This new hydrogel bio-ink renews hope in organ transplants

In the USA, 17 people die every day while waiting for an organ transplant. And every nine minutes, another person is added to the transplant waiting list.

According to Health Resources and Services Administration, apotential solution to remedy this shortage is to develop 3D printable biomaterials. In the form of complex organs, they would be able to host cells and form tissues.

PhD students at the University of Pennsylvania found the solution for assembling tissue engineering scaffolds. This stalemate has long hampered advancement of the manufacture of artificial biological tissues.

A new hydrogel bio-ink

So far, bulk hydrogel bio-inks failed to integrate properly in the body and support the cells in the heavy fabric constructions.

This new hydrogel bio-ink uses nanoparticles self-assembled and hydrogel microparticles. Researchers were able to achieve levels of porosity, shape fidelity and cellular integration never reached before.

A revolution for bio-printing?

So far, the bio-inks are based on bulk hydrogels. Polymers that can contain a considerable amount of water make them up, while retaining their structure. However, their pores are a limiting factor the interaction between cells, between cells-matrices, as well as the transfer of oxygen and nutrients. They also delay the integration of the bio-inks with the fabrics. That is, remodeling is required to allow cell infiltration and migration.

“The main limitation of 3D bioprinting using conventional bulk hydrogel bioinks is the trade-off between shape fidelity and cell viability, which is regulated by the stiffness and porosity of the material. ‘Hydrogel’.

The University of Pennsylvania assistant professor of chemical engineering and study author

We have overcome this limit now by reversibly binding the hydrogel microparticles. The use of nanoparticles that self-assemble made this process possible. Manufacturing a hydrogel bio-ink with well-preserved porosity, better printability and shape fidelity is now feasible.

Challenges for the future

However, cell viability and migration remained problematic. To achieve satisfactory 3D printing results, the hydrogels must to hug each other. Except that it compromises the space between the microparticles of hydrogels or microgels. This has a negative impact on cell porosity, viability and motility.

“Our work is based on the principle that nanoparticles can adsorb onto the surfaces of polymeric microgels and reversibly cause the microgels to adhere to each other, while not filling the pores between the microgels.”

Sheikhi

This dynamic bonding eliminates the need for tight packing through interfacial self-assembly of nanoparticles and preservation of microscale pores.

“By addressing one of the persistent challenges in 3D bioprinting of granular hydrogels, our work could open new avenues in tissue engineering and functional organ printing.”

Sheikhi

SOURCE: MIRA NEWS