Electrospun Polymer-Free Nanofibers Incorporating Hydroxypropyl-β-cyclodextrin/Difenoconazole via Supramolecular Assembly for Antifungal Activity

Abstract

In this study, flexible and self-standing hydroxypropyl-β-cyclodextrin/difenoconazole inclusion complex (HPβCD/ DZ-IC) nanofibers were prepared by polymer-free electrospinning, which exhibited potential to be a new fast-dissolving pesticide formulation. Scanning electron microscopy and optical microscopy were applied to evaluate the morphology of nanofibers, which showed that the resulting HPβCD/DZ-IC nanofibers were bead-free and uniform. In addition, the proton nuclear magnetic resonance ( 1 H NMR) spectrum suggested a stoichiometric ratio of 1:0.9 (HPβCD/DZ). Other characterization methods, such as UV−vis absorption, fluorescence spectroscopy, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA), were applied in this study. On the one hand, UV−vis absorption, fluorescence spectroscopy, FT-IR, XRD, and TGA provided useful information for the successful formation of an inclusion complex; on the other hand, the results of TGA indicated the thermal stability of DZ was enhanced after the formation of inclusion complexes. Besides, the phase solubility test could explain the increased water solubility of the nanofibers of inclusion complexes formed by DZ and HPβCD. The results of molecular docking studies demonstrated the most favorable binding interactions when HPβCD combined with DZ. The dissolution test and the antifungal performance test exhibited the characteristics of fast dissolution and the excellent antifungal performance of HPβCD/DZ-IC nanofibers, respectively.

Evaluation and Characterization of Curcumin-β-Cyclodextrin and Cyclodextrin-Based Nanosponge Inclusion Complexation

“…The formation of cyclodextrin-based inclusion complexes can enhance and sustain drugs’ stability [ 28 ] and improve their aqueous solubility [ 29 , 30 , 31 ]. The formation of cyclodextrin-based inclusion complexes was recently proven to enhance the solubilities and thermal stabilities of difenoconazole, thiophanate, and thiram and improve the physical characteristics of environmentally safe cyclodextrin-based nanofiber pesticidal formulations [ 32 , 33 , 34 , 35 ]. A recently published study reported a 206-fold improvement in curcumin solubility and proved prolonged curcumin release from the resulting inclusion complexes [ 23 ].…”

α-Mangostin/γ-Cyclodextrin Inclusion Complex: Formation and Thermodynamic Study

“…The chemical shift of α-M/γ-CD CX was influenced by the guest molecule (α-M) entering into the hydrophobic cavity. This phenomenon indicates that the complex of α-M/γ-CD CX was formed [16][17][18].…”

“…A number of studies using CDs inclusion complexes have been reported for water solubility enhancement. The inclusion complex of α-, β-CD with 5-fluorouracil buprofen [14,15], HP-β-CD with thiophanante-methyl, thiram, difenoconazole [16][17][18], and γ-CD with forchlorfenuron were formed and increased their water solubility [19,20].…”

Fabrication and Characterization of Antifungal Hydroxypropyl-β-Cyclodextrin/Pyrimethanil Inclusion Compound Nanofibers Based on Electrospinning

“…Cyclodextrin (CD) is a series of cyclic oligosaccharides produced from amylose under the action of cyclodextrin glucotransferase. , CD has a unique annular cavity with internal hydrophobic and external hydrophilic properties. − Due to this special structure, it is possible for CD to encapsulate various inorganic or organic materials and form inclusion compounds, effectively improving the guest molecule properties, such as water solubility, thermostability. − CD has the characteristics of nontoxicity, low price, and ease of formation, which provides good application prospects in the fields of medicine, food, enzyme simulation analysis, supramolecular chemistry, and so on. Compared with the original CD, the chemically modified CD derivatives have better water solubility and other outstanding chemical or physical properties .…”