As the most versatile and promising cell source, stem cells have been studied in regenerative medicine for two decades. Currently available culturing techniques utilize a 2D or 3D microenvironment for supporting the growth and proliferation of stem cells. However, these culture systems fail to fully reflect the supportive biological environment in which stem cells reside in vivo, which contain dynamic biophysical growth cues. Herein, a 4D programmable culture substrate with a self‐morphing capability is presented as a means to enhance dynamic cell growth and induce differentiation of stem cells. To function as a model system, a 4D neural culture substrate is fabricated using a combination of printing and imprinting techniques keyed to the different biological features of neural stem cells (NSCs) at different differentiation stages. Results show the 4D culture substrate demonstrates a time‐dependent self‐morphing process that plays an essential role in regulating NSC behaviors in a spatiotemporal manner and enhances neural differentiation of NSCs along with significant axonal alignment. This study of a customized, dynamic substrate revolutionizes current stem cell therapies, and can further have a far‐reaching impact on improving tissue regeneration and mimicking specific disease progression, as well as other impacts on materials and life science research.
Biomineralized materials are sophisticated material systems with hierarchical 3D material architectures, which are broadly used as model systems for fundamental mechanical, materials science, and biomimetic studies. The current knowledge of the structure of biological materials is mainly based on 2D imaging, which often impedes comprehensive and accurate understanding of the materials’ intricate 3D microstructure and consequently their mechanics, functions, and bioinspired designs. The development of 3D techniques such as tomography, additive manufacturing, and 4D testing has opened pathways to study biological materials fully in 3D. This review discusses how applying 3D techniques can provide new insights into biomineralized materials that are either well known or possess complex microstructures that are challenging to understand in the 2D framework. The diverse structures of biomineralized materials are characterized based on four universal structural motifs. Nacre is selected as an example to demonstrate how the progression of knowledge from 2D to 3D can bring substantial improvements to understanding the growth mechanism, biomechanics, and bioinspired designs. State‐of‐the‐art multiscale 3D tomographic techniques are discussed with a focus on their integration with 3D geometric quantification, 4D in situ experiments, and multiscale modeling. Outlook is given on the emerging approaches to investigate the synthesis–structure–function–biomimetics relationship.
more » « less- NSF-PAR ID:
- 10445251
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Materials
- Volume:
- 34
- Issue:
- 20
- ISSN:
- 0935-9648
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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