3D Printing Therapeutic Proteins With A New Bioink By Texas A&M Engineering Team

According to the university, the team has designed a new class of hydrogel bioinks (3D structures that can absorb and retain considerable amounts of water) loaded with therapeutic proteins made from an inert polymer: polyethylene glycol (PEG). The main advantage for tissue engineering is that it does not provoke the immune system, however, due to the low viscosity of the PEG polymer solution, it is difficult to 3D print this type of polymer. To overcome this limitation, the team has found that combining PEG polymers with nanoparticles leads to an interesting class of bioink hydrogels that can support cell growth and may have enhanced printability compared to polymer hydrogels by themselves.

In the paper Printing Therapeutic Proteins in 3D using Nanoengineered Bioink to Control and Direct Cell Migration published by the team last May, they propose using the high surface area and charged characteristics of 2D nanosilicates (or nanoclays, nanoparticles of layered mineral silicates) to sequester and deliver biologically active therapeutics. Therapeutic proteins such as vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF) were incorporated into the bioink for in vitro testing, which was then used to fabricate a 3D structure using the HYREL System 30M 3D printer, a machine constructed with new custom extrusions, for easy mounting of various accessories, and three heads with full 200 x 200 x 200mm print volume, among other features.

The nanoengineered bioink loaded with therapeutic proteins is based on a nanoclay platform pioneered by Gaharwar that can be used for precise deposition of protein therapeutics, which Gaharwar developed as a new way to deliver treatment for cartilage regeneration and to eventually impact the treatment of osteoarthritis. This bioink formulation has unique shear-thinning properties with high printability and structural fidelity, that allow the material to be injected, quickly stop flowing and then cure to stay in place.

Charles Peak, senior author of the study and Assistant Instructional Professor at the Department of Biomedical Engineering at Texas A&M, said that “the prolonged delivery of the bioactive therapeutic could improve cell migration within 3D printed scaffolds and can help in rapid vascularization of scaffolds.”

While team leader, Gaharwar, said that the prolonged delivery of the therapeutic could also reduce overall costs by decreasing the therapeutic concentration as well as minimizing the negative side effects associated with supraphysiological doses (amounts greater than normally found in the body).

“Overall, this study provides proof of principle to print protein therapeutics in 3D that can be used to control and direct cell functions,” he suggested.