bFGF-containing electrospun gelatin scaffolds with controlled nano-architectural features for directed angiogenesis.
Current therapeutic angiogenesis strategies are focused on the development of biologically responsive scaffolds that can deliver multiple angiogenic cytokines and/or cells in ischemic regions. Herein, we report on a novel electrospinning approach to fabricate cytokine-containing nanofibrous scaffolds with tunable architecture to promote angiogenesis. Fiber diameter and uniformity were controlled by varying the concentration of the polymeric (i.e. gelatin) solution, the feed rate, needle to collector distance, and electric field potential between the collector plate and injection needle. Scaffold fiber orientation (random vs. aligned) was achieved by alternating the polarity of two parallel electrodes placed on the collector plate thus dictating fiber deposition patterns. Basic fibroblast growth factor (bFGF) was physically immobilized within the gelatin scaffolds at variable concentrations and human umbilical vein endothelial cells (HUVEC) were seeded on the top of the scaffolds. Cell proliferation and migration was assessed as a function of growth factor loading and scaffold architecture. HUVECs successfully adhered onto gelatin B scaffolds and cell proliferation was directly proportional to the loading concentrations of the growth factor (0-100 bFGF ng/mL). Fiber orientation had a pronounced effect on cell morphology and orientation. Cells were spread along the fibers of the electrospun scaffolds with the aligned orientation and developed a spindle-like morphology parallel to the scaffold's fibers. In contrast, cells seeded onto the scaffolds with random fiber orientation, did not demonstrate any directionality and appeared to have a rounder shape. Capillary formation (i.e. sprouts length and number of sprouts per bead), assessed in a 3-D in vitro angiogenesis assay, was a function of bFGF loading concentration (0 ng, 50 ng and 100 ng per scaffold) for both types of electrospun scaffolds (i.e. with aligned or random fiber orientation).
Department of Biomedical Engineering, University of Miami, Coral Gables, FL, USA.
Ramon B
RB
Montero
Ximena
X
Vial
Dat Tat
DT
Nguyen
Sepehr
S
Farhand
Mark
M
Reardon
Si M
SM
Pham
Gavriil
G
Tsechpenakis
Fotios M
FM
Andreopoulos
D002196:Capillaries / Q000166:cytology / Q000187:drug effects / Q000254:growth & development*; D002478:Cells, Cultured; D003692:Delayed-Action Preparations / Q000138:chemical synthesis / Q000494:pharmacology*; D004563:Electrochemistry / Q000379:methods; D042783:Endothelial Cells / Q000166:cytology / Q000502:physiology*; D004867:Equipment Design; D016222:Fibroblast Growth Factor 2 / Q000737:chemistry / Q000494:pharmacology*; D005780:Gelatin / Q000737:chemistry; D006801:Humans; D008422:Materials Testing; D049329:Nanostructures / Q000737:chemistry*; D018919:Neovascularization, Physiologic / Q000187:drug effects* / Q000502:physiology; D012399:Rotation; D054457:Tissue Scaffolds
D003692:Delayed-Action Preparations; D016222:Fibroblast Growth Factor 2; D005780:Gelatin