Highly monodisperse colloidal coacervates based on a bioactive lactose-modified chitosan: From synthesis to characterization. (15th October 2017)

• Record Type: Journal Article
• Authors: Furlani, Franco; Sacco, Pasquale; Marsich, Eleonora; Donati, Ivan; Paoletti, Sergio
• Is Part Of: Carbohydrate polymers. Volume 174(2017)
• Page Start: 360
• Page End: 368
• Publication Date: 2017-10-15
• Subjects: Ionotropic gelation -- Coacervation -- Lactose-modified chitosan -- Bioactivity -- Homogeneity -- Drug delivery; Polysaccharides -- Periodicals; Polysaccharides -- Periodicals; Polysaccharides -- Périodiques; Electronic journals; 547.78
• DOI: 10.1016/j.carbpol.2017.06.097
• Languages: English
• ISSNs: 0144-8617

Abstract

Graphical abstract: Highlights: Coacervation of a lactose-modified chitosan (CTL60) and tripolyphosphate (TPP) is herein investigated. Coacervation is ensured only at pH 4.5 and not at 7.4. CTL60 favors the formation of highly homogeneous coacervates. Lactitol side chains on chitosan backbone ensure cryo-preservation of coacervates. CTL60 coacervates dissolve upon increasing pH, ionic strength and temperature. Abstract: The present contribution aims at describing the fabrication of coacervates in the nano-size range starting from a 1-deoxylactit-1-yl chitosan (in this manuscript termed as CTL60) and the multivalent anion tripolyphosphate (TPP). Colloidal coacervates have been obtained for precise values of the molar ratio of TPP to CTL60 repeating unit. Coacervation is ensured only at pH 4.5 and not at 7.4, thus demonstrating the key role of electrostatic interactions in the stabilization of the coacervates. At a variance with chitosan, CTL60 favors the formation of highly homogeneous coacervates with very low values of the polydispersity index (PDI). Moreover, CTL60 coacervates can be freeze-dried without any cryoprotectant, they can host a model molecule and are stable up to three weeks at 4 °C. Conversely, such coacervates dissolve upon increasing pH and ionic strength. By considering the bioactive polycation CTL60, the present system can be suggested as a first step in the development of innovative biologically-active nano-carriers to be used as drug delivery systems.