Three-Dimensional Bioprinting and Its Potential in the Field of Articular Cartilage Regeneration

Abstract

Three-dimensional (3D) bioprinting techniques can be used for the fabrication of personalized, regenerative constructs for tissue repair. The current article provides insight into the potential and opportunities of 3D bioprinting for the fabrication of cartilage regenerative constructs. Although 3D printing is already used in the orthopedic clinic, the shift toward 3D bioprinting has not yet occurred. We believe that this shift will provide an important step forward in the field of cartilage regeneration. Three-dimensional bioprinting techniques allow incorporation of cells and biological cues during the manufacturing process, to generate biologically active implants. The outer shape of the construct can be personalized based on clinical images of the patient's defect. Additionally, by printing with multiple bio-inks, osteochondral or zonally organized constructs can be generated. Relevant mechanical properties can be obtained by hybrid printing with thermoplastic polymers and hydrogels, as well as by the incorporation of electrospun meshes in hydrogels. Finally, bioprinting techniques contribute to the automation of the implant production process, reducing the infection risk. To prompt the shift from nonliving implants toward living 3D bioprinted cartilage constructs in the clinic, some challenges need to be addressed. The bio-inks and required cartilage construct architecture need to be further optimized. The bio-ink and printing process need to meet the sterility requirements for implantation. Finally, standards are essential to ensure a reproducible quality of the 3D printed constructs. Once these challenges are addressed, 3D bioprinted living articular cartilage implants may find their way into daily clinical practice.

Keywords: additive manufacturing; bio-ink; bioprinting; regenerative medicine.

Figure 1.

Evolution of cartilage repair and bioprinting of cartilage. Additive manufacturing techniques and in particular bioprinting are enabling to produce patient-specific, complex architectures that mimic the composition of articular cartilage. With the development of novel bioactive bio-inks and the combination of different 3D bioprinting techniques, functional cartilage constructs will be obtained. Optimized and mature bioprinted grafts will have to meet high quality standards in order to be used as clinical devices for cartilage and joint healing. TKA = total knee arthroplasty; ACI = autologous chondrocyte implantation; MACI = matrix-induced autologous chondrocyte implantation; iPSC = induced pluripotent stem cell; MEW = melt electrospinning writing.