Posted by A novel polymer, β-cyclodextrin-epichlorohydrin-cyanoguanidine polymer (CDPC) was synthesized to evaluate its potential as an efficient carrier for the encapsulation of resveratrol (RES), with a particular focus on applications in cartilage repair. [1] CDPC was synthesized by reacting β-cyclodextrin (β-CD) with epichlorohydrin in the presence of cyanoguanidine (CyG), a nitrogen-rich compound that remains non-protonated under physiological pH. The incorporation of CyG into the polymer network was tuned by adjusting CyG to β-CD molar ratio. Dynamic light scattering revealed nanoscale polymer-RES complexes with average sizes of 4 nm for CDP/RES and 18 nm for CDPC/RES, while zeta potential values indicated that these complexes are neutral to slightly negatively charged. CDPC demonstrated intrinsic antioxidant activity, further enhanced upon RES encapsulation. Cytocompatibility assays confirmed that both CDP and CDPC were non-toxic to human chondrocytes. Confocal microscopy of FITC-labeled CDP and CDPC demonstrated effective internalization of these polymers by chondrocytes. Moreover, the CDP/RES and CDPC/RES complexes enhanced chondrocyte metabolic activity and extracellular matrix deposition, demonstrating their potential as carriers for drug delivery in cartilage tissue regeneration.
Another study aimed to enhance RES’s solubility, stability, and antibacterial efficacy by formulating ternary inclusion complexes (TC) using sulfobutyl ether β-cyclodextrin (SBEβCD, Dexolve) and hydrophilic polymers, polyethylene glycol 4000 (PEG), and polyvinylpyrrolidone (PVP). [2] The TC-PVP formulation showed highest CE (3.12) and Kₛ (1730.76 M⁻¹), achieving a favorable 1:1 molar ratio and reduced formulation bulk. The characterization confirmed formation of amorphous inclusion complexes with improved properties. In vitro dissolution was significantly improved (TC-PVP >TC-PEG >BC >RES; p < 0.001) (BC: binary complex of RES/SBEβCD). Molecular docking revealed hydrogen bonding between RES and SBEβCD. Antibacterial activity was markedly enhanced against S. aureus and B. subtilis, with MIC values reduced two-fold (from 312.5 to 156.25 µg/mL).
References:
1. A. Elmeligy M, Rasoulian F, Kalantarifard S, Filo J, Dinparvar S, M. Omer A, et al. Cyclodextrin-epichlorohydrin-cyanoguanidine polymer for resveratrol delivery to enhance human chondrocyte function in cartilage repair. ChemRxiv. 2025; https://doi.org/10.26434/chemrxiv-2025-4znj6 This content is a preprint and has not been peer-reviewed.
2. Alahmed, T.A.A., Xin, T.K., Sheong, L.L. et al. SBEβCD-Enabled Resveratrol Complexes: Ternary Systems with Hydrophilic Polymers for Enhanced Stability and Antimicrobial Efficacy. J Pharm Innov 20, 304 (2025). https://doi.org/10.1007/s12247-025-10198-y