MSCs, ADSCs, and AFS cells and their delivery
A critical criterion of tissue engineered constructs is a viable cell source capable of differentiating into a tissue-specific lineage. The availability of cells necessary for tissue repair may be limited in vivo, so the addition of therapeutic cells may be necessary for tissue regeneration. On this front, work in our lab utilizes stem cells from various anatomical sources to populate and mineralize 3-D delivery systems (hydrogels, injectables, growth factors); ultimately intending to implant the constructs in an in vivo critically sized rat femoral defect model to guide bone regeneration. Cell types used by our lab include mesenchymal stem cells (MSCs - human and rat bone marrow-derived), adipose derived stem cells (ADSCs), and human amniotic fluid stem cells (hAFS cells).
Nanofiber meshes fabricated by an electrospinning process are a novel type of membrane scaffold that have structural features in the same size-scale of extracellular matrix (ECM) components and a large surface area. Preliminary results from our lab have demonstrated that nanofiber meshes can support the proliferation and differentiation of osteoprogenitor cells as well as enhance bone repair in a rat segmental bone defect model when combined with appropriate delivery of growth factors. The meshes may function by demarcating the osseous from the non-osseous region and by guiding osteoprogenitor cells from the adjacent periosteum into the defect - a process termed guided bone regeneration. Delivering cells within a tissue-engineered periosteum made using a nanofiber mesh may improve in vivo cell viability, and we are currently exploring these possibilities.