Abstract
Prostaglandin E~2~ (PGE~2~) is an arachidonic acid metabolite involved in physiological homeostasis and numerous pathophysiological conditions. Furthermore, it has been demonstrated that prostaglandins have a stimulating effect not only on angiogenesis in situ and in vitro but also on chondrocyte proliferation in vitro. Thus, PGE~2~ represents an interesting signaling molecule for various tissue engineering strategies. However, under physiological conditions, PGE~2~ has a halfβlife time of only 10 min, which limits its use in biomedical applications. In the present study, we investigated if the incorporation of PGE~2~ into biodegradable polyβLβlactideβcoβglycolide microspheres results in a prolonged release of this molecule in its active form. PGE~2~βmodified microspheres were produced by a cosolvent emulsification method using CHCl~3~ and HFIP as organic solvents and PVA as emulsifier. Thirteen identical batches were produced; and to each batch 1.0 mL of serumβfree medium was added. The medium was removed at defined time points and then analyzed by gas chromatography tandem mass spectrometry (GC/MS/MS) to measure the residual PGE~2~ content. In this study we demonstrated the prolonged release of PGE~2~, showing a linear increase over the first 12 h, followed by a plateau and a slow decrease. The microspheres were further characterized by scanning electron microscopy. Β© 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009