precisely printable and biocompatible silk fibroin bioink for digital light processing 3d printing
Bio-printing technology has received wide attention in the field of tissue engineering, but there are still some major engineering challenges that need to be overcome, including the lack of bio-ink with biological compatibility and printing adaptability.
Here we show a kind of silk protein (SF)
For digital light processing (DLP)
3D bio-printing in tissue engineering applications. The SF-based bioink (Sil-MA)
Is by the use of acrylic shrink glycerin (GMA)
In the manufacturing process of SF solutions.
Mechanical and flow properties of Sil-
MA gel proved to be outstanding in experimental testing and can be adjusted by changing Sil-MA contents. This Sil-
MA bioink enables us to construct highly complex organ structures, including the heart, blood vessels, brain, trachea and ears with excellent structural stability and reliable biocompatibility. Sil-
Good horse bio ink-
Suitable for DLP printing process, can be applied to tissue and organ engineering according to specific biological requirements.
Recently, bioprinting technology has moved towards the goal of creating more complex structures with different tissue components and internal microvessels.
Bio-printing allows the placement of cells, bio-materials, and bio-active molecules in a precise manner, resulting in complex three-dimensional (3D)
Tissue structure for biological and clinical applications.
The biological printing technology can be divided into inkjet printing and extrusion printing (
Simulation of molten deposition; FDM), light-
Auxiliary biological printing including digital light processing (DLP)and laser-Based on printing (Table).
Similar to traditional double-Inkjet bio-printing
Size inkjet printing has the advantages of relatively low cost and moderate printing speed (mmu2009s);
However, disadvantages include the inability to use high
The viscosity material and high cell density due to nozzle blockage and inability to build 3D tissue structure.
The extrusion bioprinter was developed by modifying the inkjet printer and using an air pump or a screw piston to distribute the bioink.
Due to this design, the extrusion type printer is compatible with gels of various viscosity, however, the more viscous gel and relatively long printing time produce greater mechanical stress on the packaged cells, cell activity can be reduced by 40-80%.
In contrast, DLP bioprinter can overcome these limitations.
They create models in one layerby-
Different layers fashion from other printing methods aggregated by UV light (UV)light.
Therefore, DLP implements high resolution (about 1u2009μm)
And print fast (~30u2009min, mmu2009s)
Regardless of the complexity and area of the layer.
In addition, DLP printing nozzles-increase cell viability by more than 85-95% due to short printing time
Free printing technology
Printable materials or bio-inks need to meet several basic standards in terms of printing suitability, biocompatibility and bionic properties (including structural and mechanical stability.
All these requirements are essential for the long term
In particular, bioink must be able to deposit in one layer when using DLP mode-by-
Layer fashion, create Z
The definition of the layer, and it is curing.
A gel that forms a 3D cross-linked hydration fiber and is suitable as a bio-ink for 3D bio-printing.
They can be used as cell substrates and provide a mechanically supported environment that can be modified to simulate natural tissues and their extracellular substrates.
Only a small number of biological materials are reported to be able to produce gels for 3D bio-printing, including fiberglass, Agar, gelatin, hyaluronic acid and seaweed.
A diacrylic acid composed of a few sugars and ethylene glycol (PEGDA)
A mixture of polydiacrylic acid and hyaluronic acid acrylic acid, and a mixture of peg da and gelatin acrylic acid (GelMA)
The gel is reported to be a potential bio-ink for DLP printing.
However, the gel based on the synthetic material has an inherent low cell adhesion capability, natural material-
The rigidity of the base gel is insufficient, and it is difficult to control the rigidity of the matrix.
In DLP printing, the kinetics of polymerization can be adjusted by changing the power of the light source, the printing rate, and the type and concentration of the photoinitiator, however, in the end, the biological material itself controls the printing suitability and mechanical properties of the printed material. Silk fibroin (SF)
The natural fiber protein produced by it has been used in a variety of biomedical and biotechnology applications, including wound dressings, enzyme-fixed substrates, artificial blood vessels and structural implants.
SF can be processed into different forms and structures, including in all-
Has been applied to the field of organizational engineering.
SF is chemically modified for other purposes such as coupling reaction, amino-
Acid Modification and grafting reaction according to specific application.
Add acrylic acid to Amine-
The method containing the side base of the material can be used to lightly aggregate it into a gel.
The degradation time of the material can also be customized by changing the degree and location of methane.
We assume that SF will be an excellent bio-ink for DLP 3D bio-printing through A-propylene.
Until now, because there is no cross-linking site necessary for photoaggregation, SF itself is not used for DLP printing, and we do not believe that SF used to perform photoaggregation directly with an acrylic base.
In this study, we demonstrate a technique to develop an effective bio-ink for DLP printing by chemical modification of SF with acrylic shrink glycerin (GMA)(Sil-MA).
We evaluated the degree of alpha-propylene on SF modified by various ma quantities and based on Sil-
MA concentration relative to the sewing potential.
In addition, we prove that Sil-
MA gel prepared by DLP printing and its printing adaptability to different organs with complex structure.