Electrospinning of dexamethasone/cyclodextrin inclusion complex polymer fibers for dental pulp therapy

Beta-cyclodextrin (β-CD) is an oligosaccharide commonly used to improve the aqueous solubility of lipophilic drugs (e.g., dexamethasone, DEX). Here we present the development of a drug delivery system to provide sustained release of DEX by β-CD-inclusion complex (IC) to amplify the mineralization capacity of stem cells from human-extracted deciduous teeth (SHEDs) as a potential direct pulp capping strategy. First, IC of DEX (DEX-CD-IC) was synthesized with β-CD. To confirm DEX-CD-IC complex formation, X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) analyses were performed. XRD data indicated that IC formation was achieved due to formation of a new crystalline structure, whereas FTIR revealed the presence of the IC from the shifting of the peaks of each component in DEX-CD-IC. Then, electrospun poly(lactic-co-glycolic acid, PLGA) fibers (PLGA/DEX-CD-IC) were processed by varying the concentration of DEX-CD-IC (5%, 10 %, and 15 %). The release of DEX from fibers was determined by ultraperformance liquid chromatography for 28 days. Thanks to the solubility enhancement of DEX by IC, electrospun PLGA/DEX-CD-IC fibers released DEX in a more sustained fashion compared to PLGA/DEX fibers. No deleterious effect was found in terms of SHEDs' proliferation when cultured with or on electrospun fibers, regardless of the IC presence. Importantly, a more pronounced odontogenic differentiation was stimulated by electrospun fibers loaded with the lowest DEX-CD-IC concentration (5%), as a result of the sustained DEX release. In sum, PLGA/DEX-CD-IC fibers have great potential in vital dental pulp therapy, owing to its sustained DEX release, cytocompatibility, and odontogenic differentiation capacity.