Preparation and characterization of collagen microspheres for sustained release of VEGF.
In this study, we prepared injectable collagen microspheres for the sustained delivery of recombinant human vascular endothelial growth factor (rhVEGF) for tissue engineering. Collagen solution was formed into microspheres under a water-in-oil emulsion condition, followed by crosslinking with water-soluble carbodiimide. Various sizes of collagen microspheres in the range of 1-30 mum diameters could be obtained by controlling the surfactant concentration and rotating speed of the emulsified mixture. Particle size proportionally decreased with increasing the rotating speed (1.8 mum per 100 rpm increase in the range of 300-1,200 rpm) and surfactant concentration (3.1 mum per 0.1% increase in the range of 0.1-0.5%). The collagen microspheres showed a slight positive charge of 8.86 and 3.15 mV in phosphate-buffered saline and culture medium, respectively. Release study showed the sustained release of rhVEGF for 4 weeks. Released rhVEGF was able to induce capillary formation of human umbilical vein endothelial cells, indicating the maintenance of rhVEGF bioactivity after release. In conclusion, the results suggest that the collagen microspheres have potential for sustained release of rhVEGF.
Division of Clinical Cell Therapy, Center for Translational and Advanced Animal Research (CTAAR), Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8575, Japan. nagain@m.tains.tohoku.ac.jp
Nobuhiro
N
Nagai
Norihiro
N
Kumasaka
Takeaki
T
Kawashima
Hirokazu
H
Kaji
Matsuhiko
M
Nishizawa
Toshiaki
T
Abe
D001672:Biocompatible Materials; D003094:Collagen; D045703:Emulsifying Agents; D004655:Emulsions; D042783:Endothelial Cells / Q000187:drug effects; D006801:Humans; D008863:Microspheres; D023822:Tissue Engineering; D014471:Umbilical Veins / Q000187:drug effects; D042461:Vascular Endothelial Growth Factor A / Q000494:pharmacology; D042442:Vascular Endothelial Growth Factors / Q000494:pharmacology*
D001672:Biocompatible Materials; D045703:Emulsifying Agents; D004655:Emulsions; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D003094:Collagen