During development, growth factors (GFs) such as bone morphogenetic proteins 
(BMPs) exert important functions in several tissues by regulating signaling for 
cell differentiation and migration. In vivo, the extracellular matrix (ECM) not 
only provides support for adherent cells, but also acts as reservoir of GFs. 
Several constituents of the ECM provide adhesive cues, which serve as binding 
sites for cell trans-membrane receptors, such as integrins. In conveying 
adhesion-mediated signaling to the intracellular compartment, integrins do not 
function alone but rather crosstalk and cooperate with other receptors, such as 
GF receptors. Here, we present a strategy for the immobilization of BMP-2 onto 
cellular fibronectin (cFN), a key protein of the ECM, to investigate GF-mediated 
signaling and migration. Following biotinylation, BMP-2 was linked to 
biotinylated cFN using NeutrAvidin as cross-linker. Characterization with quartz 
crystal microbalance with dissipation monitoring and enzyme-linked immunosorbent 
assay confirmed the efficient immobilization of BMP-2 on cFN over a period of 
24 h. To validate the bioactivity of matrix-immobilized BMP-2 (iBMP-2), we 
investigated short- and long-term responses of C2C12 myoblasts, which are an 
established in vitro model for BMP-2 signaling, in comparison to soluble BMP-2 
(sBMP-2) or in absence of GFs. Similarly to sBMP-2, iBMP-2 triggered Smad 1/5 
phosphorylation and translocation of the complex to the nucleus, corresponding 
to the activation of BMP-mediated Smad-dependent pathway. Additionally, 
successful suppression of myotube formation was observed after 6 days in sBMP-2 
and iBMP-2. We next implemented this approach in the fabrication of cFN 
micropatterned stripes by soft lithography. These stripes allowed cell-surface 
interaction only on the patterned cFN, since the surface in between was 
passivated, thus serving as platform for studies on directed cell migration. 
During a 10-h observation time, the migratory behavior, especially the cells' 
net displacement, was increased in presence of BMP-2. As such, this versatile 
tool retains the bioactivity of GFs and allows the presentation of ECM adhesive 
cues.