# Fabrication Method for Shape-Controlled 3D Tissue Using High-Porosity Porous Structure

## TL;DR

A new method creates 3D tissues with specific shapes using a high-porosity structure without using non-natural materials or harmful chemicals.

## Contribution

A novel fabrication method for shape-controlled 3D tissues using a high-porosity porous structure without non-natural materials.

## Key findings

- 3D tissues with an I-shape were successfully fabricated using a high-porosity porous structure.
- Cells in the fabricated tissues maintained over 90% viability without using proteolytic enzymes.
- The method allows rapid release of 3D tissues while preserving their shape and cell health.

## Abstract

Shape-controlled 3D tissues resemble natural living tissues in human and animal bodies and are essential materials for developing and improving technologies in regenerative medicine, drug discovery, and biological robotics. In previous studies, shape-controlled 3D tissues were fabricated using scaffold structures or 3D bioprinting techniques. However, controlling the shape of 3D tissues without leaving non-natural materials inside the 3D tissue and efficiently fabricating them remains challenging. In this paper, we propose a novel method for fabricating shape-controlled 3D tissues free of non-natural materials using a flexible high-porosity porous structure (HPPS). The HPPS consisted of a micromesh with pore sizes of 14.87 ± 1.83 μm, lattice widths of 2.24 ± 0.10 μm, thicknesses of 9.96 ± 0.92 μm, porosity of 69.06 ± 3.30%, and an I-shaped microchamber of depth 555.26 ± 11.17 μm. U-87 human glioma cells were cultured in an I-shaped HPPS microchamber for 48 h. After cultivation, the 3D tissue was released within a few seconds while maintaining its I-shape. Specific chemicals, such as proteolytic enzymes, were not used. Moreover, the viability of the released cells composed of shape-controlled 3D tissues free of non-natural materials was above 90%. Therefore, the proposed fabrication method is recommended for shape-controlled 3D tissues free of non-natural materials without applying significant stresses to the cells.