(450g) Electrospinning of Photo-Crosslinked Poly(N-isopropylacrylamide) Fibers for Tissue Engineering

Poly(N-isopropylacrylamide) poly(NIPAAm) is a thermoresponsive polymer that undergoes a volume phase transition at a lower critical solution temperature of 33°C in aqueous solutions. This polymer has a hydrophilic amide group and a hydrophobic isopropyl group on its side chain; making possible the interaction with hydrophilic and hydrophobic surfaces. Below the LCST, poly(NIPAAm) interacts with water molecules through the hydrophilic group forming a swollen hydrated structure. Above the LCST, entropic contributions condense the polymer chains, while collapsing out of the solution. Taking advantage of its thermo-responsive behavior, poly(NIPAAm) has been investigated for potential applications such as: controlled drug delivery, separations, and thermo-responsive surfaces among others.

Stimuli-responsive surfaces can be fabricated using various techniques such as grafting, coating, self assembling, electrospinning, etc. The electrospinning technique has shown to be an efficient technique for the fabrication of these surfaces. Our work aim to asses the buckling and thermoresponsive behavior of electrospun photo-crosslinked copolymers synthesized from poly(NIPAAm) and methacroyloxybenzophenone(MaBP) fibers and how this affects the attachment and detachment of cells onto the fibers. Poly(NIPAAm) fibers were produced by electrospinning a solution of poly(NIPAAm) in acetone in order to obtain continuous fibers. Different poly(NIPAAm) concentrations were electrospun. The substrate was treated with 3-aminopropyltriethoxysilane that hydrogen bonded to the polymer, preventing the fibers from dissolving when they are in contact with water.