micro-scaled geometry have contributed to the development of multipurpose hydrogel scaffolds, the application of hydrogel sheets to assess multicellular structures is still challenging. To expand the technical applicability of hydrogel sheets, we here demonstrate that a single layer of the hydrogel sheet can be integrated as an interposed module in a microfluidic device for multicellular analysis.

Construction of Modular Hydrogel Sheets for Micropatterned Macro-scaled 3D Cellular Architecture.

Hydrogels can be patterned at the micro-scale using microfluidic or micropatterning technologies to provide an in vivo-like three-dimensional (3D) tissue geometry. The resulting 3D hydrogel-based cellular constructs have been introduced as an alternative to animal experiments for advanced biological studies, pharmacological assays and organ transplant applications. Although hydrogel-based particles and fibers can be easily fabricated, it is difficult to manipulate them for tissue reconstruction.

Freestanding stacked mesh-like hydrogel sheets enable the creation of complex macroscale cellular scaffolds.

Hydrogel-based bottom-up tissue engineering depends on assembly of cell-laden modules for complex three-dimensional tissue reconstruction. Though sheet-like hydrogel modules enable rapid and controllable assembly, they have limitations in generating spatial microenvironments and mass transport. Here, we describe a simple method for forming large-scale cell-hydrogel assemblies via stacking cell-embedded mesh-like hydrogel sheets to create complex macroscale cellular scaffolds.

Facile and biocompatible fabrication of chemically sol-gel transitional hydrogel free-standing microarchitectures.

We report a facile method to fabricate free-standing, 3D hydrogel microarchitectures of chemically sol-gel transitional hydrogels, which is based on the use of hydrophilic substrate and aerosol of gelling agent without molding (or sandwiching) process. Using proposed methods, we fabricated hydrogel microarchitectures of sheets, meshes, or microunits without morphological distortions on the microscale. These hydrogel microarchitectures could be easily and stably exfoliated from the substrates and cultured (in the case of containing cells).