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International Journal of Bioprinting 3D bioprinting of nerve guidance conduits

and filtered for topic abstracts and keywords. The statistical aggregates, such as micro-tissues, or hybrid cell-material
data is shown in Figure 3. The statistics include original constructs, through bioprinting or bioassembly, and
research, reviews, and conference papers. As shown in subsequent tissue maturation process”. 35(p.5) This definition
Figure 3, research on nerve conduits has increased steadily includes the fabrication of scaffolds with hierarchical
since the 1990s, with a current focus on the development structural properties or smart-surface properties within
and study of ideal biomaterials and technologies for nerve the realm of bioprinting. The advent of 3D bioprinting has
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conduit biomanufacturing. led to more solutions for nerve conduits. Although various
biomaterials and preparation strategies have been widely
Traditional techniques for the preparation of
nerve conduits mainly include solvent casting, phase investigated, there are still challenges in achieving good
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biocompatibility, appropriate mechanical properties, and
separation, gas foaming, electrospinning, and freeze- effective nerve regeneration at the same time. Meanwhile,
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drying. These techniques have inherent limitations, emerging technologies such as 3D bioprinting offer
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such as poor repeatability, low resolution, and limited unprecedented possibilities for constructing NGCs with
control of the manufacturable shape, which greatly limit fine structures, adjustable functions, and individualized
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the structure and application of nerve conduits. Additive
manufacturing (AM) can effectively overcome (some of) features. However, their synergistic integration with
applicable biomaterials and bioactive factors is still in its
the limitations of these traditional technologies. AM infancy. Therefore, a review of the design principles of
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(commonly known as 3D printing) is a manufacturing nerve conduits, the selection of biomaterials, and the latest
approach that allows the fabrication of constructs through advances in 3D bioprinting technologies are needed to
layer-by-layer (LBL) deposition of materials starting from identify the current critical issues and provide guidance
a digital model file, which is widely used in aerospace, for future research in this area. Hence, this review will
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automotive manufacturing, healthcare, construction, discuss the application of bioprinting technology in the
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textile, and other fields. AM enables the fabrication of 3D biofabrication of neural conduits, with a focus on its
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complex parts, including scaffolds, lattice structures, and research progress and challenges, specifically divided into
customized patterns, in a wide range of materials, including three main sections: (i) a discussion of the advantages and
biopolymers and hydrogels, enabling rapid prototyping of limitations of various nerve conduit structures, which
biological conduits with variable designs and providing provides guidance on selecting appropriate designs under
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new solutions for the fabrication of neural conduits. different injury conditions, (ii) introduction of the main
Since 2011, 3D bioprinting has been increasingly biomaterials used in nerve conduit fabrication and their
applied to NGC research (Figure 3B). Biofabrication applications in peripheral nerve regeneration, and (iii)
is defined as “the automated generation of biologically summary of current 3D bioprinting technologies for nerve
functional products with structural organization from conduits along with relevant fabrication strategies. Finally,
living cells, bioactive molecules, biomaterials, cell the review highlights the key challenges in translating nerve

Figure 3. Publication trends in nerve conduit research and 3D printing applications (1991–2023). (A) Number of nerve conduit papers published per year
from 1991 to 2023. (B) Number of three-dimensional (3D)-printed nerve conduits and 3D bioprinting nerve conduits papers published per year from
2011 to 2023.

Volume 11 Issue 4 (2025) 36 doi: 10.36922/IJB025140120