Posted by Both cyclodextrin (CD) and porous silica possess interesting properties of adsorption and release. A silica–CD hybrid, therefore, could synergically merge the properties of the two components, giving rise to a material with appealing properties for both environmental and pharmaceutical applications. With this aim, in the present study, a first hybrid is obtained through one-pot sol–gel synthesis starting from CD and tetramethyl orthosilicate (TMOS) as a silica precursor. In particular, methyl-β-cyclodextrin (bMCD) is selected for this purpose. The obtained bMCD–silica hybrid is a dense material containing a considerable amount of bMCD (45 wt.%) in amorphous form and therefore represents a promising support. However, since a high specific surface area is desirable to increase the release/adsorption properties, an attempt is made to produce the hybrid material in the form of an aerogel. Both the synthesis of the gel and its drying in supercritical CO2 are optimized in order to reach this goal.
The dense silica–bMCD hybrid is characterized by a high content of bMCD and a packed structure; these features could be advantageous in applications where, for example, a slow but sustained release is needed. In such a dense system, in fact, an elevated number of molecules could be complexed by the bMCD; however, those molecules would need long diffusion times to be released by the hybrid. A possible application, therefore, could be the release of active principles for the long-term treatment of chronic pathologies.
On the other hand, the aerogel hybrids have a lower bMCD content, but they can be easily and rapidly exposed to the surrounding environment thanks to the high specific surface area and porosity of these materials. Possible applications for these aerogels could be in remediation, in sectors where the fast adsorption of contaminants is required, as well as in rapid drug delivery, when the fast release of active principles is desired to treat acute symptoms.
Gallo, M.; Onida, B.; Manna, L.; Banchero, M. Silica–Cyclodextrin Hybrid Materials: Two Possible Synthesis Processes. Int. J. Mol. Sci. 2024, 25, 1108. https://doi.org/10.3390/ijms25021108