Page 8 - MSAM-2-2

Materials Science in Additive Manufacturing Union of 2D nanomaterials and 3D printing

injuries, such as fractures, car accidents, and foreign body
invasion, or non-traumatic injuries, such as tumors and
neurodegenerative diseases [2,3] . Such injuries are typically
accompanied by axonal and myelin damage, neuronal
cell death or necrosis, astrocyte and microglial activation,
immune cell infiltration, and inflammation [4-6] . The PNS is
more susceptible to internal or external injuries than the
CNS due to the absence of a rigid bony layer and protection
from the blood-brain barrier . Conventional treatments
[7]
encounter significant obstacles when it comes to promoting
neurogenesis and facilitating neuronal functional recovery.
Typically, autografts or allografts are introduced to repair
nerve damage; yet, this approach presents various limitations,
including the limited capability of adsorbing multiple drug
molecules and lack of precise control over release kinetics .
[8]
Recently, two-dimensional (2D) nanomaterials have been
discovered to possess exceptional electrical conductivity,
which is beneficial for growing specific cells such as muscle
cells and neurons [9,10] . Based on the advantages of three- Figure 1. Schematic diagram of a combination of 3D printing and 2D
dimensional (3D) bioprinting, such as its ability to deposit nanomaterials for neural tissue engineering.
various types of cells and biomaterials with high precision and 3D: Three-dimensional; 2D: Two-dimensional.
maintain their viability and functionality, a 3D bioprinting weak mechanical properties, poor electrical conductivity,
approach incorporating 2D nanomaterials has the potential and insufficient bioactivity, which hinder their use in 3D
to become a promising therapy for neural tissue regeneration bioprinting applications. To overcome these challenges,
in the future (Figure 1). Consequently, researchers have been the integration of 2D nanomaterials and 3D bioprinting
increasingly studying the reactions of 2D nanomaterials has emerged as a promising strategy. The incorporation
on modulating neuronal behavior , leading to a growing of nanoparticles (NPs) into bioink can enhance cell
[11]
interest in using these materials as bioinks for treating viability by providing mechanical and structural support
neurological disorders. Furthermore, the emergence of 3D to the printed cells. NPs can create a scaffold-like structure
bioprinting technology has facilitated the construction and that mimics the ECM of the body, which is the natural
application of 3D structures with appropriate mechanical environment in that cells grow and function. This scaffold-
and biological properties for stacking living cells and like structure can help to maintain the shape and integrity
restoring tissue and organ function in various tissue repair of the printed structure, as well as to provide physical cues
applications . The investigation of nerve scaffolds has to the cells to grow and differentiate. Moreover, the NPs
[12]
been extensive, specifically focusing on mimicking the can also help to regulate the microenvironment of the
native extracellular matrix (ECM) to offer structural and printed cells. For example, they can modulate the release
[13]
biochemical cues that promote nerve regeneration . The of growth factors and cytokines, which are the signaling
cell growth and differentiation are guided by these signals to molecules that help to regulate cell behavior.
facilitate better integration with host tissues at the injury site. In this review, we will present 2D nanomaterials that
The development of 3D bioprinting technologies exhibit particular advantages in treating diseases related to
creates numerous opportunities for producing intricate nerve injury and discuss new strategies to improve nerve
cellularized structures . The goal is to create complex regeneration in combination with 3D bioprinting.
[14]
tissue structures that mimic the natural tissue environment 2. Classification and biocompatibility
and function properly . To achieve this, the printed cells
[15]
need to be viable and functional, meaning that they can of 2D nanomaterials for neural tissue
proliferate and differentiate into the desired cell types and engineering
perform their physiological functions. The use of polymeric 2.1. 2D Nanomaterials utilized for neural regeneration
hydrogels in bioink formulation has been extensively
studied due to their biocompatibility, easy processing, 2.1.1. Graphene
and rheological properties. However, there are numerous Graphene is a 2D nanomaterial composed of carbon atoms
limitations associated with polymeric materials, such as that are covalently bonded together to form a hexagonal

Volume 2 Issue 2 (2023) 2 https://doi.org/10.36922/msam.0620