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1.
Int J Biol Macromol ; 156: 608-620, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32302627

RESUMO

Novel porous films based on xanthan gum (XG), poly(vinyl alcohol) (PVA), and red grape pomace (RGP), as entrapped natural antioxidant agent, were prepared by freeze/thawing, a versatile and non-destructive method. The stability of XG/PVA films was dependent on the crystalline zones created by PVA under freeze/thawing treatment. After three cryogenic cycles, the introduction of RGP into the 3D polymer matrix plays a major role by hindering the access of water into the cavities already formed during the first and second cryogenic cycles. By contrast, XG/PVA-based cryogels with enhanced mechanical strength were obtained when the number of freeze/thawing cycles increased from three to seven, while pores stability was improved by entrapment of RGP. The remarkable antioxidant and antimicrobial activity of XG/PVA/RGP cryogel films compared to the XG/PVA films, indicates the potential application of these systems in food packaging.

2.
Rev Med Chir Soc Med Nat Iasi ; 119(4): 1189-94, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26793868

RESUMO

AIM: To develop sustained release matrix tablets based on xanthan as highly water-soluble, cost-effective, non-toxic, easily available, and suitable hydrophilic systems. MATERIAL AND METHODS: Xanthan and lignin epoxy-modified resin (LER) mixture were crosslinked using epichlorohydrin as crosslinking agent leading to superabsorbent hydrogels with high swelling rate in aqueous mediums. RESULTS AND CONCLUSIONS: These hydrogels were tested as carries by the loading/delivery behaviour of bisoprolol fumarate in physiological conditions and based on the obtained results these hydrogels may show interest for application in medical and pharmaceutical areas. The amount of drug loaded in polymer networks was found to be ranging between 14.4% and 19.2%. Drug release was retarded and the release mechanism of the active principle was found to depend on matrix composition.


Assuntos
Anti-Hipertensivos/farmacocinética , Bisoprolol/farmacocinética , Portadores de Fármacos/química , Hidrogéis/química , Lignina/química , Polissacarídeos Bacterianos/química , Anti-Hipertensivos/síntese química , Anti-Hipertensivos/química , Bisoprolol/síntese química , Bisoprolol/química , Química Farmacêutica , Preparações de Ação Retardada/química , Liberação Controlada de Fármacos , Técnicas In Vitro
3.
Adv Mater ; 25(27): 3739-44, 2013 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-23754442

RESUMO

A zipper-assembly of micelles into 2D/3D coatings is reported. Block copolymer micelles that incorporate a poly(n-octadecyl methacrylate) block are zipped and unzipped on demand onto a PMMA surface. The mechanism implies an interdigitation of molecular brushes enabling 15 nm micelles to be assembled into monolayers or multilayers.


Assuntos
Polímeros/química , Micelas , Tamanho da Partícula , Propriedades de Superfície
4.
Int J Biol Macromol ; 54: 230-7, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23274678

RESUMO

This paper reports the morphological and thermal characterization of xanthan/lignin hydrogels. It has been emphasized the effect of the lignin type on the hydrogel properties. The hydrogels described here were obtained by chemical crosslinking, in the presence of epichlorohydrine as a cross-linker agent. The obtained materials were analyzed by AFM, TG/DTG, DSC, and FT-IR spectroscopy. It has been established that hydrogels have a porous morphology. The lignin type influences the hydrogel morphology which is either fibrilar as in case of hydrogel containing aspen wood lignin (which has the highest content of COOH groups and lowest content of phenolic OH groups) or smooth surface for other hydrogels. The specific intermolecular interactions are stronger in the case of 70 xanthan (X)/30 aspen wood lignin (AWL) hydrogel. The thermal properties of the hydrogels also depend on lignin type, the lowest thermal stability being found for the hydrogel containing lignin with the highest content of functional groups (AWL).


Assuntos
Hidrogéis/química , Lignina/química , Polissacarídeos Bacterianos/química , Temperatura , Varredura Diferencial de Calorimetria , Microscopia de Força Atômica , Espectroscopia de Infravermelho com Transformada de Fourier , Propriedades de Superfície , Termogravimetria , Madeira/química
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