title: An aerogel obtained from chemo-enzymatically oxidized fenugreek galactomannans as a versatile delivery system.
abstract: We describe a new aerogel obtained from laccase-oxidized galactomannans of the leguminous plant fenugreek (Trigonella foenum-graecum) and suggest its potential practical use. Laccase/TEMPO oxidation of fenugreek in aqueous solution caused a viscosity increase of over 15-fold. A structured, elastic, stable hydrogel was generated, due to formation of carbonyl groups from primary OH of galactose side units and subsequent establishment of hemiacetalic bonds with available free hydroxyl groups. Upon lyophilization of this hydrogel, a water-insoluble aerogel was obtained (EOLFG), capable of uptaking aqueous or organic solvents over 20 times its own weight. The material was characterized by scanning electron microscopy, FT-IR, elemental analysis and (13)C CP-MAS NMR spectroscopy and its mechanical properties were investigated. To test the EOLFG as a delivery system, the anti-microbial enzyme lysozyme was used as model active principle. Lysozyme was added before or after formation of the aerogel, entrapped or absorbed in the gel, retained and released in active form, as proven by its hydrolytic glycosidase activity on lyophilized Micrococcus lysodeikticus cells wall peptidoglycans. This new biomaterial, composed of a chemo-enzymatically modified plant polysaccharide, might represent a versatile, biocompatible "delivery system" of active principles in food and non-food products.
authors.affiliation: Istituto di Chimica del Riconoscimento Molecolare, CNR, Via Mario Bianco 9, 20131 Milano, Italy. Electronic address: bianca.rossi@polimi.it.
authors.forename: Bianca
authors.initials: B
authors.lastname: Rossi
authors.affiliation: Istituto Scienze delle Produzioni Alimentari, CNR, Via Celoria 2, 20133 Milano, Italy. Electronic address: paola.campia@ispa.cnr.it.
authors.forename: Paola
authors.initials: P
authors.lastname: Campia
authors.affiliation: Istituto di Chimica del Riconoscimento Molecolare, CNR, Via Mario Bianco 9, 20131 Milano, Italy. Electronic address: luca.merlini@icrm.cnr.it.
authors.forename: Luca
authors.initials: L
authors.lastname: Merlini
authors.affiliation: Istituto Scienze delle Produzioni Alimentari, CNR, Via Celoria 2, 20133 Milano, Italy. Electronic address: milena.brasca@ispa.cnr.it.
authors.forename: Milena
authors.initials: M
authors.lastname: Brasca
authors.affiliation: Department of Chemistry, Materials, and Chemical Engineering "G. Natta" and Local Unit INSTM, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano, Italy. Electronic address: nadia.pastori@polimi.it.
authors.forename: Nadia
authors.initials: N
authors.lastname: Pastori
authors.affiliation: PackLAB, Unimi Food Packaging Laboratory, DeFENS, Department of Food, Environmental and Nutritional Sciences, University of Milan, ViaCeloria 2, 20133 Milano, Italy. Electronic address: stefano.farris@unimi.it.
authors.forename: Stefano
authors.initials: S
authors.lastname: Farris
authors.affiliation: Department of Chemistry, Materials, and Chemical Engineering "G. Natta" and Local Unit INSTM, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano, Italy; Università degli Studi e-Campus, Via Isimbardi 10, 22060 Novedrate, Como, Italy. Electronic address: lucio.melone@polimi.it.
authors.forename: Lucio
authors.initials: L
authors.lastname: Melone
authors.affiliation: Department of Chemistry, Materials, and Chemical Engineering "G. Natta" and Local Unit INSTM, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano, Italy. Electronic address: carlo.punta@polimi.it.
authors.forename: Carlo
authors.initials: C
authors.lastname: Punta
authors.affiliation: Istituto di Chimica del Riconoscimento Molecolare, CNR, Via Mario Bianco 9, 20131 Milano, Italy. Electronic address: yves.galante@icrm.cnr.it.
authors.forename: Yves M
authors.initials: YM
authors.lastname: Galante
mesh_terms: D003497:Cyclic N-Oxides / Q000737:chemistry; D004058:Diffusion; D004337:Drug Carriers / Q000737:chemistry*; D005612:Freeze Drying; D005690:Galactose / Q000031:analogs & derivatives; D005782:Gels; D006868:Hydrolysis; D042845:Laccase / Q000378:metabolism*; D008351:Mannans / Q000737:chemistry*; D055595:Mechanical Phenomena; D009113:Muramidase / Q000737:chemistry; D010084:Oxidation-Reduction; D012995:Solubility; D029910:Trigonella / Q000737:chemistry*; D014867:Water / Q000737:chemistry
chemical_list: D003497:Cyclic N-Oxides; D004337:Drug Carriers; D005782:Gels; D008351:Mannans; D014867:Water; C012990:galactomannan; D042845:Laccase; D009113:Muramidase; C003959:TEMPO; D005690:Galactose
keywords: Aerogel; Delivery system; Fenugreek; Galactomannans; Laccase oxidation; Lysozyme