4D Biofabrication Using Shape‐Morphing Hydrogels

TLDR

Bioprinting holds great promise for complex biological structures, yet printing hollow tubular structures remains the most critical challenge. This study develops an advanced 4D biofabrication method using shape‑morphing biopolymer hydrogels to print hollow self‑folding tubes with precise diameter and architectural control. The method prints shape‑morphing hydrogels that self‑fold into tubes, allowing fine tuning of diameter and architecture through printing and post‑printing parameters. Using alginate and hyaluronic acid with mouse bone marrow stromal cells, the approach achieved internal tube diameters as small as 20 µm, comparable to the smallest blood vessels, preserved cell viability for at least 7 days, and enabled dynamically reconfigurable, responsive architectures.

Abstract

Abstract Despite the tremendous potential of bioprinting techniques toward the fabrication of highly complex biological structures and the flourishing progress in 3D bioprinting, the most critical challenge of the current approaches is the printing of hollow tubular structures. In this work, an advanced 4D biofabrication approach, based on printing of shape‐morphing biopolymer hydrogels, is developed for the fabrication of hollow self‐folding tubes with unprecedented control over their diameters and architectures at high resolution. The versatility of the approach is demonstrated by employing two different biopolymers (alginate and hyaluronic acid) and mouse bone marrow stromal cells. Harnessing the printing and postprinting parameters allows attaining average internal tube diameters as low as 20 µm, which is not yet achievable by other existing bioprinting/biofabrication approaches and is comparable to the diameters of the smallest blood vessels. The proposed 4D biofabrication process does not pose any negative effect on the viability of the printed cells, and the self‐folded hydrogel‐based tubes support cell survival for at least 7 d without any decrease in cell viability. Consequently, the presented 4D biofabrication strategy allows the production of dynamically reconfigurable architectures with tunable functionality and responsiveness, governed by the selection of suitable materials and cells.