Elaboration of functional cyclodextrin based nanofibres for biomedical application

Electrospun nanofibrous membranes have proven to be ideal scaffolds for biomedical applications such as wound dressing and tissue engineering, mostly due to their high porosity and their morphology that mimics the structure of human tissues. In this work, we investigated two different strategies based on the use of cyclodextrins to functionalize these scaffolds with molecules of interest. Scaffolds made of polyelectrolyte complexes of carboxymethylcellulose and chitosan were first prepared by blend or coaxial electrospinning for wound dressing applications. Methylene blue, a molecule known to present antibiotic activity, was added, alone or as an inclusion complex with cyclodextrin, in the polymer solution before electrospinning. The preliminary biological assessment suggested that the fibrous membranes exhibited good antibacterial activity. In a second part, electrospun poly(e-caprolactone) (PCL) scaffolds were prepared for tissue engineering applications. As this polyester can not easily be functionalized, PCL and cyclodextrins were combined to form pseudo-polyrotaxanes (pPRs) with various architectures. Core:shell PCL:pPR fibres were prepared by coaxial electrospinning. Fluorescein isothiocyanate was then grafted onto the fibre surface to prove the presence of available and reactive cyclodextrin hydoxyl groups at the surface of the PCL fibres. This reaction opens the way for innovative and versatile biofunctionalization of PCL.