Biomanufacturing

Abstract: Three-dimensional (3D) printing is becoming an increasingly common technique to fabricate scaffolds and devices for tissue engineering applications. This is due to the potential of 3D printing to provide patient-specific designs, high structural complexity, rapid on-demand fabrication at a low-cost. One of the major bottlenecks that limits the widespread acceptance of 3D printing in biomanufacturing is the lack of diversity in “biomaterial inks”. Printability of a biomaterial is determined by the printing technique. Although a wide range of biomaterial inks including polymers, ceramics, hydrogels and composites have been developed, the field is still struggling with processing of these materials into self-supporting devices with tunable mechanics, degradation, and bioactivity. This review aims to highlight the past and recent advances in biomaterial ink development and design considerations moving forward. A brief overview of 3D printing technologies focusing on ink design parameters is also included.

Abstract: Novel technologies are emerging that incorporate cells as part of the building blocks for various biomanufacturing processes, such as solid freeform fabricated tissue constructs for tissue regeneration, three-dimensional pharmacokinetic models, cell-based microelectromechanical systems, sensors, and microfluidic devices. However, the effects of these biomanufacturing processes on cells have not been fully studied. This paper examines the effect of solid freeform fabrication-based direct cell writing process, focusing on dispensing pressure and nozzle size, on the viability and functional behavior of HepG2 cells encapsulated within alginate. Our experimental results revealed a process-induced mechanical damage to cell membrane integrity, causing a quantifiable loss in cell viability due to incremental increases and decreases in the studied process parameters of dispensing pressure and nozzle size, respectively. The experimental results also suggested that cells may require a recovery period following direct cell writing biofabrication. The general finding of this study may be applicable to freeform fabrication of cell-based tissue constructs and three-dimensional biological models.