Characterization of cellular carriers for use in injectable tissue-engineering composites.

Injectable composite tissue-engineering scaffolds are systems that incorporate individual cell carriers within a gel delivery matrix. This study assessed low-temperature casting as a possible method to produce synthetic cell-carrier beads. Porous poly-L-lactide beads were manufactured by low-temperature casting. Two porogens, either glucose or sodium chloride, were incorporated into the beads and subsequently leached. Beads were seeded with primary culture aortic smooth muscle rat cells and were evaluated over a 13-day period using a series of chemical, biochemical, and histological assays. Results indicate that low-temperature casting is a viable technique to produce injectable beads on the order of 1.5-2.0 mm. The manufactured beads supported smooth muscle cell attachment and proliferation; where the beads formed with sodium chloride allowed enhanced proliferation. Differences in physical qualities, namely buoyancy and topography, were dependent on porogen selection and may provide a mechanism for bead and composite customization.