Bioprinting: speed up in functional tissue fabrication

The High-throughput Integrated Tissue Fabrication System for Bioprinting (HITS-Bio) is a digitally controlled nozzle array developed by researchers at Penn State. This technique addresses long-standing challenges in bioprinting, including scalability, precision, and high cell density, which are critical for creating functional tissues. 

“This technique is a significant advancement in rapid bioprinting of spheroids,” said Ibrahim T. Ozbolat professor at Penn State and chair in 3D Bioprinting and Regenerative Medicine. “It enables the bioprinting of tissues in a high-throughput manner at a speed much faster than existing techniques with high cell viability.”

Bioprinting uses bioink - cells encapsulated in a hydrogel substrate - to layer living cells, which grow and mature into 3D tissues over time. However, traditional methods struggle to replicate the high cell density found in human tissues. Spheroids, clusters of cells with natural density, present a promising alternative but require scalable and precise handling techniques. 

HITS-Bio's 4x4 nozzle array allows simultaneous manipulation of 16 spheroids, enabling rapid and precise tissue assembly. This approach significantly reduces production time while preserving cellular integrity. 

To validate HITS-Bio, the team fabricated cartilage tissue - a structure containing 600 spheroids - in under 40 minutes. This surpasses existing bioprinting technologies. 

Additionally, researchers demonstrated the method’s potential for surgical applications. Using a rat model, spheroids were printed directly into a skull wound site. The cells, programmed with microRNA technology, transformed into bone tissue, accelerating healing. After six weeks, the wound was 96% healed, a significant improvement over traditional methods. 

“Since we delivered the cells in high dosages with this technique, it actually sped up the bone repair,” said Ozbolat. 

The HITS-Bio platform offers opportunities to scale up tissue fabrication, including creating complex structures such as liver tissue or entire organs. Future developments aim to integrate blood vessels into printed tissues, a critical step for clinical applications. While cartilage and bone applications were successful due to their lower vascular requirements, incorporating vascular networks will broaden the technique's potential for transplantation. 

MEDICA-tradefair.com; Source: Penn State