Lab Canada

3D skin tissue printer wins technology award

Toronto, ON – Proprietary 3D bioprinting technology, PrintAlive Bioprinter, developed by University of Toronto students Arianna McAllister and Lian Leng, has won the Canadian stage of the 2014 James Dyson Award. The bioprinter represents a huge leap forward in producing high-resolution human microtissue arrays with unprecedented speed and control, improving the recovery and healing time of burn victims. McAllister and Leng will receive $3,500 to further develop their prototype, and will progress to the international stage of the award.

The James Dyson Award is an international student design award run in 18 countries. The contest is open to university level students (or recent graduates) in the fields of product design, industrial design and engineering, who “design something that solves a problem.” The award has an international prize fund of over ~$180,000 CAD (£100,000), with ~$50,000 CAD (£30,000) going to the winner and ~$18,000 CAD (£10,000) to their university. The winner of the international prize is announced in early November.

3D bioprinting technology

Most skin tissue has unique 3D hierarchal architectures to organize multiple cell types and sub-structures. This spatial organization is crucial in tissues biological function and when simulating the structure and function of human tissues in vitro.

Existing bioprinters rely on a top-down assembly approach when organizing multiple cell types and sub-structures, limiting the complexity of different 3D skin structures and drastically reducing the amount of skin tissue produced. Timing and quantity of cross-sectional skins are important; particularly for severe burn victims where both the epidermal and dermal layers of the skin are destroyed and prompt wound closure is critical for favourable patient outcomes and reduced mortality rates.

To solve the problem of printing 3D complex skin tissues, McAllister and Leng built on the existing printing approach of using arrays of microfabricated channels, where uncrosslinked biopolymer is distributed and organized into the final hydrogel shape inside the microfluidic device. They developed custom devices to print viable human keratinocytes and fibroblasts in a structure that mimics the epidermal and dermal layers of human skin in both single and bilayered grafts. The preliminary in vivo data suggests improved wound healing after implantation of their cell-populated patterns grafts. The bioprinter currently focuses on skin replacement, however future applications of the bioprinter could include replacing cardiac tissue damaged by heart attacks.

Biomedical and Mechanical Engineering student, Arianna McAllister said: “As we move towards more complex animal models, we are hoping that our cell-populated sheets and bioprinting approach can one day be used as on-demand custom grafts for patients with severe burns. Compared to the current standard of care, this would significantly reduce the amount of donor cells needed and the overall printing and culture time before application to the wound. Using the patients’ own cells would completely eliminate immunologic rejection, and the need for painful autografting and tissue donation.”

Since 2008, McAllister and Leng have developed hundreds of design iterations to optimize the machine’s design and accommodate new skin pattern tissues. The team also developed several generations of an automated collection reservoir to wind and collect the gels after formation. Currently, the University of Toronto students have developed a second generation, pre-commercial prototype of the machine and hope to scale up their device from its current bench top process to a higher volume automated process.