Three dimensional printing-based strategies for functional cartilage regeneration

Abstract

The regeneration of cartilage has made great progress in the past few decades, Previous techniques for constructing tissue-engineered cartilage scaffolds mainly include particulate-leaching, gas-foaming, freeze-drying, and phase-separation techniques. Cartilage is heterogeneous, and it is difficult for traditional scaffolds to simulate such anisotropy. Therefore, the functional regeneration of cartilage is challenging. With advancements in additive manufacturing, it has become possible to prepare functional bionic scaffolds for structures and components by the codeposition of biological materials, cells, and active biomolecules, thereby achieving functional cartilage regeneration. This article reviews the applications of three dimensional (3D) printing techniques in the regeneration of cartilage at different anatomical locations, including articular cartilage, meniscus, intervertebral disc, and auricle. In addition, methods for preparing biomimetic constructs with regional structural gradients and regional componential gradients are discussed, with multinozzle 3D bioprinting technology as a future research direction for the functional regeneration and repair of cartilage. This article primarily reviews the applications of three-dimensional printing in cartilage tissue engineering at different anatomical locations and summarizes their strengths and limitations. In addition, we believe that four-dimensional concept and biological microenvironment should not be ignored for functional cartilage regeneration in the future. Finally, we hope the review provide scientist inspiration with constructing anisotropic tissue-engineered organ or tissue.