Relevance:

• GS 3 || Science & Technology || Fourth Industrial Revolution || 3D Printing

Why in the news?

Due to the global organ shortage and limited organ donors, thousands of patients are left wanting organs and tissues in cases of severe injuries, illness or genetic conditions.

Present context:

• Tissue engineering is an emerging field that works on producing artificial tissue and organ substitutes as permanent solutions to replace or repair damage.
• Due to the global organ shortage and limited organ donors, thousands of patients are left wanting organs and tissues in cases of severe injuries, illness or genetic conditions. Many of these patients die before transplants are available

What is 3D Printed Organ?

• Bioprinting is a method that enables cellular structures to be made from bioinks loaded with stem cells. Layer by layer, the biomaterial is deposited to create skin, tissue or even an organ.
• Bioprinting projects are growing, and each new project is one-step closer to being a fully functional and viable solution.
• Laboratories and research centers are bioprinting human livers, kidneys and hearts. The objective is to make them suitable for transplantation, and viable long-term solutions.
• In fact, this method could allow to cope with the lack of organ donors, and to better study and understand certain diseases.

Tissue engineering:

• Tissue engineering is a biomedical engineering discipline that uses a combination of cells, engineering, materials methods, and suitable biochemical and physicochemical factors to restore, maintain, improve, or replace different types of biological tissues.
• Tissue engineering is the construction of bio artificial tissues in vitro as well as the in vivo alteration of cell growth and function via implantation of suitable cells isolated from donor tissue and biocompatible scaffold materials.

Printing with cells:

• Stem cell biologists have suspected for years that 3D printing could be used with living material, and wondered if it was possible to print three-dimensional shapes out of human cells
• The advantage of printing in three dimensions is that cells develop and retain their proper functions better and longer
• Scientists thus have to use materials for 3D printing that the cells can tolerate and can grow in, called biocompatible materials. There are many types of these materials, most of which are a material called hydrogels

Biocompatible scaffold materials:

• Scaffolds are materials that have been engineered to cause desirable cellular interactions to contribute to the formation of new functional tissues for medical purposes. Cells are often ‘seeded’ into these structures capable of supporting three-dimensional tissue formation.
• Alginate is a naturally occurring anionic polymer typically obtained from brown seaweed, and has been extensively investigated and used for many biomedical applications, due to its biocompatibility, low toxicity, relatively low cost
• 3D temporary organ structures – called scaffolds – that may help regenerate damaged tissues and potentially lead to creating artificial organs.
• These tissues can also be used in various tissue engineering applications, including nerve repair in structures constructed from biomaterials

Example of bio printing:

• Bioprinting a kidney:Wake Forest Institute for Regenerative Medicine, presented a 3D bioprinted kidney for the first time. At Harvard, for example, researchers have succeeded in bioprinting a 3D model of a vascularized proximal tubule to better understand the structure and function of the kidney.
• Bioprinted corneas:The World Health Organisation estimates that 10 million people worldwide require surgery to prevent corneal blindness, and 4.9 million already suffer from complete blindness due to corneal scarring.
  • One of the most challenging aspects was using the right materials to hold the concave shape of the cornea as well as finding an ink thin enough to squirt through a 3D bioprinter’s nozzle. Using only one healthy human cornea they were able to 3D print 50 artificial ones; a breakthrough advancement in ophthalmology.
• Bioprinted ovaries:In May 2017, researchers from Northwestern University were developing a solution for women with fertility issues. They were able to map the location of structural proteins in a pig ovary, allowing them to create a bioink to bioprint functional ovaries for human use
• Bioprinting a mini liver: Researchers at the University of São Paulo in Brazil have succeeded in creating miniature versions of a human liver from blood cells.To create the liver tissue, the team used the Inkrediblebioprinter, marketed by the manufacturer CELLINK, one of the most recognized in the industry.
• Bioprinted ear project:The ear implant was created using the patient’s cartilage cells, reducing the risk of rejection once implanted. In addition, this type of custom-made bioprinting solution is actually less-expensive than other alternatives.
• Bioprinting a pancreas:Foundation for Research and Development of Science” has set itself the goal of developing a functional 3D printed pancreas by 2020,for the bioprinting, a biopsy of the patient, and stem cell harvest is first performed. The cells are then converted into cells capable of producing insulin and glucagon. These are then used as bioink to print the pancreas.
• Bioprinted skin: The market for bioprinted skin is growing steadily, the startup company Poietis has developed 4D printed skin, which in the future could be transplanted for victims of burns or skin diseases.

What are the benefits of 3D printed organs?

• New materials:It gives bioengineers absolutely new materials.They can literally build with natural materials, something impossible to achieve with any other technology.
• Perfect replica of the patient’s organ: Many impressive researches led to lab grown organ, it will able to actually design a perfect replica of the patient’s organ and then manufacture it
• Rejection risk: Using the patient’s tissue means the DNA of new organ would perfectly match the patients, therefore the rejection risk would be totally eliminated.
• Organ shortage:Bioprinting technology could also fix this issue. The future of medicine and 3D printing techniques is no more waiting for transplant lists and organ donations wouldn’t be needed at all
• Mobility: Another benefit of 3D printing is mobility. In the future, every hospital will hopefully own 3D printers, so new organs could be produced locally.
• Drug and cosmetic testing: Bio 3D printed structures can be used for drug and cosmetic testing, as they can react like humans. Personalized medicine is another benefit of medical 3D printing, this would mean no more risky treatments such as chemo for cancer patients.

Challenges associated with 3D printing of organ:

• Alginate is a challenging material to work with because it collapses easily during 3D printing.
• Research focuses on the development of new techniques to improve its printability.
• For nerve repair, alginate has favourable properties for living cells growth and functions, but its poor 3D printability considerably limits its fabrication. It means that alginate flows easily during the printing process, and results in a collapsed structure.
• Developed a fabrication method where cells are contained within a porous alginate structure that is created with a 3D printer.
• Previous research used moulding techniques to create a bulk alginate without a porous structure to improve nerve regeneration; the cells do not like such a solid environment.
• However, 3D-printing a porous alginate structure is challenging and often impossibl
• Research addresses this issue by printing a porous structure made of alginate layer by-layer rather than a moulded bulk algiante. Such structure has interconnected pores and provides a cell friendly environment.
• Cells can easily communicate with each other and start the regeneration while the 3D-printed alginate provides a temporary support for them.

Additional info:

• Bio-ink: Bio-ink is a combination of living cells and a compatible base, like collagen, gelatine, hyaluronan, silk, alginate or nanocellulos a compatible base provides cells with scaffolding to grow on and nutriment to survive on. The complete substance is based on the patient and is function-specific.

Conclusion:

As you it can be seen that the upcoming year of 2022 might be the year of 3D printed human organs revolution. Additive Manufacturing truly has the power to change the face of the medical industry. Starting with educational models, to 3D printed vessels, hearts, livers or bones, doctors and scientists are using a new approach to 3D printing to save millions of lives.

Mains oriented question:

What are pros and cons associated with 3D printing generated organ in medical world? Can it be said as fourth revolution in medical science? (200 words)