Guided growth of smooth muscle cell on poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) scaffolds with uniaxial...

Scaffolds of biopolyester poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) with uniaxial microtubular structure were successfully prepared by directional freezing and phase-separation techniques. These special structures guided the rabbit aorta smooth muscle cells (RaSMCs) to grow along the tubular structure. The structure of the scaffolds including tubular size and architecture, as well as scaffold mechanical properties could be adjusted by changing the PHBHHx concentration, PHBHHx solvent, and phase-separation temperature. In addition, the scaffolds demonstrated anisotropic mechanical properties, with much more improved strength along the longitudinal direction of the microtubules compared with those along the transverse direction. Three-day and 7-day cell culture of RaSMCs seeded on the scaffolds with different microtubular sizes showed similar cellular metabolic activity but different cell distribution and morphology owing possibly to different scaffold tubular sizes. The scanning electron microscopy and H&E staining demonstrated that RaSMCs were guided to grow along the microtubular structures of scaffolds prepared from the 2.5% or 3.0% PHBHHx/benzene solution. This study demonstrated the possibility of using PHBHHx scaffolds to achieve guided cell growth.