Injectable Thixotropic β–Cyclodextrin–Functionalized Hydrogels Based on Guanosine Quartet Assembly

Abstract

Facile method for the preparation of β–cyclodextrin–functionalized hydrogels based on guanosine quartet assembly was described. A series of seven hydrogels were prepared by linking β–cyclodextrin molecules with guanosine moieties in different ratios through benzene–1,4–diboronic acid linker in the presence of potassium hydroxide. The potassium ions acted as a reticulation agent by forming guanosine quartets, leading to the formation of self–sustained transparent hydrogels. The ratios of the β–cyclodextrin and guanosine components have a significant effect on the internal structuration of the components and, correspondingly, on the mechanical properties of the final gels, offering a tunablity of the system by varying the components ratio. The insights into the hydrogels’ structuration were achieved by circular dichroism, scanning electron microscopy, atomic force microscopy, and X–ray diffraction. Rheological measurements revealed self–healing and thixotropic properties of all the investigated samples, which, in combination with available cyclodextrin cavities for active components loading, make them remarkable candidates for specific applications in biomedical and pharmaceutical fields. Moreover, all the prepared samples displayed selective antimicrobial properties against S. aureus in planktonic and biofilm phase, the activity also depending on the guanosine and cyclodextrin ratio within the hydrogel structure.

Photothermal Hydrogel Composites Featuring G4-Carbon Nanomaterial Networks for Staphylococcus aureus Inhibition

“…On the contrary, the primary toxicity mechanism of SWNTs lies in their direct contact and subsequent damage to cells. Consequently, the diameter of CNTs becomes a critical factor influencing the deactivation of microbial cells. − Moreover, β-CD molecules possess the capability to disrupt bacterial membranes, which leads to the efflux of K + ions from the bacterial membrane , thus enhancing the antimicrobial activity of both hydrogels under investigation.…”

“…Recently, we reported the successful preparation of an injectable supramolecular hydrogel based on β-cyclodextrin (β-CD), cross-linked by guanosine quartets (G4), with selective antimicrobial properties . The proposed synthetic pathway enables precise and controllable covalent integration of β-CD entities within the supramolecular matrix, affording the ability to fine-tune its physical characteristics.…”

Dynameric G-quadruplex–dextran hydrogels for cell growth applications

“…S3, ESI †). 10,11 The amount of cross-linked G4 in each hydrogel induced changes in the internal structure as shown by the scanning electron microscopy (SEM) and atomic force microscopy (AFM) analyses of the xerogels (Fig. 2 and Fig.…”

“…S1, ESI †). 11,19,20 In FTIR, the DGH1-3 xerogels compared to G and BDBA displayed characteristic changes for the formation of new bonds at 1800-1600 cm À1 and 1400-1000 cm À1 (Fig. S2, ESI †).…”

“…It offers the entire hydrogel self-healable and injectable properties. [9][10][11][12][13][14] However, low-molecular weight-based hydrogels, including G4 ones, lack tunable strength and toughness and are difficult to handle, thus limiting their applications to some extent. 15 We recently reported reinforcement of G4-based hydrogels by dispersing single-walled carbon nanotubes as scaffolding pillars for the G4 matrix.…”