A Novel Post-Electrospinning Treatment to Improve the Fibrous Structure of the Chitosan Membrane

Guided bone regeneration (GBR) membranes function as barriers in preventing soft tissue migration into dental osteogenic spaces. Chitosan is a biocompatible and degradable natural polysaccharide, which has shown potential in tissue regeneration and GBR applications. Trifluoroacetic acid (TFA) is a common solvent used to make the chitosan polymer solution for electrospinning process. However, the TFA salts remaining in the electrospun nano-sized fibers induce the chitosan fiber swelling and dissolution when placed in aqueous solutions leading to loss of nano-fiber structure. The aim of this work was to evaluate an innovative method using triethylamine (TEA)/ di-tert-butyl dicarbonate (tBoc) to treat the electrospun chitosan membrane without losing nanofibrous structure or compromising compatibility. After the treatment, the nanofibrous structure was well maintained in water overnight, which was confirmed by the SEM. FTIR analyses confirmed TFA salt removal. Surgical fixation tests indicated TEA/tBoc membranes have appropriate clinical handability. The TEA/tBoc treated membrane also showed good cytocompatibility with osteoblastic cells, as well as suitable degradation ration (23.7%) after 7 weeks