Release of Bioactive Transforming Growth Factor β 3 from Microtextured Polymer Surfaces in Vitro and in Vivo

Abstract

Transforming growth factor β₃ (TGF-β₃) has been under investigation with the objective of improving wound healing. Yet, little experimental knowledge exists about applications of TGF-β₃ in implantology and tissue engineering. The aims of this study were to determine the release kinetics and bioactivity of TGF-β₃ released from microtextured silicone and poly-L-lactic acid (PLA) surfaces in vitro and in vivo. We loaded surfaces with 100 ng of TGF-β₃. An in vitro assay showed that TGF-β₃ was released in a burstlike manner. Released TGF-β₃ was capable of inhibiting the proliferation of mink lung epithelial cells, indicating that released TGF-β₃ had remained at least partly active. Subsequently, an in vivo experiment (1 h-3 days) was performed with implants loaded with TGF-β₃. In cryosections, TGF-β₃ activity was assessed by an in situ bioassay. We found that active TGF-β₃ was released for up to 24 h. Furthermore, released TGF-β₃ could be detected up to 320 μm from the implant. On the basis of these observations, we conclude that TGF-β₃ loaded onto microtextured polymer membranes remains functional when released in vitro and in vivo and, therefore, may represent an alternative for introducing a growth factor into a wound to achieve long-term and long-range biological effects.