Annie Behre

Tissues are not homogeneous, and their function is closely linked to the specific organization of multiple components. For example, the osteochondral (OC) interface between bone and cartilage contains a transition consisting of gradients in biochemical and physical properties that are critical for normal biomechanical function. Fabricating a biomaterial that recreates these gradients is challenging, which limits ability to engineer native-like, functional tissues. Solvent-cast direct-write (SC-DW) three-dimensional (3D) printing uses computer-controlled deposition of polymer-based ink solutions to form 3D constructs¹. The Chow Lab is exploiting this technique to 3D print inks containing poly(caprolactone) (PCL) and peptide-modified PCL (peptide-PCL) conjugates to fabricate peptide-functionalized scaffolds in a single step². Here, two different peptide-PCL conjugates, HAbind-PCL and E3-PCL, which have been shown to promote human mesenchymal stem cell (hMSC) differentiation into chondrogenesis³ or osteogenesis³, respectively, were used to demonstrate multi-peptide organization within a single scaffold. The print pattern was also modified during fabrication to create a variety of scaffold architectures. This platform thus enables us to simultaneously and independently control both the biochemical and physical organization within a continuous construct. To confirm peptide presentation and compare peptide concentration, constructs were fluorescently labeled using fluorescein-HA and/or amino-Cy3 to specifically label HAbind and E3 peptides, respectively. Fluorescence intensity was quantified using ImageJ. Scaffold morphology was characterized using scanning electron microscopy (SEM).