OBJECTIVETo prepare a platinum microcoil coated with polymers and vascular endothelial growth factor (VEGF), and evaluate its surface characteristics and property of sustained VEGF release.

METHODSThe surface of the platinum microcoils (GDC) were modified by coating P(DLLA-co-TMC) copolymer and immobilizing heparin on the surface of GDC. VEGF was then loaded onto the surface of GDC and the controlled release of VEGF within GDC was achieved. The morphology was observed by scanning electron microscope, and the sustained release of VEGF was evaluated by enzyme-linked immunosorbent assay (ELISA).

RESULTSPlatinum coils were prepared by successive deposition of P(DLLA-co-TMC) copolymer and anionic heparin, and VEGF was immobilized through affinity interaction with heparin. The accumulative release of VEGF increased obviously during the entire testing period without burst release.

CONCLUSIONThe use of P(DLLA-co-TMC) copolymer allows immobilization of VEGF on the platinum coils for controlled VEGF release, and improves the biological property of the coils.