Preparation, Characterization, and Antioxidant Activity of L-Ascorbic Acid/HP-β-Cyclodextrin Inclusion Complex-Incorporated Electrospun Nanofibers

Abstract

L-Ascorbic acid (LAA) is a key vitamin, implicated in a variety of physiological processes in humans. Due to its free radical scavenging activity, it is extensively employed as an excipient in pharmaceutical products and food supplements. However, its application is greatly impeded by poor thermal and aqueous stability. Herein, to improve the stability and inhibit oxidative degradation, we prepared LAA-cyclodextrin inclusion complex-incorporated nanofibers (NFs). The continuous variation method (Job plot) demonstrated that LAA forms inclusions with hydroxypropyl-β-cyclodextrin (HP-β-CD) at a 2:1 molar stoichiometric ratio. The NFs were prepared via the single step electrospinning technique, without using any polymer matrix. The solid-state characterizations of LAA/HP-β-CD-NF via powder x-ray diffractometry (PXRD), Fourier-transform infrared (FT-IR) analysis, differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), and nuclear magnetic resonance (1H NMR and 2D-NOESY) spectroscopy, reveal the effective encapsulation of the LAA (guest molecule) inside the HP-β-CD (host) cavity. The SEM micrograph reveals an average fiber diameter of ~339 nm. The outcomes of the thermal investigations demonstrated that encapsulation of LAA within HP-β-CD cavities provides improved thermal stability of LAA (by increasing the thermal degradation temperature). The radical scavenging assay demonstrated the enhanced antioxidant potential of LAA/HP-β-CD-NF, as compared to native LAA. Overall, the study shows that cyclodextrin inclusion complex-incorporated NFs, are an effective approach for improving the limitations associated with LAA, and provide promising avenues in its therapeutic and food applications.

Antimicrobial Activities of Pistacia lentiscus Essential Oils Nanoencapsulated into Hydroxypropyl-beta-cyclodextrins

“…Similar findings were shown by Saha et al, 79 Rodríguez-López et al, 80 and Khan et al, 81 in which they could successfully report the effective encapsulation of different molecules into the cavities of HPβCD performing 2D-NMR spectroscopy, which showed similar positive correlations between the protons of the investigated molecules and the protons of the HPβCD (H3 and H5). 79 − 81 …”

“…Hence, the NOE cross correlation, crossed peaks, can be observed in a NOESY spectrum by the interaction presented by any two protons located near each other in the space (within 0.4 nm). , The 2D-NOESY spectrum of the PO-ICs obtained (Figure ) depicted a considerable correlation, spatial proximity, between HPβCD protons (H3 and H5) and PO protons, supporting the chemical shifts revealed above, which eventually refer to the positive establishment of the PO-ICs and particularly the successful encapsulation of PO components into HPβCD cavities. Similar findings were shown by Saha et al, Rodríguez-López et al, and Khan et al, in which they could successfully report the effective encapsulation of different molecules into the cavities of HPβCD performing 2D-NMR spectroscopy, which showed similar positive correlations between the protons of the investigated molecules and the protons of the HPβCD (H3 and H5). − …”

Improved antimicrobial activities of Boswellia sacra essential oils nanoencapsulated into hydroxypropyl-beta-cyclodextrins

“…Similar results were reported previously showing the effective encapsulation of various molecules into HPbCD cavities while revealing similar strong correlations as could be shown by 2D NMR spectroscopy analyses. 60,61 It is worth noting that the 2D-HNMR NOESY analysis was conducted ve months aer the initial preparation of BO-ICs, supporting their high stability prole.…”