Purpose: In vivo experiments indicate that gas-plasma-treated D,L-polylactide polymers expressing basic fibroblast growth factor (bFGF) exhibit enhanced angiogenesis. bFGF is not a single entity, but it is instead a family of isoforms. Consequently, we sought to determine which bFGF isoforms and levels initiate angiogenesis in nude mice peritoneums.
Methods: Cytoplasmic and nuclear bFGF were characterized for nude mice peritoneums incubated with nontreated scaffolds containing HAEC (CW), its respective polymer-only scaffolds (Cp) and gas-plasma treated scaffolds with HAEC (TW) and without cells (Tp). NuPAGE electrophoresis and WesternBreeze Chemiluminescent kits were used to analyze relative bFGF densities and molecular weights. VEGF was quantified using ImageJ.
Results: bFGF bands were located at molecular weights of 24, 48, 58, 72 and 80 kDa, depending on whether they were from cytoplasms or nuclei. At 12, 24 and 72 days, 58-kDa bFGF bands were observed from nuclei of TW and Tp, 80-kDa bFGF bands were only observed in cytoplasmic fractions < or = 24 days. Total cytoplasmic and nuclear bFGF intensities increased from 12 to 24 days, then declined by 72 days.
Conclusions: (1) Gas-plasma treated scaffolds up-regulate bFGF isoforms. (2) bFGF was expressed in the nuclei; however, 80-kDa bFGF was seen only in cytoplasms.