Current strategies for cell delivery in cartilage and bone regeneration.

Several cell-based tissue-engineering therapies are emerging to regenerate damaged tissues. These strategies use autologous cells in combination with bioresorbable delivery materials. Major functions of a delivery scaffold are to provide initial mechanical stability, homogenous three-dimensional cell distribution, improved tissue differentiation, suitable handling and properties for delivery and fixation into patients. Delivery of cells can be achieved using injectable matrices, soft scaffolds, membranes, solid load-bearing scaffolds or immunoprotective macroencapsulation. Thus, to expand the clinical potential, next generation therapies will depend on smart delivery concepts that make use of the regenerative potential of stem cells, morphogenetic growth factors and biomimetic materials.