Bioprinting of Pancreatic Cancer Cells for Improved Drug Testing

Currently, many drugs are preclinically tested on two-dimensional cell cultures. However, this method does not adequately replicate the cellular interactions or diffusion gradient that occur in three-dimensional tissues, leading to poor indicators of how a drug may affect human tissues. The objective of this project was to use bioprinted pancreatic cancer cell cultures as a platform for three-dimensional drug testing. Various bioink formulations of cellulose, gelatin, and alginate were evaluated to determine which provided the best printability and cell viability. A cellulose nanocrystal and alginate hydrogel showed superior printability due to its shear thinning properties. Additionally, initial cell viability was nearly 80%, and it remained above 60% over four days. Use of a custom spinning bioreactor at 50 rpm resulted in no improvements to cell viability. Overall, the system shows potential as a drug testing platform to evaluate the effectiveness of various drug formulations on three-dimensional pancreatic cancer cell cultures

Deterioration in the Physico-Mechanical and Thermal Properties of Biopolymers Due to Reprocessing

Biopolymers are an emerging class of materials being widely pursued due to their ability to degrade in short periods of time. Understanding and evaluating the recyclability of biopolymers is paramount for their sustainable and efficient use in a cost-effective manner. Recycling has proven to be an important solution, to control environmental and waste management issues. This paper presents the first recycling assessment of Solanyl, Bioflex, polylactic acid (PLA) and PHBV using a melt extrusion process. All biopolymers were subjected to five reprocessing cycles. The thermal and mechanical properties of the biopolymers were investigated by GPC, TGA, DSC, mechanical test, and DMA. The molecular weights of Bioflex and Solanyl showed no susceptible effect of the recycling process, however, a significant reduction was observed in the molecular weight of PLA and PHBV. The inherent thermo-mechanical degradation in PHBV and PLA resulted in 20% and 7% reduction in storage modulus, respectively while minimal reduction was observed in the storage modulus of Bioflex and Solanyl. As expected from the Florry-Fox equation, recycled PLA with a high reduction in molecular weight (78%) experienced 9% reduction in glass transition temperature. Bioflex and Solanyl showed 5% and 2% reduction in molecular weight and experienced only 2% reduction in glass transition temperature. These findings highlight the recyclability potential of Bioflex and Solanyl over PLA and PHBV