Silica-maltose composites: obtaining drug carrier systems through tailored ultrastructural nanoparticles.

ABSTRACT

The formation of tailored silica-maltose composites through a simple and direct sol-gel chemistry approach is demonstrated. The ultrastructural organization of the composite associated with their tailorability allows envisaging a future application in drug delivery field. Ultraviolet-visible spectroscopy is used to follow the maltose encapsulation yield, whereas a combination of characterization techniques is employed to reconstruct the multilevel hierarchical structure of composites. Scanning electron microscopy shows that the overall size of spherical composites can be tuned from 250 to 750 nm by changing the amount of maltose within the structure. Composite size distribution indicates that this synthesis approach produces structures with low polydispersity as required for drug delivery purposes. Small-angle X-ray scattering and nitrogen adsorption-desorption techniques show evidence that the composite is elementarily formed by fundamental silica spheres with size ranging from approximately 4 to approximately 7 nm. Surface area of composites is reduced when maltose concentration is increased, which indicates that carbohydrate molecules are preferentially located into the interstitial space between fundamental silica spheres. Through an ultrastructural control over the synthesis process, it has been shown that sol-gel method employed here presents considerable potential for producing efficient drug carrier systems.