Tuning bio-aerogel properties. Part 3: Exploring silica-pectin composite aerogels for drug delivery.

The release of the model drug theophylline from silica-pectin aerogels was investigated. The composite aerogels were prepared via impregnation of pectin alcogels with silica sol, followed by in situ silica gelation and drying with supercritical CO. The structural and physico-chemical properties of the aerogels were tuned via the preparation conditions (type of silica sol, calcium crosslinking of pectin or not).

Tuning bio-aerogel properties for controlling drug delivery. Part 2: Cellulose-pectin composite aerogels.

The release of the model drug theophylline from cellulose-pectin composite aerogels was investigated. Cellulose and pectin formed an interpenetrated network, and the goal was to study and understand the influence of each component and its solubility in simulated gastric and intestinal fluids on the kinetics of release. Cellulose was dissolved, coagulated in water, followed by impregnation with pectin solution, crosslinking of pectin with calcium (in some cases this step was omitted), solvent exchange and supercritical CO drying.

Tuning bio-aerogel properties for controlling theophylline delivery. Part 1: Pectin aerogels.

A comprehensive study of release kinetics of a hydrophilic drug from bio-aerogels based on pectin was performed. Pectin aerogels were made by polymer dissolution, gelation (in some cases this step was omitted), solvent exchange and drying with supercritical CO. Theophylline was loaded and its release was studied in the simulated gastric fluid during 1 h followed by the release in the simulated intestinal fluid.

Thermal conductivity/structure correlations in thermal super-insulating pectin aerogels.

Pectin aerogels were synthesized via dissolution-solvent exchange-drying with supercritical CO. The goal was to correlate thermal conductivity with aerogel morphology and properties in order to understand how to obtain a thermal super-insulating material with the lowest possible conductivity. Polymer concentration, solution pH and presence of bivalent ions were varied to tune pectin gelation mechanism and the state of matter, solution or gel.