title: Binding and encapsulation of doxorubicin on smart pectin hydrogels for oral delivery.
abstract: Pectins (Pec) of 33 to 74 % esterification degree were tested with doxorubicin (Dox), a very high toxic drug widely used in cancer therapies. Pec with 35 and 55 % DE were selected because of the Dox binding higher than Pec microspheres of 35 and 55 % obtained by ionotropic gelation with Ca⁺² have 88 and 66 % Dox loading capacity. Kinetic Dox release showed more than 80.0 and about 30.0 % free drug from 35 % and 55 % Pec formulations at pH 7.4, and 37 °C after 1-h incubation, respectively. Besides, Dox release decrease to 12 % in 55 % Pec microsphere formulation after 1-year storage at 4 °C. FTIR analysis of Pec-Dox complex showed hipsochromic shifts for the σ(C=O), δ(N-H) and σ(C-C) vibrational modes compared to Dox spectrum suggesting strong interaction between the drug cargo and the matrix. Rheological studies of Pec and Pec-Dox samples flow behavior exhibited a shear-thinning nature. Fifty-five percent of Pec showed higher viscosity than the viscosity for 35 % Pec in all range of temperatures analyzed, and decreased when the temperature is raised. Besides, Pec-Dox complexes have higher viscosity values than those of the corresponding Pec samples, and viscosity curves as function of shear rate for 35 % Pec-Dox are above the curves of 55 % Pec-Dox. In both cases, the results are confirming significant interaction between the cargo and the matrix, which also was established in viscoelastic dynamic analysis.
authors.affiliation: CINDEFI-Institute of Applied Biotechnology, UNLP-CONICET CCT La Plata, School of Sciences, Universidad Nacional de La Plata, 1900 La Plata, Argentina.
authors.forename: Valeria E
authors.initials: VE
authors.lastname: Bosio
authors.forename: Victoria
authors.initials: V
authors.lastname: Machain
authors.forename: Azucena Gómez
authors.initials: AG
authors.lastname: López
authors.forename: Ignacio O Pérez
authors.initials: IO
authors.lastname: De Berti
authors.forename: Sergio G
authors.initials: SG
authors.lastname: Marchetti
authors.forename: Magdalena
authors.initials: M
authors.lastname: Mechetti
authors.forename: Guillermo R
authors.initials: GR
authors.lastname: Castro
mesh_terms: D000284:Administration, Oral; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000737:chemistry* / Q000378:metabolism; D002214:Capsules; D004317:Doxorubicin / Q000008:administration & dosage / Q000737:chemistry* / Q000378:metabolism; D004337:Drug Carriers / Q000737:chemistry*; D020100:Hydrogels / Q000737:chemistry*; D007700:Kinetics; D008863:Microspheres; D010368:Pectins / Q000737:chemistry*; D012212:Rheology
chemical_list: D000970:Antineoplastic Agents; D002214:Capsules; D004337:Drug Carriers; D020100:Hydrogels; D004317:Doxorubicin; D010368:Pectins