Sericin and Fibroin: 3D Bioprinting of Tissues and Organs
Introduction to 3D Bioprinting
3D bioprinting is a revolutionary technology that enables the fabrication of functional, biological replicas of naturally occurring body parts, such as organs. This process involves using cellular bio-inks, which are composed of living cells and biocompatible materials, to artificially grow organs in a lab setting . Sericin and Fibroin are playing a crucial role in advancing these technologies. Let us understand how.
Bioinks: Classifications and Components
A bioink is a natural or synthetic polymer selected for its biocompatible components and favorable rheological properties. It supports living cells and promotes cell adhesion, proliferation, and differentiation during the maturation process . Bioinks can be classified into two main categories:
- Synthetic Bioinks: These are engineered materials, such as polyethylene glycol (PEG), polylactic acid (PLA), and polycaprolactone (PCL), designed to have precise control over their chemical and physical properties .
- Natural Bioinks: Derived from biological sources, these include collagen, gelatin, alginate, fibrin, and hyaluronic acid. They are inherently biocompatible and often have built-in biological cues to promote cellular interactions .
In addition to the main polymer component, bioinks often include other materials to optimize their performance. Some examples include gelatin methacrylol (GelMA), collagen, poly(ethylene glycol) (PEG), alginate, and hyaluronic acid .
Silk Proteins in 3D Bioprinting: Sericin and Fibroin
Silk proteins, particularly sericin and fibroin, have shown great potential as components in bioinks for 3D bioprinting. A study by Sharda et al. (2020) found that silk fibroin composite scaffolds possessed certain mechanical properties and a porous network structure, which are conducive to the transportation of bioactive substances and the discharge of cell metabolites. Furthermore, they improved cell adhesion and growth, an important requirement for medical tissue engineering .
Another study by Silva et al. (2022) highlighted that sericin-based bioinks have shown promising characteristics, such as enhanced mechanical strength, thermal stability, and resistance to protease degradation. These properties make sericin an attractive component for bioinks used in bone regeneration applications .
Sericin, a globular protein composed of random coil and β-sheets, plays a crucial role in 3D bioprinting. Its unique properties, such as biocompatibility, biodegradability, anti-inflammatory activity, and antioxidant effects, make it an ideal component for bioinks. Sericin enhances the biological performance of silk fibroin bioinks by promoting cell adhesion, growth, and proliferation .
Recent Advancements in 3D Bioprinting with Silk Proteins
Researchers have made significant progress in using silk proteins for 3D bioprinting of functional tissue constructs and simple organs:
3D Printed Heart Valves Using Silk Fibroin
Researchers have successfully 3D printed functional heart valve scaffolds using silk fibroin bioinks. In a study by Duan et al., a silk fibroin-gelatin bioink was used to print trileaflet valve conduits with encapsulated human aortic valve interstitial cells. The printed valves exhibited appropriate mechanical properties and supported cell growth and remodeling .
Silk-Based Vascular Grafts
Silk fibroin has been explored as a scaffold material for engineering small-diameter vascular grafts. A recent study replaced the inferior vena cava of rats with a silk fibroin vascular graft. The silk grafts demonstrated high patency rates (94.7% at 4 weeks) and rapid endothelialization, outperforming ePTFE grafts. This highlights the potential of silk as a promising scaffold for blood vessel replacement .
3D Printed Bone Grafts with Silk Fibroin
Silk fibroin has also been used to fabricate 3D printed bone grafts. Researchers have created silk-based scaffolds with tunable architectures that mimic the structure of native bone. These constructs, when seeded with mesenchymal stem cells, supported bone tissue formation both in vitro and in vivo .
Technical Specifications of Sericin for Bioinks
For sericin to be effectively used in bioinks, it should meet certain technical specifications. The extraction method significantly influences sericin’s yield and characteristics. High-quality sericin for bioinks should have a molecular weight ranging from 20 to 400 kDa and be free from impurities such as soap residues .
Conclusion
While the field of 3D bioprinting with silk proteins is still in its early stages, the unique properties of silk fibroin and sericin make them highly attractive as bioink components. As 3D bioprinting techniques continue to advance, silk-based materials will likely play a key role in the development of engineered tissues and organs [3, 4, 6, 7, 8, 9].
Serione is a leading supplier of high-quality sericin and silk fibroin that meet the stringent requirements for use in bioinks. Our silk proteins are carefully extracted and purified to ensure optimal performance in 3D bioprinting applications. Contact us today to learn more about how our silk proteins can enhance your bioink formulations and accelerate your research and development efforts in this exciting field.
References:
- Built In. (2023). 3D-Printed Organs: The Future of Medicine.
- CELLINK. (2023). What is Bioink?
- Sharda, A., et al. (2020). Silk Fibroin Based Composite Scaffolds for Tissue Engineering Applications. Frontiers in Bioengineering and Biotechnology, 8, 1-18.
- Silva, S. S., et al. (2022). Sericin-Based Hydrogels for Biomedical Applications. Polymers, 14(22), 4931.
- Sigma-Aldrich. (2023). 3D Bioprinting: Bioinks.
- Ribeiro, V. P., et al. (2022). Sericin: A Promising Protein for Tissue Engineering and Regenerative Medicine. Biomolecules, 12(8), 1119.
- Duan, B., et al. (2013). Three-dimensional printed trileaflet valve conduits using biological hydrogels and human valve interstitial cells. Acta Biomaterialia, 10(5), 1836-1846.
- Enomoto, S., et al. (2020). Silk fibroin vascular graft: a promising tissue-engineered scaffold material for abdominal venous system replacement. Journal of Vascular Surgery: Venous and Lymphatic Disorders, 8(6), 1049-1058.
- Ghosh, S., et al. (2012). A silk-based scaffold platform with tunable architecture for engineering critically-sized tissue constructs. Biomaterials, 33(35), 9188-9197.