Fabrication of a layered microstructured polycaprolactone construct for 3-D tissue engineering

Abstract

Successful artificial tissue scaffolds support regeneration by promoting cellular organization as well as appropriate mechanical and biological functionality. We have previously shown in vitro that 2-D substrates with micron-scale grooves (5 μm deep, 18 μm wide, with 12 μm spacing) can induce cell orientation and ECM alignment. Here, we have transferred this microtopography onto biodegradable polycaprolactone (PCL) thin films. We further developed a technique to layer these cellularized microtextured scaffolds into a 3-D tissue construct. A surface modification technique was used to attach photoreactive acrylate groups on the PCL scaffold surface onto which polyethylene glycol (PEG-DA) -diacrylate gel could be photopolymerized. PEG-DA serves as an adhesive layer between PCL scaffolds, resulting in a VSMC-seeded layered 3-D composite structure that is highly organized and structurally stable. The PCL surface modification chemistry was confirmed via XPS, and the maintenance of cell number and orientation on the modified PCL scaffolds was demonstrated using colorometric and imaging techniques. Cell number and orientation were also investigated after cells were cultured in the layered 3-D configuration. Such 3-D tissue mimics fabricated with precise cellular organization will enable the systematic testing of the effects of cellular orientation on the functional and mechanical properties of tissue engineered blood vessels.