Biofabrication for osteochondral tissue regeneration: bioink printability requirements

Abstract

Biofabrication allows the formation of 3D scaffolds through a precise spatial control. This is of foremost importance when aiming to mimic heterogeneous and anisotropic architecture, such as that of the osteochondral tissue. Osteochondral defects are a supreme challenge for tissue engineering due to the compositional and structural complexity of stratified architecture and contrasting biomechanical properties of the cartilage-bone interface. This review highlights the advancements and retreats witnessed by using developed bioinks for tissue regeneration, taking osteochondral tissue as a challenging example. Methods, materials and requirements for bioprinting were discussed, highlighting the pre and post-processing factors that researchers should consider towards the development of a clinical treatment.

Recent progress in extrusion 3D bioprinting of hydrogel biomaterials for tissue regeneration: a comprehensive review with focus on advanced fabrication techniques

“…The introduction of 3D bioprinting in TE has attained prominent progress in simulating the anatomy of articular cartilage tissue [179], and among various dispensing techniques, EBB is the most prevalent and affordable method [180,181]. Applying this particular technique, researchers have reported the production of cartilage-like constructs through the combination of various hydrogels [46,[182][183][184][185][186][187][188]; However, the most efficient strategy has involved simultaneous deposition of thermoplastic polymers utilizing multi-dispenser systems while structural materials able of maintaining mechanical forces, and hydrogels as cell carriers [189][190][191][192][193][194]. Besides, researchers have endeavored to modify bioinks' attributes, such as printability, mechanical properties, and degradation rate [177,178,195,196].…”

Microfluidic technologies to engineer mesenchymal stem cell aggregates—applications and benefits

“…The focus of many studies is on incorporating various hydrogels for the generation of microgel structures that could be solid spheres, hard shell and soft core, and hollow type microgels (Ashida et al, 2013;Sakai et al, 2014;Khanmohammadi et al, 2016). Multicellular aggregates encapsulated within microgels serve as bioinks inducing (Pajoumshariati et al, 2018;Chen et al, 2019b;Abdulghani and Morouço, 2019). They can be engineered as three-dimensional building blocks for the production of macromaterials with the capability of recreating the shape of a damaged tissue.…”

Osteoarthritis, Exercise, and Tissue Engineering: A Stimulating Triad for Health Professionals

“…The articular cartilage is a flexible connective tissue that aligns the surface of the bones in the synovial joints throughout the body, allowing a movement with almost zero friction on its surface. The extracellular matrix is stratified into four distinct (architecturally and biochemically) zones (the surface zone, the midzone, the deep zone, and the calcified zone), which together give rise to its viscoelastic properties [4, 7]. It is avascular, alymphatic, and aneural and, therefore, has a very low endogenous regeneration capacity [8].…”

“…Total contemplation over osteochondral defects should be considered: anatomy, structure and composition resembling native tissue; biomechanics, ability to yield similar mechanical behavior; and physiology, fully restore joint functionality [65]. The different compositions and mechanical properties of bone and cartilage indicate the complexity of this tissue interface, making it challenging for the design and fabrication of tissue engineered scaffolds (for more details, we have recently published a review on biofabrication for osteochondral tissue [4]).…”

“…It will increase the load over the joints, and if there is joint malalignment, it will be worse than better [3]. On the other hand, recent improvements in tissue engineering have demonstrated the suitability of novel bilayer scaffolds [4]. However, it is unclear how these scaffolds will behave responding to the normal mechanical loading over time.…”