Three-Dimensional Printing Strategies for Irregularly Shaped Cartilage Tissue Engineering: Current State and Challenges

Abstract

Although there have been remarkable advances in cartilage tissue engineering, construction of irregularly shaped cartilage, including auricular, nasal, tracheal, and meniscus cartilages, remains challenging because of the difficulty in reproducing its precise structure and specific function. Among the advanced fabrication methods, three-dimensional (3D) printing technology offers great potential for achieving shape imitation and bionic performance in cartilage tissue engineering. This review discusses requirements for 3D printing of various irregularly shaped cartilage tissues, as well as selection of appropriate printing materials and seed cells. Current advances in 3D printing of irregularly shaped cartilage are also highlighted. Finally, developments in various types of cartilage tissue are described. This review is intended to provide guidance for future research in tissue engineering of irregularly shaped cartilage.

Tissue‐engineered tracheal implants: Advancements, challenges, and clinical considerations

“…Consequently, PCL has been widely employed in tracheotomy research, producing substitutes that exhibit remarkable resistance to compressive stresses and assist cartilage regeneration 47 . Despite these advancements, PCL scaffolds face challenges in pre‐clinical studies, triggering an inflammatory reaction that leads to the granulation formation and subsequent lumen stenosis 48 . Explorations into novel materials for 3D printing, such as polyurethane (PU), have demonstrated adequate mechanical support and facilitated cartilage formation 49 .…”

“… 47 Despite these advancements, PCL scaffolds face challenges in pre‐clinical studies, triggering an inflammatory reaction that leads to the granulation formation and subsequent lumen stenosis. 48 Explorations into novel materials for 3D printing, such as polyurethane (PU), have demonstrated adequate mechanical support and facilitated cartilage formation. 49 Continual endeavors in 3D printing of tracheal scaffolds, employing diverse materials and distinctive tubular designs reveal promising initial outcomes, although limited by single‐cell type technologies, deficiency of mechanical characterization, and inadequate revascularization.…”

The application and progress of tissue engineering and biomaterial scaffolds for total auricular reconstruction in microtia

“…The use of high molecular weight polymers in 3D printing of irregularly shaped cartilage has also been reported in several studies, including poly (lactic-co-glycolic acid) (PLGA) (Wei et al, 2020), PLA (Rosenzweig et al, 2015), PCL (Xu et al, 2019;Li et al, 2021a), and polyurethane (Kim et al, 2019), to print cartilage scaffolds that are stable due to their optimal mechanical properties. Although natural bio-ink has good biocompatibility, its stability and mechanical properties are less satisfactory, and it is inclined to represent more rapid degradation, while synthetic bio-ink has excellent mechanical properties, but the lack of biological activity remains to be a major drawback (Wang et al, 2021). Zopf et al (2015) developed a 3D-printed PCL scaffold seeded with swine chondrocytes, which was then injected with a hydrogelbased construct involving growth and differentiation factors, which increased chondroinductivity in animal models after transplantation.…”

Upregulated desmin/integrin β1/MAPK axis promotes elastic cartilage regeneration with increased ECM mechanical strength

“…Such heterogeneity has been applied in osteochondral tissue engineering to mimic gradient microstructure to induce osteochondral regeneration [11]. The external ear has been distinguished by its intricate morphology and varied biomechanical properties across the auricular cartilage [12][13][14][15]. The composition and arrangement of the ECM have been found to vary in different regions of auricular cartilage and evolve with age [16][17][18][19].…”