Electrospinner: Application of Silk Fibroin (SF)-Based Bioink Sil-MA in DLP 3D Bioprinting

Background

Challenges of 3D bioprinting: Although 3D bioprinting technology has received widespread attention in the field of tissue engineering, it still faces major engineering challenges such as the lack of biocompatible and printable bioinks.

Preparation of Sil-MA bioink

Chemically modified silk fibroin: The authors demonstrated a bioink (Sil-MA) made of silk fibroin (SF) by adding glycidyl methacrylate (GMA) to the SF solution for methacrylation to prepare Sil-MA hydrogels suitable for digital light processing (DLP) 3D bioprinting.

Characterization of Sil-MA

Methacrylation degree: The methacrylation degree of Sil-MA was evaluated by 1H-NMR spectroscopy, and it was found that with the increase of GMA amount, Sil-MA showed characteristic resonance peaks, indicating successful methacrylation.

Pore size change: FE-SEM images showed that the pore size decreased with the increase of methacrylation degree and Sil-MA concentration.

Mechanical properties and water absorption

Compressive elastic modulus: The compressive elastic modulus increased with the increase of Sil-MA concentration and strain.

Compressive stress: For every 10% increase in Sil-MA concentration, the compressive stress increased by 2.6 times.

Tensile strength and elongation at break: The higher the concentration of Sil-MA hydrogel, the greater the tensile strength and elongation at break.

Resolution and printing suitability of DLP printing

Complex organ structures: Using 30% Sil-MA, researchers successfully printed complex organ structures including heart, blood vessels, brain, trachea and ears, showing high structural stability and biocompatibility.

Cytocompatibility

Cell viability and toxicity tests: Cells encapsulated in Sil-MA hydrogels survived at all tested concentrations, and CCK-8 assays showed that cells grew well in Sil-MA hydrogels.

Cartilage tissue engineering

In vitro histological evaluation: Cricocartilaginous tracheae made using Sil-MA hydrogels showed good cell distribution and cartilage tissue formation.

Connection with electrospinning technology

Biomaterial design: Although electrospinning technology was not used in this study, the preparation and application of Sil-MA hydrogels have similarities with electrospinning technology in the preparation of high-performance biomedical materials, especially in simulating extracellular matrix and promoting cell growth.

Tissue engineering applications: Electrospinning technology can prepare nanofibers with high specific surface area and high porosity, which are essential for cell adhesion and proliferation, and complement the application of Sil-MA hydrogels in tissue engineering.

Conclusion

Biopatibilitv and biomaterial potential: DLP 3D printed Sil-MA hydrogels may become a promising biomaterial in tissue engineering due to their excellent biocompatibility. Sil-MA bioink uses only natural polymers, but exhibits the same strength and stability as materials prepared by combining natural polymers with synthetic materials.

Electrospinning Nanofibers Article Source:

https://doi:10.1038/s41467-018-03759-y