Biomedical Engineering Reference
In-Depth Information
Supercritical Solvent Impregnation of Natural
Bioactive Compounds
in
N
-Carboxybutylchitosan and Agarose
Membranes for the Development of Topical
Wound Healing Applications
A.M.A. Dias, M.E.M. Braga, I.J. Seabra, and H.C. de Sousa
Abstract
Supercritical Solvent Impregnation (SSI) was used to load topical
membrane-type wound dressing biomaterials with natural based bioactive
compounds namelly quercetin as an antiinflammatory and thymol as anaesthetic and
skin permeation enhancer. The biodegradable and biocompatible membranes where
prepared as film- and foam-like structures of
N
-carboxybutylchitosan and agarose
to study the influence of morphological structure on the fluid handling capacities
of the materials. Results show that SSI is a feasible and advantageous process
that permits to 'tune' the relative loaded amounts of the bioactive substances by
changing the operational conditions. The process also promotes the size reduction
of quercetin particles with a significant improvement in its solubility in aqueous
solutions and consequently in its bioavailability. The prepared materials present a
sustained delivery for quercetin and adequate fluid handling capacities that are in
the typical and desired ranges for commercial wound dressings.
1
Wound Healing
A wound is defined as a break in the epithelial and/or sub-epithelial integrity
of the tissues which can be caused accidentally, intentionally or be a part of a
disease process [
1
]. Wounds can be classified as acute wounds (resulting from
incision or trauma) or chronic wounds (venous leg ulcers, pressure and diabetic
foot ulcers) being also usually distinguished as open wounds (incisions, lacerations,
A.M.A. Dias (
) • M.E.M. Braga • I.J. Seabra • H.C. de Sousa
CIEPQPF, Chemical Engineering Department, FCTUC, University of Coimbra, Rua Sılvio Lima,
Polo II - Pinhal de Marrocos, 3030-790 Coimbra, Portugal
e-mail:
adias@eq.uc,pt
;
marabraga@eq.uc.pt
;
hsousa@eq.uc.pt
I.J. Seabra
ESAC, Politechnic Institute of Coimbra, Bencanta, 3040-316 Coimbra, Portugal
e-mail:
iseabra@esac.pt
