Three-dimensional (3D) bioprinting has emerged as a game-changer technology in the field of tissue engineering. Bioink is an important component used in the 3D bioprinting process and consists of biomaterials, cells, and growth factors. Current research on bioink formulations mostly uses animal-derived biomaterials for soft tissue engineering, which possess challenges of batch-to-batch variability, immunogenicity, and microbial growth with aging.

Herein we explored the use of pharmaceutical polymers in prospective hydrogel-based bioink formulations for soft tissue engineering.

Bioink formulations containing partially pregelatinized starch, sodium alginate along with either hydroxypropyl methylcellulose or polyvinyl alcohol-polyethylene glycol graft co-polymer or sodium carboxymethyl cellulose were assessed for tensile strength of thin films, viscosity, the structural integrity of crosslinked scaffolds, and effects of moist heat sterilization on physical, chemical and microbial contaminations.

We established the use of hydrogel-based formulations containing pharmaceutical polymers. These can provide tensile strength appropriate for soft tissue engineering and viscosity in a suitable range for extrusion-based bioprinting. Structural integrity revealed polyvinyl alcohol- polyethylene glycol graft co-polymer based formulations were able to withstand in culture media for longer than other formulations. The moist heat sterilization process was able to eliminate microbial contamination effectively without altering the physicochemical properties of the hydrogels.

We demonstrated the use of pharmaceutical polymers in prospective bioink formulations for soft tissue engineering. This study paves the way for clean bioprinting without using any animal products.

Graphical Abstract