Effect of heparin oligomer chain length on the activation of valvular interstitial cells.

A key event in connective tissue remodeling involves the transformation of fibroblasts to myofibroblasts, also revealed by expression of α-smooth muscle actin (-SMA). However, misregulation of this transition can lead to fibrosis, an overgrowth and hardening of tissue due to excess extracellular matrix deposition, a process that is linked to heart valve disease and many others. Both disease treatment and regenerative strategies would benefit from strategies for the controlled delivery and presentation of bioactive factors that can promote or suppress this transformation. In this regard, the ability of heparin to complex a plethora of growth factors offers a broad range of possibilities for this purpose. Here, the effects of heparin chain length and structure on valvular interstitial cell (VIC) phenotypic expression were explored. Heparin from porcine intestinal mucosa was depolymerized with heparinase and fractionated to obtain oligosaccharides of different sizes. VICs cultured with octasaccharides and decasaccharides exhibited higher expression of -SMA when compared to other saccharides and full-length heparin. No activation of VICs was observed in response to full-length heparin presence in media.