Electrospun poly(octamethylene citrate) thermoset fibrous mat from chitin nanocrystal constructed Pickering emulsion

Poly(octamethylene citrate) (POC) is a promising bioelastomer material in tissue engineering field. However, its thermosetting characteristic reveals a big challenge to manufacture fibrous membranes via electrospinning. Herein, an Pickering emulsion, with dimethyl carbonate solution of POC prepolymer (pre-POC) as a dispersed oil phase (o), Pullulan (Pull) aqueous solution as a continuous water phase (w), and chitin nanocrystal (ChiNC) as a particle-type emulsifier, was successfully constructed and electrospun to form POC/Pull core/shell structured fibers, in which the ChiNCs did not merely reside on the core/shell interface, but moved into the POC core layer to reinforce the POC matrix. On the one hand, the core/shell structured fiber mat could be used as a double-layer drug release system to release hydrophilic drugs from outer layer and hydrophobic drugs from core layer. On the other hand, after washing off the Pull shell layer, a pure POC elastomer fiber mat was obtained, of which the mechanical properties were comparable to that of the ChiNC reinforced POC dense films.