A.O. Lobo
Federal University of Piaui,
Brazil
Keywords: bioprinting, 3D printing, crio(bio)printing, microfibers, cartilage, bone, tissue engineering, mechanical properties, hydrogels
Summary:
To date, the use of soft hydrogels for bone and cartilage regeneration has been limited due to their low mechanical moduli (fracture and stiffness). To solve this problem, cryoprinting and cryo(bio)printing offer an alternative to improve the crystallinity of cross-linked hydrogels. Recently, we have developed a strategy to combine electrospun and rotationally spun ultrathin fibers with 3D bioprinted hydrogels to produce scaffolds for tissue engineering of bone and cartilage. First, ultrathin PCL and PLA fibers were produced using home-made electrospinning and rotational jet spinning devices. Subsequently, different biomimetic joint tissues were 3D printed using a combination of natural and synthetic photo- and thermoresponsive hydrogels reinforced with micro- and nanofiber layers. The same method was cryo-(bio)printed at -20°C. We characterized the fabricated ultrathin fibers and microfabricated structures using rheological, thermal, structural, morphological and mechanical techniques. Mesenchymal stem cells and chondrocytes were incorporated into the synthesized bioinks and 3D bio- and cryo(bio)printed and cytotoxicity and live/dead cells were also investigated. The microfabricated joint structure that was cryo(bio)printed showed an improvement in mechanical properties by 2-3 folds compared to bioprinting with three layers (with microfiber reinforcement). All developed biomimetic joint structures were non-cytotoxic and promoted cell growth and differentiation. The developed strategy of cryo(bio)printing in combination with microfiber reinforcement showed interesting properties to be used as an alternative for tissue engineering of hard tissue.