Biofabrication: A photochemical toolbox to engineer the microenvironment of cells

Abstract

Biofabrication: A photochemical toolbox to engineer the microenvironment of cells

Baudis S.*

Christian Doppler Laboratory for Advanced Polymers for Biomaterials and 3d Printing, Institute of Applied Synthetic Chemistry, TU Wien, Austria

*stefan.baudis@tuwien.ac.at, www.baudislab.com

Biofabrication is all about mimicking the extracellular matrix (ECM) of tissues. Cells in suitable (micro-)environment will remodel the artificial matrix and consequently form tissues. The ECM is a gel of macromolecules, mainly fibrous proteins and polysaccharides. Hence, suitable foundations for bioinks are hydrogel precursors derived from natural (e.g., gelatin, hyaluronan, etc.) or biocompatible synthetic polymers (e.g. poly(vinyl alcohol)). These macromolecules can easily be modified with enes (e.g., methacrylates, vinylesters, norbornenes) or thiols and combined with other (macromolecular) crosslinkers in thiol-ene coupling reactions to form hydrogel networks with arbitrary shape in high resolution in the presence of living cells. Furthermore, the incorporation of photo-labile bonds into hydrogel network enables the photodegradation of formed constructs by light – additional means to engineer the cellular microenvironment. Doing so, the encapsulation of cells in artificial ECM is enabled by 3D printing (see Figure) – especially the two-photon fabrication was found to be a superior tool as this enables the activation of above mentioned photochemistries in 3D within the material by focusing infrared laser into the bioinks. Figure: Fibroblast cells, encapsulated in hyaluronic acid based bioink.

Consequently, these material platforms in combination with two-photon technology enable spatiotemporal control of the properties of artificial ECM in the presence of living cells. Thus, this combination is an ideal platform technology to study the behavior of cells in different microenvironments.

Acknowledgements: Christian Doppler Research Association, Austrian Federal Ministry for Digital & Economic Affairs, National foundation for Research, Technology & Development.