Bioprinting has seen a number of significant developments in the last 12 months, but a momentous step forward in this area has been announced recently by Tao Xu et al of the Wake Forest Institute for Regenerative Medicine.
The premise for developing bioprinting — still an emerging technique — is the ability to fabricate viable, 3D tissue constructs through the precise deposition of cells and hydrogels in a layer-by-layer fashion. As you can imagine this brings a range of issues and challenges, one of which has been the lack of structural integrity and adequate mechanical properties for use in vivo, which limits use in load-bearing tissue engineering applications, such as cartilage.
In response to this, the research team from Wake Forest Institute have developed a hybrid printing system that has shown some very positive results. The hybrid nature of this printer comes from combining inkjet printing capabilities with an electrospinning system that can be used to fabricate viable tissues for cartilage tissue engineering applications. This combination has resulted in the team successfully producing a structure made from natural and synthetic materials, whereby synthetic materials ensure the strength of the construct and natural gel materials provide an environment that promotes cell growth.
The process itself involved combining flexible electrospun synthetic polymer one layer at a time, with a solution of cartilage cells from a rabbit ear that were deposited using the traditional ink jet printer. The constructs were square with a 10cm diagonal and a 0.4mm thickness.
According to James Yoo, a Professor at the Wake Forest Institute for Regenerative Medicine, and an author on the study: “This is a proof of concept study and illustrates that a combination of materials and fabrication methods generates durable implantable constructs. Other methods of fabrication, such as robotic systems, are currently being developed to further improve the production of implantable tissue constructs.”
Furthermore, the team has stated that future potential also lies in cartilage constructs that could be clinically applied by using an MRI scan of a body part, such as the knee, as a blueprint for creating a matching construct. A careful selection of scaffold material for each patient’s construct would allow the implant to withstand mechanical forces while encouraging new cartilage to organise and fill the defect.