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International Journal of Bioprinting 3D-printed nanocomposites: Synthesis & applications

According to the results of this work, a composite shows no adverse response. 100-102 Engineered human organ-
hydrogel made of MXene and PEG shows potential as an mimicking scaffolds can be produced using bioprinting
electroactive scaffold for the treatment of heart damage. strategy. Unlike current intraoperative procedures, 3D
printing can generate customized devices with exceptional
4.5. Biofiber-based composites accuracy. Thus, most 3D printing-related biomedical
Biomass can completely decompose in the soil without applications include the production of non-living structures,
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generating harmful chemicals. Low cost, availability, such as gadgets used in orthopedics, surgical equipment,
degradability, widespread accessibility, light weight, and osteonecrosis implants. In order to improve the
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acceptable tensile stiffness, and diminished healthcare functionality and viability of bioprinted constructions,
implications are all benefits of lignocellulosic fibers. controlled filler orientation is crucial since it mimics
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Therefore, natural fibers (e.g., from poplar wood or other the natural structure of tissues and organs. Many tissues
biopolymers) are commonly incorporated into polymer including muscles, skin, vessel, and nerves exhibit parallel
matrix to develop hybrid biocomposites with high stiffness, alignment in the arrangement of cells and ECM. For example,
light weight, biodegradability, and recyclability. In addition the cytoskeletons and nuclei of tenocytes are elongated
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to being low-cost, degradable, widely accessible, and light along the direction of parallel-aligned collagen fibers in
weight, lignocellulosic fibers have appropriate tensile stiffness tendon. The alignment of cells plays a significant role in
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and do not cause profound healthcare implications. the cell functions; for instance, the alignment of cardiac cells
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Biorefinery lignin derived from Pinus radiata was is fundamental to heart contraction. In addition, radially
blended with polyhydroxybutyrate composites and melt- alignment of tissue is observed in cornea, meniscus, dura
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extruded to form composite filaments. The rheology mater, etc. To simulate human tissue and engineer tissue
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findings show that adding lignin as fillers at a weight-to- or organ for replacement, developing controlled anisotropic
weight ratio of 20% caused a change in the melt viscosity scaffolds is therefore vital as the matrix microenvironment
and made the material suitable for 3D printing. Zhao et is responsible for cellular behaviors including attachment,
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al. prepared poplar/PLA composites with variable sized movement, proliferation, and differentiation in vivo.
poplar fiber mesh. As poplar fibers shrank, poplar/PLA Anisotropic topographies have a significant impact
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tensile strength increased from 34 to 54 MPa. Composites on how cells behave in terms of both morphology and
made from shorter poplar fibers showed more compact function, particularly fibroblasts, osteoblasts, neurons,
and mesenchymal stem cells (MSCs). The transverse or
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fracture surfaces and fewer voids. Liu et al. synthesized PLA longitudinal topological signals in anisotropic scaffold could
composites with sugarcane bagasse. Adding sugarcane be sensed by cells and guide cellular fate by modulating cell
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bagasse to PLA lowered tensile and flexural strength growth and differentiation, which in turn regulates tissue
but enhanced flexural modulus in printed samples. In regeneration and their microenvironment.
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another study, two types of polyethylene were mixed with
thermal–mechanical pulp fibers to make biocomposites. Cell adhesion that regulates the signal transmission
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The hydrophilic character of thermal–mechanical pulp between cell membrane and ECM during adhesion and
fibers was changed by enzymatically grafting hydrophobic migration can be modulated via the nano- or micro-
compounds (octyl gallate and lauryl gallate). Ethylene scale topographies in the anisotropic scaffolds. 108,109
filaments with low melt flow index have low void Cell movement is usually influenced by several factors
percentage and thickness variability. The morphologies, including durotaxis, haptotaxis, chemotaxis, galvanotaxis,
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mechanical properties, crystallization properties, and and mechanotaxis. Among these, mechanotaxis is of
heat resistance of 3D-printed materials were also studied. great importance in regulating cell fate. Research has
This research shows that biocomposites can be made from explored the mechanical feedback to cells. Cells sense the
massive amounts of residual lignin. internal matrix stiffness and external mechanical loads
and transduce the mechanical signal into physiological
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5. Engineering strategies for filler responses to guide cell growth and differentiation. As
alignment in bioprinting substrate stiffness increases, 3T3 fibroblasts become less
motile while spreading more widely, an indication of
Tissue engineering is a multidisciplinary biomedical the significant role that substrate stiffness plays in tissue
engineering field that integrates biological science and regeneration by influencing cell behavior and cellular fate.
engineering. It represents a new approach to constructing Stiffer ones are prone to guide cells to produce stress fibers
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artificial tissues for clinical studies, translation, and and enter cell cycle, increasing cell traction, spreading, and
drug delivery since the patient-specific autologous cell- proliferation. In contrast to stiffer ones, softer substrates
incorporated scaffold generated through this approach promote cell secretory activity. The cellular response to

Volume 10 Issue 2 (2024) 88 doi: 10.36922/ijb.1637