title: Cross-linked poly(acrylic acids) microgels and agarose as semi-interpenetrating networks for resveratrol release.
abstract: Carbomers, cross-linked poly(acrylic acid) microgels, have been widely used in pharmaceutical formulations as swollen hydrogels. Agarose, whose thermoreversibility may be exploited for drug loading, forms a gel with a mechanism involving coil-helix transition at about 36 °C. In this work carbomer microgels were combined with agarose networks in a semi-interpenetrating polymer network structure, aiming at obtaining suitable delivery systems for the loading and release of molecules with poor bioavailability but high therapeutic interest, like resveratrol. The rheological properties of the formulations and their in vitro cytocompatibility were studied and optimized acting on the neutralizing agent (triethylamine (N,N-diethylethanamine), triethanolamine (tris(2-hydroxyethyl)amine) and sodium hydroxide) and amount of OH donors (1,2-propanediol and glycerol). As a preparation method, autoclaving was introduced to simultaneously obtain heating and sterilising. Among the different neutralizing agents, NaOH was chosen to avoid the use of amines, considering the final application. Without the addition of alcohols as typical OH donors to induce Carbomer gelification, gels with appropriate rheological properties and stability were produced. For this formulation, the release of resveratrol after 7 days was about 80 % of the loaded mass, suggesting it is an interesting approach to be exploited for the development of innovative resveratrol delivery systems.
authors.affiliation: Department of Chemistry, Materials and Chemical Engineering "G.Natta" and Unità di Ricerca Consorzio INSTM, Politecnico di Milano, Milan, Italy, marta.tunesi@polimi.it.
authors.forename: Marta
authors.initials: M
authors.lastname: Tunesi
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Prina
authors.forename: Fabiola
authors.initials: F
authors.lastname: Munarin
authors.forename: Serena
authors.initials: S
authors.lastname: Rodilossi
authors.forename: Diego
authors.initials: D
authors.lastname: Albani
authors.forename: Paola
authors.initials: P
authors.lastname: Petrini
authors.forename: Carmen
authors.initials: C
authors.lastname: Giordano
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D000818:Animals; D002460:Cell Line; D003432:Cross-Linking Reagents / Q000737:chemistry*; D005782:Gels; D006801:Humans; D051379:Mice; D000077185:Resveratrol; D012212:Rheology; D012685:Sepharose / Q000737:chemistry*; D013267:Stilbenes / Q000008:administration & dosage*
chemical_list: D000180:Acrylic Resins; D003432:Cross-Linking Reagents; D005782:Gels; D013267:Stilbenes; C006903:carbopol 940; D012685:Sepharose; D000077185:Resveratrol