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International Journal of Bioprinting 3D bioprinting of nerve guidance conduits

However, despite their innovative vision and current a promising approach to achieve controlled regulation of
implementation in clinical studies, these conduits are the biodegradation rate, mechanical strength, and other
still limited to small-diameter nerves and may not be properties of the conduit. This customization allows the
effective for bridging longer nerve gaps. Advancements conduit to meet the specific requirements of different types
in biomaterials and 3D bioprinting technologies can of injuries and injury gaps, thereby providing superior
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therefore offer the potential for developing novel nerve performance in the repair and regeneration of PNIs.
conduits that address such limitations by incorporating Although 3D bioprinting has made significant
bioactive factors to further enhance nerve regeneration, progress in the fabrication of peripheral NGCs, and
while offering more complex NGC geometrical structures. the prospects are bright, many challenges remain. The
The use of composite biomaterials functionalized with biomaterials available for printing are limited, and the
biomolecules or embedded with SCs or NSCs also performance in terms of degradability, biocompatibility,
inevitably complicates the certification process. The and mechanical properties needs to be improved. Future
regulatory approval typically focuses on certifying the research on NGCs should focus more on enhancing their
core biomaterial, such as the scaffold, while the integration bio-hybridity by controlling the embedment of stem
of patient-derived cells is subject to separate approval cells with neurotrophic factors and targeted drugs. This
processes. Consequently, one of the biggest obstacles at the strategy aims to further expand the potential for nerve
moment is regulatory approval. Furthermore, most of the regeneration, addressing the various needs of nerve repair
research to date has been based on small animal models, effectively. In addition, future studies of nerve repair
which do not fully capture the complexity of human mechanisms will provide a better direction for the design
peripheral nerve regeneration. Validation using large of new 3D-printed NGCs. The integration of bioelectronic
animal models is necessary to accurately mimic human interfaces, smart biomaterials, and 4D printing is another
anatomical and physiological conditions. Ultimately, the emerging direction in the field of NGCs that has the
scalability of such prototypes heavily depends on factors potential to completely transform the next generation
like batch-to-batch variation, long-term sterility, scalability, of NGCs. The development of NGCs that adjust to the
and rigorous quality control, all of which are crucial for physiological conditions of the regenerating nerve is
successful product commercialization. For customized or achievable through 4D printing, which involves the
multi-material structures, the scalability of bioprinting generation of dynamic structures capable of responding
platforms remains a significant challenge. Advancements to environmental stimuli, such as temperature, pH, or
in process automation, closed-loop control systems, and electrical signals. The regenerative capacity of NGCs
real-time quality assurance technologies will increase could also be enhanced using smart biomaterials
their technological availability and market awareness. engineered to actively release bioactive molecules or
Within this framework, stronger cooperation between all exhibit a controlled degradation profile. In addition,
stakeholders involved, including academic researchers, bioelectronic interfaces offer the possibility of integrating
physicians, regulatory agencies, and business partners, is electrical stimulation within NGCs to stimulate (and
needed to move forward.
potentially accelerate) in situ nerve regeneration.
6. Conclusion Through regulating neuronal activity, boosting axonal
regeneration, and supporting neuroplasticity, electrical
NGCs have a broad application prospect in the field of stimulation has been demonstrated to stimulate nerve
nerve repair for their ability to construct NTE conduits growth. Electrical signals can promote cell proliferation,
using a combination of designs and biomaterials chosen release neurotrophic factors, and improve the conduit
to mimic the natural structure of peripheral nerves regenerating axon alignment. This controlled stimulation
and provide a favorable microenvironment for nerve can also support the formation of synaptic connections
regeneration. Although there are various current solutions, and improve functional recovery in nerve tissues.
most of these conduits are still in the experimental stage Bioelectronic interfaces could be incorporated into
and have not reached clinical translation. None of them can NGCs using biocompatible conductive materials,
currently fully substitute autologous nerve grafts to repair such as poly(3,4-ethylenedioxythiophene) polystyrene
peripheral nerve defects. Recently, AM has been exploited sulfonate or graphene, enabling precise control over the
for the fabrication of multi-material and multi-functional electrical signals applied. Therefore, the integration of
NGCs. An ideal 3D-bioprinted personalized NGC should these technologies promotes the development of highly
mimic the precise structural details of the nerve region to customizable, multi-functional NGCs that not only
be replaced by guiding tissue regeneration. In this concept, provide structural support but also actively participate in
biocomposites of natural and synthetic origins are seen as the nerve regeneration process.

Volume 11 Issue 4 (2025) 56 doi: 10.36922/IJB025140120