Post-loading of proangiogenic growth factors in PLGA microspheres

Active self-encapsulation (ASE) is a recently developed post-loading method based on absorption of (positively charged) proteins in microporous PLGA microspheres loaded with negatively charged polysaccharides (trapping agents). The aim this study was to investigate ASE for simultaneous loading and controlled release multiple growth factors. For purpose, vascular endothelial factor (VEGF), fibroblast (FGF) insulin-like (IGF) were containing high molecular weight dextran sulfate (HDS) as trapping agent; performed concentrated solution low ionic strength pH 5 under conditions at which the are positively charged. Subsequent pore closure induced by incubation factor-loaded 42.5 °C, i.e. above Tg (hydrated) (~30 °C). A 1:1:1 combination VEGF, FGF IGF (4.3%) efficiency (91%). vitro kinetics bioactivity factors studied 4 weeks using ELISA an cell proliferation assay, respectively. While released quickly, VEGF continuously their bioactive form, whereby had synergistic angiogenic effect. Therefore, suitable co-loading can provide sustained profiles factors, attractive vascularization biomaterial implants.