Review and proposition for model-based multivariable-multiobjective optimisation of extrusion-based bioprinting

Abstract

Consequent to the development of bioprinting technologies for biomedical applications, especially in tissue engineering, a comprehensive review of extrusion-based bioprinting (EBB) has been written. The review was executed in a manner that laid a foundation for effective optimisation strategies to improve the print resolution or shape fidelity and cell viability of EBB through bioink. However, before achieving this aim the shearing characteristic of the bioink (i.e., shear-thinning or thickening) was described by the Ostwald-de Waele and Herschel-Bulkley models, among other reported models. The dependence of bioink shearing characteristics on temperature and time was also discussed. Emphasis on how these dependencies can be influenced by crosslinking of bioink molecules was further highlighted, which can be covalent (chemical-, photo-cross-linking, etc.) or noncovalent (physical cross-linking, host-guest inclusion, ionic interaction, etc.). Models from literature that can physically describe print resolution and cell viability in EBB were discussed and compared. Therefore, multivariable-multiobjective optimisation strategies were proposed with these models.