(GINOP-2.3.2-15-2016-00008) Támogató: Emberi Erőforrások Minisztériuma
Szakterületek:
Kémiai tudományok
Természettudományok
Silica-gelatin hybrid aerogels of varying gelatin content (from 4 wt.% to 24 wt.%)
can be conveniently impregnated with hydrophobic active agents (e.g. ibuprofen, ketoprofen)
in supercritical CO2 and used as drug delivery systems. Contrast variation neutron
scattering (SANS) experiments show the molecular level hybridization of the silica
and the gelatin components of the aerogel carriers. The active agents are amorphous,
and homogeneously dispersed in these porous, hybrid matrices. Importantly, both fast
and retarded drug release can be achieved with silica-gelatin hybrid aerogels, and
the kinetics of drug release is governed by the gelatin content of the carrier. In
this paper, for the first time, a molecular level explanation is given for the strong
correlation between the composition and the functionality of a family of aerogel based
drug delivery systems. Characterization of the wet aerogels by SANS and by NMR diffusiometry,
cryoporometry and relaxometry revealed that the different hydration mechanisms of
the aerogels are responsible for the broad spectrum of release kinetics. Low-gelatin
(4–11 wt.%) aerogels retain their open-porous structure in water, thus rapid matrix
erosion dictates fast drug release from these carriers. In contrast to this, wet aerogels
of high gelatin content (18–24 wt.%) show well pronounced hydrogel-like characteristics,
and a wide gradual transition zone forms in the solid-liquid interface. The extensive
swelling of the high-gelatin hybrid backbone results in the collapse of the open porous
structure, that limits mass transport towards the release medium, resulting in slower,
diffusion controlled drug release.
