Manipulating bioink chemistry and mechanical properties for long-term cell health after 3D printing of gel-phase bioinks

摘要

We proved that the PEGX bioink method is compatible with changing the cross-linking chemistry in inks based on natural and synthetic base polymers, as we have shown printable formulations with pseudo-click and copper-free click reactions that led to highly viability cells post-printing. With our post-printing secondary PEG crosslinking treatment, mechanical and degradation (1 day to >4 weeks) properties of printed structures can be tuned in the presence of cells to cover a range (150 Pa to 2kPa) relevant for soft tissue engineering. Enabled by the unique ability of this method to manipulate bioink mechanical properties, we observed that a certain mass flow rate must be reached or exceeded for optimal cell viability post-3D printing. This study is the first of hopefully many by us and others that will help build a foundational understanding of the relationship between extrudable biomaterial properties (chemical, mechanical, and biological) and cell health post-printing to enable fabrication of biomimetic 3D printed structures for various tissue and organ engineering applications.