New bio-ink has promise to create 3D printed bone structures


Bioprinting is an additive manufacturing approach using biomaterials with cell and growth factors to create tissue-like structures that imitate natural tissues. This has potential for many medical uses, including designing patient-specific bone grafts. Traditional treatments for bone defects or injuries are slow and expensive. Creating replacement bone tissues with bioprinting could create new treatments for arthritis, bone fractures, dental infections and craniofacial defects.

Bioprinting requires cell-laden biomaterials that can flow through the nozzle like a liquid and solidify almost immediately after being deposited. The bio-ink acts as cell carriers and structural components that are printable and create robust and cell-friendly microenvironment. Current bioinks lack sufficient biocompatibility, printability, structural stability and tissues specific functions required for clinical use.

The new bio-ink is called Nano Iconic-Covalent Entanglement (NICE) bioinks. The team combined two reinforcement techniques, nanoreinforcement and iconic-covalent networks, to create better reinforcement and stronger structures. After bioprinting cell-laden NICE networks, they cross-linked the networks to create strong scaffolds. This allowed the team to create full scale and cell-friendly reconstructions of human body parts.

After bioprinting, the enclosed cells start depositing new proteins that are rich in a cartilage-like extracellular matrix that calcifies and forms mineralized bone over three months. Five percent of the printed scaffolds created calcium that was similar to cancellous bone.

Researchers used a next-generation genomics technique called whole transcriptome sequencing (RNA-seq) to understand how the bioprinted structures create stem cell differentiation. RNA-seq takes a snapshot of all genetic communication inside a cell at a given moment.

The team plans to demonstrate in vivo functionality of 3D bioprinted bone tissue.

A paper on this research was published in Applied Materials and Interfaces., 5 May 2020