Chinese scientists are delving further into successful bioprinting in ‘3D printing of complex GelMA-based scaffolds with nanoclay,’ exploring why photo-crosslinkable gelatin methacrylate (GelMA) has become so enticing for researchers attempting to engineer tissue. In a realm rife with obstacles, however, GelMA is no exception—constricted by viscosity issues and long cross-linking time.
The authors decided to bolster the ink further with nanoclay, in the hopes of being able to print stable, complex scaffolds. During this study, they evaluated windows for printability, issues with porosity and mechanical strength, and biocompatibility.
Obviously, without cell viability, there is no bioink and there are no spectacular innovations to write about. A wide range of hydrogels have been used successfully, with alginate commonly involved due to rapid crosslinking speed. Here, however, the researchers explain that alginate is not always conducive to attachment of cells or good function. Gelatin methacrylate (GelMA), however, is known to crosslink easily during light exposure. The researchers point out also that it maintains the biocompatibility of gelatin.
In attempting to overcome multiple issues with the use of GelMA, such as low viscosity and extensive time required for cross-linking, they examined the use of pre-crosslinking, post-crosslinking, in-situ crosslinking, and two-step crosslinking. Ultimately, the consensus was that all the methods were unsuitable, resulting in inferior stability. With the addition of nanoclay, however, the authors discovered that the ink had higher viscosity, and the GelMA scaffolds had better shape fidelity.
“After extrusion, the nanoclay rapidly converted to the gel state upon the release of shear stress, thereby forming stable hydrogel filament,” stated the authors. “Finally, the 3D structure was printed layer-by-layer by stacking the filament, and the GelMA within the filament was covalently crosslinked under UV light, resulting in a stable scaffold.”
They also found that nanoclay at higher levels resulted in less expansion due to more shear stress, meaning that nanoclay with higher concentration needed greater yield stress for deformation. In further discussion, the authors states that greater balance needs to researched for printing with GelMA/Nanoclay, and that so far, they surmise that if ‘cell-laden structures’ are to be directly 3D printed, they are forced to give up shape fidelity. Along with that, greater control is required of the following:
- Mechanical strength
- Degradation rate
- Tissue regeneration capacity
“Through systematic experiments that included rheological testing, printability analysis, property characterization, and biocompatibility characterization, we have answered several fundamental questions relating to this ink, including the formation mechanism for shear-thinning and rapid-gelling and the printability window for the fabrication of complex GelMA scaffolds, as well as showing that the addition of nanoclay improved the basic properties and had no effect on the excellent biological performance of the scaffolds,” concluded the researchers.
“Therefore, this method provides an easy way to fabricate complex GelMA-based scaffolds with good shape fidelity. It is very likely that this method will have versatile applications in the individualized therapy of tissue defects.”
The world of tissue engineering and bioprinting is rich in a variety of scaffolds, and while here we have learned more about the use of GelMA-based scaffolds, researchers around the world are constantly experimenting with new ways to sustain cells and make inks that are cell-laden. We have followed studies regarding transparent bioinks for fabricating corneas, making neural tissue, and 3D printing complex structures like alginate/gelatin hydrogels. What do you think of this news? Let us know your thoughts! Join the discussion of this and other 3D printing topics at 3DPrintBoard.com.[Source / Images: ‘3D printing of complex GelMA-based scaffolds with nanoclay’]
You May Also Like
Additive Manufacturing and 3D Printing in 2019
Additive manufacturing is changing the world. Another term for 3D printing, additive manufacturing differs from other forms of manufacturing in that, rather than removing material like machining, it adds material...
Tunisia: Researchers 3D Print Optimized Car Leaf Spring out of Carbon PEEK
Authors Amir Kessentini, Gulam Mohammed Sayeed Ahmed, and Jamel Madiouli have performed research and analysis after 3D printing a car part, with their findings outlined and recently published in ‘Design...
PEEK, PEKK and ULTEM May Just be the 3D Printing Thermoplastics You Need in Your Life
There was definitely life before plastics, but today we can’t imagine living without them. Before they were even invented (the first synthetic polymer was developed in 1869 by John Wesley...
Roboze Argo 500 Sets the Standard for the Production of Large Scale Finished Components with High Temperature and Composite Polymers
Bari, Italy With its new Argo 500, Roboze aims to become the leader in the large-scale 3D printing industry with high performance plastics. The Argo 500 is the result of constant...
View our broad assortment of in house and third party products.