Please use this identifier to cite or link to this item: https://hdl.handle.net/1822/13890

TitlePreparation of chitosan scaffolds loaded with dexamethasone for tissue engineering applications using supercritical fluid technology
Author(s)Duarte, Ana Rita C.
Mano, J. F.
Reis, R. L.
KeywordsDrug delivery
Scaffolds
Chitosan
Supercritical fluids
Impregnation
Dexamethasone
Issue date2009
PublisherElsevier
JournalEuropean Polymer Journal
Abstract(s)Supercritical fluid impregnation was tested to prepare a new scaffold loaded with a bioactive compound. Dexamethasone is used in osteogenic media to direct the differentiation of stem cells towards the osteogenic lineage. Dexamethasone was impregnated in chitosan scaffolds at different operating conditions, in order to optimize the impregnation process. Pressure and temperature affect the carbon dioxide density and influence the swelling of the polymer and the drug solubility in the fluid phase, therefore these are two important parameters that were studied in this work. Chitosan sponges prepared by freeze drying were impregnated with the active compound at pressures from 8.0 up to 14.0 MPa and temperatures from 35 up to 55 C. The effect of the impregnation contact time (3 h and 6 h) was also evaluated. From the experiments performed we can conclude that the yield of impregnation is lower when increasing pressure and temperature. The contact time will mainly influence the amount of drug impregnated in the scaffold and for higher contact times the impregnation yield is also higher. Scanning electron microscopy shows particles of dexamethasone in the bulk of the scaffold, which confirms the feasibility of the supercritical fluid impregnation technology for the preparation of delivery devices. The loading capacity of the scaffolds was determined by spectroscopic analysis and the highest loading was achieved for the experiments performed at 8.0 MPa and 35 C. Furthermore, in vitro drug release studies were carried out and the results show that dexamethasone was sustainably released. Supercritical fluid impregnation proved to be feasible for the preparation of a drug delivery system for bone tissue engineering purposes.
TypeArticle
URIhttps://hdl.handle.net/1822/13890
DOI10.1016/j.eurpolymj.2008.10.004
ISSN0014-3057
Peer-Reviewedyes
AccessOpen access
Appears in Collections:3B’s - Artigos em revistas/Papers in scientific journals

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