Controlled release of transforming growth factor-β from lipid-based microcylinders

Abstract

The release of transforming growth factor-β (TGF-β) from a lipid microstructure has been demonstrated. Lipid microcylinders, with dimensions of 100 × 0.5 μm and composed of a diacetylenic lipid, have been loaded with 25 ng TGF-β/mg lipid. Physical and bioactive release characteristics of TGF-β from these microcylinders and from microcylinders embedded in an agarose hydrogel are reported. Release of TGF-β from lipid microcylinders follows typical diffusionlimited characteristics, where 10–12% of the TGF is released in the first 10h at 37°C. The release rate is shown to be temperature controlled and dependent on the integrity of the lipid microcylinder. Immobilization of the lipid microcylinder in a hydrogel matrix composed of agarose and gelatin does not impair the diffusion of TGF-β from the lipid microcylinders. The utilization of microcylinders as release vehicles in wound repair is discussed.

Key Words:

• Control release
• wound repair
• microcylinders
• transforming growth factor-β