Emulsion templating is a relatively new fabrication method that generates porous scaffolds through the polymerization of high internal phase emulsions (HIPEs). Current studies focus on developing polyHIPEs with inherent osteoinductivity and investigating the utility of these candidate scaffolds as cell carriers. Specifically, we propose to develop HIPEs that utilize hydroxyapatite (HA) nanoparticles to impart osteoinductive character to the bone graft by facilitating osteogenic differentiation of human mesenchymal stem cells (hMSCs). In addition, we will investigate the potential of cell encapsulation in HIPEs prior to curing as a means to deliver and retain MSCs at the defect site. In addition to using polyHIPE as an injectable scaffold, we are exploring 3D printing of these emulsions to create tissue grafts with complex architectures. We currently have demonstrated that these emulsions inks can be printed with our cure-on-dispense technology, allowing for retention of microscale architecture and macroscale geometries. This new technology permits both the reproduction of anatomical features, as well as the microprinting of vessels to facilitate neovascularization into the microcellular foam graft.
In collaboration with CECT, our lab aims to develop and characterize osteoblastic differentiation on polyHIPE scaffolds containing HA nanoparticles, and evaluate deployment variables of polyHIPE scaffolds and viability of hMSCs after encapsulation. Emulsion inks will be developed for the purpose of 3D printing, and the printed polyHIPE scaffolds will be characterized with regards to their ability in reproducing anatomical structures with improved mechanical properties and permeability. Finally, hMSC bioactivity will be assessed as a function of graft printing variables and distance from microprinted channels.